Ventilatory response to CO2 following intravenous ketamine in children

Anesthesiology. 1989 Mar;70(3):422-5. doi: 10.1097/00000542-198903000-00010.


The effects of intravenous ketamine (bolus of 2 followed by a continuous infusion at a rate of 40 on ventilatory response to carbon dioxide were studied in nine children ranging in age from 6 to 10 yr and in weight from 20 to 48 kg. Ketamine did not affect resting respiratory rate, tidal volume, end-tidal CO2 tension (PETCO2), or minute ventilation. Five minutes after the ketamine bolus, the slope VE/PETCO2 decreased significantly (P less than 0.05) from 1.71 +/- 0.47 to 1.05 +/- 0.23 1.min-1.mmHg-1 (mean +/- SD). After 30 min of continuous iv ketamine infusion, the slope returned to 1.65 +/- 0.44 1.min-1.mmHg-1, a significantly higher value (P less than 0.05) compared with the nadir and not significantly different from control. The minute ventilation at a PETCO2 of 60 mmHg decreased from 824 +/- 98 to 626 +/- 26 5 min after iv ketamine, and remained depressed (640 +/- 125 P less than 0.05) throughout the 30-min ketamine infusion. In addition, the slope VT/PETCO2 and the VT 60 did not change during the study; nonetheless, the slope f/PETCO2 and the f 60 decreased significantly following iv bolus ketamine, and the f 60 remained significantly decreased following ketamine infusion. The authors conclude that clinically useful doses of iv ketamine significantly alter ventilatory control in children.

MeSH terms

  • Analysis of Variance
  • Anesthesia, Intravenous* / methods
  • Carbon Dioxide / physiology*
  • Child
  • Depression, Chemical
  • Drug Evaluation
  • Humans
  • Ketamine* / administration & dosage
  • Ketamine* / adverse effects
  • Respiration / drug effects*
  • Respiratory Function Tests


  • Carbon Dioxide
  • Ketamine