Ketamine and oxycodone in the management of postoperative pain

Military Medicine, Jun 2000 by Levanen, Jaakko

Effects on Hemodynamics

Throughout the recovery room period, the mean systolic and diastolic blood pressures remained at higher levels in the ketamine group than in the oxycodone group (p

The mean systolic pressure in the ketamine group was 128.6 mm Hg at baseline (range, 101-163 mm Hg) and 135.7 mm Hg at 180 minutes (range, 109-183 mm Hg); in the oxycodone group, the values were 129.5 mm Hg at baseline (range, 118-- 145 mm Hg) and 126.5 mm Hg at 180 minutes (range, 105-155 mm Hg). In the ketamine group, the mean diastolic pressure was 65.8 mm Hg at baseline (range, 51-81 mm Hg) and 69.9 mm Hg at 180 minutes (range, 57-92 mm Hg); in the oxycodone group, the values were 68.0 mm Hg at baseline (range, 54-76 mm Hg) and 64.9 mm Hg at 180 minutes (range, 51-84 mm Hg).

The mean pulse rate was constantly higher in the ketamine group (range, 49-118 beats/min; mean at baseline, 63 beats/ min; mean at 180 minutes, 75 beats/min) than in the oxycodone group (range, 40-113 beats/min; mean at baseline, 60 beats/min; mean at 180 minutes, 65 beats/min) (Fig. 4). Nevertheless, the differences were not statistically significant.

Also, the pooled mean pulse pressure (systolic minus diastolic pressure) was constantly higher in the ketamine group (mean, 64.3 mm Hg; range, 61.4-68.7 mm Hg; baseline, 62.8 mm Hg; range, 50-87 mm Hg) than in the oxycodone group (mean, 60.5 mm Hg; range, 58.4-67.2 mm Hg; baseline, 61.4 mm Hg; range, 49-70 mm Hg). The difference was statistically significant (p

Effects on Respiration

Oxygen Saturation

During the recovery room period, the mean oxygen saturation was 97.46% (range, 94.0-99.0%) in the ketamine group and 96.72% (range, 92.0-99.0%) in the oxycodone group (Fig. 5). None of the patients in either group required supplementary oxygen.

Respiratory Rate

The mean respiratory rate was higher in the ketamine group than in the oxycodone group throughout the recovery room period. The respiratory rate varied between 14 /- 2.3 and 16 /-- 2.6 breaths/min (range, 10-22 breaths/min) in the ketamine group and between 13 /- 1.8 and 15 /- 3.3 breaths/min (range, 8-18 breaths/min) in the oxycodone group (Fig. 5).

Sedation, Anxiety, and Awareness

At the end of the recovery room period (180 minutes), the patients in the oxycodone group were more sedated than the patients in the ketamine group (Table III). The mean VAS scores were 6.8 vs. 5.1, respectively (p

Side Effects and Patient Acceptance

Nausea occurred in three patients (15%) in the ketamine group, although it was not associated with the drug, and in two patients (10%) in the oxycodone group. One severe case of vomiting, not associated with the analgesic used, and two cases of itching (10%), one mild and one severe, occurred in the oxycodone group. In the patients with nausea and vomiting not attributable to the drugs, the causes were swallowing of blood and postoperative pharyngeal irritation. Pruritus was reported by two patients in the oxycodone group.

Mild central nervous system side effects were registered in 12 patients (60%) in the ketamine group. Unreal dreams were experienced by 3 patients (15%), two mild and one severe, as were hallucinations (all moderate). Two patients had nightmares (one mild, one moderate), and 4 patients were slightly confused or agitated. Only 1 patient in the oxycodone group was slightly agitated.