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Background The correct identification of the appropriateness of fluid administration is important for the treatment of critically ill patients. Static and dynamic indices used to identify fluid responsiveness have been developed throughout the years, nonetheless fluid responsiveness does not indicate that fluid administration is appropriate, and indexes to evaluate appropriateness of fluid administration are lacking. The aim of this study was to evaluate if central venous pressure (CVP) anddynamic indices could correctly identify fluid appropriateness for critically ill patients. Methods Data from 31 ICU patients, for a total of 53 observations, was included in the analysis. Patients were divided into two cohorts based on the appropriateness of fluid administration. Fluid appropriateness was defined in presence of a low cardiac index (< 2.5 l/min/m2) without any sign of fluid overload, as assessed by global end-diastolic volume index, extravascular lung water index or pulmonary artery occlusion pressure. Results For 10 patients, fluid administration was deemed appropriate, while for 21 patients it was deemed inappropriate. Central venous pressure was not different between the two cohorts (mean CVP 11 (4) mmHg in the fluid inappropriate group, 12 (4) mmHg in the fluid appropriate group, p 0.58). The same is true for pulse pressure variation (median PPV 5 [2, 9] % in the fluid inappropriate group, 4 [3, 13] % in the fluid appropriate group, p 0.57), for inferior vena cava distensibility (mean inferior vena cava distensibility 24 (14) % in the fluid inappropriate group, 22 (16) % in the fluid appropriate group, p 0.75) and for changes in end tidal carbon dioxide during a passive leg raising test (median d.ETCO2 1.5 [0.0, 2.0]% in the fluid inappropriate group, 1.0 [0.0, 2.0] % in the fluid appropriate group, p 0.98). There was no association between static and dynamic indices and fluid appropriateness. Conclusions Central venous pressure, pulse pressure variation, changes in end tidal carbon dioxide during a passive leg raising test, inferior vena cava distensibility were not associated with fluid appropriateness in our cohorts.

Pressure support ventilation (PSV) should be titrated considering the pressure developed by the respiratory muscles (Pmusc) to prevent under- and over-assistance. The esophageal pressure (Pes) is the clinical gold standard for Pmusc assessment, but its use is limited by alleged invasiveness and complexity. The least square fitting method and the end-inspiratory occlusion method have been proposed as non-invasive alternatives for Pmusc assessment. The aims of this study were: (1) to compare the accuracy of Pmusc estimation using the end-inspiration occlusion (Pmusc,index) and the least square fitting (Pmusc,lsf) against the reference method based on Pes; (2) to test the accuracy of Pmusc,lsf and of Pmusc,index to detect overassistance, defined as Pmusc ≤ 1 cmH2O. We studied 18 patients at three different PSV levels. At each PSV level, Pmusc, Pmusc,lsf, Pmusc,index were calculated on the same breaths. Differences among Pmusc, Pmusc,lsf, Pmusc,index were analyzed with linear mixed effects models. Bias and agreement were assessed by Bland–Altman analysis for repeated measures. The ability of Pmusc,lsf and Pmusc,index to detect overassistance was assessed by the area under the receiver operating characteristics curve. Positive and negative predictive values were calculated using cutoff values that maximized the sum of sensitivity and specificity. At each PSV level, Pmusc,lsf was not different from Pmusc (p = 0.96), whereas Pmusc,index was significantly lower than Pmusc. The bias between Pmusc and Pmusc,lsf was zero, whereas Pmusc,index systematically underestimated Pmusc of 6 cmH2O. The limits of agreement between Pmusc and Pmusc,lsf and between Pmusc and Pmusc,index were ± 12 cmH2O across bias. Both Pmusc,lsf ≤ 4 cmH2O and Pmusc,index ≤ 1 cmH2O had excellent negative predictive value [0.98 (95% CI 0.94–1) and 0.96 (95% CI 0.91–0.99), respectively)] to identify over-assistance. The inspiratory effort during PSV could not be accurately estimated by the least square fitting or end-inspiratory occlusion method because the limits of agreement were far above the signal size. These non-invasive approaches, however, could be used to screen patients at risk for absent or minimal respiratory muscles activation to prevent the ventilator-induced diaphragmatic dysfunction.

The most beneficial effect of corticosteroid therapy in COVID-19 patients has been shown in subjects receiving invasive mechanical ventilation (IMV), corresponding to a score of 6 on the World Health Organization (WHO) COVID-19 Ordinal Scale for Clinical Improvement (OSCI). The aim of this observational, single-center, prospective study was to assess the association between corticosteroids and hospital mortality in coronavirus disease 2019 (COVID-19) patients who did not receive IMV (OSCI 3-5). Included were 1,311 COVID-19 patients admitted to nonintensive care wards, and they were divided in two cohorts: (i) 480 patients who received corticosteroid therapy and (ii) 831 patients who did not. The median daily dose was of 8 mg of dexamethasone or equivalent, with a mean therapy duration of 5 (3-9) days. The indication to administer or withhold corticosteroids was given by the treating physician. In-hospital mortality was similar between the two cohorts after adjusting for possible confounders (adjusted odds ratio (ORadj) 1.04, 95% confidence interval (CI), 0.81-1.34, P = 0.74). There was also no difference in Intensive Care Unit (ICU) admission (ORadj 0.81, 95% CI, 0.56-1.17, P = 0.26). COVID-19 patients with noninvasive mechanical ventilation (NIMV) had a lower risk for ICU admission if they received steroid therapy (ORadj 0.58, 95% CI, 0.35-0.94, P = 0.03). In conclusion, corticosteroids were overall not associated with a difference in hospital mortality for patients with COVID-19 with OSCI 3-5. In the subgroup of patients with NIMV (OSCI 5), corticosteroids reduced ICU admission, whereas the effect on mortality requires further studies.

BACKGROUND: The ratio of dead space to tidal volume (VD/VT) is associated with mortality in patients with ARDS. Corrected minute ventilation ([Formula: see text]) is a simple surrogate of dead space, but, despite its increasing use, its association with mortality has not been proven. The aim of our study was to assess the association between [Formula: see text] and hospital mortality. We also compared the strength of this association with that of estimated VD/VT and ventilatory ratio.METHODS: We performed a retrospective study with prospectively collected data. We evaluated 187 consecutive mechanically ventilated subjects with ARDS caused by novel coronavirus disease (COVID-19). The association between [Formula: see text] and hospital mortality was assessed in multivariable logistic models. The same was done for estimated VD/VT and ventilatory ratio.RESULTS: Mean ± SD [Formula: see text] was 11.8 ± 3.3 L/min in survivors and 14.5 ± 3.9 L/min in nonsurvivors (P < .001) and was independently associated with mortality (adjusted odds ratio 1.15, P = .01). The strength of association of [Formula: see text] with mortality was similar to that of VD/VT and ventilatory ratio.CONCLUSIONS: [Formula: see text] was independently associated with hospital mortality in subjects with ARDS caused by COVID-19. [Formula: see text] could be used at the patient's bedside for outcome prediction and severity stratification, due to the simplicity of its calculation. These findings need to be confirmed in subjects with ARDS without viral pneumonia and when lung-protective mechanical ventilation is not rigorously applied.

The sacroiliac joints connect the base of the sacrum to the ilium. When inflamed, they are suspected to cause low back pain. Inflammation of the sacroiliac joints is called sacroiliitis. The severity of the pain varies and depends on the degree of inflammation. Sacroiliitis is a hallmark of seronegative spondyloarthropathies. The presence or absence of chronic sacroiliitis is an important clue in the diagnosis of low back pain. This article aims to provide a concise overview of the anatomy, physiology, and molecular biology of sacroiliitis to aid clinicians in the assessment and management of sacroiliitis. For this narrative review, we evaluated articles in English published before August 2019 in PubMed. Then, we selected articles related to the painful manifestations of the sacroiliac joint. From the retrieved articles, we found that chronic sacroiliitis may be caused by various forms of spondyloarthritis, such as ankylosing spondyloarthritis. Sacroiliitis can also be associated with inflammatory bowel disease, Crohn’s disease, gout, tuberculosis, brucellosis, and osteoarthritis, indicating common underlying etiological factors. The pathophysiology of sacroiliitis is complex and may involve internal, environmental, immunological, and genetic factors. Finally, genetic factors may also play a central role in progression of the disease. Knowing the genetic pre-disposition for sacroiliitis can be useful for diagnosis and for formulating treatment regimens, and may lead to a substantial reduction in disease severity and duration and to improved patient performance.

The Pfizer/BioNtech Comirnaty vaccine (BNT162b2 mRNA COVID-19) against SARS-CoV-2 is currently in use in Italy. Antibodies to evaluate SARS-CoV-2 infection prior to administration are not routinely tested, therefore, two doses may be administered to asymptomatic previously exposed subjects. The aim of this study is to assess if any difference in antibody concentration between subjects exposed and not exposed to SARS-CoV-2 prior to BNT162b2 was present after the first dose and after the second dose of vaccine. Data were retrospectively collected from the clinical documentation of 337 healthcare workers who underwent SARS-CoV-2 testing before and after BNT162b2. Total anti RBD (receptor-binding domain) antibodies against SARS-CoV-2′s spike protein were measured before and 21 days after the first dose, and 12 days after the second dose of BNT162b2. Twenty-one days after the first dose, there was a statistically significant difference in antibody concentration between the two groups, which was also maintained twelve days after the second dose. In conclusion, antibody response after receiving BNT162b2 is greater in subjects who have been previously exposed to SARS-CoV-2 than in subjects who have not been previously exposed to the virus, both after 21 days after the first dose and after 12 days from the second dose. Antibody levels, 21 days after the first dose, reached a titer considered positive by the test manufacturer in the majority of subjects who have been previously infected with SARS-CoV-2. Evaluating previous infection prior to vaccination in order to give the least effective number of doses should be considered.

BACKGROUND: ARDS in patients with coronavirus disease 2019 (COVID-19) is characterized by microcirculatory alterations in the pulmonary vascular bed, which could increase dead-space ventilation more than in non-COVID-19 ARDS. We aimed to establish if dead-space ventilation is different in patients with COVID-19 ARDS when compared with patients with non-COVID-19 ARDS.METHODS: A total of 187 subjects with COVID-19 ARDS and 178 subjects with non-COVID-19 ARDS who were undergoing invasive mechanical ventilation were included in the study. The association between the ARDS types and dead-space ventilation, compliance of the respiratory system, subjects' characteristics, organ failures, and mechanical ventilation was evaluated by using data collected in the first 24 h of mechanical ventilation.RESULTS: Corrected minute ventilation (V˙E), a dead-space ventilation surrogate, was higher in the subjects with COVID-19 ARDS versus in those with non-COVID-19 ARDS (median [interquartile range] 12.6 [10.2-15.8] L/min vs 9.4 [7.5-11.6] L/min; P < .001). Increased corrected V˙E was independently associated with COVID-19 ARDS (odds ratio 1.24, 95% CI 1.07-1.47; P = .007). The best compliance of the respiratory system, obtained after testing different PEEPs, was similar between the subjects with COVID-19 ARDS and the subjects with non-COVID-19 ARDS (mean ± SD 38 ± 11 mL/cm H2O vs 37 ± 11 mL/cm H2O, respectively; P = .61). The subjects with COVID-19 ARDS received higher median (interquartile range) PEEP (12 [10-14] cm H2O vs 8 [5-9] cm H2O; P < .001) and lower median (interquartile range) tidal volume (5.8 [5.5-6.3] mL/kg vs 6.6 [6.1-7.3] mL/kg; P < .001) than the subjects with non-COVID-19 ARDS, being these differences maintained at multivariable analysis. In the multivariable analysis, the subjects with COVID-19 ARDS showed a lower risk of anamnestic arterial hypertension (odds ratio 0.18, 95% CI 0.07-0.45; P < .001) and lower neurologic sequential organ failure assessment score (odds ratio 0.16, 95% CI 0.09-0.27; P < .001) than the subjects with non-COVID-19 ARDS.CONCLUSIONS: Indirect measurements of dead space were higher in subjects with COVID-19 ARDS compared with subjects with non-COVID-19 ARDS. The best compliance of the respiratory system was similar in both ARDS forms provided that different PEEPs were applied. A wide range of compliance is present in every ARDS type; therefore, the setting of mechanical ventilation should be individualized patient by patient and not based on the etiology of ARDS.

OBJECTIVES: Early tracheotomy, defined as a procedure performed within 10 days from intubation, is associated with more ventilator free days, shorter ICU stay, and lower mortality than late tracheotomy. During the coronavirus disease 2019 pandemic, it was especially important to save operating room resources and to have a shorter ICU stay for patients, when ICUs had insufficient beds. In this context of limited resources, early percutaneous tracheostomy could be an effective way to manage mechanically ventilated patients. Nevertheless, current recommendations suggest delaying or avoiding the tracheotomy in coronavirus disease 2019 patients. Aim of the study was to analyze the hospital mortality of coronavirus disease 2019 patients who had received early percutaneous tracheostomy and factors associated with removal of tracheostomy cannula at ICU discharge.DESIGN: Cohort study.SETTING: Coronavirus disease 2019 ICU.PATIENTS: Adult patients with coronavirus disease 2019 3 days after ICU admission.INTERVENTIONS: None.MEASUREMENTS AND MAIN RESULTS: Three days after ICU admission, 164 patients were present in ICU and included in the analysis. One-hundred and twenty-one patients (74%) were tracheostomized, whereas the other 43 (26%) were managed with translaryngeal intubation only. In multivariable analysis, early percutaneous tracheostomy was associated with lower hospital mortality. Sixty-six of tracheostomized patients (55%) were discharged alive from the hospital. Age and male sex were the only characteristics that were independently associated with mortality in the tracheostomized patients (45.5% and 62.8% in tracheostomized and nontracheostomized patients, respectively; p = 0.009). Tracheostomy tube was removed in 47 of the tracheostomized patients (71%). The only variable independently associated with weaning from tracheostomy at ICU discharge was a faster start of spontaneous breathing after tracheotomy was performed.CONCLUSIONS: Early percutaneous tracheostomy was safe and effective in coronavirus disease 2019 patients, giving a good chance of survival and of weaning from tracheostomy cannula at ICU discharge.

Since the start of the novel coronavirus 2019 (COVID-19) pandemic, corticosteroid use has been the subject of debate. The available evidence is uncertain, and knowledge on the subject is evolving. The aim of our cohort study was to evaluate the association between corticosteroid therapy and hospital mortality, in patients hospitalized with COVID-19 after balancing for possible confounders. One thousand four hundred forty four patients were admitted to our hospital with a positive RT-PCR test for SARS-CoV-2, 559 patients (39%) were exposed to corticosteroids during hospital stay, 844 (61%) were not exposed to corticosteroids. In the cohort of patients exposed to corticosteroids, 171 (30.6%) died. In the cohort of patients not exposed to corticosteroids, 183 (21.7%) died (unadjusted p p = 0.25). Patients in the corticosteroids cohort had a reduced risk of ICU admission (adjusted p

BACKGROUND: A recent systematic review recommends against the use of any of the current COVID-19 prediction models in clinical practice. To enable clinicians to appropriately profile and treat suspected COVID-19 patients at the emergency department (ED), externally validated models that predict poor outcome are desperately needed.OBJECTIVE: Our aims were to identify predictors of poor outcome, defined as mortality or ICU admission within 30 days, in patients presenting to the ED with a clinical suspicion of COVID-19, and to develop and externally validate a prediction model for poor outcome.METHODS: In this prospective, multi-center study, we enrolled suspected COVID-19 patients presenting at the EDs of two hospitals in the Netherlands. We used backward logistic regression to develop a prediction model. We used the area under the curve (AUC), Brier score and pseudo-R2 to assess model performance. The model was externally validated in an Italian cohort.RESULTS: We included 1193 patients between March 12 and May 27 2020, of whom 196 (16.4%) had a poor outcome. We identified 10 predictors of poor outcome: current malignancy (OR 2.774; 95%CI 1.682-4.576), systolic blood pressure (OR 0.981; 95%CI 0.964-0.998), heart rate (OR 1.001; 95%CI 0.97-1.028), respiratory rate (OR 1.078; 95%CI 1.046-1.111), oxygen saturation (OR 0.899; 95%CI 0.850-0.952), body temperature (OR 0.505; 95%CI 0.359-0.710), serum urea (OR 1.404; 95%CI 1.198-1.645), C-reactive protein (OR 1.013; 95%CI 1.001-1.024), lactate dehydrogenase (OR 1.007; 95%CI 1.002-1.013) and SARS-CoV-2 PCR result (OR 2.456; 95%CI 1.526-3.953). The AUC was 0.86 (95%CI 0.83-0.89), with a Brier score of 0.32 and, and R2 of 0.41. The AUC in the external validation in 500 patients was 0.70 (95%CI 0.65-0.75).CONCLUSION: The COVERED risk score showed excellent discriminatory ability, also in an external validation. It may aid clinical decision making, and improve triage at the ED in health care environments with high patient throughputs.

Background The evaluation of patient effort is pivotal during pressure support ventilation, but a non-invasive, continuous, quantitative method to assess patient inspiratory effort is still lacking. We hypothesized that the concavity of the inspiratory flow-time waveform could be useful to estimate patient’s inspiratory effort. The purpose of this study was to assess whether the shape of the inspiratory flow, as quantified by a numeric indicator, could be associated with inspiratory effort during pressure support ventilation. Methods Twenty-four patients in pressure support ventilation were enrolled. A mathematical relationship describing the decay pattern of the inspiratory flow profile was developed. The parameter hypothesized to estimate effort was named Flow Index. Esophageal pressure, airway pressure, airflow, and volume waveforms were recorded at three support levels (maximum, minimum and baseline). The association between Flow Index and reference measures of patient effort (pressure time product and pressure generated by respiratory muscles) was evaluated using linear mixed effects models adjusted for tidal volume, respiratory rate and respiratory rate/tidal volume. Results Flow Index was different at the three pressure support levels and all group comparisons were statistically significant. In all tested models, Flow Index was independently associated with patient effort (p Flow Index prediction of inspiratory effort agreed with esophageal pressure-based methods. Conclusions Flow Index is associated with patient inspiratory effort during pressure support ventilation, and may provide potentially useful information for setting inspiratory support and monitoring patient-ventilator interactions.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has led to widespread use of hydroxychloroquine and azithromycin despite the lack of conclusive evidence for their safety and efficacy. We evaluated the association between treatment with hydroxychloroquine and/or azithromycin and hospital mortality as the primary outcome. We compared the hospital mortality of patients treated with hydroxychloroquine alone, azithromycin alone, or their combination to the mortality of patients who received neither drug. A logistic multivariate model with overlap weight propensity score was used for estimation of odds ratios (ORs) with 95% confidence intervals (95% CIs). One thousand four hundred and three patients with SARS-CoV-2 infection were admitted to the hospital. At the time of the analysis, the outcome was available for 1376 (98%) of them. Five hundred and eighty-seven patients (42%) received azithromycin and 377 patients (27%) received hydroxychloroquine, alone or in combination. In-hospital mortality was 26%. After the adjusted analysis, azithromycin alone was associated with lower mortality (OR 0.60, 95% CI 0.42&ndash, 0.85) compared to no treatment. Hydroxychloroquine alone (OR 0.76, 95% CI 0.53&ndash, 1.08) and the combination of azithromycin and hydroxychloroquine (OR 1.13, 95% CI 0.77&ndash, 1.69) were not associated with hospital mortality. In this cohort of patients, azithromycin alone was associated with lower hospital mortality but hydroxychloroquine was not associated with increased or reduced mortality. While we await randomized clinical trials, these data support the use of azithromycin in novel coronavirus disease 2019 (COVID-19) and can contribute to better understanding of its role in further meta-analyses.

BackgroundSince the start of the novel coronavirus 2019 (COVID-19) pandemic, corticosteroid use has been the subject of debate. The available evidence is uncertain, and knowledge on the subject is evolving. The aim of our cohort study was to evaluate the association between corticosteroid therapy and hospital mortality, in patients hospitalized with COVID-19 after balancing for possible confounders.ResultsOne thousand four hundred forty four patients were admitted to our hospital with a positive RT-PCR test for SARS-CoV-2, 559 patients (39%) were exposed to corticosteroids during hospital stay, 844 (61%) were not exposed to corticosteroids.In the cohort of patients exposed to corticosteroids, 171 (30.6%) died. In the cohort of patients not exposed to corticosteroids, 183 (21.7%) died (unadjusted p ConclusionsTreatment with corticosteroids did not affect hospital mortality in patients with COVID-19 after balancing for confounders. A possible advantage of corticosteroid therapy was to reduce Intensive Care Unit admission, which could be useful in reducing pressure on the Intensive Care Units in times of limited resources, as during the COVID-19 pandemic.

BACKGROUND: Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) infection is associated with hypercoagulability caused by direct invasion of endothelial cells and\or proinflammatory cytokine release. Thromboprophylaxis with enoxaparin is recommended by current guidelines, but evidence is still weak. The aim of this study was to assess the impact of thromboprophylaxis with enoxaparin on hospital mortality in patients admitted for Coronavirus disease 2019 (COVID-19). The effects of enoxaparin on intensive care admission and hospital length-of-stay were evaluated as secondary outcomes.METHODS: Observational cohort study, with data collected from patients admitted to Poliambulanza Foundation with positive real time reverse transcription polymerase chain reaction (RT-PCR) for SARS-CoV-2 from 20th February to 10th May 2020. Multivariate logistic regression with overlap weight propensity score was used to model hospital mortality and intensive care admission, hospital length-of-stay was analyzed with a multivariate Poisson regression. Seven hundred and ninety nine (57%) patients who received enoxaparin at least once during the hospitalization were included in the enoxaparin cohort, 604 (43%) patients who did not were included in the control cohort.FINDINGS: At the adjusted analysis enoxaparin was associated with lower in-hospital mortality (Odds Ratio 0·53, 95% C.I. 0·40-0·70) compared with no enoxaparin treatment. Hospital length-of-stay was longer for patients treated with enoxaparin (Incidence Rate Ratios 1·45, 95% C.I. 1·36-1·54). Enoxaparin treatment was associated with reduced risk of intensive care admission at the adjusted analysis (Odds Ratio 0·48, 95% C.I. 0·32-0·69).INTERPRETATION: This study shows that treatment with enoxaparin during hospital stay is associated with a lower death rate and, while results from randomized clinical trials are still pending, this study supports the use of thromboprophylaxis with enoxaparin in all patients admitted for COVID-19. Moreover, when enoxaparin is used on the wards, it reduces the risk of Intensive Care Unit admission.

BackgroundIn mechanically ventilated acute respiratory distress syndrome (ARDS) patients infected with the novel coronavirus disease (COVID-19), we frequently recognised the development of pneumomediastinum and/or subcutaneous emphysema despite employing a protective mechanical ventilation strategy. The purpose of this study was to determine if the incidence of pneumomediastinum/subcutaneous emphysema in COVID-19 patients was higher than in ARDS patients without COVID-19 and if this difference could be attributed to barotrauma or to lung frailty.MethodsWe identified both a cohort of patients with ARDS and COVID-19 (CoV-ARDS), and a cohort of patients with ARDS from other causes (noCoV-ARDS).Patients with CoV-ARDS were admitted to an intensive care unit (ICU) during the COVID-19 pandemic and had microbiologically confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. NoCoV-ARDS was identified by an ARDS diagnosis in the 5 years before the COVID-19 pandemic period.ResultsPneumomediastinum/subcutaneous emphysema occurred in 23 out of 169 (13.6%) patients with CoV-ARDS and in three out of 163 (1.9%) patients with noCoV-ARDS (pCoV-ARDS patients had a high incidence of pneumomediastinum/subcutaneous emphysema despite the use of low tidal volume (5.9±0.8 mL·kg−1 ideal body weight) and low airway pressure (plateau pressure 23±4 cmH2O).ConclusionsWe observed a seven-fold increase in pneumomediastinum/subcutaneous emphysema in CoV-ARDS. An increased lung frailty in CoV-ARDS could explain this finding more than barotrauma, which, according to its etymology, refers to high transpulmonary pressure.

Background: Viral infectivity depends on interactions between components of the host cell plasma membrane and the virus envelope. Here we review strategies that could help stem the advance of the SARS-COV-2 epidemic. Methods and Results: We focus on the role of lipid structures, such as lipid rafts and cholesterol, involved in the process, mediated by endocytosis, by which viruses attach to and infect cells. Previous studies have shown that many naturally derived substances, such as cyclodextrin and sterols, could reduce the infectivity of many types of viruses, including the coronavirus family, through interference with lipid-dependent attachment to human host cells. Conclusions: Certain molecules prove able to reduce the infectivity of some coronaviruses, possibly by inhibiting viral lipid-dependent attachment to host cells. More research into these molecules and methods would be worthwhile as it could provide insights the mechanism of transmission of SARS-COV-2 and, into how they could become a basis for new antiviral strategies.

Objective The aim of our study was to determine the incidence, characteristics, and clinical outcomes of patients with the novel coronavirus (COVID-19) infection who had presented with and been treated for acute limb ischemia (ALI) during the 2020 coronavirus pandemic. Methods We performed a single-center, observational cohort study. The data from all patients who had tested positive for COVID-19 and had presented with ALI requiring urgent operative treatment were collected in a prospectively maintained database. For the present series, successful revascularization of the treated arterial segment was defined as the absence of early ( Results We evaluated the data from 20 patients with ALI who were positive for COVID-19. For the period from January to March, the incidence rate of patients presenting with ALI in 2020 was significantly greater than that for the same months in 2019 (23 of 141 [16.3%] vs 3 of 163 [1.8%]; P Conclusions In our preliminary experience, the incidence of ALI has significantly increased during the COVID-19 pandemic in the Italian Lombardy region. Successful revascularization was lower than expected, which we believed was due to a virus-related hypercoagulable state. The use of prolonged systemic heparin might improve surgical treatment efficacy, limb salvage, and overall survival.

ObjectiveSingle cases and small series of Guillain-Barré syndrome (GBS) have been reported during the SARS-CoV-2 outbreak worldwide. We evaluated incidence and clinical features of GBS in a cohort of patients from two regions of northern Italy with the highest number of patients with COVID-19.MethodsGBS cases diagnosed in 12 referral hospitals from Lombardy and Veneto in March and April 2020 were retrospectively collected. As a control population, GBS diagnosed in March and April 2019 in the same hospitals were considered.ResultsIncidence of GBS in March and April 2020 was 0.202/100 000/month (estimated rate 2.43/100 000/year) vs 0.077/100 000/month (estimated rate 0.93/100 000/year) in the same months of 2019 with a 2.6-fold increase. Estimated incidence of GBS in COVID-19-positive patients was 47.9/100 000 and in the COVID-19-positive hospitalised patients was 236/100 000. COVID-19-positive patients with GBS, when compared with COVID-19-negative subjects, showed lower MRC sum score (26.3±18.3 vs 41.4±14.8, p=0.006), higher frequency of demyelinating subtype (76.6% vs 35.3%, p=0.011), more frequent low blood pressure (50% vs 11.8%, p=0.017) and higher rate of admission to intensive care unit (66.6% vs 17.6%, p=0.002).ConclusionsThis study shows an increased incidence of GBS during the COVID-19 outbreak in northern Italy, supporting a pathogenic link. COVID-19-associated GBS is predominantly demyelinating and seems to be more severe than non-COVID-19 GBS, although it is likely that in some patients the systemic impairment due to COVID-19 might have contributed to the severity of the whole clinical picture.

Background Post-traumatic cerebral infarction (PTCI) is common after traumatic brain injury (TBI). It is unclear what the occurrence of a PTCI is, how it impacts the long-term outcome, and whether it adds incremental prognostic value to established outcome predictors. Methods This was a prospective multicenter cohort study of moderate and severe TBI patients. The primary objective was to evaluate if PTCI was an independent risk factor for the 6-month outcome assessed with the Glasgow Outcome Scale (GOS). We also assessed the PTCI occurrence and if it adds incremental value to the International Mission for Prognosis and Clinical Trial design in TBI (IMPACT) core and extended models. Results We enrolled 143 patients, of whom 47 (32.9%) developed a PTCI. In the multiple ordered logistic regression, PTCI was retained in both the core and extended IMPACT models as an independent predictor of the GOS. The predictive performances increased significantly when PTCI was added to the IMPACT core model (AUC = 0.73, 95% C.I. 0.66–0.82; increased to AUC = 0.79, 95% CI 0.71–0.83, p = 0.0007) and extended model (AUC = 0.74, 95% C.I. 0.65–0.81 increased to AUC = 0.80, 95% C.I. 0.69–0.85; p = 0.00008). Patients with PTCI showed higher ICU mortality and 6-month mortality, whereas hospital mortality did not differ between the two groups. Conclusions PTCI is a common complication in patients suffering from a moderate or severe TBI and is an independent risk factor for long-term disability. The addition of PTCI to the IMPACT core and extended predictive models significantly increased their performance in predicting the GOS. Trial registration The present study was registered in ClinicalTrial.gov with the ID number NCT02430324.

Background: Post-traumatic cerebral infarction (PTCI) is common in patients dying after a traumatic brain injury (TBI). It is unclear what the occurrence of a PTCI is, how it impacts the long-term outcome, and whether it adds incremental prognostic value to established outcome predictors. Methods: This was a prospective multicenter cohort study of moderate and severe TBI patients admitted to nine Italian intensive care units (ICUs). The primary objective was to evaluate if PTCI was an independent risk factor for the 6-month outcome assessed with the Glasgow Outcome Scale (GOS). We also assessed the PTCI occurrence and if it adds incremental value to the International Mission for Prognosis and Clinical Trial design in TBI (IMPACT) core and extended models. Findings: We enrolled 143 patients; 47 (32·9%) developed a PTCI for a total of 94. The mean (SD) onset time of a PTCI was 6·2 (11·4). In the multiple ordered logistic regression, PTCI was retained in both the core and extended IMPACT models as an independent predictor of the GOS. The predictive performances increased significantly when PTCI was added to the IMPACT core model (AUC=0·73, 95% C.I. 0·66-0·82; increased to AUC=0·79, 95% CI 0·71-0·83, p=0·0007) and extended model (AUC=0·74, 95% C.I.: 0·65-0·81 increased to AUC=0·80, 95% C.I. 0·69-0·85; p=0·00008). Patients with a PTCI showed higher ICU mortality (10 patients [21·3%] vs one patient [1·0%], p

The purpose of this study was to evaluate early and midterm results of tibial bypasses comparing precuffed expanded polytetrafluoroethylene (PTFE) graft (Distaflo) and heparin-bonded PTFE graft (Propaten) with a distal vein patch.This is a retrospective cohort analysis evaluating patients who underwent PTFE femorocrural bypasses between April 2004 and December 2010 at the Vascular Surgery Division of the Poliambulanza Foundation Hospital (Brescia, Italy). Results were analyzed in terms of primary and secondary graft patency, limb salvage, and survival with univariate (Kaplan-Meier curves and log-rank test) and multivariate (Cox regression) analyses.After analyzing many patients, we found 79 femorotibial bypass PTFE grafts. We used a Propaten graft and vein patch in 40 patients and a Distaflo graft in 39 patients. The two groups were comparable for main risk factors, except for age. Indication for surgical revascularization was critical limb ischemia in all patients. In 54 cases (68%), it was a redo bypass because of a previously failed revascularization. Perioperative mortality within 30 days from intervention was 2.5%, whereas overall mortality during follow-up was 29%, with a 36-month survival rate of 58% (95% confidence interval [CI]: 0.44-0.77) on life table analysis. We observed a significant difference between two groups in terms of survival at 36 months (Propaten: 0.84 [95% CI: 0.69-1]; Distaflo: 0.21 [95% CI: 0.07-0.63]; P0.001; 95% CI: 0.07-0.63; odds ratio [OR]: 0.21). At 24 months, the two groups (Propaten vs. Distaflo) were equivalent in terms of primary patency (Propaten: 0.33 [95% CI: 0.21-0.53]; Distaflo: 0.47 [95% CI: 0.32-0.70]; P = 0.793), secondary patency (Propaten: 0.36 [95% CI: 0.23-0.57]; Distaflo: 0.49 [95% CI: 0.33-0.72]; P = 0.855), and limb salvage (Propaten: 0.65 [95% CI: 0.51-0.84]; Distaflo: 0.57 [95% CI: 0.41-0.79]; P = 0.18). At Cox regression analysis, age of80 years (P0.04; 95% CI: 0.23-0.95; OR: 0.47), peroneal artery distal anastomosis (P0.04; 95% CI: 1.04-5.62; OR: 2.42), simultaneous adjunctive procedures (P0.02; 95% CI: 1.21-17.74; OR: 4.64), and redo bypass (P0.05; 95% CI: 1-6.26; OR: 2.5) were associated with long-term poorer primary patency rates. Postoperative treatment with warfarin therapy compared with antiplatelet therapy was independently associated with better secondary patency (P0.04; 95% CI: 0.20-0.95; OR: 0.44) and limb salvage (P0.03; 95% CI: 0.11-0.87; OR: 0.32) rates.Distaflo and Propaten with a distal vein patch in our experience have similar patency and limb salvage results, although further randomized and larger studies are necessary. Postoperative anticoagulation therapy seems better than antiplatelet therapy in terms of patency and limb salvage rate.

Objective The history of left ventricular reconstruction has demonstrated that the full spectrum of recoverable physiologic parameters is essential for a good functional result. We report the long-term outcome of a new surgical technique that arranges myocardial fibers in a near-normal disposition, also recovering left ventricular twisting. Methods Between May 2006 and October 2013, 29 consecutive patients with previous anterior myocardial infarction and heart failure symptoms underwent physiologic left ventricular reconstruction surgery and coronary revascularization. Patients were examined by means of standard echocardiography and 2-dimensional speckle tracking at 8 time steps until 7 years after surgery. Ten geometric and functional parameters were evaluated at each step and analyzed by the linear mixed model test. Results Hospital mortality was 0%. The mean percentage of indexed end-diastolic and end-systolic volume reduction was 45.7% and 50.9%, respectively. Ejection fraction and all of the volumes were significantly different in the postoperative period with a steady correction during time. Diastolic parameters were not worsened by surgical reconstruction. Ejection fraction and deceleration time showed a significant improvement during time. Left ventricular torsion increased immediately after the surgical correction from 2.8 ± 4.4 degrees to 8.7 ± 3.9 degrees ( P = .02) and was still present 4 years after surgery. Conclusions Surgical conduction of ventricular reconstruction should be standardized to achieve the full spectrum of recoverable physiologic parameters. The renewal of ventricular torsion should be pursued as an adjunctive element of ventricular efficiency, mainly in ventricles that work at a critical level in the Frank–Starling relationship and pressure-volume loop.

BACKGROUND: Properly titrated opiates decrease respiratory rate but do not affect tidal volume or induce respiratory acidosis. OBJECTIVE: To determine whether remifentanil improves breathing pattern or reduces inspiratory effort in patients with acute respiratory failure and tachypnea or rapid shallow breathing. METHODS: We studied 14 patients who developed tachypnea and/or rapid shallow breathing if the pressure support level was reduced. During pressure support ventilation, each patient received 30-min infusions, separated by 30 min, of remifentanil and placebo. Measurements were obtained before commencing and before stopping each infusion, and after 3 min of unassisted breathing. The main outcomes were rapid shallow breathing index and change in pressure-time product. RESULTS: Remifentanil did not significantly affect tidal volume. During pressure support ventilation, remifentanil infusion reduced respiratory rate, pressure-time product, and cardiovascular double product (heart rate × systolic arterial pressure) without modifying the sedation score. Mean PaCO2 showed a small and clinically negligible increase during remifentanil, but PaCO2 increased more in the hypercapnic patients than in the normocapnic patients. Remifentanil reduced the rapid shallow breathing index after 3 min of unassisted breathing. CONCLUSIONS: Remifentanil improved respiratory pattern and decreased inspiratory muscles effort in patients with tachypnea or rapid shallow breathing, but did not affect oxygenation or sedation. Though the acid-base balance did not show clinically relevant changes on average, we cannot exclude the possibility that remifentanil might prolong weaning in hypercapnic patients. (ClinicalTrials.gov registration [NCT00665119][1]) [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00665119&atom=%2Frespcare%2F56%2F6%2F827.atom

We compared the risk of pulmonary aspiration in patients whose lungs were mechanically ventilated through a laryngeal mask airway (35 630 procedures) or tracheal tube (30 082 procedures). Three cases of pulmonary aspiration occurred with the laryngeal mask airway and seven with the tracheal tube. There were no deaths related to pulmonary aspiration. The incidence and outcome of pulmonary aspiration detected in this study were similar to those previously reported. The adjusted odds ratio (OR) for pulmonary aspiration with the laryngeal mask airway was 1.06 (95% CI 0.20-5.62). Unplanned surgery (OR 30.5, 95% CI 8.6-108.9) and male sex (OR 8.6, 95% CI 1.1-68) were associated with an increased risk of aspiration and age < 14 years with a reduced risk (OR 0.21, 95% CI 0.07-0.64). There were contraindications and exclusions to the use of the laryngeal mask airway but in this selected population the use of an laryngeal mask airway was not associated with an increased risk of pulmonary aspiration compared with a tracheal tube.

We analyzed ventilation-induced changes in arterial blood pressure and photoplethysmography from waveforms obtained by monitoring 57 patients in the operating room and intensive care unit. Analysis of systolic and pulse pressure variations during positive pressure ventilation, DeltaUp, DeltaDown, and changes in the preejection period on both arterial and photoplethysmographic waveforms were possible in 49 (86%) patients. The pulse pressure variation and preejection period were similar when calculated using both arterial blood pressure and photoplethysmography, whereas the other variables were different. Photoplethysmographic pulse variation >9% identified patients with arterial pulse pressure variation >13% (area under ROC curve = 0.85) or DeltaDown >5 mm Hg (area under ROC curve = 0.85). In hypotensive patients, photoplethysmographic pulse variation >9% remained the best threshold value (pulse pressure variation >13%: area under ROC curve = 0.90; DeltaDown >5 mm Hg: area under ROC curve = 0.93) for predicting fluid responsiveness. In conclusion, this study showed that pulse variations observed in the arterial pressure waveform and photoplethysmogram are similiar in response to positive pressure ventilation. Furthermore, photoplethysmographic pulse variation > 9% identifies patients with ventilation-induced arterial blood pressure variation that is likely to respond to fluid administration.

To compare the effects of norepinephrine and metaraminol on hemodynamics in septic shock patients.Open-label, controlled clinical trial in the general intensive care unit of a university-affiliated hospital.Ten consecutive septic shock patients receiving norepinephrine to maintain the mean arterial pressure higher than 65 mmHg.Patients were monitored with pulmonary artery catheter and indirect calorimetry. At the baseline hemodynamic variables were obtained during norepinephrine infusion. Subsequently norepinephrine was replaced by metaraminol infusion in a dose sufficient to keep mean arterial pressure constant. After 20 min of stable arterial pressure a new set of measurement was repeated.Mean arterial pressure did not differ significantly with norepinephrine or metaraminol; there was no relationship between the norepinephrine and metaraminol doses. Replacement norepinephrine with metaraminol did not modify hemodynamic variables; in particular there were no changes in heart rate, stroke volume index, pulmonary artery occlusion pressure, or oxygen consumption index.This study shows that metaraminol increases arterial pressure as does norepinephrine in septic shock patients. Despite similar effects of norepinephrine and metaraminol, there was no relationship between the dose of the two drugs.

Background: The pressure-time product (PTP) is often used to compare conditions with different breathing patterns. Being the pressure-time product calculated with pressures changes over a minute, mechanical load and inspiration time per minute should be its main determinants. The aim of this study was to investigate if the method of PTP computation is affected by the breathing pattern when mechanical load and inspiratory time per minute are constant. Methods: Respiratory mechanics and the PTP developed by the ventilator were calculated in 10 mechanically ventilated patients at three different respiratory rate/tidal volume combinations, provided that minute ventilation and inspiratory time per minute were constant. Results: The static elastance did not change at different tidal volumes. Despite the constant elastic load over a minute, the elastic PTP showed an increment greater than 200% from the higher to the lower respiratory rate, responsible for approximately 80% of the whole PTP increment. On the contrary a ‘corrected’ elastic PTP (calculated using the square root of the elastic pressure-time area), the elastic double product of the respiratory system and the mean elastic pressure per minute, did not significantly change. Conclusions: Changes in breathing pattern markedly affected the PTP independently by the mechanical load and the inspiratory time per minute. In these conditions it could not correctly estimate the metabolic cost of breathing. The use of a ‘corrected’ PTP, the mean inspiratory pressure per minute or the double product of the respiratory system, could overcome this limitation.

Background: The ProSeal Laryngeal Mask Airway (PLMA) ventilation tube is narrower and shorter than the standard Laryngeal Mask Airway (LMA) and is without the vertical bars at the end of the tube. In this randomized, crossover study, PLMA and LMA resistances were compared. Methods: Respiratory mechanics was calculated in 26 anesthetized, mechanically ventilated patients with both LMA and PLMA. The laryngeal mask positioning was fiberoptically evaluated. Differences in the respiratory mechanics of the LMA and the PLMA were attributed to the differences between the laryngeal masks. Results: In the total study population the airway resistance was 1.5 ± 2.6 hPa.l−1.s−1 (P = 0.005) higher with the PLMA than with the LMA. During the PLMA use, the peak expiratory flow reduced by 0.02 ± 0.05 l min−1 (P = 0.046), the expiratory resistance increased by 0.6 ± 1.3 hPa.l−1.s−1 (P = 0.022), and the time constant of respiratory system lengthened by 0.09 ± 0.18 s (P = 0.023). These differences doubled when the LMA was better positioned than the PLMA, whereas they disappeared when the PLMA was positioned better than the LMA. Conclusions: The standard LMA offers a lower resistive load than the PLMA. Moreover, the fitting between the laryngeal masks and the larynx, as fiberoptically evaluated, plays a major role in determining the resistive properties of these devices.

Background The ProSeal™ laryngeal mask airway (PLMA) may have advantages over the laryngeal mask airway (LMA† †LMA® is the property of Intavent Limited.) in obese patients. We tested this hypothesis in a clinical setting. Methods Sixty obese patients (BMI >30) were randomized to receive mechanical ventilation (tidal volume 7 ml kg−1, PEEP 10 cm H2O), through either the PLMA or the LMA. A gastric tube was used in all patients. Cuff pressure was set at 60 cm H2O and increased progressively until excessive leak occurred. The incidence of sore throat was assessed at recovery and after 1 week. Results The mean leak fraction was 6.1 (sd 2.9)% with the LMA and 6.4 (3.5)% with the PLMA (P=0.721). With the PLMA, with no sign of ventilation problems, the drainage tube was not patent in three patients. The cuff pressure was >100 cm H2O in 38% of the LMA group and 7% of the PLMA group (P=0.05). The incidence of sore throat was similar in both groups and it was similarly scored in the recovery room and 1 week after surgery. Conclusions Both the PLMA and the LMA can be used for mechanical ventilation of obese patients. The patency of the PLMA drainage tube needs to be checked constantly even when an optimal airtight seal is present. In obese patients the LMA requires a greater cuff pressure than the PLMA, but sore throat is not related to the cuff pressure. Sore throat assessment in the recovery room appears as reliable as assessment later.

Background The tracheal tube (TT) produces reversible bronchoconstriction and increases pulmonary airway resistance compared to the laryngeal mask airway (LMA). The possible persistence of this effect in the postoperative period has not been studied. The aim of this study was to compare the early postoperative pulmonary function in healthy patients undergoing minor surgical procedures with the LMA or with the TT. Methods Sixty patients scheduled for saphenous vein stripping under general anaesthesia were randomised to receive the LMA or the TT. Before anaesthesia and 20 min after LMA or TT removal, pulse oxymetry values (SpO(2)) were recorded and patients performed forced spirometry in the supine position. Results Preoperative pulmonary function was normal in both groups. There were no differences between groups in the preoperative respiratory function test and SpO(2). Following surgery SpO(2), forced expiratory volume in the first second (FEV1), forced vital capacity (FVC) and peak expiratory flow (PEF) decreased in both groups. The FEV1/FVC did not change in either of the groups. In the TT group, compared to patients using the LMA, there was a greater relative decrease of SpO(2) (2.7 +/- 2.7% vs. 1.3 +/- 2.2%, P=0.017), FEV1 (17.6 +/- 12.2% vs. 8 +/- 17.4%, P=0.008), FVC (15.8 +/- 12.4% vs. 9 +/- 13.4%, P=0.023) and PEF (20.6% +/- 15.3% vs. 8.1 +/- 33.3%, P=0.033). Conclusions This study demonstrates greater early postoperative respiratory restrictive syndrome and lower arterial oxygen saturation following tracheal intubation compared to LMA use in patients without respiratory disease.

To quantify the impact on peak airway pressure of pressure-controlled and volume-controlled ventilation during Laryngeal Mask Airway (LMA) use.Prospective, crossover clinical study.University-affiliated hospital.32 ASA physical status I and II patients undergoing general anesthesia with the LMA.Patients were ventilated for three minutes both with pressure-controlled and volume-controlled ventilation, provided that tidal volume (V(T) ) and inspiratory time (It) were constant.The monitored parameters were electrocardiography, arterial blood pressure, pulse oximetry, capnography, neuromuscular transmission, airway pressure and flow, and concentration of ventilated vapors and gases. The actually delivered V(T) was similar with both types of ventilation (volume-controlled = 0.67 +/- 0.13 lt, pressure-controlled = 0.67 +/- 0.14 lt; p = 0.688). Peak airway pressure was lower during pressure-controlled ventilation (14.6 +/- 3.5 cmH(2)O) than during volume-controlled ventilation (16 +/- 4 cmH(2)O) (p0.001). Furthermore, we noted that the higher the airway pressure with volume-controlled ventilation, the greater was the reduction in airway pressure during pressure-controlled ventilation.Pressure-controlled rather than volume-controlled ventilation can improve the effectiveness of mechanical ventilation in patients with high airway pressure.

Study objectives To compare the effectiveness of two modalities of external ventilation during rigid bronchoscopy: intermittent negative pressure ventilation (INPV) and external high-frequency oscillation (EHFO). Design Prospective, controlled, randomized, nonblinded study. Setting University-affiliated hospital. Patients Seventy patients undergoing interventional rigid bronchoscopy for tracheobronchial lesions were enrolled into the study. Interventions Mechanical ventilation was performed by INPV or EHFO. When pulse oximetry was Measurements and results Arterial blood gases were sampled preoperatively and intraoperatively. Most patients in both groups had normal intraoperative Pa co 2 (mean, 43.6 ± 11.8 mm Hg under EHFO and 37.4 ± 8.2 mm Hg under INPV; p = 0.012), and acidemia occurred in 9 of 35 patients of EHFO group and in 2 of 35 patients of INPV group (p = 0.049). Hypercapnia (Pa co 2 > 50 mm Hg) was observed in 10 patients under EHFO and in 2 with INPV (p = 0.026). Intraoperative mean Pa o 2 was similar (101.4 ± 52.9 mm Hg with EHFO and 124.2 ± 50.3 mm Hg with INPV; p = 0.07), but O 2 supply was different (3.5 ± 2.3 L/min during INPV and 8.5 ± 6.2 L/min during EHFO; p o 2 Conclusions External negative pressure ventilation appears to be a suitable choice during rigid bronchoscopy: both EHFO and INPV ensure effective ventilation and comfortable operating conditions in the majority of patients. Some patients may receive inadequate ventilation with EHFO, developing respiratory acidosis and requiring manually assisted ventilation. In comparison with INPV, EHFO requires a higher fraction of inspired oxygen.

Objective. Work of breathing (WoB) is currently employed to assess the afterload on the respiratory muscles and to estimate the energy expenditure for breathing. Since WoB depends on the ventilated tidal volume (TV), WoB*L-1, the indicized form of WoB has been employed as a measure of WoB which is independent of TV. Actually, the independence of WoB*L-1 from the ventilated TV has never been demonstrated. The aim of this study was to verify the predicted TV-independence of WoB*L-1 on an in vitro model. Methods. Our experimental model was constituted as follows: two endotracheal tubes, with internal diameter measuring respectively 6.5 and 8.5 mm, were alternatively connected with two rubber balloons whose compliance was respectively 0.02 and 0.06 L/hPa; the system was mechanically ventilated at ten different tidal volumes, ranging from 0.3–1 l. Flow rate was kept constant (35 l/m) during the whole experiment. Results. Both elastic components of the model showed a static volume–pressure relationship which was linear in the experimental range of TV. In all combinations of resistance and compliance WoB increased quadratically whereas WoB*L-1 increased linearly with the growing TV (p < 0.001). Conclusions. These results demonstrate the TV-dependence of WoB*L-1 and suggest that WoB*L-1, if TV changes, cannot be considered as an index of respiratoy muscle afterload and should not be used as a guide for weaning patients from the mechanical ventilation. Finally, we introduced a new parameter (WoB1L) which seems to be a more TV-independent measure of respiratory work.

Study objective To evaluate the efficacy of negative pressure ventilation (NPV) in avoiding or reducing apneas and related hypoxemia and respiratory acidosis during laser therapy (LT) of endobronchial lesions. Design A prospective, controlled, randomized study. Setting An operating theater of a respiratory endoscopy and laser therapy unit. Population and intervention Twenty-seven consecutive patients referred to LT were entered into the study. Fourteen patients were randomly assigned to LT under general anesthesia and spontaneous assisted ventilation (control group) whereas in 13 cases, NPV by a poncho-wrap ventilator (NPV group) was added to the procedure. Measurements and results The prevalence and the duration of apnea/hypopnea periods assessed by respiratory inductive plethysmography during LT were significantly reduced under NPV, compared to the control group. As compared to baseline, during LT, all control patients developed mild to severe hypercapnia (PaCO2 ranging from 55 to 76 mm Hg) and respiratory acidosis (pH from 7.33 to 7.19), whereas only three patients undergoing NPV (23%) developed hypercapnia (PaCO2 from 52 to 68 mm Hg) and related acidosis (pH from 7.29 to 7.21). Optimal oxygenation was achieved in all of the patients; nevertheless, patients under NPV needed a lower mean oxygen supply; five of them (38%) could be treated at a fraction of inspired oxygen of 0.21 for the whole procedure. Conclusion NPV may be useful in reducing apneas during laser therapy under general anesthesia, thus reducing hypercapnia, related acidosis, and need of oxygen supplementation.

In reply: We are grateful to Dr Appendini and colleagues for their comment and appreciation. The similar expiratory time used in patients with high and low auto-PEEP levels does not diminish the lack of relationship between auto-PEEP and expiratory time (if anything, it made the statistical

Background: The power of breathing (PoB) is used to estimate the mechanical workload of the respiratory system. Aim of this study was to investigate the effect of different tidal volume-respiratory rate combinations on the PoB when the elastic load is constant. In order to assure strict control of the experimental conditions, the PoB was calculated on an airway pressure-volume curve in mechanically ventilated patients. Methods: Ten patients received three different tidal volume-respiratory rate combinations while minute ventilation was constant. Respiratory mechanics, PoB and its elastic and resistive components were calculated. Alternative methods to estimate the elastic workload were assessed: elastic work of breathing per litre per minute, elastic workload index (the square root of elastic work of breathing multiplied by respiratory rate) and elastic double product of the respiratory system (the elastic pressure multiplied by respiratory rate). Results: Despite constant elastance and minute ventilation, the elastic PoB showed an increment greater than 200% from the lower to the greater tidal volume, accounting for approximately 80% of the whole PoB increment. On the contrary, elastic work of breathing per litre per minute, elastic workload index and elastic double product did not change. Conclusion: Changes in breathing pattern markedly affect the PoB despite constant mechanical load. Other indexes could assess the elastic workload without tidal volume dependence. Power of breathing use should be avoided to compare different mechanical loads or efficiencies of the respiratory muscles when tidal volume is variable.

Study objective To compare the frequency of airway seal and sore throat with the LMA-ProSeal™ (PLMA) and the standard Laryngeal Mask Airway™ (LMA) during laparoscopic surgery. Design Prospective, controlled, randomized, nonblinded clinical study. Setting University-affiliated hospital. Patients 60 adult, ASA physical status I, II, and III patients undergoing laparoscopic surgery with general anesthesia, without contraindication to the use of the laryngeal mask. Inteventions Patients were randomized to receive mechanical ventilation [tidal volume ( V T ) 7 mL/kg -1 ; positive end-expiratory pressure (PEEP) 10 cmH 2 O] through the PLMA or the standard LMA, both equipped with a gastric tube. Measurements Heart rate, arterial pressure, inspiratory and expiratory V T , airway pressure, end-tidal CO 2 partial pressure, and pulse oximetry were recorded. The leak fraction was calculated as the difference between the inspiratory and expiratory V T divided by the inspiratory V T . Postoperative sore throat frequency was scored in the recovery room ("early") and 1 week after surgery ("late"). Main results All patients were successfully ventilated through the assigned laryngeal mask. The leak fraction was 7 ± 3% with the LMA and 7 ± 4% with the PLMA ( p = 0.731). In one patient, the PLMA drainage tube was not patent despite a leak fraction of 5%, and there was no clinically detectable air leak. During the recovery room stay, the frequency of sore throat was scored as mild in 13% and 10% of patients with the standard LMA and the PLMA, respectively, and was absent in the remaining patients ( p = 0.99, between groups). There were no differences in the frequency of sore throat between the "early" and "late" evaluations ( p = 0.99). Conclusions The PLMA and the LMA show similar airtight efficiency during laparoscopy. The patency of the PLMA drainage tube should always be confirmed. The sore throat evaluation performed in recovery room appears as reliable as later evaluations.