Transport of Mechanically Ventilated Patients in the Prone Position.

OBJECTIVE: We present seven cases of patients with severe respiratory failure refractory to conventional ventilation who were safely transported in the prone position. METHODS: We describe all cases of patients transported by a regional critical care network in the prone position from January 2010-June 2015. All patients were mechanically ventilated for respiratory failure and transported by specialized nonphysician critical care teams. Utilizing direct medical oversight and real-time technical support from the clinical department, each patient underwent a thorough bedside evaluation, transport ventilator trial, and transfer to a transport stretcher either with the endotracheal tube secured by an anesthesia pillow or overhanging the stretcher. RESULTS: Seven patients with acute respiratory distress syndrome were transported in the prone position. Four were female (57%), with a median weight of 78 kg (range 58-131) and median age of 53 years (range 37-78). Initial vital signs demonstrated a median oxygen saturation of 94% (range 90-97%) supported with a FiO2 of 100% for all patients with a median positive end-expiratory pressure (PEEP) of 16 (range 14-20). Seven patients were transported, six by helicopter and one transported by ground ambulance. The median transport time was 36 minutes (IQR 19, 51). There were no deaths or major incidents (tube dislodgement or line displacement) during patient transport. CONCLUSION: The transport of mechanically ventilated patients with respiratory failure in the prone position is feasible and safe, with minimal complications identified in this case series.

Incidence of re-arrest and critical events during prolonged transport of post-cardiac arrest patients.

AIM: To determine the feasibility of transporting post-cardiac arrest patients to tertiary-care facilities, the rate of re-arrest, and the rate of critical events during critical care transport team (CCTT) care. METHODS: Retrospective chart review of cardiac arrest patients transported via CCTT between 1/1/2001 and 5/31/2009. Demographic information, re-arrest, and critical events during transport were abstracted. We defined critical events as hypotension (systolic blood pressure<90mmHg), hypoxia (oxygen saturation<90%), or both hypotension and hypoxia at any time during CCTT care. Comparisons were performed using Chi-squared test and a Cox proportional hazards model was employed to determine predictors of events. RESULTS: Of the 248 patients studied, the majority was male (61%), presented in ventricular fibrillation or ventricular tachycardia (VF/VT, 50%), and comatose (80%). Re-arrest was uncommon (N=15; 6%). Critical events affected 58 patients (23%) during transport. Median transport time was 63min (IQR 51, 81) in both those who experienced a critical event and those who did not. Vasopressor use was associated with any decompensation during CCTT (Hazard Ratio 1.81; 95%CI 1.29, 2.54). Three patients (20%) suffering re-arrest survived to hospital discharge. Survival (Chi square 11.77; p<0.01) and good neurologic outcome (Chi square 5.93; p=0.01) were higher in patients who did not suffer any event during transport. CONCLUSIONS: Transport of resuscitated cardiac arrest patients to a tertiary-care facility via CCTT is feasible, and the duration of transport is not associated with re-arrest during transport. Repeat cardiac arrest occurs infrequently, while critical events are more common. Outcomes are worse in those experiencing an event.

Tonic inhibition of single nucleus accumbens neurons in the rat: a predominant but not exclusive firing pattern induced by cocaine self-administration sessions.

Inhibition of nucleus accumbens neurons is hypothesized to be a mechanism that contributes to the reinforcing (addictive) effects of cocaine and other drugs. To test this hypothesis, the activity of single nucleus accumbens neurons of rats was recorded extracellularly during cocaine self-administration sessions. Fifty-eight percent of neurons were tonically inhibited during cocaine self-administration relative to predrug baseline; thirty-one percent were tonically excited. A majority of both excited and inhibited neurons showed phasic increases in firing time-locked to self-infusion. The high percentage of tonically inhibited neurons is in line with the strong inhibitory effects of cocaine and amphetamine observed in previous anesthetized and slice recording studies; however, the prevalence of inhibition, relative to excitation, was less than might have been expected on the basis of the earlier recording studies. The present results support the hypothesis that accumbal (tonic) inhibition contributes to drug taking. However, they also suggest that changes in firing that are distinct from the tonic inhibition may additionally contribute to accumbal mediation of drug taking and drug addiction. The uniform observation of predominant inhibition among the various electrophysiology studies is consistent with the heuristic value of anesthetized and slice recording methods in identifying potential neurophysiological correlates of drug taking; however, the existence of firing patterns (e.g., phasic increases) uniquely associated with self-administration behavior (and thus absent in anesthetized and slice studies), as well as the unique presence of the primary behavior of interest in studies such as the present one, underscores the importance of conducting electrophysiological investigations of drug taking and drug addiction in the self-administering animal in parallel with anesthetized and slice studies whenever possible.

Neurons in accumbens subterritories of the rat: phasic firing time-locked within seconds of intravenous cocaine self-infusion.

Individual neurons were recorded extracellularly in the nucleus accumbens (NAcc) of rats during cocaine self-administration sessions. NAcc neurons exhibited a variety of phasic changes in firing rate within the few seconds before and/or after cocaine self-infusion. Analysis of the topographical distribution of the phasic firing patterns showed that there were no differences between NAcc subterritories in the nature of phasic changes in firing exhibited by neurons in relation to cocaine self-infusion. However, the prevalence of phasic firing was lower in the border regions of the caudal shell and within the caudal shell itself relative to the remainder of the NAcc.