Non-invasive respiratory support for the management of transient tachypnea of the newborn.

BACKGROUND: Transient tachypnea of the newborn (TTN) is characterized by tachypnea and signs of respiratory distress. Transient tachypnea typically appears within the first two hours of life in term and late preterm newborns. Supportive management might be sufficient. Non-invasive (i.e. without endotracheal intubation) respiratory support may, however, be administered to reduce respiratory distress during TTN. In addition, non-invasive respiratory support might improve clearance of lung liquid thus reducing the effort required to breathe, improving respiratory distress and potentially reducing the duration of tachypnea. OBJECTIVES: To assess benefits and harms of non-invasive respiratory support for the management of transient tachypnea of the newborn. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 2), MEDLINE (1996 to 19 February 2019), Embase (1980 to 19 February 2019) and CINAHL (1982 to 19 February 2019). We applied no language restrictions. We searched clinical trial registries for ongoing studies. SELECTION CRITERIA: Randomized controlled trials, quasi-randomized controlled trials and cluster trials on non-invasive respiratory support provided to infants born at 34 weeks' gestational age or more and less than three days of age with transient tachypnea of the newborn. DATA COLLECTION AND ANALYSIS: For each of the included trials, two review authors independently extracted data (e.g. number of participants, birth weight, gestational age, duration of oxygen therapy, need for continuous positive airway pressure [CPAP] and need for mechanical ventilation, duration of mechanical ventilation, etc.) and assessed the risk of bias (e.g. adequacy of randomization, blinding, completeness of follow-up). The primary outcomes considered in this review were need for mechanical ventilation and pneumothorax. We used the GRADE approach to assess the certainty of evidence. MAIN RESULTS: We included three trials (150 infants) comparing either CPAP to free-flow oxygen, nasal intermittent mandatory ventilation to nasal CPAP, or nasal high-frequency percussive ventilation versus nasal CPAP. Due to these different comparisons and to high clinical heterogeneity in the baseline clinical characteristics, we did not pool the three studies. The use of CPAP versus free oxygen did not improve the primary outcomes of this review: need for mechanical ventilation (risk ratio [RR] 0.30, 95% confidence interval [CI] 0.01 to 6.99; 1 study, 64 participants); and pneumothorax (not estimable, no cases occurred). Among secondary outcomes, CPAP reduced the duration of tachypnea as compared to free oxygen (mean difference [MD] -21.10 hours, 95% CI -22.92 to -19.28; 1 study, 64 participants). Nasal intermittent ventilation did not reduce the need for mechanical ventilation as compared with CPAP (RR 4.00, 95% CI 0.49 to 32.72; 1 study, 40 participants) or the incidence of pneumothorax (RR 1.00, 95% CI 0.07 to 14.90; 1 study, 40 participants); duration of tachypnea did not differ (MD 4.30, 95% CI -19.14 to 27.74; 1 study, 40 participants). In the study comparing nasal high-frequency ventilation to CPAP, no cases of mechanical ventilation of pneumothorax occurred (not estimable; 1 study, 46 participants); duration of tachypnea was reduced in the nasal high-frequency ventilation group (MD -4.53, 95% CI -5.64 to -3.42; 1 study, 46 participants). The quality of the evidence was very low due to the imprecision of the estimates and unclear risk of bias for detection bias and high risk of bias for reporting bias. Tests for heterogeneity were not applicable for any of the analyses as no studies were pooled. Two trials are ongoing. AUTHORS' CONCLUSIONS: There is insufficient evidence to establish the benefit and harms of non-invasive respiratory support in the management of transient tachypnea of the newborn. Though two of the included trials showed a shorter duration of tachypnea, clinically relevant outcomes did not differ amongst the groups. Given the limited and low quality of the evidence available, it was impossible to determine whether non-invasive respiratory support was safe or effective for the treatment of transient tachypnea of the newborn.

Ambient Noise Production by High-Frequency Neonatal Ventilators.

OBJECTIVE: To assess sound levels of 4 high-frequency neonatal ventilators to determine whether there is a safety benefit in using modern high-frequency ventilators compared with older models. STUDY DESIGN: We performed a bench study comparing noise production of the Sensormedics 3100A Oscillator, Bunnell Life Pulse Jet Ventilators Model 203 and Model 204, and Dräger VN500 in high-frequency mode. A wide range of ventilation settings was examined. All measurements were performed in triplicate using a high-fidelity sound meter, with data analyzed using ANOVA and regression analyses. RESULTS: The Dräger ventilator was quietest overall, with average sound levels of 49.8 ± 0.49 dB across all settings. The average noise from the Sensormedics was 53.6 ± 2.01 dB, for Bunnell Model 203 was 54.1 ± 1.09 dB, and for Bunnell Model 204 was 53.7 ± 1.45 dB. Adjustments made to frequency/rate and mean airway pressure/positive end-expiratory pressure had minimal effect on noise, and increasing amplitude/peak inspiratory pressure resulted in significantly more noise by all ventilators. At all settings, the Sensormedics and Bunnell ventilators were louder than the Dräger, and the difference became greater as amplitude/peak inspiratory pressure was increased. CONCLUSIONS: The Dräger VN500 in high-frequency mode produces significantly less noise that both the Sensormedics and Bunnell ventilators. These data suggest that using the Dräger VN500 as a high-frequency ventilator may reduce the potential for adverse outcomes created by ventilator noise.

Use of High-Frequency Percussive Ventilation to Expand Organ Donor Pool.

A 34-year-old woman was brought in to the emergency department after a motor vehicle accident. She had signs of traumatic head injury with Glasgow Coma Scale score of 3, and her neurological examination was consistent with brain death. She was persistently hypoxic on conventional mechanical ventilation and high-frequency percussive ventilation was initiated. The patient's oxygenation improved and was sustained long enough to provide time for organ procurement. This is the first case portraying high-frequency percussive ventilation as a bridge for donors failing on conventional mechanical ventilation.

High-Frequency Percussive Ventilation Facilitates Weaning from Extracorporeal Membrane Oxygenation in Adults.

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is an invaluable rescue therapy for patients suffering from cardiopulmonary arrest, but it is not without its drawbacks. There are cases where patients recover their cardiac function, yet they fail to wean to mechanical conventional ventilation (MCV). The use of high-frequency percussive ventilation (HFPV) has been described in patients with acute respiratory failure (RF) who fail MCV. We describe our experience with five patients who underwent VA-ECMO for cardiopulmonary arrest who were successfully weaned from VA-ECMO with HFPV after failure to wean with MCV. Weaning trials of HFPV a day before decannulation or at the time of separation from VA-ECMO were conducted. Primary endpoint data collected include pre- and post-HFPV partial pressures of oxygen (PaO2) and PaO2/FIO2 (P/F) ratios measured at 2 and 24 hours after institution of HFPV. Additional periprocedural data points were collected including length of time on ECMO, hospital stay, and survival to discharge. Four of five patients were placed on VA-ECMO subsequent to percutaneous coronary intervention. One patient had cardiac arrest secondary to RF. Mean PaO2 (44 ± 15.9 mmHg vs. 354 ± 149 mmHg, p < .01) and mean P/F ratio (44 ± 15.9 vs. 354 ± 149, p < .01) increased dramatically at 2 hours after the initiation of HFPV. The improvement in mean PaO2 and P/F ratio was durable at 24 hours whether or not the patient was returned to MCV (n = 3) or remained on HFPV (n = 2) (44 ± 15.9 mmHg vs. 131 ± 68.7 mmHg, p = .036 and 44 ± 15.9 vs. 169 ± 69.9, p < .01, respectively). Survival to discharge was 80%. The data presented suggest that HFPV may be used as a strategy to shorten time on ECMO, thereby reducing the negative effects of the ECMO circuit and improving its cost efficacy.

Effect of Postextubation High-Flow Nasal Cannula vs Noninvasive Ventilation on Reintubation and Postextubation Respiratory Failure in High-Risk Patients: A Randomized Clinical Trial.

Importance: High-flow conditioned oxygen therapy delivered through nasal cannulae and noninvasive mechanical ventilation (NIV) may reduce the need for reintubation. Among the advantages of high-flow oxygen therapy are comfort, availability, lower costs, and additional physiopathological mechanisms. Objective: To test if high-flow conditioned oxygen therapy is noninferior to NIV for preventing postextubation respiratory failure and reintubation in patients at high risk of reintubation. Design, Setting, and Participants: Multicenter randomized clinical trial in 3 intensive care units in Spain (September 2012-October 2014) including critically ill patients ready for planned extubation with at least 1 of the following high-risk factors for reintubation: older than 65 years; Acute Physiology and Chronic Health Evaluation II score higher than 12 points on extubation day; body mass index higher than 30; inadequate secretions management; difficult or prolonged weaning; more than 1 comorbidity; heart failure as primary indication for mechanical ventilation; moderate to severe chronic obstructive pulmonary disease; airway patency problems; or prolonged mechanical ventilation. Interventions: Patients were randomized to undergo either high-flow conditioned oxygen therapy or NIV for 24 hours after extubation. Main Outcomes and Measures: Primary outcomes were reintubation and postextubation respiratory failure within 72 hours. Noninferiority margin was 10 percentage points. Secondary outcomes included respiratory infection, sepsis, and multiple organ failure, length of stay and mortality; adverse events; and time to reintubation. Results: Of 604 patients (mean age, 65 [SD, 16] years; 388 [64%] men), 314 received NIV and 290 high-flow oxygen. Sixty-six patients (22.8%) in the high-flow group vs 60 (19.1%) in the NIV group were reintubation (absolute difference, -3.7%; 95% CI, -9.1% to ∞); 78 patients (26.9%) in the high-flow group vs 125 (39.8%) in the NIV group experienced postextubation respiratory failure (risk difference, 12.9%; 95% CI, 6.6% to ∞) [corrected]. Median time to reintubation did not significantly differ: 26.5 hours (IQR, 14-39 hours) in the high-flow group vs 21.5 hours (IQR, 10-47 hours) in the NIV group (absolute difference, -5 hours; 95% CI, -34 to 24 hours). Median postrandomization ICU length of stay was lower in the high-flow group, 3 days (IQR, 2-7) vs 4 days (IQR, 2-9; P=.048). Other secondary outcomes were similar in the 2 groups. Adverse effects requiring withdrawal of the therapy were observed in none of patients in the high-flow group vs 42.9% patients in the NIV group (P < .001). Conclusions and Relevance: Among high-risk adults who have undergone extubation, high-flow conditioned oxygen therapy was not inferior to NIV for preventing reintubation and postextubation respiratory failure. High-flow conditioned oxygen therapy may offer advantages for these patients. Trial Registration: clinicaltrials.gov Identifier: NCT01191489.

High-frequency oscillation ventilation for hypercapnic failure of conventional ventilation in pulmonary acute respiratory distress syndrome.

INTRODUCTION: High-frequency oscillation ventilation (HFOV) is regarded as particularly lung protective. Recently, HFOV has been shown to be not beneficial for acute respiratory distress syndrome (ARDS) patients in general. Due to its special physical effects, it could be beneficial, however, in inhomogeneous ARDS. This study evaluates the effect of HFOV on PaCO2 removal in hypercapnic patients with ARDS of pulmonary origin. METHODS: Between October 2010 and June 2014 patients with ARDS of pulmonary origin with PaO2/FiO2 ratio >60 mmHg, but respiratory acidosis (pH <7.26) under optimized protective ventilation were switched to HFOV, using moderate airway pressure (adopting the mean airway pressure of the prior ventilation). Data from these patients were analyzed retrospectively; PaCO2 and pH before, 1 h and 24 h after the start of HFOV were compared. RESULTS: Twenty-six patients with PaO2/FiO2 ratio 139 ± 49 and respiratory acidosis (PaCO2 68 ± 12 mmHg) were put on HFOV after 17 ± 22 h of conventional ventilation. Mean airway pressure was 19 cm H2O (15 to 28). PaCO2 decreased significantly: after 1 hour the mean difference was -14 ± 10 mmHg; P <0.01 and after 24 hours -17 ± 12 mmHg; P <0.01; n = 24. CO2 clearance improved in all but two patients; in those, extracorporeal lung support was initiated. Oxygenation remained unchanged after 1 h and slightly increased after 24 h. No complications related to HFOV were observed. Twenty-two patients improved and could be weaned from HFOV. Twenty patients (77%) were alive on day 30. CONCLUSIONS: HFOV could be a useful alternative in patients with ARDS of pulmonary origin with hypercapnic failure of lung-protective conventional ventilation.

Sojourn in excessively high oxygen saturation ranges in individual, very low-birthweight neonates.

AIM: To investigate the variability in sojourn times at high oxygen saturations (SpO2 ) in individual patients and to examine whether there are subsets of patients or treatments that are associated with differing sojourn times at SpO2 ≥93%. METHODS: Pulse oximetry data (Masimo) were studied in 71 premature babies receiving supplemental oxygen. Outcome measure was proportion of time per 12-h shift that individual babies spent in the range SpO2 ≥93%. We studied whether an inordinate proportion of time spent at SpO2 ≥93% was attributable to any subset of babies, mode of ventilation or nursing shifts, whether sojourn times were statistically independent shift-to-shift and whether an educational intervention reduced the amount of time spent at SpO2 ≥93%. RESULTS: The proportion of time spent by the populations overall at SpO2 ≥93% was distributed equally among babies. However, high-frequency ventilation was associated with the least amount of time at SpO2 ≥93% compared with other modes of respiratory support (p < 0.0001), while nasal cannulae were associated with the highest proportion of time at SpO2 ≥93% (p < 0.001). CONCLUSION: Measures to improve compliance with targeted SpO2 ranges should be applied universally although further improvement may be achieved by specifically targeting babies receiving supplemental oxygen via nasal cannula.

High-frequency oscillation in adults: a utilization review.

OBJECTIVES: High-frequency oscillation is used for adults with acute lung injury/acute respiratory distress syndrome. Given the uncertain benefits, our objective was to describe contemporary patient selection, high-frequency oscillation utilization, and outcomes. DESIGN: Utilization review. SETTING: Ten academic centers (Ontario, Canada; January 1, 2005-January 31, 2007). PATIENTS: We included 190 consecutive adults treated with high-frequency oscillation and retrospectively abstracted data on patient demographics, gas exchange, hemodynamics, settings during conventional ventilation and high-frequency oscillation, adjunctive therapies, and outcomes. We used logistic regression to explore associations with oxygenation response and hemodynamic and ventilatory complications (2 hrs after high-frequency oscillation initiation) and mortality. Continuous data are reported as mean (sd) or median (quartile 1, quartile 3). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patients (60.0% male; mean age, 52; sd 17) had predominantly acute lung injury/acute respiratory distress syndrome (89.8%) and were severely ill (mean Acute Physiology and Chronic Health Evaluation II score, 28; sd, 9) and hypoxemic (mean Pao2/Fio2, 80; sd, 42). High-frequency oscillation was started a median of 2 (1, 8) days after intubation and continued for a median of 3 (2, 7) days. During high-frequency oscillation, adjunctive treatments (neuromuscular blockade, 75.6%; recruitment maneuvers, 49.5%; nitric oxide, 34.0%; steroids, 63.1%) and new barotrauma or chest tube placement (23.5%) were common. Ten patients (5.3%) had technical complications; five required a new ventilator. Reasons for stopping high-frequency oscillation included death or withdrawal of life support (39.1%), significant improvement in respiratory failure (37.6%), and inadequate improvement (23.3%). One hundred and twenty-eight of 189 patients died in hospital. Most (62.5%) had a positive oxygenation response after 2 hrs of high-frequency oscillation (mean absolute increase in PaO2/FiO2, 22 [SD, 54]; 95% confidence interval of mean 14-31). A minority had lower PaO2/FiO2 (32.5%) or a hemodynamic (27.5%) or ventilatory (30.5%) complication. Older age, Acute Physiology and Chronic Health Evaluation II score, and Paco2 before high-frequency oscillation were independently associated with mortality. CONCLUSIONS: Most patients treated with high-frequency oscillation have acute respiratory distress syndrome and severe hypoxemia that modestly improves 2 hrs after high-frequency oscillation application. However, oxygenation worsens in some patients, complications are common, and mortality is high.

High-frequency oscillatory ventilation and short-term outcome in neonates and infants undergoing cardiac surgery: a propensity score analysis.

INTRODUCTION: Experience with high-frequency oscillatory ventilation (HFOV) after congenital cardiac surgery is limited despite evidence about reduction in pulmonary vascular resistance after the Fontan procedure. HFOV is recommended in adults and children with acute respiratory distress syndrome. The aim of the present study was to assess associations between commencement of HFOV on the day of surgery and length of mechanical ventilation, length of Intensive Care Unit (ICU) stay and mortality in neonates and infants with respiratory distress following cardiac surgery. METHODS: A logistic regression model was used to develop a propensity score, which accounted for the probability of being switched from conventional mechanical ventilation (CMV) to HFOV on the day of surgery. It included baseline characteristics, type of procedure and postoperative variables, and was used to match each patient with HFOV with a control patient, in whom CMV was used exclusively. Length of mechanical ventilation, ICU stay and mortality rates were compared in the matched set. RESULTS: Overall, 3,549 neonates and infants underwent cardiac surgery from January 2001 through June 2010, 120 patients were switched to HFOV and matched with 120 controls. After adjustment for the delay to sternal closure, duration of renal replacement therapy, occurrence of pulmonary hypertension and year of surgery, the probability of successful weaning over time and the probability of ICU delivery over time were significantly higher in patients with HFOV, adjusted hazard ratios and 95% confidence intervals: 1.63, 1.17 to 2.26 (P = 0.004). and 1.65, 95% confidence intervals: 1.20 to 2.28 (P = 0.002) respectively. No association was found with mortality. CONCLUSIONS: When commenced on the day of surgery in neonates and infants with respiratory distress following cardiac surgery, HFOV was associated with shorter lengths of mechanical ventilation and ICU stay than CMV.

Benefits of high frequency oscillatory ventilation for premature infants.

BACKGROUND: High frequency oscillatoryventilation based on optimal lung volume strategy is one of the accepted modes of ventilatory support for respiratory distress syndrome in very low birth weight infants. In 1999 itwas introduced in our unit as the primary ventilation modality for RDS. OBJECTIVES: To evaluate if the shift to HFOV influenced the outcome of ventilated VLBW infants in the neonatal intensive care unit of Carmel Medical Center. METHODS: Data were obtained from the medical charts of VLBW infants born at Carmel Medical Center, and late mortality data from the Israel Ministry of Internal Affairs records. A retrospective analysis and a comparison with a historical control group ventilated by the conventional method were performed. RESULTS: A total of 232 VLBW infants with RDS were mechanically ventilated during the period 1995 to 2003: 120 were ventilated using HFOV during 1999-2003 and 102 infants using CV during 1995-1999. The mean gestational age of survivors was 27.4 +/- 2 weeks in the HFOV group and 28.4 +/- 2 in the conventional ventilation group (P = 0.03). The sub-sample of infants with birth weight < 1000 g ventilated with HFOV showed higher survival rates than the infants in the conventional ventilation group, 53 vs. 25 (64.6% vs. 44.6%) respectively (P < 0.05). A trend for lower incidence of pulmonary interstitial emphysema was observed in the HFOV group. CONCLUSIONS: The introduction of HFOV based on optimal lung volume strategy proved to be an efficient and safe method of ventilation support for VLBW infants in our unit.

Elective high-frequency oscillatory ventilation in preterm infants with respiratory distress syndrome: an individual patient data meta-analysis.

BACKGROUND: Despite the considerable amount of evidence from randomized controlled trials and meta-analyses, uncertainty remains regarding the efficacy and safety of high-frequency oscillatory ventilation as compared to conventional ventilation in the early treatment of respiratory distress syndrome in preterm infants. This results in a wide variation in the clinical use of high-frequency oscillatory ventilation for this indication throughout the world. The reasons are an unexplained heterogeneity between trial results and a number of unanswered, clinically important questions. Do infants with different risk profiles respond differently to high-frequency oscillatory ventilation? How does the ventilation strategy affect outcomes? Does the delay--either from birth or from the moment of intubation--to the start of high-frequency oscillation modify the effect of the intervention? Instead of doing new trials, those questions can be addressed by re-analyzing the individual patient data from the existing randomized controlled trials. METHODS/DESIGN: A systematic review with meta-analysis based on individual patient data. This involves the central collection, validation and re-analysis of the original individual data from each infant included in each randomized controlled trial addressing this question.The study objective is to estimate the effect of high-frequency oscillatory ventilation on the risk for the combined outcome of death or bronchopulmonary dysplasia or a severe adverse neurological event. In addition, it will explore whether the effect of high-frequency oscillatory ventilation differs by the infant's risk profile, defined by gestational age, intrauterine growth restriction, severity of lung disease at birth and whether or not corticosteroids were given to the mother prior to delivery. Finally, it will explore the importance of effect modifying factors such as the ventilator device, ventilation strategy and the delay to the start of high-frequency ventilation. DISCUSSION: An international collaborative group, the PreVILIG Collaboration (Prevention of Ventilator Induced Lung Injury Group), has been formed with the investigators of the original randomized trials to conduct this systematic review. In the field of neonatology, individual patient data meta-analysis has not been used previously. Final results are expected to be available by the end of 2009.

High-frequency oscillatory ventilation as a rescue therapy for adult trauma patients.

BACKGROUND: High-frequency oscillatory ventilation is an alternative ventilation mode that improves oxygenation in trauma patients in whom conventional ventilation strategies have been unsuccessful. OBJECTIVE: To evaluate the effect of high-frequency oscillatory ventilation on oxygenation, survival, and parameters predictive of survival in trauma patients. METHODS: A retrospective case series of 24 adult patients admitted to the trauma intensive care unit at a level I trauma center between November 2001 and July 2005 and treated with high-frequency oscillatory ventilation. Survivors and nonsurvivors were compared for mechanism and severity of injury, oxygenation parameters related to high-frequency oscillatory ventilation, and hospital course. RESULTS: Of the 8577 patients admitted during the study period, acute respiratory distress syndrome developed in 103 (1%). Of those 103 patients, 24 (23%) were treated with high-frequency oscillatory ventilation. Most of the patients treated with high-frequency oscillatory ventilation had sustained blunt trauma (79%). Oxygenation parameters improved significantly with high-frequency oscillatory ventilation in all patients, regardless of survival. Of the 24 patients treated with this ventilation mode, 15 (62%) survived. Survival did not correlate with improved oxygenation parameters but with the number of failed organ systems and injury severity. CONCLUSION: Although high-frequency oscillatory ventilation improves oxygenation, severity of traumatic injury and organ failure, not respiratory parameters, are predictors of survival. High-frequency oscillatory ventilation should be considered for pulmonary rescue of severely injured patients with acute respiratory distress syndrome.

Factors effecting adoption of new neonatal and pediatric respiratory technologies.

OBJECTIVE: There remains significant variation in the level and rate of adoption of new pediatric respiratory technologies, in spite of two decades of focus on "evidence-based medicine". Nearly 50 years ago Rogers introduced a rubric for understanding issues that effect the adoption of technologies that included four factors plus evidence of advantage. We sought to determine whether Rogers' factors were useful in understanding contrasts between clinical utilization of technology and evidence of advantage. DESIGN, SETTING, PARTICIPANTS: We conducted a written survey at two international neonatal/pediatric respiratory conferences. We asked about use of four specific indications for high-frequency ventilation (HFV) and nasal continuous positive airway pressure (nCPAP). RESULTS: These four specific respiratory therapies were aggressively used by most, despite significant differences in the evidence supporting their utility: elective use of HFV (57.4%); HFV to treat ARDS (62.7%); nCPAP for weaning following extubation (83.9%); and nCPAP to avoid intubation (82.1%). CONCLUSIONS: Evidence of outcomes advantage should be the key factor in assessing potentially beneficial technologies. However, we suggest that understanding the influence of observe-ability, complexity and subjectivity of relative advantage explains much of the contrast between adoption level and outcome evidence. These factors described by Rogers, that encourage adoption of mediocre technologies or that retard adoption of potentially beneficial technologies, should be understood and acknowledged. This perspective can be applied not only to national adoption patterns, but also to adoption of best practices within an individual unit.

Major complications during anaesthesia for elective laryngeal surgery in the UK: a national survey of the use of high-pressure source ventilation.

BACKGROUND: Anaesthesia for laryngeal surgery may be complex and associated with complications. METHODS: We conducted a national survey exploring airway management and ventilation during elective laryngeal surgery, focusing primarily on injector and jet ventilation (i.e. high-pressure source ventilation: HPSV). RESULTS: Responses were received from 229 centres (75%). Several hospitals reported major complications during HPSV in the previous 5 yr, including three deaths. Complications during manual techniques led to seven discharge delays, three critical care admissions and three deaths. During the use of a high-frequency jet ventilation (HFJV), complications led to one discharge delay, two critical care admissions and no deaths. Complications were evenly spread between supraglottic, subglottic and transtracheal techniques. All deaths occurred in departments without HFJV. Three centres perform more than 100 transtracheal jet ventilation cases per year. None of these hospitals reported serious complications. Respondents in hospitals reporting serious complications were more likely to have plans to change practice (P=0.03). Elective laryngeal surgery is performed in 62% hospitals, of which 67% use HPSV. Supraglottic, subglottic and transtracheal techniques are used by 86, 50 and 35%, respectively. Manual ventilation devices are used widely. Only 17% of those using HPSV use an HFJV. Two-thirds of respondents initiate manual ventilation with pressures above 2 atm and only 6% start at < or =1 atm. I.V. cannulae are used for direct tracheal access by 18% and subcricoid insertion by 9%. CONCLUSIONS: HPSV may cause serious complications and there are wide variations in clinical practice. This is an area where guideline development and examination of outcome data are warranted.

Refractory Hypoxemia and Use of Rescue Strategies. A U.S. National Survey of Adult Intensivists.

RATIONALE: The management of severe and refractory hypoxemia in critically ill adult patients is practice based. Variability across individual practitioners and institutions is not well documented. OBJECTIVES: To conduct a nationwide survey of critical care physicians in the United States regarding accepted definitions and management strategies for severe and refractory hypoxemia. METHODS: A web-based survey was distributed to a stratified random sample of adult intensivists listed in the American Medical Association Physician Masterfile. The survey was generated by using a mixed-methods approach. MEASUREMENTS AND MAIN RESULTS: In the survey, 4,865 e-mails were sent and 791 (16.3%) were opened. Among those who opened the e-mail message, 50% (n = 396) responded, representing 8.1% of total surveys sent. Seventy-two percent stated that their institutions lacked a protocol for identification and management of severe or refractory hypoxemia in the setting of acute respiratory failure. While the majority of respondents used low-Vt ventilation (81%), high positive end-expiratory pressure (86%), recruitment maneuvers (89%), and either bolus or infusion neuromuscular blockade (94%), there was marked variability in the use of specific rescue strategies as tier 1 or 2 interventions: prone position (27.8% vs. 47.8%, respectively), extracorporeal membrane oxygenation (2.3% vs. 51.2%, respectively), airway pressure release ventilation (49% vs. 34.5%, respectively), inhaled vasodilators (30.1% vs. 40%, respectively), and high-frequency oscillatory ventilation (7.8% vs. 40%, respectively). The variability was partly explained by providers' expertise with particular rescue strategies (77.7%), advance directives (70.1%), the training of allied health staff (62.3%), and institutional availability (53.8%). CONCLUSIONS: U.S. adult critical care physicians predominantly employ lung-protective ventilation for severe hypoxemia. A wide variation in other rescue strategies is noted, which is partly explained by user expertise and availability. Less than 30% institutions have formal protocols for management of refractory hypoxemia.

A Comparative Effectiveness Study of Rescue Strategies in 1,000 Subjects With Severe Hypoxemic Respiratory Failure.

BACKGROUND: Subjects with severe hypoxemic respiratory failure have shown a high mortality in previous studies. METHODS: All adult ICU patients requiring mechanical ventilation from 2005 to 2010 at Mayo Clinic were screened for severe hypoxemia (Murray lung injury score of ≥ 3). Extracorporeal membrane oxygenation, prone positioning, high-frequency oscillatory ventilation (HFOV), and inhaled vasodilators were considered as rescue strategies. A propensity-based scoring was created for the indication or predilection to use each strategy. A model was created to evaluate the association of each rescue strategy with hospital mortality. RESULTS: Among 1,032 subjects with severe hypoxemia, 239 subjects received some form of rescue strategy (59 received a combination of therapies, and 180 received individual therapies). Inhaled vasodilators were the most common, followed by HFOV. Rescue strategies were used in younger subjects with severe oxygenation deficits. Subjects receiving rescue strategies had higher mortality and longer ICU stays. None of the strategies individually or in combination showed a significant association with hospital mortality after adjusting covariates by propensity scoring. Adjusted Odds ratios and respective 95% CI were as follows: HFOV 0.67 (0.35-1.27), extracorporeal membrane oxygenation 0.63 (0.18-1.92), prone position 1.07 (0.49-2.28), and inhaled vasodilators 1.17 (0.78-1.77). CONCLUSIONS: In this retrospective comparative effectiveness study, there was no association of rescue strategies with hospital mortality in subjects with severe hypoxemia.