Sleep in Critically III Chemically Paralyzed Patients Requiring Mechanical Ventilation: Discussion
Nine patients had temperatures > 38.5°C, and five patients had temperatures < 36.8°C. When temperature was compared to sleep stage, again there was no correlation. It was noted that three of five patients with temperatures < 36.8°C had the lowest amount of mDelta activity. Too few patients had renal insufficiency and/or hyperbilirubinemia to perform an analysis on their effect on sleep architecture. There was no association between ventilator mode and arousals (p = 0.96) or awakenings (p = 0.78). PS and IMV/PS mode were combined, as only two patients received PS ventilation alone. Volume control/SIMV was analyzed independently and combined with pressure control/IMV. read
Sleep Architecture and Correlation of Drug Dosage: Although not statistically different than the NMBA/CS group, the CS group had the largest amount of mDelta activity (49.6% vs 43%) and also the highest amount of benzodiazepine (58 mg vs 52 mg) [Table 2, 3]. The CS group had significantly more morphine (39.8 mg vs 12.8 mg) than the CS/NMBA group. Although there was a significant difference in the amount of narcotics and benzodiazepines between the IS and CS groups and the IS and CS/NMBA groups (Table 2), there was no statistically significant correlation between drug dosage and any stage of sleep. Two of the three patients in the CS group, with > 80% mDelta, received the largest doses of lorazepam per body weight of any group.
This is the first study to our knowledge to prospectively compare various groups of critically ill patients requiring mechanical ventilation based on medication regimen. This is one of the largest studies investigating sleep in severely ill patients in the ICU and adds new information in a novel group of patients: those receiving chemical paralysis. As noted in previous studies” in patients requiring mechanical ventilation, all of our patients displayed abnormal sleep/wake cycles with erratic progression through the sleep stages. No patient demonstrated normal 90- to 120-min sleep cycles with progressive increases in REM duration. Overall TST was not reduced in any group and was increased in those patients receiving CS, as anticipated.
Category: Respiratory Symptoms
Tags: ICU, mechanical ventilation, polysomnography, sleep