Anesthesia and analgesia
-
Anesthesia and analgesia · Nov 1998
Randomized Controlled Trial Comparative Study Clinical TrialThe effect of location of transcutaneous electrical nerve stimulation on postoperative opioid analgesic requirement: acupoint versus nonacupoint stimulation.
Transcutaneous electrical nerve stimulation (TENS) has been used as a complementary (supplemental) therapy to opioid analgesics for pain relief after surgery. Simultaneous stimulation at a classical Chinese acupoint site and periincisional dermatomes significantly decreases the postoperative analgesic requirement. This sham-controlled study was designed to assess the relative effectiveness of acupoint versus nonacupoint stimulation on the postoperative hydromorphone (HM) requirement, the incidence of opioid-related side effects, and the overall recovery profile. One hundred women undergoing total abdominal hysterectomy or myomectomy procedures with a standardized general anesthesia were randomly assigned to one of four postoperative analgesic treatment regimens (n = 25 each): Group I = sham-TENS (no electrical current) at the Zusanli (ST36) acupoints, Group II = nonacupoint-TENS at the shoulders, Group III = dermatomal-TENS at the level of the surgical incision, and Group IV = acupoint-TENS at the Zusanli acupoints. The frequency of TENS was set in the standard dense-and-disperse mode of 2/100 Hz. The intensity of stimulation was set at 0 mA for patients in Group I and at 9-12 mA for patients in Groups II, III, and IV. A patient-controlled analgesia (PCA) device programmed to deliver bolus doses of HM 0.2-0.4 mg IV on demand with a minimal lockout interval of 10 min was used to quantify the postoperative opioid analgesic requirement. Standard 100-mm visual analog scales were used to assess pain, as well as sedation, fatigue, and nausea, at specific intervals after surgery. The numbers of PCA demands and delivered bolus doses, requirements for supplemental medication, and any opioid-related side effects were recorded. In the first 24 h postoperatively, the opioid requirements in Groups III and IV were decreased by 37% and 39%, respectively, compared with the control (sham) group and 35% and 38%, respectively, compared with Group II. The duration of PCA usage and the incidences of nausea and dizziness were also significantly decreased in Groups III and IV compared with Groups I and II. We conclude that periincisional dermatomal and Zusanli acupoint stimulation were equally effective in decreasing the postoperative opioid analgesic requirement and in reducing opioid-related side effects. Both of these positions were more effective than the nonacupoint (shoulder) location. ⋯ The location of the stimulating electrodes seems to be an important determinant of the efficacy of transcutaneous electrical nerve stimulation in decreasing the need for opioid analgesics in the postoperative period. This study demonstrates that transcutaneous electrical nerve stimulation applied at the dermatomal level of the skin incision is as effective as Zusanli acupoint stimulation, and both were more effective than stimulation at a nonacupoint (shoulder) location.
-
Anesthesia and analgesia · Nov 1998
Randomized Controlled Trial Clinical TrialPreoperative dextromethorphan reduces intraoperative but not postoperative morphine requirements after laparotomy.
N-methyl-D-aspartate (NMDA) antagonists combined with opioids are thought to be effective in the control of pain states. We evaluated morphine use and analgesia in 37 patients postlaparotomy. Patients received 60 mg of oral dextromethorphan or placebo the night before and again 1 h before surgery. Morphine was titrated intraoperatively to maintain blood pressure and heart rate within 20% of baseline and postoperatively via patient-controlled analgesia (PCA). The dextromethorphan and placebo groups were compared for morphine use intraoperatively, in recovery, via PCA in the first 4 and 24 h, and total use over the study period. Pain scores at rest and on activity for the first 4 and 24 h were also compared. Intraoperatively, the dextromethorphan group required less morphine: 13.1+/-4.3 vs 17.6+/-6.0 mg (P = 0.012). Postoperatively, there was no significant difference between the dextromethorphan and placebo groups for morphine use: in the recovery room 10.9+/-7.7 vs 12.1+/-7.7 mg; the first 4 h of PCA 15.9+/-9.3 vs 12.7+/-5.1 mg; the first 24 h of PCA 76.4+/-44.7 vs 61.8+/-27.5 mg; or in total morphine use 100.4+/-49.5 vs 91.5+/-3.1 mg. Pain scores for the two groups were not statistically different throughout the study period. We conclude that 60 mg of oral dextromethorphan given the night before and repeated an hour before surgery does not provide a postoperative morphine-sparing effect or improve analgesia after laparotomy. ⋯ Patients given dextromethorphan before surgery had significantly reduced intraoperative morphine requirements. However, postoperative morphine requirements were unaltered. Dextromethorphan may need to be continued postoperatively to improve postoperative analgesia.
-
Anesthesia and analgesia · Nov 1998
Randomized Controlled Trial Clinical TrialThe effects of propofol, isoflurane, and sevoflurane on oxygenation and shunt fraction during one-lung ventilation.
Propofol's effect on hypoxic pulmonary vasoconstriction during one-lung ventilation (OLV) has not been determined. Twenty patients who had long-term OLV for esophageal surgery were allocated randomly to one of two study groups; one in which isoflurane administration preceded propofol, and another in which sevoflurane administration preceded propofol. Arterial and mixed venous blood samples and hemodynamics were measured as follows: before OLV, during OLV, OLV at 4 cm of positive end-expiratory pressure (PEEP), OLV after conversion from volatile anesthetics to propofol, OLV at 4 cm of PEEP, and after OLV. After the application of 4 cm of PEEP during propofol anesthesia, PaO2 increased significantly in both groups. The shunt fraction (Qs/Qt) increased significantly after the initiation of OLV in both groups and decreased significantly after the conversion from volatile anesthetics to propofol in both groups. Propofol can be used safely during OLV because PaO2 increased after the application of 4 cm of PEEP during propofol anesthesia, and Qs/Qt decreased significantly after the conversion from inhaled anesthetics to propofol anesthesia. ⋯ During one-lung ventilation, the arterial partial pressure of oxygen values with propofol were greater than those with isoflurane and sevoflurane, and shunt fraction values with propofol were lower than those with both volatile anesthetics. Propofol improved oxygenation and shunt fraction during one-lung ventilation compared with volatile anesthetics.