Respiratory Care
Bethlehem Markos
Low-tidal volume ventilation
Respir CMechanical ventilation in postoperative (post-op) patients is essential in care because it can determine the patient’s overall outcome, especially in post-op cardiovascular surgery patients. The risks of hemodynamic instability and consideration of total body organ function make choosing the correct strategy of mechanical ventilation vital (Ball, et al. Crit Care. 2016;22[4]:386). The current standard of practice for mechanically ventilated patients is to use low-tidal volume (LTV) ventilation, meaning administering 6-7 mL/kg of ideal body weight (Hoegl, et al. Anesthesiology. 2016;29[4]:94). The benefits of LTV ventilation include significantly decreased risk in lung injury, decreased risk of developing ARDS, and lessening of hemodynamic compromise (Hoegl, et al. 2016); (Stephens, et al. Crit Care Med. 2015;43:1477). Also, due to its high efficacy in terms of cost-effective care, such as shorter ICU stays and less number of days supported by mechanical ventilation, many hospitals have incorporated LTV strategy into the care of almost all post-op patients (Stephens, et al. 2015). However, no randomized controlled trials have been conducted in post-op cardiovascular patients undergoing mechanical ventilation to determine if LTV ventilation (6-7 mL/kg) has superior efficacy over higher levels of ventilation (8-10 mL/kg). This patient population tends to have normal lung function and, therefore, a LTV strategy could possibly be too conservative, whereas larger tidal volumes may be more comfortable and provide better ventilation considering the increased dead space in post-op cardiovascular patients. In order to address this gap in the literature, it is essential to determine if significant differences exist in patient mortality, ventilator days, hospital stay, and incidence of pulmonary complications for this population undergoing ventilation volumes of approximately 6 mL/kg or 8 mL/kg of ideal body weight.
Bethlehem Markos
Fellow-in-Training
Sleep Medicine
In case you missed it: Recent findings in obstructive sleep apnea
Lauren Tobias
On behalf of the Sleep Medicine NetWork, I would like to highlight a few key articles related to OSA:
A potential drug combo to treat OSA (Taranto-Montemurro, et al. Am J Respir Crit Care Med. Articles in Press. Published on 05-November-2018 as 10.1164/rccm.201808-1493OC) The apnea-hypopnea index (AHI) decreased by over 20 events/hour in a small group of patients receiving atomoxetine and oxybutynin, presumably via increased activity of the upper airway dilator muscles.
CPAP may reduce hospitalizations (Truong, et al. J Clin Sleep Med. 2018;14[2]:183) Patients nonadherent to CPAP had greater all-cause 30-day readmission rates over an 8-year period after adjusting for comorbidities, suggesting the potential of CPAP to prevent recurrent hospitalizations.
Patients getting in-lab sleep testing are increasingly complex (Colaco, et al. J Clin Sleep Med. 2018;14[4]:631) Patients undergoing PSG as opposed to home testing have more medical comorbidities than in the past, with implications for how labs are staffed and what monitoring is available.
OSA severity predicts amyloid burden (Sharma. Am J Respir Crit Care Med. 2018;197[7]:933) This study highlights a potential pathway in which OSA impacts amyloid deposition and, thereby, vulnerability to developing Alzheimer disease.
A drug for residual sleepiness in OSA (Schweitzer, et al. Am J Respir Crit Care Med Articles in Press. Published on 06-December-2018 as 10.1164/rccm.201806-1100OC) For patients with OSA whose sleepiness persisted despite PAP adherence, this 12-week randomized trial showed dose-dependent improvements in wakefulness with use of solriamfetol, a dopamine/norepinephrine reuptake inhibitor.
Lauren Tobias, MD
Steering Committee Member