Effect of Recruitment Maneuvers and PEEP on Respiratory Failure After Cardiothoracic Surgery in Obese Subjects: A Randomized Controlled Trial.

BACKGROUND: Obesity may increase the risk of respiratory failure after cardiothoracic surgery. A recruitment maneuver followed by PEEP might decrease the risk of respiratory failure in obese subjects. We hypothesized that the routine use after heart surgery of a recruitment maneuver followed by high or low PEEP level would decrease the frequency of respiratory failure in obese subjects. METHODS: In a pragmatic, randomized controlled trial, we assigned obese subjects (ie, with body mass index [BMI] ≥ 30 kg/m2) in the immediate postoperative period of cardiothoracic surgery to either volume control ventilation with 5 cm H2O of PEEP (control group) or a recruitment maneuver followed by 5 or 10 cm H2O of PEEP in the intervention arms (RM5 and RM10 groups, respectively). The primary outcome was the proportion of subjects with postextubation respiratory failure, defined as the need for re-intubation, bi-level positive airway pressure, or high-flow nasal cannula within the first 48 h. RESULTS: The study included 192 subjects: 65 in the control group (BMI 33.5 ± 3.2 kg/m2), 66 in the RM5 group (BMI 34.5 ± 3.2 kg/m2, and 61 in RM10 group (BMI 33.8 ± 4.8 kg/m2). Postextubation respiratory failure occurred in 14 subjects in the control group (21.5% [95% CI 13.3-35.3]), 21 subjects in the RM5 group (31.8% [95% CI 21.2-44.6]), and 9 subjects in the RM10 group (14.7% [95% CI 7.4-26.7]) (P = .07). The recruitment maneuver was stopped prematurely due to severe hypotension in 8 (12.1%) RM5 subjects and in 4 (6.6%) RM10 subjects (P = .28). There were no significant differences between the 3 groups for the frequencies of atelectasis, pneumonia, and death in the ICU. CONCLUSIONS: The routine use after heart surgery of a recruitment maneuver followed by 5 or 10 cm H2O of PEEP did not decrease the frequency of respiratory failure in obese subjects. A recruitment maneuver followed by 5 cm H2O of PEEP is inappropriate.

Neuromuscular Blockade Monitoring in Acute Respiratory Distress Syndrome: Randomized Controlled Trial of Clinical Assessment Alone or With Peripheral Nerve Stimulation.

BACKGROUND: Whether train-of-four (TOF) monitoring is more effective than clinical monitoring to guide neuromuscular blockade (NMB) in patients with acute respiratory distress syndrome (ARDS) is unclear. We compared clinical monitoring alone or with TOF monitoring to guide atracurium dosage adjustment with respect to drug dose and respiratory parameters. METHODS: From 2015 to 2016, we conducted a randomized controlled trial comparing clinical assessments every 2 hours with or without corrugator supercilii TOF monitoring every 4 hours in patients who developed ARDS (Pao2/Fio2 <150 mm Hg) in a cardiothoracic intensive care unit. The primary outcome was the cumulative atracurium dose (mg/kg/h). Secondary outcomes included respiratory parameters during the neuromuscular blockade. RESULTS: A total of 38 patients in the clinical + TOF (C + TOF) group and 39 patients in the clinical (C) group were included in an intention-to-treat (ITT) analysis. The cumulative atracurium dose was higher in the C + TOF group (1.06 [0.75-1.30] vs 0.65 [0.60-0.89] mg/kg/h in the C group; P < .001) compared to C group, as well as the atracurium daily dose (C + TOF - C group mean difference = 0.256 mg/kg/h [95% confidence interval {CI}, 0.099-0.416], P = .026). Driving pressures during neuromuscular blocking agent (NMBA) administration did not differ between groups (P = .653). Intensive care unit (ICU) mortality was 22% in the C group and 27% in the C + TOF group (P = .786). Days on ventilation were 17 (8-26) in the C group and 16 (10-35) in the C + TOF group. CONCLUSIONS: In patients with ARDS, adding TOF to clinical monitoring of neuromuscular blockade did not change ICU mortality or days on mechanical ventilation (MV) but did increase atracurium consumption when compared to clinical assessment alone. TOF monitoring may not be needed in all patients who receive neuromuscular blockade for ARDS.

Efficacy of early passive tilting in minimizing ICU-acquired weakness: A randomized controlled trial.

Purpose: To investigate whether passive tilting added to a standardized rehabilitation therapy improved strength at Intensive Care Unit (ICU) discharge. Material and methods: This single-center trial included patients admitted to an adult surgical ICU and ventilated for at least 3 days. Patients were randomized to daily standardized rehabilitation therapy alone or with tilting on a table for at least 1 h. The primary outcome was the Medical Research Council (MRC) sum score at ICU discharge. Muscular recovery was a secondary outcome. Results: Of 145 included patients, 125 received mobilization, 65 in the Tilt group and 60 in the Control group. Total mobilization duration (median [25th­75th percentiles]) in the Tilt group was 1020 [580­1695] versus 1340 [536­2775] minutes in the Control group (p = 0.313). MRC sum scores at ICU discharge were not significantly different between groups (Tilt, 50 [45­56] versus 48 [45­54]; p = 0.555). However, the number of patients with weakness was higher in the Tilt group at baseline (Tilt: 60/65 versus 48/60, p = 0.045) and muscular recovery was better in the Tilt group (p = 0.004). Conclusions: Passive tilting added to a standardized rehabilitation therapy did not improve muscle strength at ICU discharge in surgical patients even if a faster recovery with tilting is suggested.

High-Flow Nasal Cannula Therapy Versus Intermittent Noninvasive Ventilation in Obese Subjects After Cardiothoracic Surgery.

BACKGROUND: Obese patients are considered at risk of respiratory failure after cardiothoracic surgery. High-flow nasal cannula has demonstrated its non-inferiority after cardiothoracic surgery compared to noninvasive ventilation (NIV), which is the recommended treatment in obese patients. We hypothesized that NIV was superior to high-flow nasal cannula for preventing or resolving acute respiratory failure after cardiothoracic surgery in this population. METHODS: We performed a post hoc analysis of a randomized, controlled trial. Obese subjects were randomly assigned to receive NIV for at least 4 h/d (inspiratory pressure, 8 cm H2O; expiratory pressure, 4 cm H2O; FIO2 , 0.5) or high-flow nasal cannula delivered continuously (flow, 50 L/min, FIO2 0.5). RESULTS: Treatment failure (defined as re-intubation, switch to the other treatment, or premature discontinuation) occurred in 21 of 136 (15.4%, 95% CI 9.8-22.6%) subjects with NIV compared to 18 of 135 (13.3%, 95% CI 8.1-20.3%) subjects with high-flow nasal cannula (P = .62). No significant differences were found for dyspnea and comfort scores. Skin breakdown was significantly more common with NIV after 24 h (9.2%, 95% CI 5.0-16.0 vs 1.6%, 95% CI 1.0-6.0; P = .01). No significant differences were found for ICU mortality (5.9% for subjects with NIV vs 2.2% for subjects with high-flow nasal cannula, P = .22) or for any of the other secondary outcomes. CONCLUSIONS: Among obese cardiothoracic surgery subjects with or without respiratory failure, the use of continuous high-flow nasal cannula compared to intermittent NIV (8/4 cm H2O) did not result in a worse rate of treatment failure. Because high-flow nasal cannula presents some advantages, it may be used instead of NIV in obese patients after cardiothoracic surgery.