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Background: Because ICU ventilators incorporate flow velocity measurement, cough peak expiratory flow (CPF) can be assessed without disconnecting the patient from the ICU ventilator. Our goal was to estimate the correlation between CPF obtained with the built-in ventilator flow meter (ventilator CPF) and CPF obtained with an electronic portable handheld peak flow meter connected to the endotracheal tube., Methods: Cooperative mechanically ventilated patients who entered the weaning process and who were ventilated with pressure support < 15 cm H 2 O and PEEP < 9 cm H 2 O were eligible for the study. Their CPF measurements obtained on the extubation day were kept for analysis., Results: We analyzed CPF obtained in 61 subjects. The mean ± SD value of ventilator CPF and peak flow meter CPF were 72.6 ± 27.5 L/min and 31.1 ± 13.4 L/min. The Pearson correlation coefficient was 0.63 (95% CI 0.45-0.76), P < .001. The ventilator CPF had an area under the receiver operating characteristic curve of 0.84 (95% CI 0.75-0.93) to predict a peak flow meter CPF < 35 L/min. Neither ventilator CPF nor peak flow meter CPF differed significantly between subjects who were or were not re-intubated within 72 h ( n = 5) and failed to predict re-intubation at 72 h (area under the receiver operating characteristic curve of 0.64 [95% CI 0.46-0.82] and 0.47 [95% CI 0.22-0.74])., Conclusions: CPF measurements using a built-in ventilator flow meter were feasible in routine practice with cooperative ICU subjects who were intubated and correlated with CPF assessed by an electronic portable peak flow meter., Competing Interests: The authors have disclosed no conflicts of interest., (Copyright © 2023 by Daedalus Enterprises.)

Background: This prospective study investigated whether taking into account diaphragmatic excursion (DE) measured by ultrasonography would improve the performance of the rapid shallow breathing index (RSBI) to predict extubation success or failure., Objectives: The aim of the study was to compare the new composite index named the rapid shallow diaphragmatic index (RSDI), and the RSBI measured during a spontaneous breathing trial regarding their ability to predict the need for re-intubation at 72 h., Methods: One hundred mechanically ventilated patients underwent daily 30-min spontaneous breathing trials (SBTs) under pressure support ventilation of 6 cm H 2 O and end-expiratory pressure of 0 cm H 2 O until the SBT was considered successful and followed by extubation. The performances of RSBI (respiratory rate/tidal volume) and of the ratio RSBI/DE measured at 5 and 25 min of the successful SBT were compared in terms of area under the receiver operating characteristics curve (AUC), for predicting extubation success at 72 h. As secondary analysis, extubation and weaning success at 7 d were also considered. As exploratory analyses, predictive indices incorporating both clinical characteristics, the DE, and ultrasound diaphragm thickening fraction (DTF) were investigated., Results: RSBI and RSBI/DE showed AUCs with 95% confidence intervals consistently extending below 0.50, either at the 5th (0.55 [0.36-0.74] and 0.55 [0.34-0.75], respectively) or at the 25th minute of SBT (0.49 [0.27-0.71] and 0.50 [0.29-0.68], respectively) for predicting weaning success at 72 h or at 7 d (5th min: 0.53 [0.37-0.70] and 0.54 [0.37-0.70], respectively; 25th min: 0.54 [0.37-0.71] and 0.55 [0.39-0.71], respectively). An exploratory index incorporating the accessory respiratory muscle activity, DE, DTF, and respiratory rate at 5th min of SBT showed AUCs for predicting extubation success at 7 d in the 78 patients with DTF measurement (0.77 [0.64-0.90]) that were significantly higher than that of the RSBI (P = 0.017) and RSBI/DE (P < 0.001) in the same respective populations., Conclusions: The RSBI and the ratio RSBI/DE failed to predict weaning success when measured during an SBT performed under minimal pressure support. Predictive indices incorporating ultrasound DE and DTF may merit further investigation., Competing Interests: Conflict of interest The authors declare that they have no financial or nonfinancial competing interests related to this submission., (Copyright © 2021 Australian College of Critical Care Nurses Ltd. Published by Elsevier Ltd. All rights reserved.)

Background: Antibiotic nebulization theoretically allows the delivery of high doses to the lungs together with limited systemic exposure and toxicity. This study aimed to describe amikacin pharmacokinetics, and especially its absorption, in patients treated with high-dose nebulized amikacin., Patients and Methods: Twenty critically ill patients experiencing ventilator-associated pneumonia received a 20 mg/kg infusion of amikacin, followed by either three other infusions or three nebulizations of 60 mg/kg amikacin. An extensive sampling regimen allowed measurement of amikacin serum concentrations at 0.5, 1, 1.5, 2, 3, 4, 6, 10 and 24 h after each administration. Amikacin pharmacokinetics was studied by population compartmental modelling., Results: Amikacin pharmacokinetics was best described using a two-compartment structural model with first-order distribution and elimination, in which lung absorption was described using a transit model. Estimated means (interindividual variability) of the main parameters were: bioavailability F = 2.65% (22.1%); transit compartments n = 1.58 (fixed); transit constant k tr  = 1.38 h -1 (33.4%); central volume V c  = 10.2 L (10.5%); and elimination constant k 10  = 0.488 h -1 (35.8%). The addition of interoccasion variability on F (44.0%) and k 10 (41.7%) allowed the description of intraindividual variability of bioavailability and elimination. Amikacin clearance was positively correlated with baseline creatinine clearance., Conclusions: Our pharmacokinetic model provided an accurate description of amikacin concentrations following nebulization. There was wide interindividual and interoccasion variability in the absorption and elimination of amikacin. Nevertheless, systemic exposure after nebulization was always much lower than after infusion, an observation suggesting that nebulized high doses are safe in this regard and may be used to treat ventilator-associated pneumonia., (© The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Pulse pressure variation (PPV) has been shown to predict fluid responsiveness in ventilated intensive care unit (ICU) patients. The present study was aimed at assessing the diagnostic accuracy of PPV for prediction of fluid responsiveness by using the grey zone approach in a large population., Methods: The study pooled data of 556 patients from nine French ICUs. Hemodynamic (PPV, central venous pressure (CVP) and cardiac output) and ventilator variables were recorded. Responders were defined as patients increasing their stroke volume more than or equal to 15% after fluid challenge. The receiver operating characteristic (ROC) curve and grey zone were defined for PPV. The grey zone was evaluated according to the risk of fluid infusion in hypoxemic patients., Results: Fluid challenge led to increased stroke volume more than or equal to 15% in 267 patients (48%). The areas under the ROC curve of PPV and CVP were 0.73 (95% confidence interval (CI): 0.68 to 0.77) and 0.64 (95% CI 0.59 to 0.70), respectively (P<0.001). A grey zone of 4 to 17% (62% of patients) was found for PPV. A tidal volume more than or equal to 8 ml.kg(-1) and a driving pressure (plateau pressure - PEEP) more than 20 cmH2O significantly improved the area under the ROC curve for PPV. When taking into account the risk of fluid infusion, the grey zone for PPV was 2 to 13%., Conclusions: In ventilated ICU patients, PPV values between 4 and 17%, encountered in 62% patients exhibiting validity prerequisites, did not predict fluid responsiveness.

A single-use flexible bronchoscope with a large suction channel has become available recently and we have evaluated this innovative device. Firstly, bronchoalveolar lavage was performed and quantified in ventilated piglets. Next, the bronchoscope was evaluated in three intensive care units and a satisfaction questionnaire was carried out. Sixteen bronchoalveolar lavages were performed in piglets with a recovery rate of 83 (79-86 [72-89])% of the instilled volume. Quality and performance of all devices tested was identical. The medical satisfaction questionnaire was as follows: 'acceptable' to 'very good' for quality of aspiration, manoeuvrability and quality of vision; 'very good' to 'perfect' for setting up and insertion. This encouraging preliminary evaluation demonstrates the effectiveness of this new single-use device, which may obviate the need for disinfection procedures and, thereby, eradicate a potential vector of patient cross-contamination., (© 2014 The Association of Anaesthetists of Great Britain and Ireland.)

Importance: Monitoring of residual gastric volume is recommended to prevent ventilator-associated pneumonia (VAP) in patients receiving early enteral nutrition. However, studies have challenged the reliability and effectiveness of this measure., Objective: To test the hypothesis that the risk of VAP is not increased when residual gastric volume is not monitored compared with routine residual gastric volume monitoring in patients receiving invasive mechanical ventilation and early enteral nutrition., Design, Setting, and Patients: Randomized, noninferiority, open-label, multicenter trial conducted from May 2010 through March 2011 in adults requiring invasive mechanical ventilation for more than 2 days and given enteral nutrition within 36 hours after intubation at 9 French intensive care units (ICUs); 452 patients were randomized and 449 included in the intention-to-treat analysis (3 withdrew initial consent)., Intervention: Absence of residual gastric volume monitoring. Intolerance to enteral nutrition was based only on regurgitation and vomiting in the intervention group and based on residual gastric volume greater than 250 mL at any of the 6 hourly measurements and regurgitation or vomiting in the control group., Main Outcome Measures: Proportion of patients with at least 1 VAP episode within 90 days after randomization, as assessed by an adjudication committee blinded to patient group. The prestated noninferiority margin was 10%., Results: In the intention-to-treat population, VAP occurred in 38 of 227 patients (16.7%) in the intervention group and in 35 of 222 patients (15.8%) in the control group (difference, 0.9%; 90% CI, -4.8% to 6.7%). There were no significant between-group differences in other ICU-acquired infections, mechanical ventilation duration, ICU stay length, or mortality rates. The proportion of patients receiving 100% of their calorie goal was higher in the intervention group (odds ratio, 1.77; 90% CI, 1.25-2.51; P = .008). Similar results were obtained in the per-protocol population., Conclusion and Relevance: Among adults requiring mechanical ventilation and receiving early enteral nutrition, the absence of gastric volume monitoring was not inferior to routine residual gastric volume monitoring in terms of development of VAP., Trial Registration: clinicaltrials.gov Identifier: NCT01137487.

Objective: To evaluate the impact of intrahospital transport of critically ill ventilated patients on the acquisition of ventilator-associated pneumonia., Design: An exposed/unexposed matched cohort study., Setting: An 18-bed adult medical-surgical intensive care unit in a 1,100-bed regional and teaching hospital in France., Patients: From January 1, 2001, to December 31, 2002, 118 of 228 ventilated patients transported out of the intensive care unit (exposed patients) were matched with 118 unexposed patients selected among 295 ventilated patients who did not undergo intrahospital transport., Interventions: None., Measurements and Main Results: The matching process was conducted according to six criteria: duration of mechanical ventilation, duration of antibiotherapy, indication for ventilatory support, age, probability of death, and surgical procedures or not during intensive care unit stay. The rates of ventilator-associated pneumonia (as defined by usual clinical and biological criteria plus positive culture of bronchoscopy directed catheter) acquisition between exposed and unexposed patients were compared by univariate analysis and then by multivariate analysis (conditional logistic regression and Cox's proportional-hazards model) to account for potential confounding factors. The ventilator-associated pneumonia rate was 26% in exposed patients compared with 10% in the matched unexposed patients. Using conditional logistic regression, two factors were independently associated with ventilator-associated pneumonia: intrahospital transport (odds ratio, 3.1; 95% confidence interval, 1.4-6.7) and the need for reintubation. Using Cox's model, three independent risk factors were identified: the need for reintubation, enteral nutrition, and intrahospital transport (odds ratio, 2.9; 95% confidence interval, 1.4-5.7). The intensive care unit mortality rate was similar (p > .1) in exposed (35%) and unexposed patients (26%)., Conclusions: Intrahospital transport appears to be a significant risk factor for ventilator-associated pneumonia. However, the respective roles of intrahospital transport and of the cause that leads clinicians to transport patients (mainly for radiographic examinations) are difficult to dissociate even after multiple statistical adjustments. When intrahospital transport is needed, very cautious measures must be taken before and during intrahospital transport to prevent ventilator-associated pneumonia. In addition, in the few days after intrahospital transport, intensive search for ventilator-associated pneumonia is justified.

Objective: To evaluate the obesity-related mortality rate in an intensive care unit., Design: An exposed/unexposed matched cohort study., Setting: An 18-bed adult medical-surgical intensive care unit in a 1,100-bed regional and teaching hospital in France., Patients: From January 1, 1999, to December 31, 2001, 170 mechanically ventilated exposed patients (obese patients with body mass index of >30 kg/m) were matched with 170 mechanically ventilated unexposed patients (with ideal body mass index of 18.5-24.9 kg/m)., Interventions: None., Measurements and Main Results: The matching process was conducted according to eight criteria: cause of admission, indication for ventilatory support, immunologic status, cardiac status, probability of death (+/-5%), age (+/-7 yrs), gender, and acquisition of severe events appearing within 24 hrs before admission (defined as resuscitated cardiac arrest, acute respiratory distress syndrome, or septic shock). The mortality rate between exposed and unexposed patients was compared by univariate analysis and then was adjusted for other possible confounding factors by multivariate analysis, using conditional logistic regression. The matching process was successful for 1,360 of 1,360 criteria. Obesity was significantly associated with intensive care unit mortality (odds ratio, 2.1; 95% confidence interval, 1.2-3.6). Obesity-related excess mortality was verified mainly for the youngest patients (odds ratio, 2.5; 95% confidence interval, 1.6-6.1) and for the patients with a probability of intensive care unit death of 11-50% (odds ratio, 2.6; 95% confidence interval, 1.2-5.5). This excess mortality rate could be explained by the higher risk of intensive care unit acquired complications among obese patients than among the unexposed ones (odds ratio, 4; 95% confidence interval, 1.4-11.8)., Conclusions: Obesity is an independent risk factor for intensive care unit death and should be regarded as a severe comorbidity in such units.

Objective: To test the hypothesis that passive leg raising (PLR) induces changes in arterial pulse pressure that can help to predict the response to rapid fluid loading (RFL) in patients with acute circulatory failure who are receiving mechanical ventilation., Design: Prospective clinical study., Setting: Two medical ICUs in university hospitals., Patients: Thirty-nine patients with acute circulatory failure who were receiving mechanical ventilation and had a pulmonary artery catheter in place., Interventions: PLR for > 4 min and a subsequent 300-mL RFL for > 20 min., Measurements and Main Results: Radial artery pulse pressure (PPrad), heart rate, right atrial pressure, pulmonary artery occlusion pressure (PAOP), and cardiac output were measured invasively in a population of 15 patients at each phase of the study procedure (i.e., before and during PLR, and then before and after RFL). PPrad, PAOP, and stroke volume (SV) significantly increased in patients performing PLR. These changes were rapidly reversible when the patients' legs were lowered. Changes in PPrad during PLR were significantly correlated with changes in SV during PLR (r = 0.77; p < 0.001). Changes in SV induced by PLR and by RFL were significantly correlated (r = 0.89; p < 0.001). Finally, PLR-induced changes in PPrad were significantly correlated to RFL-induced changes in SV (r = 0.84; p < 0.001). In a second population of 24 patients, we found the same relationship between PLR-induced changes in PPrad and RFL-induced changes in SV (r = 0.73; p < 0.001)., Conclusion: The response to RFL could be predicted noninvasively by a simple observation of changes in pulse pressure during PLR in patients with acute circulatory failure who were receiving mechanical ventilation.

Objective: To evaluate the mortality rate attributable to nosocomial ventilator-associated pneumonia in an intensive care unit., Design: Prospective, matched, risk-adjusted cohort study., Setting: A 18-bed adult medical-surgical intensive care unit in a 1,100-bed regional and teaching hospital in France., Patients: From January 1, 1996, to April 30, 1999, 135 patients who developed nosocomial pneumonia were matched with 135 control patients without nosocomial pneumonia., Interventions: None., Measurements and Main Results: Nosocomial pneumonia was identified on the basis of results of distal bronchial samples. The matching process was conducted according to the following primary criteria: cause of admission, indication for ventilatory support, immunologic status, cardiac status, probability of death (+/-5%), Glasgow Coma Scale score (+/-2 points), age (+/-7 yrs), and duration of exposure to risk. When possible, case and control patients were matched according to five secondary criteria: respiratory and alcoholism status before admission, diagnosis categories, surgical procedure or not, and gender. The mortality rates were compared between case and control patients by using the Kaplan-Meier estimate and the log-rank test. The influence of nosocomial pneumonia on mortality rate then was tested by adjusting for the secondary criteria and other possible confounding factors by using the Cox proportional-hazards model. The matching process was successful for 1,080 of 1,080 primary criteria. The crude intensive care unit mortality rate was higher in patients with nosocomial pneumonia than in control patients (41 vs. 14%; p <.0001). In actuarial survival analysis, the probability of intensive care unit death was higher in the case patients (odds ratio = 2.7, 95% confidence interval = 1.8-3.1, p =.028). After adjustment, the occurrence of nosocomial pneumonia remained an independent risk factor of death (odds ratio = 2.1, 95% confidence interval = 1.2-3.6, p =.008). Nosocomial pneumonia attributable to multiresistant microorganisms was significantly associated with death (odds ratio = 2.6, 95% confidence interval = 1.1-5.8, p =.02). The length of intensive care unit stay was higher in case than in control patients (31 +/- 19 vs. 26 +/- 17 days, p <.0001)., Conclusions: Nosocomial pneumonia is independently associated with death in the intensive care unit. In addition, it increases the length of intensive care unit stay.

The predisposing factors and complications of unplanned extubation (UEX) in mechanically ventilated adult patients are not well recognized. We designed a prospective multicenter observational study to identify risk factors and describe the complications of UEX. We followed 426 ventilated patients over a 2-mo period. Clinical characteristics such as diagnosis on admission and reasons for ventilation were used to classify the patients. The presence or absence of potential risk factors was daily noted, including the types of ventilators, tracheal tubes, tube fixations, ventilatory support modes, route for intubation, and the use of intravenous sedation. Circumstances and complications of UEX were prospectively recorded. Forty-six (10.8%) patients experienced at least one episode of UEX. Ten UEX occurred during nursing procedures. At the moment of UEX, 61% of patients were agitated. The rates of mortality, laryngeal complications, nosocomial pneumonia after extubation, and the length of mechanical ventilation were similar in UEX and non-UEX patients. Patients were more often reintubated after UEX (28 of 46) than after planned extubation (28 of 284). All the non-reintubated UEX patients survived. One death occurred as a direct consequence of UEX. By use of multivariate analysis, we identified four factors contributing to UEX: chronic respiratory failure, endotracheal tube fixation with only thin adhesive tape, orotracheal intubation, and the lack of intravenous sedation. Considering these factors, we hypothesized that simple measures should be adopted to minimize the incidence of UEX and its related complications: more vigilance during procedures at patients' bedsides, adequate sedation of agitated patients, strong fixation of the tracheal tube, particular attention paid to orally intubated patients, and daily reassessment of the possibility of weaning from the ventilator.