Wittwer, Erica D

Abstract Rationale Mechanically ventilated intensive care unit patients receive sedatives based on clinician observations of arousal and motor activity with potential for negative consequences and poor mitigation of symptoms. Objectives To test the preliminary efficacy of patient self-managed sedative therapy compared to usual care of nurse-administered sedation on self-reported anxiety, duration of mechanical ventilation, and delirium incidence (CAM-ICU). Methods A two-group, open-label, randomized, multicenter clinical trial in 5 Midwestern hospitals enrolled 161 patients receiving invasive mechanical ventilation who were willing and able to use a push-button device to self-administer sedation for up to 7 days. Patients were randomized 1:1 using center-stratified blocks to usual care (n = 81) or intervention (n = 80) with self-administered dexmedetomidine. Intervention patients were allowed 3 self-administered dexmedetomidine boluses per hour (0.25 mcg/kg) with 20-minute lock-outs. The initial basal infusion (0.2 mcg/kg/hr) was adjusted by nurses between 0.1-0.7 mcg/kg/hr based on patient-delivered boluses in the prior 2 hours. Analysis consisted of linear mixed-effects model for comparisons of anxiety ratings over time and duration of mechanical ventilation. Incidence of delirium was analyzed using generalized estimating equations. Measurement and Main Results Sample characteristics had a female (54.7%) and Caucasian preponderance (92.5%) with a median age of 62 years on protocol for a median of 88 hours. Nine intervention patients were extubated prior to protocol initiation. Patient self-reported three times daily anxiety ratings with a visual analog scale (VAS) ranged from 0-100 over time but were not significantly different between groups in either an intention-to-treat (ITT) or per protocol (PP) analysis (p = 0.94, p = 0.30 respectively). While intervention patients had shorter duration of MV [(mean 50.8(52.8) vs. usual care 68.7(58.2) hours), p = 0.02 ITT], PP analysis resulted in no difference between groups (mean 56.4 (53.0) vs. 68.7(58.2), p = 0.23). 10.2% of intervention patients developed new incidence of delirium vs. 8.5% of usual care which was not significantly different between groups by either ITT (p = 0.65) or PP analyses (p = 0.58). Conclusions Intervention patients had similar outcomes compared to usual care patients. Self-administration of sedative therapy is a safe, novel patient-centered intervention warranting further rigorous investigation for anxiety self-management.

A 40 year old woman who underwent combined heart-lung transplant for familial severe pulmonary hypertension experienced episodes of nonsustained ventricular tachycardia followed by sudden ventricular fibrillation arrest 8 days after transplant. Postarrest investigations revealed left lower lobe herniation into the right lower hemithorax, prompting emergent reoperation, and hernia reduction. Arrhythmias resolved following reduction of the herniated lung and facilitated rapid weaning from vasopressor and ventilatory support. To our knowledge, this is the first reported case of cardiac arrest due to lung herniation after combined heart-lung transplantation. Herein, we describe this rare presentation and offer insights and management strategies for the cardiac intensivist.