The Comparison Of Sedation Quality, Side Effects, And Recovery Profiles Of Propofol Alone, Propofol-Fentanyl And Propofol-Ketamine PCS For MAC

Dae-Woo Kim MD, Jin-Woo Choi MD, Hyun-Tak Lee MD, Se-Ho Moon MD, Keon-Hee Ryu MD

Department of Anesthesiology, College of Medicine, The Catholic University of Korea, Seoul, Korea

Background and Goal of Study:

Monitored anesthesia care (MAC) is that anesthesiologists are asked to be available on a “stand-by” basis to provide monitoring and sedation during palliative outpatients surgical procedures with local anesthesia. Propofol has been the most widely used IV adjuvant during MAC, even though it lacks analgesic properties. Fentanyl is often administered in combination with propofol to reduce pain resulting from the injection of local anesthetic solutions and traction on deeper tissue structures, however it can produce respiratory depression. Ketamine, possesses analgesic properties, may be a useful alternative to opioid adjuncts during propofol sedation and its sympathomimetic actions may be effective in counteracting the hemodynamic depression of propofol, however, the psychomimetic effects would be a limiting factor for its use in the outpatient setting. Patient-controlled sedation (PCS) with propofol has been used successfully as an adjunct to local anaesthetic procedures. It allows patients to titrate the drug dose on an individual basis, reducing the risk of over- or under-dosage, a potential disadvantage of anaesthetist-administered sedation. This study was designed to compare sedation quality, side effects, and recovery profiles of propofol alone (group P), propofol-fentanyl (group PF) and propofol-ketamine (group PK) using PCS for breast biopsy procedures using local anesthesia.

Methods:

Anxiety VAS, pain VAS and digit symbol substitution test (DSST, to assess the level of cognitive function) were measured in 45 excision breast biopsy patients with local anesthesia. The DSST score represented the number of correct symbol substitutions made in 60 s. Vital signs, respiratory (SpO2, RR, and ETCO2) variables, BIS, and OAA/S scores were recorded. Before administration of the local anaesthetic and immediately after pump connection to a peripheral i.v. cannula, instruction on the use of a commercially available PCS machine (Perfusor fm^®, B. Braun, Germany, infusion rate 1800 ml/h) was given verbally by the anesthesiologist to ensure they understood how to use the device on the day of surgery and reinforced by a written description. The patient was encouraged to make the first demand by pressing the hand-held triggering device and to make a demand in the event of any discomfort or anxiety. Patients were randomly assigned to receive 3 PCS groups: group P (1% propofol 10 ml + saline 4 ml + 2% lidocaine 1 ml); group PF (1% propofol 10 ml + fentanyl 100 μg + saline 2 ml + 2% lidocaine 1 ml ) ; group PK (1% propofol 10 ml + ketamine 50 mg + saline 3 ml + 2% lidocaine 1 ml). The pump, charged with respective group regimen, was programmed to deliver on demand a bolus dose of 1 ml with a lockout period of 1 min after each delivered dose. At the end of surgery, the total amount of regimen administered, the number of attempts at self-administration of regimen (Demand) and the number of successful attempts (Apply) as noted from the PCS display, were recorded. Perioperative side effects (e.g., pain on injection, excessive sedation [OAA/S < 4], hypoventilation [ventilatory frequency ≤ 8 bpm], desaturation [SpO2 < 90%], hypotension [systolic pressure ≤ 100 mm Hg], dizziness, unpleasant feeling, Nausea and vomitting) were also noted.

Results:

There were no differences among the three PCS groups with respect to demographic, hemodynamic, respiratory variables. A/D ratio in PK group had a significant increase over P group. The incidence of excessive sedation and dizziness were significantly more frequent in the PK group patients (P < 0.05)(Table 1). OAA/S scores were significantly decreased in the PK group during near the end of surgery, whereas BIS scores were only at the end of surgery (P < 0.05)(Figure 1). During 15 min after arrival at recovery room, significantly fewer patients in the PK group gave correct responses on the DSST than other groups (P < 0.05)(Figure 2).

Conclusions:

In contrast to past studies of ketamine as an alternative to opioid adjuncts during propofol PCS, it has no more advantage than supplemental fentanyl in terms of sedation level and side effects.

Table 1: Demographic Data, Side Effects for the Three PCS Groups

Figure 1: Changes in anxiety, pain visual analogue scale (VAS) scores, bispectral (BIS) values, observer assessment of alertness/sedation (OAA/S) scores for the three PCS groups.

B = baseline; PCS5 = 5 min after PCS start; Inc = just after incision; OP15 = 15 min after incision; Opend = the end of surgery; R0 = just after arrival at recovery room; R15 = 15 min after arrival at recovery room; R30 = 30 min after arrival at recovery room * P < 0.05, significantly different from other groups. Data are expressed as mean ± SD or mean value alone (OAA/S).

Figure 2: The number of symbols correctly drawn on the digit symbol substitution test (DSST) for the three PCS groups. * P < 0.05, significantly different from other groups. 

References

1. Badrinath S, et al. Anesth Analg 2000; 90:858-62.

2. Frey K, et al. Anesth Analg 1999; 89:317-21.