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Purpose Prone positioning (PP) improves oxygenation and outcome of patients with acute respiratory distress syndrome undergoing invasive ventilation. We evaluated feasibility and efficacy of PP in awake, non-intubated, spontaneously breathing patients with hypoxemic acute respiratory failure (ARF). Material and Methods We retrospectively studied non-intubated subjects with hypoxemic ARF treated with PP from January 2009 to December 2014. Data were extracted from medical records. Arterial blood gas analyses, respiratory rate, and hemodynamics were retrieved 1 to 2 hours before pronation (step PRE), during PP (step PRONE), and 6 to 8 hours after resupination (step POST). Results Fifteen non-intubated ARF patients underwent 43 PP procedures. Nine subjects were immunocompromised. Twelve subjects were discharged from hospital, while 3 died. Only 2 maneuvers were interrupted, owing to patient intolerance. No complications were documented. PP did not alter respiratory rate or hemodynamics. In the subset of procedures during which the same positive end expiratory pressure and F io 2 were utilized throughout the pronation cycle (n = 18), PP improved oxygenation (Pa o 2/F io 2 124 ± 50 mmHg, 187 ± 72 mmHg, and 140 ± 61 mmHg, during PRE, PRONE, and POST steps, respectively, P co 2 were unchanged. Conclusions PP was feasible and improved oxygenation in non-intubated, spontaneously breathing patients with ARF.

Extracorporeal membrane oxygenation (ECMO) is one of the terms used to describe a number of different techniques used for prolonged cardiac and/or respiratory support. During ECMO a fraction of the patient venous return is diverted through an artificial lung for gas exchange (oxygenation and CO2 removal) and then returned to the patient. Depending on the returning vessel (venous or arterial), ECMO can be used for cardiac (veno-arterial bypass (VA-ECMO)) or respiratory support. For respiratory support blood can be drained either from a venous vessel (veno-venous ECMO (VV-ECMO)) or from an arterial vessel (arteriovenous bypass (AV-ECMO)). During VV and VA-ECMO, the blood is withdrawn from the patient through the action of a pump, whereas during AV-ECMO, the blood flow is driven by the patient’s arterial pressure. For respiratory support in ARDS patients, VV-ECMO represents the simplest and more rational choice [1]. Depending on the extracorporeal blood flow (ECBF), VV-ECMO can be used to support both oxygenation and CO2 removal (ECBF 3–7 l/min, total extracorporeal support) or to provide mainly CO2 removal (ECBF 0.5–2.5 l/min, partial extracorporeal support). This chapter will focus mainly on the application of VV-ECMO in ARDS patient.

Purpose: Standard polyvinylchloride (PVC) endotracheal tube (ETT) cuffs do not protect from aspiration across the cuff, a leading cause of ventilator-associated pneumonia (VAP). In a long-lasting in vitro study we compared the effect of different cuff materials (PVC, polyurethane, and guayule latex), shapes (cylindrical, conical), and positive end expiratory pressures (PEEP) in reducing fluid leakage across the cuff. Methods: We compared fluid leakage across a cylindrical double-layer guayule latex prototype cuff, three cylindrical PVC cuffs (Mallinckrodt Hi-Lo, Mallinckrodt HighContour, Portex Ivory), one conical PVC cuff (Mallinckrodt TaperGuard), and two polyurethane cuffs (Mallinckrodt SealGuard, conical; Microcuff, cylindrical). Ten centimeters of dyed water was poured above the cuffs inflated (pressure 30 cmH 2O) in a vertical cylinder (diameter 20 mm). A respiratory circuit connected the bottom of the cylinder to a breathing bag inflated at four pressures (PEEP = 0, 5, 10, 15 cmH2O). Pictures were taken every 60 s for 24 h to measure leakage as a reduction in the water column above the cuff. Five new ETTs of each type were tested. Results: The guayule latex cuffs showed no leakage at all the PEEP levels. Both the cylindrical and conical polyurethane cuffs showed limited leakage (2.1 ± 1.8 cm of water) only for PEEP zero. The PVC cuffs showed reduced leakage with increasing PEEP: 8.4 ± 1.5, 7.8 ± 2.2, 2.2 ± 1.0, and 0 cm of water at 0, 5, 10, and 15 cmH2O, respectively. Among all the PVC cuffs, the conical shape ensured higher sealing properties. Conclusions: The guayule latex cuffs always prevented fluid leakage; the polyurethane and PVC cuffs required incremental levels of PEEP to prevent fluid leakage ever-present at zero PEEP. © Copyright jointly held by Springer and ESICM 2010.

Purpose: We investigated the effects of periodical high pressure breaths (SIGH) or biphasic positive pressure ventilation (BIPAP) during helmet continuous positive airway pressure (CPAP) in patients with acute hypoxic respiratory failure. Methods: We used a recently developed electromechanical expiratory valve (TwinPAP®, StarMed, Mirandola, Italy), which is time-cycled between two customizable positive end-expiratory pressure (PEEP) levels. We studied 21 patients (67 ± 17 years old) undergoing helmet CPAP. Continuous flow CPAP system was set at 60 l/min flow rate while maintaining clinical FiO2 (51 ± 15%). Five steps, lasting 1 h each, were applied: (1) spontaneous breathing with PEEP 0 cmH2O (SB), (2) CPAP with PEEP 8 cmH2O (CPAPbasal), (3) low PEEP, 8 cmH2O, for 25 s and high PEEP, 25 cmH2O, for 5 s (SIGH), (4) low PEEP, 8 cmH2O, for 3 s and high PEEP, 20 cmH2O, for 3 s (BIPAP), (5) CPAP with PEEP 8 cmH2O (CPAPfinal). We randomized the sequence of SIGH and BIPAP. Results: PaO2 was significantly higher during all steps compared to SB. When compared to CPAP basal, both SIGH and BIPAP induced a further increase in PaO 2. PaO2 during SIGH and BIPAP were not different. The oxygenation improvement was maintained during CPAPfinal. Conclusions: Superimposed, nonsynchronized positive pressure breaths delivered during helmet CPAP by means of the TwinPAP® system may improve oxygenation in patients with acute hypoxemic respiratory failure, even at a rate as low as two breaths per minute. © 2010 jointly held by Springer and ESICM.

Daily nursing in critical care patients may alter vital parameters, especially in the most critically ill patients. The aim of our study was to evaluate feasibility and safety of daily nursing on patients undergoing venous–venous extracorporeal membrane oxygenation (vv-ECMO) for severe respiratory failure. Daily nursing was performed following defined phases (sponge bath, elevation with scooping stretcher, change position of endotracheal tube, dressing replacement). We recorded physiological and ECMO parameters before and during daily nursing in 5 patients for several days (total: 25 daily nursing) and adverse events: desaturation, hypertension, reduction of mixed venous oxygen saturation, arterial oxygen saturation or ECMO blood flow and elevation in minute ventilation. Sedative drug dosage and additional bolus were recorded. Daily nursing was performed in 92 % of cases (23/25), with a minimum of two adverse events per daily nursing. Hypertension and tachycardia were mostly recorded at the beginning, while desaturation, reduction in mixed venous oxygen saturation and blood flow were recorded during elevation with scooping stretcher. Increase in minute ventilation was frequent in spontaneous breathing patients. Additional bolus of sedation was required before and/or during nursing. Daily nursing significantly alters physiologic parameters; thus, it should be performed only when physicians are readily available to treat adverse events.

Regionalization/centralization to tertiary care centre allows treatment of severe critically ill patients with full technology, staff and expertise resources but requires interhospital transportation of unstable severely ill patients. When patients already connected to ECMO systems or requiring ECMO assistance need transportation, special concerns ensue due to the high risk for adverse events (severity of illness, risk for technical failure during transportation). Transportation must be performed by a specialized skilled multidisciplinary team composed at least of two ECMO physicians, an ECMO specialist and a nurse. Ambulance ground, as compared to air transportation, may be considered when geographically advantageous, when weather does not allow flight transportation and for short distances. Enlarged fuel, electrical and oxygen supplies must be provided, and ECMO system must be protected against shocks, vibrations and sudden decelerations.

To investigate the effect of a wide range of assistance levels during neurally adjusted ventilatory assist (NAVA) and pressure support ventilation (PSV) on respiratory pattern, breathing variability, and incidence of tidal volumes (V (T)) above 8 and 10 ml/kg in acute respiratory failure patients.Eight increasing NAVA levels (0.5, 1, 1.5, 2, 2.5, 3, 4, and 5 cmH(2)O/μV) and four increasing pressure support (PSV) levels (4, 8, 12, and 16 cmH(2)O) were applied to obtain 10 min of stable recordings in 15 patients.One out of 15 patients did not sustain the NAVA levels of 3, 4, and 5 cmH(2)O/μV and was excluded. The 5 cmH(2)O/μV NAVA level was not tolerated by three patients and it was excluded. Increasing NAVA levels were associated with decreased diaphragm electrical activity (EAdi), and, at variance with PSV, with small changes in V (T), no changes in respiratory rate (RR), and increases in V (T) and EAdi variability. At high NAVA levels, an increase in V (T) variability was associated with increased incidence of V (T) above 8 and 10 ml/kg and an uncomfortable respiratory pattern in some patients.Increasing NAVA levels were associated with no effect on RR, small increase in V (T), and increase in V (T) and EAdi variability. Effective decrease in EAdi occurred at NAVA levels below 2-2.5 cmH(2)O/μV, while preserving respiratory variability and low risks of V (T) above 8 or 10 ml/kg.

Introduction Severe mixed β-blocker and calcium channel blocker intoxication presents a significant risk for patient mortality. Although treatment is well-established, it sporadically fails to support the patient through massive overdoses, thus requiring non-conventional treatments. We report the use of extra-corporeal life support in a patient with refractory hemodynamic impairment due to multi-drug intoxication. Although sometimes used in clinical practice, extra-corporeal membrane oxygenation for intoxications has rarely been reported. Case presentation A 36-year-old Caucasian man presented to our hospital with refractory hypotension, severe cardiac insufficiency and multi-organ failure due to mixed intoxication with atenolol, nifedipine, Lacidipine and sertraline. Together with standard treatment, we performed extra-corporeal membrane oxygenation to overcome refractory cardiogenic shock and lead the patient to achieve a full recovery. Conclusion Standard of care for β-blocker and calcium channel blocker intoxication is well-defined and condensed into protocols of treatment. Although aimed at clearing the noxious agents from the patient's system, standard measures may fail to provide adequate hemodynamic support to allow recovery. In selected cases, extra-corporeal membrane oxygenation could be considered a bridge to drug clearance while preventing multi-organ failure due to profound shock.

Purpose Transfer of severely hypoxic patients is a high-risk procedure. Extracorporeal Membrane Oxygenation (ECMO) allows safe transport of these patients to tertiary care institutions. Our ECMO transportation program was instituted in 2004; here we report results after 5 years of activity. Methods This is a clinical observational study. Criteria for ECMO center activation were: potentially reversibile respiratory failure, PaO2 2 >0.6 for >12 hours, PEEP >5 cmH20, Lung Injury Score (LIS) ≥3 or respiratory acidosis with pH Results Sixteen patients were possible candidates for ECMO transfer. Two patients were excluded while 14 (mean±SD, age 35.4±18.6, SOFA 8.4±3.7, Oxygenation Index 43.7±13.4) were transported to our institution (distance covered 102±114 km, global duration of transport 589±186 minutes). Two patients improved after iNO-trial and were transferred and subsequently managed without ECMO. The remaining 12 patients were transferred on veno-venous ECMO with extracorporeal blood flow 2.7±1 L·min−1, gas flow 3.8±1.8 L·min−1, and FiO2 1. Data were recorded 30 minutes before and 60 minutes after initiation of ECMO. ECMO improved PCO2 (75±23 vs. 53±9 mmHg, p−1, p2O, pConclusions ECMO effectively enabled high-risk ground transfer of severely hypoxic patients.

Purpose: We assessed the performance of different continuous positive airway pressure (CPAP) helmets equipped with a safety valve during discontinuation of fresh gas flow. Methods: This was a physiological study of five healthy volunteers. We delivered CPAP (fresh gas flow 60 l/min, FiO 2 60%, PEEP 5 cmH2O) with three different helmets in a random sequence: 4Vent (Rüsch), HelmHAR-cp (Harol) and CaStar CP210 (StarMed). For each helmet we randomly applied, for up to 4 min, three disconnections of fresh gas flow: helmet inlet (Dinlet), flowmeter (Dflowmeter) and gas source (Dsource). We continuously recorded from a nostril: end-tidal CO2 (PetCO2), inspiratory CO2 (PiCO2), fraction of inspired oxygen (FiO2) and respiratory rate (RR). Results: During every disconnection we observed an increase in PiCO2 and PetCO2 with a drop in FiO2, while RR did not change. FiO2 decreased more quickly in the CaStar, equipped with the largest safety valve, during D source and Dflowmeter, while FiO2 decreased more quickly during Dinlet in CaStar and in 4Vent. PiCO2 resulted in a lower increase in CaStar during Dsource and D flowmeter compared to 4Vent. PetCO2 in CaStar increases more slowly compared to 4Vent during Dsource and more slowly compared to the other two helmets during Dflowmeter. During Dinlet similar degrees of CO2 rebreathing and PetCO2 were recorded among all the helmets. Conclusions: To minimize CO2 rebreathing during disconnection of the fresh gas supply while performing helmet CPAP, it is desirable to utilize large helmets with a large anti-suffocation valve. Monitoring and alarm systems should be employed for safe application of helmet CPAP. © 2011 jointly held by Springer and ESICM.

We report a case of severe posttraumatic acute respiratory distress syndrome (ARDS) complicated by bronchopleural fistulae (BPF). The stiff ARDS lung and huge air leaks from BPF resulted in the failure of different protective mechanical ventilation strategies to provide viable gas exchange. Lung rest, achieved by extracorporeal carbon dioxide removal (ECCO₂R), allowed weaning from mechanical ventilation, closure of BPF, and resumption of spontaneous breathing.

Purpose of Review: To describe a physiopathological-based approach to clinical management of severely hypoxemic patients that integrates the most recent findings on the use of rescue therapies. Recent Findings: Several techniques are available to improve oxygenation in severely hypoxemic patients. Survival benefits have not been proved for most of these techniques. In a recent randomized trial, centralization of acute respiratory distress syndrome patients to a specialized center able to provide extracorporeal membrane oxygenation showed better survival as compared to conventional treatment. Randomized trials failed to prove survival benefits with the use of high levels of positive end-expiratory pressure (PEEP) or prone positioning. However, pooled data from two meta-analyses showed significant higher survival in the most severe patients both with the use of higher PEEP and prone positioning. Summary: Treatment of severely hypoxemic patients should aim to improve oxygenation while limiting ventilator-induced lung injury. A physiopathological approach that accounts for the underlying mechanisms of hypoxemia, and physiological and clinical effects of different treatments is likely the best guide we have to treat severely hypoxemic patients. © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Continuous positive airway pressure (CPAP) is administered to patients to maintain the airway at a selected pressure (usually named the positive end-expiratory pressure, PEEP) higher than that of the atmosphere one. PEEP application has several well-known effects on the respiratory system and hemodynamics, whose description is not among the aims of this chapter. The applied pressure is kept constant throughout the whole respiratory cycle so that intrapulmonary pressure swings around the set level. Patients can breath spontaneously at the selected pressure without any active support of inspiration; it follows that CPAP cannot be strictly considered a form of ventilation. © 2010 Springer-Verlag Berlin Heidelberg.

PURPOSE: Extracorporeal CO2 removal is an effective procedure to allow a protective ventilatory strategy in ARDS patients, but it is technically challenging due to the high blood flow required. Increasing the CO2 transfer through the membrane lung (ML) may lower the demand of extracorporeal blood flow and consequently allow for a wider clinical application of this technique. Since only the dissolved CO2 (5% of the total CO2 content) is easily removed by the ML, we tested whether acidifying the blood entering the ML to convert bicarbonate ions towards dissolved CO2 could enhance the CO2 transfer though the ML. METHODS: Six pigs were connected to an extracorporeal circuit comprising a ML. The extracorporeal blood flow was 500 ml/min, while the gas flow was 10 l/min. A 15-min continuous infusion of 0.5 N lactic acid was added to the extracorporeal blood flow before the ML at a rate of 1, 2 and 5 mEq/min. Between steps we waited for a reequilibration time of at least 30 min. RESULTS: Acid infusion at 0, 1, 2 and 5 mEq/min increased pCO2 (56.19 +/- 7.92, 68.24 +/- 11.73, 84.28 +/- 11.17 and 136.66 +/- 18.46 mmHg, respectively) and decreased pH (7.39 +/- 0.05, 7.30 +/- 0.05, 7.20 +/- 0.05 and 6.91 +/- 0.05, respectively). ML CO2 removal increased 11, 23 and 70% during acid infusion at 1, 2 and 5 mEq/min, respectively. CONCLUSIONS: Blood acidification at the inlet of a ML with infusion of 1, 2 and 5 mEq/min of lactic acid can increase the CO2 removal capacity of the ML up to 70%.

PURPOSE: Assessing feasibility and physiological effects of sedation with sevoflurane, administered with the anesthetic conserving device (AnaConDa), in comparison with propofol and remifentanil. METHODS: Seventeen patients undergoing mechanical ventilation underwent sedation with sevoflurane delivered with AnaConDa (phase SevAn), preceded and followed by sedation with propofol and remifentanil (phases ProRe(1), ProRe(2)), with the same sedation targets. RESULTS: With both strategies it was possible to achieve the sedation targets. Time required to sedate and awake patients was greater during SevAn than ProRe(1): respectively, 3.3 +/- 3.0 versus 8.9 +/- 6.1 and 7.47 +/- 5.05 versus 16.3 +/- 11.4 min. During SevAn the PaCO(2) and minute ventilation increased. Hemodynamics was stable between ProRe(1) and SevAn, except for an increase in heart rate in the SevAn phase. Environmental pollution from sevoflurane was within the safety limits. CONCLUSIONS: Sevoflurane can be effectively and safely used for short-term sedation of ICU patients with stable hemodynamic conditions.

Objective: To assess the behavior of different helmets after discontinuation of fresh gas flow by disconnection at the helmet inlet, flow generator, or gas source. Design and setting: Randomized physiological study in a university research laboratory. Patients: Five healthy volunteers. Intervention: CPAP (FIO2 50%, PEEP 5 cmH2O) delivered in random sequence with three different helmets: 4Vent (Rüsch), PN500 (Harol), CaStar (StarMed) with antisuffocation valve open or locked. For each helmet all three disconnections were randomly employed up to 4 min. Measurements and results: During flow disconnection we measured: respiratory rate and tidal volume by respitrace; inspiratory and expiratory CO2 concentration, and FIO2 from a nostril; SpO2 by pulse oxymetry. Independently of the site of disconnection we observed a fast increase in CO2 rebreathing and minute ventilation, associated with a decrease in inspired O2 concentration. In the absence of an operational safety valve, larger helmet size and lower resistance of the inlet hose resulted in slower increase in CO2 rebreathing. The presence of the safety valve limited the rebreathing of CO2, and the increase in minute ventilation but did not protect from a decrease in FIO2 and loss of PEEP. Conclusions: While the use of a safety valve proved effective in limiting CO2 rebreathing, it did not protect from the risk of hypoxia related to decrease in FIO2 and loss of PEEP. In addition to a safety antisuffocation valve, a dedicated monitoring and alarming systems are needed to employ helmet CPAP safely. © 2006 Springer-Verlag.

Severe acute respiratory distress syndrome (ARDS) patient transportation is an extremely high-risk procedure. We report our experience in transferring these patients to our centre while on extracorporeal membrane oxygenation (ECMO).

Purpose Vascular access and cannulation are crucial issues to maximize the efficiency of extracorporeal circulation techniques and to preserve patients' safety. Techniques of cannulation have changed over the years, from surgical cutdown to percutaneous approaches, which are now considered standard practice. We describe an original modified percutaneous cannulation technique developed in our Department and we report our clinical experience and complications observed. Methods A Seldinger technique utilizing 3 guidewires with passage of a dilator over each guidewire was used. Two concentric pursestring sutures, prepared before cannulation, minimize procedure-associated bleeding. Cannulation is performed under direct fluoroscopic control. Results From 1997 to 2009, 38 patients (31 VV-ECLS, 7 VA-ECLS) have been cannulated using our technique, resulting in a total of 69 venous cannulations. Average external caliber of venous cannulae was 23 Fr (15–29 Fr). Mean duration of the entire cannulation procedure was 40 minutes (20–60 min). Adverse events occurred in 3 patients. Conclusions The technique described is safe and feasible and the incidence of procedure-related complications is very low, but it may require longer time to be performed.

Introduction: Sepsis, a leading cause of death in critically ill patients, is the result of complex interactions between the infecting microorganisms and the host responses that influence clinical outcomes. We evaluated the prognostic value of presepsin (sCD14-ST), a novel biomarker of bacterial infection, and compared it with procalcitonin (PCT). Methods: This is a retrospective, case–control study of a multicenter, randomized clinical trial enrolling patients with severe sepsis or septic shock in ICUs in Italy. We selected 50 survivors and 50 non-survivors at ICU discharge, matched for age, sex and time from sepsis diagnosis to enrollment. Plasma samples were collected 1, 2 and 7 days after enrollment to assay presepsin and PCT. Outcome was assessed 28 and 90 days after enrollment. Results: Early presepsin (day 1) was higher in decedents (2,269 pg/ml, median (Q1 to Q3), 1,171 to 4,300 pg/ml) than in survivors (1,184 pg/ml (median, 875 to 2,113); P= 0.002), whereas PCT was not different (18.5 μg/L (median 3.4 to 45.2) and 10.8 μg/L (2.7 to 41.9); P= 0.31). The evolution of presepsin levels over time was significantly different in survivors compared to decedents (P for time-survival interaction = 0.03), whereas PCT decreased similarly in the two groups (P = 0.13). Presepsin was the only variable independently associated with ICU and 28-day mortality in Cox models adjusted for clinical characteristics. It showed better prognostic accuracy than PCT in the range of Sequential Organ Failure Assessment score (area under the curve (AUC) from 0.64 to 0.75 vs. AUC 0.53 to 0.65). Conclusions: In this multicenter clinical trial, we provide the first evidence that presepsin measurements may have useful prognostic information for patients with severe sepsis or septic shock. These preliminary findings suggest that presepsin may be of clinical importance for early risk stratification.