Propofol-ketamine combination: a choice with less complications and better hemodynamic stability compared to propofol? On a prospective study in a group of colonoscopy patients

Ir J Med Sci. 2016 Aug;185(3):699-704. doi: 10.1007/s11845-015-1348-8. Epub 2015 Sep 2.


Background and aims: In this study, we compared duration for reaching desired Ramsay Sedation Score (RSS) and postoperative recovery according to Modified Aldrete Score (MAS) of propofol and propofol-ketamine combination in a group of colonoscopy patients. Rates of cardiovascular, respiratory, laryngospasm, visual and nausea/vomiting complications were also compared as secondary outcomes.

Methods: This is a double-blinded prospective randomized controlled trial. 95 patients were included and blocked randomized to either propofol (GroupP, n: 47) or propofol-ketamine (GroupPK, n: 48). GroupP patients received 0.5 mg/kg propofol and GroupPK received 0.5 mg/kg ketamine-propofol. Subjects were monitorized noninvasively preoperatively and every 5 min during procedure. RSS was recorded for every minute before starting procedure and for every 5 min during procedure. Recovery after colonoscopy was evaluated according to MAS. Same observer checked for MAS just after procedure in postoperative 1 min and for every 3 min during follow-up. Postoperative respiratory depression was defined as rate <10/min, hypercapnia/hypercarbia-arterial CO2 tension >50 mmHg or SO2 <90 while hypotension was defined as a decrease of 20 % in mean blood pressure compared to initial values.

Results: GroupPK patients needed shorter duration for achieving RSS ≥ 4 (p: 0.038) but longer duration for achieving MAS ≥ 9 (p: 0.005). GroupP's intraoperative blood pressures and heart rates were significantly lower compared to initial values. We observed that respiratory depression (19.1 vs 0 %, p: 0.001), hypotension (29.8 vs 10.4 %, p: 0.018), and nausea/vomiting (17 vs 4.2 %, p: 0.041) were significantly more common in GroupP.

Conclusion: Propofol-ketamine combination is an advantageous choice in means of achieving sedation in a shorter period of time, a better hemodynamic stability, less nausea and vomiting and respiratory complication rates. Yet it seems that this choice might be related with longer recovery duration.

Keywords: Colonoscopy; Ketamine; Propofol; Sedation.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Anesthetics, Combined
  • Colonoscopy / methods*
  • Double-Blind Method
  • Female
  • Heart Rate / drug effects
  • Humans
  • Hypertension / chemically induced
  • Hypnotics and Sedatives*
  • Hypotension / chemically induced
  • Ketamine*
  • Male
  • Middle Aged
  • Monitoring, Physiologic
  • Postoperative Nausea and Vomiting / chemically induced
  • Propofol*
  • Prospective Studies
  • Respiratory Insufficiency / chemically induced


  • Anesthetics, Combined
  • Hypnotics and Sedatives
  • Ketamine
  • Propofol