Outcomes With Single-Site Dual-Lumen Versus Multisite Cannulation for Adults With COVID-19 Respiratory Failure Receiving Venovenous Extracorporeal Membrane Oxygenation.

OBJECTIVES: To determine whether multisite versus single-site dual-lumen (SSDL) cannulation is associated with outcomes for COVID-19 patients requiring venovenous extracorporeal membrane oxygenation (VV-ECMO). DESIGN: Retrospective analysis of the Extracorporeal Life Support Organization Registry. Propensity score matching (2:1 multisite vs SSDL) was used to control for confounders. PATIENTS: The matched cohort included 2,628 patients (1,752 multisite, 876 SSDL) from 170 centers. The mean ( sd ) age in the entire cohort was 48 (11) years, and 3,909 (71%) were male. Patients were supported with mechanical ventilation for a median (interquartile range) of 79 (113) hours before VV-ECMO support. INTERVENTIONS: None. MEASUREMENTS: The primary outcome was 90-day survival. Secondary outcomes included survival to hospital discharge, duration of ECMO support, days free of ECMO support at 90 days, and complication rates. MAIN RESULTS: There was no difference in 90-day survival (49.4 vs 48.9%, p = 0.66), survival to hospital discharge (49.8 vs 48.2%, p = 0.44), duration of ECMO support (17.9 vs 17.1 d, p = 0.82), or hospital length of stay after cannulation (28 vs 27.4 d, p = 0.37) between multisite and SSDL groups. More SSDL patients were extubated within 24 hours (4% vs 1.9%, p = 0.001). Multisite patients had higher ECMO flows at 24 hours (4.5 vs 4.1 L/min, p < 0.001) and more ECMO-free days at 90 days (3.1 vs 2.0 d, p = 0.02). SSDL patients had higher rates of pneumothorax (13.9% vs 11%, p = 0.03). Cannula site bleeding (6.4% vs 4.7%, p = 0.03), oxygenator failure (16.7 vs 13.4%, p = 0.03), and circuit clots (5.5% vs 3.4%, p = 0.02) were more frequent in multisite patients. CONCLUSIONS: In this retrospective study of COVID-19 patients requiring VV-ECMO, 90-day survival did not differ between patients treated with a multisite versus SSDL cannulation strategy and there were only modest differences in major complication rates. These findings do not support the superiority of either cannulation strategy in this setting.

Anesthetic Preferences for Cardiac Anesthesia: A Survey of the Society of Cardiovascular Anesthesiologists.

BACKGROUND: Volatile anesthetics have been historically preferred for cardiac anesthesia, but the evidence for their superiority to intravenous agents is mixed. We conducted a survey to better understand the current state of practice and the rationale behind provider preferences for anesthesia for cardiac surgery with cardiopulmonary bypass. We hypothesized that anesthetic preference would vary considerably among surveyed providers without a clear majority, as would the rationale behind those preferences. METHODS: Email invitations were sent to members of the Society of Cardiovascular Anesthesiologists, who were asked to identify the anesthetics or sedatives they typically prefer to administer during induction, prebypass, bypass, postbypass, and postoperative periods and why they prefer those agents. Members' beliefs regarding the importance of anesthetics on postoperative outcomes were also assessed. RESULTS: Invitations were sent on 2 separate dates to 3328 and 3274 members, of whom 689 (21%) responded. The median (interquartile range [IQR]) respondent age was 45 (37-56) years, 79% were men, and 75% were fellowship trained. The most frequently chosen drug for induction was propofol (80%). Isoflurane was the most frequently selected primary agent for the prebypass (57%), bypass (62%), and postbypass periods (50%). Sevoflurane was the second most frequently selected (30%; 17%, and 24%, respectively). Propofol was the third most frequently selected agent for the bypass (14%) and postbypass periods (17%). Ease of use was the most frequently selected reason for administering isoflurane and sevoflurane for each period. During bypass, the second most frequently selected rationale for using isoflurane and sevoflurane was institutional practice. A total of 76% responded that the perfusionist typically delivers the bypass anesthetic. Ischemic preconditioning, organ protection, and postoperative cognitive function were infrequently selected as rationales for preferring the volatile anesthetics. Most respondents (73%) think that anesthetics have organ-protective properties, especially isoflurane (74%) and sevoflurane (59%), and 72% believed that anesthetic choice contributes to patient outcome. The median (IQR) agreement (0 = strongly disagree to 100 = strongly agree) was 72 (63-85) for the statement that "inhaled anesthetics are an optimal maintenance anesthetic for cardiac surgery." CONCLUSIONS: In a survey of cardiac anesthesiologists, a majority of respondents indicated that they prefer volatile anesthetics for maintenance of anesthesia, that anesthetic selection impacts patient outcomes, and that volatile anesthetics have organ-protective properties. The members' rationales for preferring these agents possibly reflect that practical considerations, such as ease of use, effectiveness, and institutional practice, also influence anesthetic selection during cardiac surgery in addition to considerations such as organ protection.

Increasing the reflection efficiency of the Sedaconda ACD-S by heating and cooling the anaesthetic reflector: a bench study using a test lung.

BACKGROUND: As volatile anaesthetic gases contribute to global warming, improving the efficiency of their delivery can reduce their environmental impact. This can be achieved by rebreathing from a circle system, but also by anaesthetic reflection with an open intensive care ventilator. We investigated whether the efficiency of such a reflection system could be increased by warming the reflector during inspiration and cooling it during expiration (thermocycling). METHODS: The Sedaconda-ACD-S (Sedana Medical, Danderyd, Sweden) was connected between an intensive care ventilator and a test lung. Liquid isoflurane was infused into the device at 0.5, 1.0, 2.0 and 5.0 mL/h; ventilator settings were 500 mL tidal volume, 12 bpm, 21% oxygen. Isoflurane concentrations were measured inside the test lung after equilibration. Thermocycling was achieved by heating the breathing gas in the inspiratory hose to 37 °C via a heated humidifier without water. Breathing gas expired from the test lung was cooled to 14 °C before reaching the ACD-S. In the test lung, body temperature pressure saturated conditions prevailed. Isoflurane concentrations and reflective efficiency were compared between thermocycling and control conditions. RESULTS: With thermocycling higher isoflurane concentrations in the test lung were measured for all infusion rates studied. Interpolation of data showed that for achieving 0.4 (0.6) Vol% isoflurane, the infusion rate can be reduced from 1.2 to 0.7 (2.0 to 1.2) mL/h or else to 56% (58%) of control. CONCLUSION: Thermocycling of the anaesthetic gas considerably increases the efficiency of the anaesthetic reflector and reduces anaesthetic consumption by almost half in a test lung model. Given that cooling can be miniaturized, this method carries a potential for further saving anaesthetics in clinical practice in the operating theatre as well as for inhaled sedation in the ICU.

Anesthetics to Prevent Lung Injury in Cardiac Surgery: A Randomized Controlled Trial.

OBJECTIVES: To investigate if sevoflurane based anesthesia is superior to propofol in preventing lung inflammation and preventing postoperative pulmonary complications. DESIGN: Randomized controlled trial. SETTING: Single tertiary care university hospital. PARTICIPANTS: Forty adults undergoing cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: Patients were randomized in a 1:1 ratio to anesthetic maintenance with sevoflurane or propofol. MEASUREMENTS AND MAIN RESULTS: Blood and bronchoalveolar lavage fluid was sampled before and after bypass to measure pulmonary inflammation using a biomarker panel. The change in bronchoalveolar lavage concentration of tumor necrosis factor alpha (TNFα) was the primary outcome. Secondary outcomes included lung inflammation defined as changes in other biomarkers and postoperative pulmonary complications. There were no significant differences between groups in the change in bronchoalveolar lavage TNFα concentration (median [IQR] change, 17.24 [1.11-536.77] v 101.51 [1.47-402.84] pg/mL, sevoflurane v propofol, p = 0.31). There was a significantly lower postbypass concentration of plasma interleukin 8 (median [IQR], 53.92 [34.5-55.91] v 66.92 [53.03-94.44] pg/mL, p = 0.04) and a significantly smaller postbypass increase in the plasma receptor for advanced glycosylation end products (median [IQR], 174.59 [73.59-446.06] v 548.22 [193.15-852.39] pg/mL, p = 0.03) in the sevoflurane group compared with propofol. The incidence of postoperative pulmonary complications was 100% in both groups, with high rates of pleural effusion (17/18 [94.44%] v 19/22 [86.36%], p = 0.39) and hypoxemia (16/18 [88.88%] v 22/22 [100%], p = 0.11). CONCLUSIONS: Sevoflurane anesthesia during cardiac surgery did not consistently prevent lung inflammation or prevent postoperative pulmonary complications compared to propofol. There were significantly lower levels of 2 plasma biomarkers specific for lung injury and inflammation in the sevoflurane group.

Intraoperative Oxygen Practices in Cardiac Surgery: A National Survey.

OBJECTIVE: To describe the current nationwide perspectives and practice regarding intraoperative oxygen titration in cardiac surgery. DESIGN: Prospective, observational survey. SETTING: Hospitals across the United States. PARTICIPANTS: Cardiovascular anesthesiologists and perfusionists. INTERVENTIONS: Expert- and consensus-derived electronic surveys were sent to perfusionists and cardiac anesthesiologists to evaluate the current intraoperative practices around oxygen administration. Providers were asked about individual intraoperative oxygen titration practices used at different stages of cardiac surgical procedures. Anonymous responses were collected in the Research Electronic Data Capture (REDCap). MEASUREMENTS AND MAIN RESULTS: A total of 3,335 providers were invited to participate, of whom 554 (317 anesthesiologists and 237 perfusionists) were included in the final analysis (17% response rate). During cardiopulmonary bypass (CPB), perfusionists reported a median (interquartile range [IQR]) target range from 150 (110-220)-to-325 mmHg (250-400), while anesthesiologists reported a significantly lower target range from 90 (70-150)-to-250 mmHg (158-400) (p values <0.0001 and 0.02, respectively). This difference was most pronounced at lower partial pressure of arterial oxygen (PaO2) ranges. The median PaO2 considered "too low" by perfusionists was 100 mmHg (IQR 80-125), whereas it was 60 mmHg (IQR 60-75) for anesthesiologists, who reported for both off and on bypass. The median PaO2 considered "too high" was 375 mmHg (IQR 300-400) for perfusionists and 300 mmHg (IQR 200-400) for anesthesiologists. Anesthesiologists, therefore, reported more comfort with significantly lower PaO2 values (p < 0.0001), and considered a higher PaO2 value less desirable compared with perfusionists (p < 0.0001). CONCLUSIONS: This survey demonstrated there was wide variation in oxygen administration practices between perfusionists and anesthesiologists. Hyperoxygenation was more common while on CPB.

Sleep, Pain, and Cognition: Modifiable Targets for Optimal Perioperative Brain Health.

The prevention of perioperative neurocognitive disorders is a priority for patients, families, clinicians, and researchers. Given the multiple risk factors present throughout the perioperative period, a multicomponent preventative approach may be most effective. The objectives of this narrative review are to highlight the importance of sleep, pain, and cognition on the risk of perioperative neurocognitive disorders and to discuss the evidence behind interventions targeting these modifiable risk factors. Sleep disruption is associated with postoperative delirium, but the benefit of sleep-related interventions is uncertain. Pain is a risk factor for postoperative delirium, but its impact on other postoperative neurocognitive disorders is unknown. Multimodal analgesia and opioid avoidance are emerging as best practices, but data supporting their efficacy to prevent delirium are limited. Poor preoperative cognitive function is a strong predictor of postoperative neurocognitive disorder, and work is ongoing to determine whether it can be modified to prevent perioperative neurocognitive disorders.

Intraoperative Oxygen Concentration and Neurocognition after Cardiac Surgery.

BACKGROUND: Despite evidence suggesting detrimental effects of perioperative hyperoxia, hyperoxygenation remains commonplace in cardiac surgery. Hyperoxygenation may increase oxidative damage and neuronal injury leading to potential differences in postoperative neurocognition. Therefore, this study tested the primary hypothesis that intraoperative normoxia, as compared to hyperoxia, reduces postoperative cognitive dysfunction in older patients having cardiac surgery. METHODS: A randomized double-blind trial was conducted in patients aged 65 yr or older having coronary artery bypass graft surgery with cardiopulmonary bypass. A total of 100 patients were randomized to one of two intraoperative oxygen delivery strategies. Normoxic patients (n = 50) received a minimum fraction of inspired oxygen of 0.35 to maintain a Pao2 above 70 mmHg before and after cardiopulmonary bypass and between 100 and 150 mmHg during cardiopulmonary bypass. Hyperoxic patients (n = 50) received a fraction of inspired oxygen of 1.0 throughout surgery, irrespective of Pao2 levels. The primary outcome was neurocognitive function measured on postoperative day 2 using the Telephonic Montreal Cognitive Assessment. Secondary outcomes included neurocognitive function at 1, 3, and 6 months, as well as postoperative delirium, mortality, and durations of mechanical ventilation, intensive care unit stay, and hospital stay. RESULTS: The median age was 71 yr (interquartile range, 68 to 75), and the median baseline neurocognitive score was 17 (16 to 19). The median intraoperative Pao2 was 309 (285 to 352) mmHg in the hyperoxia group and 153 (133 to 168) mmHg in the normoxia group (P < 0.001). The median Telephonic Montreal Cognitive Assessment score on postoperative day 2 was 18 (16 to 20) in the hyperoxia group and 18 (14 to 20) in the normoxia group (P = 0.42). Neurocognitive function at 1, 3, and 6 months, as well as secondary outcomes, were not statistically different between groups. CONCLUSIONS: In this randomized controlled trial, intraoperative normoxia did not reduce postoperative cognitive dysfunction when compared to intraoperative hyperoxia in older patients having cardiac surgery. Although the optimal intraoperative oxygenation strategy remains uncertain, the results indicate that intraoperative hyperoxia does not worsen postoperative cognition after cardiac surgery.

Reflection Versus Rebreathing for Administration of Sevoflurane During Minor Gynecological Surgery.

BACKGROUND: Contemporary anesthetic circle systems, when used at low fresh gas flows (FGF) to allow rebreathing of anesthetic, lack the ability for rapid dose titration. The small-scale anesthetic reflection device Anaesthetic Conserving Device (50mL Version; AnaConDa-S) permits administration of volatile anesthetics with high-flow ventilators. We compared washin, washout, and sevoflurane consumption using AnaConDa-S versus a circle system with low and minimal FGF. METHODS: Forty patients undergoing breast surgery were randomized to receive 0.5 minimal alveolar concentration (MAC) sevoflurane with AnaConDa-S (21 patients, reflection group) or with a circle system (low flow: FGF = 0.2 minute ventilation [V'E], 9 patients; or minimal flow: 0.1 V'E, 10 patients). In the reflection group, syringe pump boluses were given for priming and washin; to simulate an open system, the FGF of the anesthesia ventilator was set to 18 L·min-1 with the soda lime removed. In the other groups, the FGF was increased for washin (1 V'E for 8 minutes) and washout (3 V'E). For all patients, tidal volume was 7 mL·kg-1 and the respiratory rate adjusted to ensure normoventilation. Analgesia was attained with remifentanil 0.3 µg·kg-1·min-1. Sevoflurane consumption was compared between the reflection group and the low- and minimal-flow groups, respectively, using a post hoc test (Fisher Least Significant Difference). To compare washin and washout (half-life), the low- and minimal-flow groups were combined. RESULTS: Sevoflurane consumption was reduced in the reflection group (9.4 ± 2.0 vs 15.0 ± 3.5 [low flow, P < .001] vs 11.6 ± 2.3 mL·MAC h-1 [minimal flow, P = .02]); washin (33 ± 15 vs 49 ± 12 seconds, P = .001) and washout (28 ± 15 vs 55 ± 19 seconds, P < .001) times were also significantly shorter. CONCLUSIONS: In this clinical setting with short procedures, low anesthetic requirements, and low tidal volumes, AnaConDa-S decreased anesthetic consumption, washin, and washout times compared to a circle system.

Racial and Socioeconomic Disparities in Spinal Cord Stimulation Among the Medicare Population.

INTRODUCTION: Spinal cord stimulation (SCS) is used in the treatment of many chronic pain conditions. This study investigates racial and socioeconomic disparities in SCS among Medicare patients with chronic pain. MATERIALS AND METHODS: Patients over the age of 18 with a primary diagnosis of postlaminectomy syndrome (ICD-10 M96.1) or chronic pain syndrome (ICD-10 G89.4) were identified in the Center for Medicare and Medicaid Services (CMS) Medicare Claims Limited Data Set. We defined our outcome as SCS therapy by race and socioeconomic status. Multivariable logistic regression was used to determine the variables associated with SCS. RESULTS: We identified 1,244,927 patients treated between 2016 and 2019 with a primary diagnosis of postlaminectomy syndrome (PLS) or chronic pain syndrome (CPS). Of these patients, 59,182 (4.8%) received SCS. Multivariable logistic regression analysis revealed that, compared with White patients, Black (OR [95%CI], 0.62 [0.6-0.65], p < 0.001), Asian (0.66 [0.56-0.76], p < 0.001), Hispanic (0.86 [0.8-0.93], p < 0.001), and North American Native (0.62 [0.56-0.69], p < 0.001) patients were significantly less likely to receive SCS. In addition, patients who were dual-eligible for Medicare and Medicaid were significantly less likely to receive SCS than those eligible for Medicare only (OR = 0.38 [95% CI: 0.37-0.39], p < 0.001). CONCLUSIONS: This study suggests that racial and socioeconomic disparities exist in SCS among Medicare and Medicaid patients with PLS and CPS. Further work is required to elucidate the complex etiology underlying these findings.

Association between propofol dose and 1-year mortality in patients with or without a diagnosis of solid cancer.

BACKGROUND: Preclinical data suggest suppression of cancer proliferation by propofol, and retrospective studies suggest improved survival after cancer surgery with propofol-based anaesthesia. METHODS: To determine whether propofol dose administered for anaesthesia is associated with 1-yr mortality in patients with and without a diagnosis of solid cancer, we analysed adult patients undergoing monitored anaesthesia care or general anaesthesia at two academic medical centres in Boston, MA, USA. Logistic regression with interaction term analysis was applied with propofol dose (mg kg-1) as primary and diagnosis of solid cancer as co-primary exposure, and 1-yr mortality as the primary outcome. RESULTS: Of 280 081 patient cases, 10 744 (3.8%) died within 1 yr. Increasing propofol dose was associated with reduced odds of 1-yr mortality (adjusted odds ratio [aOR] 0.93 per 10 mg kg-1; 95% confidence interval [CI]: 0.89-0.98; absolute risk reduction fifth vs first quintile 0.5%; 95% CI: 0.2-0.7). This association was modified by a diagnosis of solid cancer (P<0.001 for interaction). Increasing propofol dose was associated with reduced odds of 1-yr mortality in patients without solid cancer (aOR: 0.78; 95% CI: 0.71-0.85), but not in patients with solid cancer (0.99; 0.94-1.04), a finding that was replicated when examining 5-yr mortality. CONCLUSIONS: Increasing propofol dose is associated with lower 1-yr mortality in patients without, but not in patients with, a diagnosis of solid cancer. We found evidence for competing effects, modifying the association between propofol dose and mortality.

Prevention of Early Postoperative Decline: A Randomized, Controlled Feasibility Trial of Perioperative Cognitive Training.

BACKGROUND: Postoperative delirium and postoperative cognitive dysfunction (POCD) are common after cardiac surgery and contribute to an increased risk of postoperative complications, longer length of stay, and increased hospital mortality. Cognitive training (CT) may be able to durably improve cognitive reserve in areas deficient in delirium and POCD and, therefore, may potentially reduce the risk of these conditions. We sought to determine the feasibility and potential efficacy of a perioperative CT program to reduce the incidence of postoperative delirium and POCD in older cardiac surgery patients. METHODS: Randomized controlled trial at a single tertiary care center. Participants included 45 older adults age 60-90 undergoing cardiac surgery at least 10 days from enrollment. Participants were randomly assigned in a 1:1 fashion to either perioperative CT via a mobile device or a usual care control. The primary outcome of feasibility was evaluated by enrollment patterns and adherence to protocol. Secondary outcomes of postoperative delirium and POCD were assessed using the Confusion Assessment Method and the Montreal Cognitive Assessment, respectively. Patient satisfaction was assessed via a postoperative survey. RESULTS: Sixty-five percent of eligible patients were enrolled. Median (interquartile range [IQR]) adherence (as a percentage of prescribed minutes played) was 39% (20%-68%), 6% (0%-37%), and 19% (0%-56%) for the preoperative, immediate postoperative, and postdischarge periods, respectively. Median (IQR) training times were 245 (136-536), 18 (0-40), and 122 (0-281) minutes for each period, respectively. The incidence of postoperative delirium (CT group 5/20 [25%] versus control 3/20 [15%]; P = .69) and POCD (CT group 53% versus control 37%; P = .33) was not significantly different between groups for either outcome in this limited sample. CT participants reported a high level of agreement (on a scale of 0-100) with statements that the program was easy to use (median [IQR], 87 [75-97]) and enjoyable (85 [79-91]). CT participants agreed significantly more than controls that their memory (median [IQR], 75 [54-82] vs 51 [49-54]; P = .01) and thinking ability (median [IQR], 78 [64-83] vs 50 [41-68]; P = .01) improved as a result of their participation in the study. CONCLUSIONS: A CT program designed for use in the preoperative period is an attractive target for future investigations of cognitive prehabilitation in older cardiac surgery patients. Changes in the functionality of the program and enrichment techniques may improve adherence in future trials. Further investigation is necessary to determine the potential efficacy of cognitive prehabilitation to reduce the risk of postoperative delirium and POCD.

Effect of Intravenous Acetaminophen vs Placebo Combined With Propofol or Dexmedetomidine on Postoperative Delirium Among Older Patients Following Cardiac Surgery: The DEXACET Randomized Clinical Trial.

Importance: Postoperative delirium is common following cardiac surgery and may be affected by choice of analgesic and sedative. Objective: To evaluate the effect of postoperative intravenous (IV) acetaminophen (paracetamol) vs placebo combined with IV propofol vs dexmedetomidine on postoperative delirium among older patients undergoing cardiac surgery. Design, Setting, and Participants: Randomized, placebo-controlled, factorial clinical trial among 120 patients aged 60 years or older undergoing on-pump coronary artery bypass graft (CABG) surgery or combined CABG/valve surgeries at a US center. Enrollment was September 2015 to April 2018, with follow-up ending in April 2019. Interventions: Patients were randomized to 1 of 4 groups receiving postoperative analgesia with IV acetaminophen or placebo every 6 hours for 48 hours and postoperative sedation with dexmedetomidine or propofol starting at chest closure and continued for up to 6 hours (acetaminophen and dexmedetomidine: n = 29; placebo and dexmedetomidine: n = 30; acetaminophen and propofol: n = 31; placebo and propofol: n = 30). Main Outcomes and Measures: The primary outcome was incidence of postoperative in-hospital delirium by the Confusion Assessment Method. Secondary outcomes included delirium duration, cognitive decline, breakthrough analgesia within the first 48 hours, and ICU and hospital length of stay. Results: Among 121 patients randomized (median age, 69 years; 19 women [15.8%]), 120 completed the trial. Patients treated with IV acetaminophen had a significant reduction in delirium (10% vs 28% placebo; difference, -18% [95% CI, -32% to -5%]; P = .01; HR, 2.8 [95% CI, 1.1-7.8]). Patients receiving dexmedetomidine vs propofol had no significant difference in delirium (17% vs 21%; difference, -4% [95% CI, -18% to 10%]; P = .54; HR, 0.8 [95% CI, 0.4-1.9]). There were significant differences favoring acetaminophen vs placebo for 3 prespecified secondary outcomes: delirium duration (median, 1 vs 2 days; difference, -1 [95% CI, -2 to 0]), ICU length of stay (median, 29.5 vs 46.7 hours; difference, -16.7 [95% CI, -20.3 to -0.8]), and breakthrough analgesia (median, 322.5 vs 405.3 µg morphine equivalents; difference, -83 [95% CI, -154 to -14]). For dexmedetomidine vs propofol, only breakthrough analgesia was significantly different (median, 328.8 vs 397.5 µg; difference, -69 [95% CI, -155 to -4]; P = .04). Fourteen patients in both the placebo-dexmedetomidine and acetaminophen-propofol groups (46% and 45%) and 7 in the acetaminophen-dexmedetomidine and placebo-propofol groups (24% and 23%) had hypotension. Conclusions and Relevance: Among older patients undergoing cardiac surgery, postoperative scheduled IV acetaminophen, combined with IV propofol or dexmedetomidine, reduced in-hospital delirium vs placebo. Additional research, including comparison of IV vs oral acetaminophen and other potentially opioid-sparing analgesics, on the incidence of postoperative delirium is warranted. Trial Registration: ClinicalTrials.gov Identifier: NCT02546765.

The Effect of Positive End-Expiratory Pressure on Intracranial Pressure and Cerebral Hemodynamics.

BACKGROUND: Lung protective ventilation has not been evaluated in patients with brain injury. It is unclear whether applying positive end-expiratory pressure (PEEP) adversely affects intracranial pressure (ICP) and cerebral perfusion pressure (CPP). We aimed to evaluate the effect of PEEP on ICP and CPP in a large population of patients with acute brain injury and varying categories of acute lung injury, defined by PaO2/FiO2. METHOD: Retrospective data were collected from 341 patients with severe acute brain injury admitted to the ICU between 2008 and 2015. These patients experienced a total of 28,644 paired PEEP and ICP observations. Demographic, hemodynamic, physiologic, and ventilator data at the time of the paired PEEP and ICP observations were recorded. RESULTS: In the adjusted analysis, a statistically significant relationship between PEEP and ICP and PEEP and CPP was found only among observations occurring during periods of severe lung injury. For every centimeter H2O increase in PEEP, there was a 0.31 mmHg increase in ICP (p = 0.04; 95 % CI [0.07, 0.54]) and a 0.85 mmHg decrease in CPP (p = 0.02; 95 % CI [-1.48, -0.22]). CONCLUSION: Our results suggest that PEEP can be applied safely in patients with acute brain injury as it does not have a clinically significant effect on ICP or CPP. Further prospective studies are required to assess the safety of applying a lung protective ventilation strategy in brain-injured patients with lung injury.

Controversies in the Management of Severe ARDS: Optimal Ventilator Management and Use of Rescue Therapies.

Groundbreaking research into the pathophysiology of the adult acute respiratory distress syndrome (ARDS) and the prevention of ventilator-induced lung injury has led to dramatic improvements in survival. Investigations over the last two decades have revolved around the development of rescue therapies that can be used for patients with severe ARDS and refractory hypoxemia. To date, the techniques of using high levels of positive end-expiratory pressure (PEEP), prompt institution of neuromuscular blockade, and early prolonged prone positioning have been shown to reduce mortality in patients with severe ARDS. PEEP titration using transpulmonary pressure estimations assisted by esophageal manometry has been shown to result in a substantial improvement in oxygenation. Extracorporeal membrane oxygenation (ECMO) has been used increasingly since the mid-2000s in part due to the H1N1 epidemic. A major randomized controlled trial conducted during this period showed a significant mortality benefit for patients with severe ARDS who were referred to a center with ECMO capabilities. The routine use of inhaled nitric oxide for patients with severe ARDS has not been shown to lead to more than a transient and limited improvement in oxygenation, which may hinder its use as a sole rescue therapy. Finally, recent studies have found that the routine use of high-frequency oscillatory ventilation in severe ARDS does not result in decreased mortality, although the technique has not been specifically investigated as rescue therapy for severe refractory hypoxemia.

Early and late effects of volatile sedation with sevoflurane on respiratory mechanics of critically ill COPD patients.

BACKGROUND: The objective was to compare sevoflurane, a volatile sedation agent with potential bronchodilatory properties, with propofol on respiratory mechanics in critically ill patients with COPD exacerbation. METHODS: Prospective study in an ICU enrolling critically ill intubated patients with severe COPD exacerbation and comparing propofol and sevoflurane after 1:1 randomisation. Respiratory system mechanics (airway resistance, PEEPi, trapped volume, ventilatory ratio and respiratory system compliance), gas exchange, vitals, safety and outcome were measured at inclusion and then until H48. Total airway resistance change from baseline to H48 in both sevoflurane and propofol groups was the main endpoint. RESULTS: Sixteen patients were enrolled and were sedated for 126 h(61-228) in the propofol group and 207 h(171-216) in the sevoflurane group. At baseline, airway resistance was 21.6cmH2O/l/s(19.8-21.6) in the propofol group and 20.4cmH2O/l/s(18.6-26.4) in the sevoflurane group, (p = 0.73); trapped volume was 260 ml(176-290) in the propofol group and 73 ml(35-126) in the sevoflurane group, p = 0.02. Intrinsic PEEP was 1.5cmH2O(1-3) in both groups after external PEEP optimization. There was neither early (H4) or late (H48) significant difference in airway resistance and respiratory mechanics parameters between the two groups. CONCLUSIONS: In critically ill patients intubated with COPD exacerbation, there was no significant difference in respiratory mechanics between sevoflurane and propofol from inclusion to H4 and H48.

Postoperative virtual reality for recovery after bariatric surgery: study protocol for a randomised clinical trial.

Background: Enhanced Recovery After Surgery (ERAS) protocols for bariatric surgery improve clinical outcomes. However, the impact of ERAS protocols on patient satisfaction is unknown. Virtual reality has been implemented as an effective adjunct to standard analgesic regimens. This study seeks to find out if immersive virtual reality in the immediate postoperative period could improve the subjective quality of recovery and further reduce opioid requirements for bariatric surgery patients compared with ERAS care alone. Methods: This is a single-centre, randomised clinical trial of patients recovering from laparoscopic bariatric surgery. Once in the post-anaesthesia care unit (PACU), participants will receive either an immersive virtual reality plus ERAS protocol or ERAS protocol alone. The primary outcome will be the Quality of Recovery-15 (QoR-15) score at PACU discharge. Secondary outcomes include PACU opioid requirements, length of PACU stay, PACU pain scores, QoR-15 score on postoperative day 1, hospital length of stay, opioid requirements, and opioid-related adverse effects until hospital discharge. Conclusions: Positive findings from this study could introduce virtual reality as a non-pharmacological adjunct during PACU care that improves subjective recovery for patients undergoing bariatric surgery. Clinical trial registration: NCT04754165.