THE USE OF DEXMEDETOMIDINE FOR POSTOPERATIVE SEDATION IN CARDIAC ICU

Abstract

Objective: This study was designed to evaluate the efficacy of dexmedetomidine as a sedative
agent in cardiac surgical ICU and its benefits in regard to opioid requirements, nausea and
vomiting, time of mechanical ventilation, length of ICU stay and hospital stay. Method:105
patients undergoing coronary artery bypass grafting or valve surgery were enrolled in this study,
between June 2009 and December 2010.
Patients were divided in to two groups; group 1, control group (56 patients), received a normal
saline infusion during surgery and post operative period and group2,dexmedetomidine group(49
patients), received an initial dose of 0.1 microg/kg for 10 min, followed by maintenance dose of
0.4 to 0.7 microg/kg/h of dexmedetomidine hydrochloride. All patients were observed in the ICU
for pain and sedation scores, analgesic requirements, intubating time, agitation, nausea /vomiting,
and length of stay.
Results: Both groups were similar for patient demographics, ASA physical status, surgical
procedure, and intraoperative use of drugs and fluids.
Total morphine requirements were much less in Dex group (10.28mg/patient) than control group
(53.65mg/patient) to achieve the same level of analgesia.
The Dex. group had more favorable average sedation score on the Ramsay Sedation Scale in
comparison with the control group (2.51 out of 6 vs. 2.32 out of 6) with a statistically significant
result (p-value=0.002). The Dex. Group achieved less pain score (3.18 out of 10 for the Dex
group vs. 3.71 out of 10 for the control group).The reduction in average pain in patients receiving
dexmedetomidine infusion was statistically significant (p-value=0.024).The Dex. Group had
earlier tracheal extubation. The average time of mechanical ventilation in the Dex group was 7.9
hours ±2.06 hours (mean ± S.D.), compared to 13.54 hours ± 5.58 hours (mean± S.D.) in the
control group (p-value <0.0001). The mean length of ICU stay in the Dex. Cohort was 21.67
hours ± 4 hours (mean ± S.D.), while it was 31.52 hours ± 20.28 hours (mean ± S.D.) in the
control group. The difference between the two treatment groups in mean length of ICU stay was
statistically highly significant (p=0.001). Lower incidence of nausea and vomiting was observed
in the Dex. Cohort of patients (14.2 % vs. 26.7% in the control group), but the reduction in
nausea and vomiting was statistically not significant (p-value=0.116).
Conclusion: Dexmedetomidine hydrochloride is effective and promising agent for sedation in
cardiac ICU as it reduces the opioid requirements, shortens time of mechanical ventilation,
decreases length of ICU stay and hospital stay. It decreases use of sedatives and narcotics,
thereby further improving respiratory safety and decreasing postoperative nausea and vomiting.
Key words: Dexmedetomidine, sedation, analgesia, mechanical ventilation, cardiac surgery