Author: Nancy Shaw
Patients receiving continuous infusion of ketamine in the intensive care unit (ICU) show significant improvement in the amount of time spent in goal ranges of pain and sedation, without increases in delirium, according to a study presented here at the 2020 Annual Meeting of the Society of Critical Care Medicine (SCCM).
“The use of continuous-infusion ketamine increases time spent in goal pain and sedation score range with no effect on incidence of delirium,” stated Christine M. Groth, Strong Memorial Hospital, University of Rochester, Rochester, New York, and colleagues.
Ketamine, a noncompetitive antagonist of N-methyl-d-aspartate receptor, has analgesic and antihyperalgesic properties and is considered beneficial as an additive sedative drug in the ICU, particularly in light of concerns with alternative drugs, eg, delirium induced by benzodiazepine and opioid tolerance.
For the multicentre study, the researchers enrolled 390 adult ICU patients at 25 institutions around the United States who were treated with ketamine continuous infusion between January 2014 and December 2017.
The patients’ pain, sedation, and delirium screenings were obtained 24 hours before the ketamine infusion and compared with the corresponding scores in the first 24 hours and hours 25 to 48 of ketamine administration.
In the 24 hours before ketamine infusion, pain scores were recorded for 285 (85%) of the patients. Scores for 293 patients (87%) in the first 24 hours and 178 patients (90%) in the 25- to 48-hour period were also recorded. The pain scores were measured a median of 10 (5-18), 11 (6-20), and 12 (6-20) times (P = .08), respectively.
The measures showed a significant increase in the median amount of time spent in the goal pain range, from 68.9% in the 24 hours before ketamine infusion to 78.6% in the goal pain range the first 24 hours of the infusion and 80.3% during 25 to 48 hours (P< .001).
Sedation scores, recorded a median of 7 to 9 times over the course of the designated study period, likewise increased, from a median of 57.1% spent in the goal sedation score range in the 24 hours before ketamine initiation to 64.1% in the first 24 hours and 68.9% in the 25- to 48-hour period (P< .001).
Of the ~44% of patients who could be screened for delirium, no significant differences were seen between median time spent delirious in the 24 hours before ketamine infusion and the first 24 hours or 24 to 48 hours after infusion (P = .23).
The patients had a mean age of 52 years, and 61% were men. Their median APACHE II score was 21 (range, 14-27).