Bispectral index (BIS) monitoring of ICU patients on continuous infusion of sedatives and paralytics reduces sedative drug utilization and cost

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Purpose

To determine whether BIS-monitored titration of sedatives in ICU patients on continuous infusions of sedatives and paralytics was cost effective and reduced the incidence of the recall phenomenon.

Methods

Four consecutive months of patients in a SICU on continuous infusions of paralytics and sedatives were studied. Patients with severe brain injury (GCS ≤ 8) were excluded. In months one and two, sedatives were titrated to patient comfort guided by vital sign changes after stimulation. Months three and four titrated sedative infusions to a BIS value between 70 and 80. Paralytic agents were titrated to a train-of-four response (2/4 at 50 mA) on a protocol. Demographic data, drug usage, as well as drug cost were abstracted. On ICU discharge, patients were queried about recalling pain or fear while they were on continuous infusions of paralytics and sedatives. Data are means ± standard deviations and were compared by unpaired t-test or Χ² as appropriate; significance assumed for P<0.05.

Results

During months one and two, the cost per patient (n=31) for sedatives was $819±2.045. Patient diagnosis was 66% trauma, 22% abdominal sepsis, 9% vascular, and 5% other. The most frequently used medications and their percent contribution to total costs were morphine 58% (5.8% cost), lorazepam 54.8% (63.2% cost), midazolam 12.9% (4.2% cost), and propofol 12.9% (24.6% cost). 18% of the patients recalled a frightening or painful experience during their period of continuous sedation. During months three and four, the cost per patient (n=26) for sedatives was $669± 1.362 - an 18% reduction in cost versus months one and two (P>0.05). Only 4% of patients recalled frightening or painful events (P<0.05). Demographics were similar compared to months one and two (P>0.05). Significant reductions occurred in lorazepam (18%), midazolam (18%) and propofol (47%) usage (P<0.05). 15.4% of patients who appeared sedated were under-sedated by BIS analysis, while 54% of patients required less sedative than initially predicted by the staff.

Conclusion

Bispectral index monitoring of ICU patients on continuous infusions of paralytics and sedatives reduces sedative drug cost as well as the recall phenomenon. Significant under-sedation may occur using subjective analysis of sedation in the ICU.