Anesthesia and analgesia
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Anesthesia and analgesia · Apr 2000
The accuracy and precision of body temperature monitoring methods during regional and general anesthesia.
We tested the hypotheses that accuracy and precision of available temperature monitoring methods are different between spinal anesthesia (SA) and general anesthesia (GA), and that patients receiving SA are at equal risk for hypothermia as those receiving GA. Patients scheduled for radical retropubic prostatectomy were enrolled. Either GA (n = 16) or SA (n = 16) was given according to patient and clinician preference. Temperatures were monitored with thermocouple probes at the tympanic membrane, axilla, rectum, and forehead skin surface. Tympanic temperatures were also measured with an infrared device, and forehead skin temperatures were monitored with two brands of liquid crystal thermometer strips. Accuracy and precision of these monitoring methods were determined by using tympanic membrane temperature, measured by thermocouple, as the reference core temperature (T(c)). At the end of surgery, T(c) was similar between SA (35.0 +/- 0.1 degrees C) and GA (35.2 +/- 0.1 degrees C) (P = 0.44). Accuracy and precision of each temperature monitoring method were similar between SA and GA. Rectal temperature monitoring offered the greatest combination of accuracy and precision. All other methods underestimated T(c). These findings suggest that patients receiving SA or GA are at equal and significant risk for hypothermia, and should have their temperatures carefully monitored, recognizing that most monitoring methods underestimate T(c). ⋯ Body temperature should be monitored during spinal anesthesia because patients are at significant risk for hypothermia. Rectal temperature is a valid method of measuring core temperature, whereas other methods tend to underestimate true core temperature.
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Anesthesia and analgesia · Apr 2000
The effect of In vitro hemodilution with gelatin, dextran, hydroxyethyl starch, or Ringer's solution on Thrombelastograph.
To determine the effects of progressive in vitro hemodilution with various plasma substitutes on whole blood coagulation, blood was obtained from six healthy volunteers. The Thrombelastograph((R)) (TEG; Haemoscope Corp., Morton Grove, IL) variables of reaction time, coagulation time, maximum amplitude, and growth angle were determined. The following plasma substitutes were tested: two gelatin solutions (4% gelatin polysuccinate and 5.5% oxypolygelatin); two dextrans (10% dextran 40 and 6% dextran 60); and five hydroxyethyl starch (HES) preparations (6% HES 70/0.5-0.55, 3% HES 200/0.5, 6% HES 200/0.5, 10% HES 200/0.5, and 6% HES 450/0.7). Ringer's solution was also tested to assist analyzing the intrinsic effect of colloid molecules on blood coagulation. The dilution ratios of citrated blood volume to plasma substitute volume were 10:2, 10:4, and 10:10. Blood coagulation was affected by plasma substitutes when the dilution ratios of citrated blood volume to colloid solution volume were 10:4 and 10:10. TEG variables did not change significantly after in vitro hemodilution with lactated Ringer's solution. The tested gelatin solutions showed less intrinsic effect on blood coagulation than other plasma substitutes. All HES preparations showed similar intrinsic effects as 6% dextran 60. The plasma substitute of 10% dextran 40 had the strongest effect on coagulation. Coagulation time was the most markedly affected TEG variable. Blood coagulation may be compromised when the dilution ratio of blood volume to colloid solution volume is >10:4. Whereas gelatin solutions have less intrinsic effect on blood coagulation, 10% dextran 40 has the strongest effect on coagulation. ⋯ Blood coagulation may be compromised when the dilution ratio of blood volume to colloid solution volume is >10:4. Whereas gelatin solutions have less intrinsic effect on blood coagulation than hydroxyethyl starch or dextran, 10% dextran 40 has the strongest effect on coagulation.
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Anesthesia and analgesia · Apr 2000
Meta AnalysisLocal anesthetic infiltration for postoperative pain relief after laparoscopy: a qualitative and quantitative systematic review of intraperitoneal, port-site infiltration and mesosalpinx block.
In a systematic review, we evaluated randomized controlled trials (RCTs) of peripheral local anesthetics (LA) compared with placebo or no treatment in the control of postoperative pain after laparoscopic surgery. A total of 41 trials with data from 2794 patients were considered appropriate for analysis. Of these 41 RCTs, 13 evaluated intraperitoneal LA after cholecystectomy, four RCTs assessed intraperitoneal LA after other procedures, eight RCTs evaluated port-site infiltration after various procedures, 12 RCTs evaluated mesosalpinx or fallopian tube block after sterilization, and four RCTs considered combined LA regimens. Outcome measures were pain scores, analgesic consumption, and time to first analgesic request. Efficacy was estimated by significant difference (P < 0.05), as reported in the original reports, and by calculation of the weighted mean difference of visual analog scale pain scores between treatment groups. Improved pain relief was observed in seven of the 13 RCTs of intraperitoneal LA after cholecystectomy and in four RCTs of other procedures. A statistically significant weighted mean difference of -13 mm visual analog scale (95% confidence intervals [CI]: -20 to -6) in favor of the treatment groups was observed after cholecystectomy. Three of eight trials of port-site infiltration showed significant differences but questionable clinical importance and validity in two; weighted mean difference was not statistically significant between treatment groups (95% CI -9 to 1). All RCTs of mesosalpinx or fallopian tube block after sterilization showed improved pain relief with a statistically significant weighted mean difference of -19 mm (95% CI -25 to -14) in favor of treatment groups. Data of combined regimens were positive, however, sparse. We conclude that there was evidence for a statistically significant but clinically questionable, important effect of intraperitoneal LA for postoperative pain control. There was evidence for a significant but short-lasting effect of mesosalpinx/fallopian tube block after sterilization, but there was a lack of evidence for any important effect of port-site infiltration. Data from combined regimens were too sparse for conclusions. ⋯ A systematic review summarizes, through transparent methodology, available information from randomized, controlled trials to produce the best available evidence-based estimate of a "true" clinical effect of an intervention. This systematic review confirms intraperitoneal and mesosalpinx local anesthetic block, not port-site infiltration, to have some impact on postoperative pain after laparoscopy.
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Anesthesia and analgesia · Apr 2000
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of intrathecal analgesia with fentanyl or sufentanil after total hip replacement.
We designed this study to compare the postoperative analgesic effects of intrathecal fentanyl and sufentanil, the end points being onset, quality, and duration of action. A total of 42 geriatric patients, scheduled for elective total hip replacement under continuous spinal anesthesia, were randomized in two double-blinded groups as soon as they experienced a pain score higher than 3 of 10 on the visual analog scale in the recovery room. Either 7.5 microg sufentanil or 40 microg fentanyl in 2 mL normal saline were intrathecally administered. Pain scores, rescue analgesia (ketorolac and morphine), and adverse effects (respiratory depression, postoperative nausea and vomiting, and itching) were recorded for 24 h after surgery. In both groups, comparing sufentanil to fentanyl, the time to a pain score <3 (9 +/- 9 vs 11 +/- 8 min), the time to the lowest pain score (18 +/- 6 vs 20 +/- 15 min), and the time to the first systemic analgesic intervention for a pain score >3 (241 +/- 102 vs 214 +/- 120 min) were comparable as were the analgesic requirements during the first 24 h. We conclude that, after total hip replacement, both lipid soluble opioids produce excellent analgesia with comparable onset, duration of action, and low incidence of minor adverse effects. ⋯ We compared the postoperative analgesic properties of 40 microg intrathecal fentanyl and 7.5 microg sufentanil after total hip replacement. Both opioids provided satisfactory analgesia, with comparable onset (11 +/- 8 vs 9 +/- 9 min) and duration of action (214 +/- 120 vs 241 +/- 102 min), as well as low incidence of minor side effects.
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Anesthesia and analgesia · Apr 2000
Randomized Controlled Trial Clinical TrialThe use of a ketamine-propofol combination during monitored anesthesia care.
Supplemental analgesics are commonly used to enhance analgesia and improve patient comfort during procedures performed under local anesthesia and sedation. Because the use of ketamine as an analgesic adjunct to propofol sedation has not been well established, we evaluated its impact on analgesia, sedation, and recovery after ambulatory surgery. One hundred female outpatients undergoing breast biopsy procedures under local anesthesia participated in this randomized, double-blinded, placebo-controlled study. After premedication with midazolam, 2 mg IV, patients received an infusion of a solution containing propofol (9.4 mg/mL) in combination with either placebo (saline) (Group 1) or ketamine, 0.94 mg/mL (Group 2), 1.88 mg/mL (Group 3), or 2.83 mg/mL (Group 4). The sedative infusion rate was varied to maintain a deep level of sedation (Observer Assessment of Alertness/Sedation score 4) and normal respiratory and hemodynamic functions. Sufentanil, 2.5 microg IV, "rescue" boluses were used as needed to treat patients' responses (if any) to local anesthetic infiltration or surgical stimulation. Ketamine produced a dose-dependent reduction in the "rescue" opioid requirements. However, there was an increase in postoperative nausea and vomiting, psychomimetic side effects, and delay in discharge times with the largest ketamine dosage (Group 4). The adjunctive use of ketamine during propofol sedation provides significant analgesia and minimizes the need for supplemental opioids. The combination of propofol (9.4 mg/mL)/ketamine (0.94-1.88 mg/mL) provides effective sedation/analgesia during monitored anesthesia care. ⋯ Ketamine, when used in subhypnotic dosages, may be an useful adjuvant to propofol sedation.