Intravenous ketorolac and subarachnoid opioid analgesia in the management of acute postoperative pain

BACKGROUND AND OBJECTIVES

Ketorolac is a parenteral nonsteroidal anti-inflammatory drug that provides analgesia through a peripheral mechanism. The purpose of this study was to evaluate whether the scheduled administration of intravenous ketorolac improves the analgesia provided by subarachnoid opioids after surgery.

METHODS

Patients undergoing major urologic surgery were enrolled in a randomized, placebo-controlled, double-blinded study and received one of two analgesic regimens. All patients were given subarachnoid opioid analgesia consisting of morphine (range, 0.55-0.8 mg) plus fentanyl (25 micrograms) at the completion of surgery just prior to awakening. In addition to subarachnoid opioids, patients received four doses of either intravenous placebo (group 1, n = 21) or ketorolac (group 2, n = 17) administered 30 minutes before the anticipated completion of surgery and at 6, 12, and 18 hours after surgery. Patients in group 2 who were 65 years old or older received 30 mg ketorolac initially, with subsequent doses of 15 mg. Those younger than 65 years of age received 60 mg ketorolac initially, with subsequent doses of 30 mg. Pain scores were assessed by a blinded observer using a 10-cm visual analog scale (VAS) at 1, 8, and 24 hours after the operation. Intravenous morphine requirements while in the postanesthesia care unit (PACU) and during the following 24 hours, as well as the incidence of pruritus, nausea, naloxone usage, and bleeding were also recorded. Results were analyzed using the Wilcoxon rank-sum, Fischer's exact, chi-square, and Student's t tests.

RESULTS

Patients receiving intravenous ketorolac (group 2) in addition to subarachnoid opioids had significantly lower pain scores 1 hour after surgery, and required less supplementary intravenous morphine within the first 24 postoperative hours (P < .05). The percentage of patients requiring no analgesic intervention while in the PACU was significantly higher for those receiving ketorolac (P = .01). The incidence of opioid-related side effects was similar between groups, and no perioperative bleeding was observed.

CONCLUSIONS

When used in conjunction with subarachnoid opioids, the scheduled administration of intravenous ketorolac during the first 24 hours after major urologic surgery significantly enhances analgesia and reduces the need for supplemental intravenous opioids without affecting the incidence of side effects. Intravenous ketorolac is a safe and useful adjuvant to subarachnoid opioids in the management of acute postoperative pain.

Development of Desiccation Tolerance during Embryogenesis in Rice (Oryza sativa) and Wild Rice (Zizania palustris) (Dehydrin Expression, Abscisic Acid Content, and Sucrose Accumulation)

The ability of seeds to withstand desiccation develops during embryogenesis and differs considerably among species. Paddy rice (Oryza sativa L.) grains readily survive dehydration to as low as 2% water content, whereas North American wild rice (Zizania palustris var interior [Fasset] Dore) grains are not tolerant of water contents below 6% and are sensitive to drying and imbibition conditions. During embryogenesis, dehydrin proteins, abscisic acid (ABA), and saccharides are synthesized, and all have been implicated in the development of desiccation tolerance. We examined the accumulation patterns of dehydrin protein, ABA, and soluble saccharides (sucrose and oligosaccharides) of rice embryos and wild rice axes in relation to the development of desiccation tolerance during embryogenesis. Dehydrin protein was detected immunologically with an antibody raised against a conserved dehydrin amino acid sequence. Both rice and wild rice embryos accumulated a 21-kD dehydrin protein during development, and an immunologically related 38-kD protein accumulated similarly in rice. Dehydrin protein synthesis was detected before desiccation tolerance had developed in both rice embryos and wild rice axes. However, the major accumulation of dehydrin occurred after most seeds of both species had become desiccation tolerant. ABA accumulated in wild rice axes to about twice the amount present in rice embryos. There were no obvious relationships between ABA and the temporal expression patterns of dehydrin protein in either rice or wild rice. Wild rice axes accumulated about twice as much sucrose as rice embryos. Oligosaccharides were present at only about one-tenth of the maximum sucrose concentrations in both rice and wild rice. We conclude that the desiccation sensitivity displayed by wild rice grains is not due to an inability to synthesize dehydrin proteins, ABA, or soluble carbohydrates.

Hemodynamic effects of mivacurium chloride administered to patients during oxygen-sufentanil anesthesia for coronary artery bypass grafting or valve replacement

The hemodynamic effects of mivacurium chloride were studied in 54 adult cardiac patients anesthetized with midazolam and sufentanil. After baseline data were collected, a placebo (N = 9) or mivacurium was administered over 60 seconds, the latter in doses of 0.15 (N = 18), 0.20 (N = 18), or 0.25 (N = 9) mg/kg. Measurements were repeated 2, 5, and 10 minutes later. Baseline measurements were similar. A slight decrease in heart rate over time reached statistical significance in several groups including the control group. Mean arterial, mean pulmonary arterial, pulmonary arterial occlusion, and right atrial pressures and cardiac output did not change, nor did systemic and pulmonary vascular resistances and cardiac index. Besides the decrease in heart rate, the only hemodynamic change to reach statistical significance was an increase in stroke volume in patients given mivacurium 0.25 mg/kg. Significant hypotension occurred in two patients; in one, a sudden decrease in mean arterial pressure of 24% occurred 1 minute after mivacurium 0.20 mg/kg. Blood pressure was restored by ephedrine 10 mg. In the other patient, given mivacurium 0.25 mg/kg, mean arterial pressure decreased 50% from 73 to 37 mm Hg. Recovery was rapid without treatment. It is concluded that mivacurium administered in doses of 0.15 to 0.25 mg/kg over 60 seconds to cardiac patients is associated with few significant hemodynamic effects. However, a small number of patients may experience significant transient hypotension when given doses greater than of 0.15 mg/kg, two times the ED95.

Hemodynamic effects of doxacurium chloride in patients receiving oxygen sufentanil anesthesia for coronary artery bypass grafting or valve replacement

Doxacurium chloride is an investigational long-acting neuromuscular blocking drug, which has been shown to be devoid of cardiovascular side effects when administered in modest doses to healthy patients. This is the first hemodynamic study of doxacurium in adult patients with cardiac disease. Forty-one patients scheduled to undergo cardiac surgery were studied. Anesthesia consisted of induction with midazolam 0.2-0.3 mg/kg and sufentanil 0.01-0.03 mg followed by an infusion of sufentanil at 0.03-0.06 mg.min-1. Baseline hemodynamic data were collected during a stable state of sufentanil anesthesia. Doxacurium was then administered in doses of 1, 2, or 3 times its ED95 of 0.025 mg/kg. Hemodynamic measurements were repeated at 2, 5, and 10 min after doxacurium injection in the absence of surgical stimulation. An additional group of control patients received saline instead of doxacurium. Baseline hemodynamic measurements were similar among groups. There was a slight decrease in heart rate in all groups over time. However, there was no significant difference between the groups of patients receiving doxacurium and the control group in which the heart rate decreased progressively from 52 beats/min at baseline to 49 beats/min 10 min after doxacurium administration. At no time was there any significant change in mean arterial pressure, right atrial pressure, or cardiac output. Likewise derived hemodynamic variables including cardiac index, stroke volume, and pulmonary vascular resistance were unchanged. In addition to the decrease in heart rate, the hemodynamic changes, which reached statistical significance, were clinically insignificant and occurred predominantly in the group of patients receiving doxacurium 0.08 mg/kg.(ABSTRACT TRUNCATED AT 250 WORDS)