Ventilator Settings Can Substantially Impact Patients' Comfort.
BACKGROUND
With increasing realization that sedatives may complicate care of mechanically ventilated patients, greater emphasis might turn to promoting comfort by titration of ventilator settings.


OBJECTIVE
Patients with acute on chronic respiratory failure (ACRF) with underlying chronic obstructive pulmonary disease (COPD) demonstrate different levels of comfort in response to varying ventilator settings compared to those with underlying obesity hypoventilation syndrome (OHS).


METHODS
Patients recovering from ACRF with underlying COPD or OHS were randomized to varying combinations of ventilator modes (assist control and pressure support), tidal volumes, and inspiratory flows for 3 minutes/setting. For each ventilator setting, physiologic variables were recorded and patients indicated their level of comfort using a 10-point Borg scale.


RESULTS
In all, 20 patients, aged 68 ± 13 years (standard deviation) and ventilated for 4.9 days, were enrolled. Of 20 patients, 13 had COPD and 7 had OHS. No ventilator mode, flow, or tidal volume provided consistently greater comfort between the groups, but patients reported substantial ranges of comfort (up to 8 Borg points) across the ventilator settings studied. There were no significant differences in heart rate, blood pressure, or airway pressures within patients across ventilator settings or between the groups, but patients with OHS were more tachypneic compared to patients with COPD while breathing on assist control of 6 mL/kg (constant flow 60 L/min) and 8 mL/kg (decelerating flow 40 L/min). There was no correlation between comfort and systolic blood pressure, heart rate, or respiratory rate.


CONCLUSIONS
Ventilator parameters may impact patients' comfort substantially. Future studies may help identify evidence-based methodology for gauging comfort following changes in ventilator settings and the settings that are most likely to positively impact various groups of patients.
Department of Medicine, Bridgeport Hospital, Yale University, Bridgeport, CT, USA.
Spyridon
S
Fortis
Department of Medicine, Bridgeport Hospital, Yale University, Bridgeport, CT, USA.
Jorge
J
Florindez
Department of Medicine, Bridgeport Hospital, Yale University, Bridgeport, CT, USA.
Shiva
S
Balasingham
Department of Medicine, Bridgeport Hospital, Yale University, Bridgeport, CT, USA.
Manuel
M
De Aguirre
Department of Medicine, Bridgeport Hospital, Yale University, Bridgeport, CT, USA.
Yaw
Y
Amoateng-Adjepong
Department of Medicine, Bridgeport Hospital, Yale University, Bridgeport, CT, USA constantinemanthous@gmail.com.
Constantine A
CA
Manthous
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D017060:Patient Satisfaction; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications; D012123:Pulmonary Ventilation / Q000502:physiology; D012121:Respiration, Artificial / Q000295:instrumentation / Q000523:psychology*; D012131:Respiratory Insufficiency / Q000209:etiology / Q000628:therapy*; D013990:Tidal Volume; D012122:Ventilators, Mechanical / Q000009:adverse effects*
anxiety; breathlessness; comfort; dyspnea; mechanical ventilation; sedation