Ronald H. Wender

The 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. Implications: 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. (Anesth Analg 1998;87:1129-34)

The recovery of cognitive function after general anesthesia in elderly patients: a comparison of desflurane and sevoflurane.

We evaluated the cognitive recovery profiles in elderly patients after general anesthesia with desflurane or sevoflurane. After IRB approval, 70 ASA physical status I–III consenting elderly patients (≥65 yr old) undergoing total knee or hip replacement procedures were randomly assigned to one of two general anesthetic groups. Propofol and fentanyl were administered for induction of anesthesia, followed by either desflurane 2%–4% or sevoflurane 1%–1.5% with nitrous oxide 65% in oxygen. The desflurane (2.5 ± 0.6 MAC · h) and sevoflurane (2.7 ± 0.5 MAC · h) concentrations were adjusted to maintain comparable depths of hypnosis using the electroencephalogram bispectral index monitor. The Mini-Mental State (MMS) test was used to assess cognitive function preoperatively and postoperatively at 1, 3, 6, and 24-h intervals. The use of desflurane was associated with a more rapid emergence from anesthesia (6.3 ± 2.4 min versus 8.0 ± 2.8 min) and a shorter length of stay in the postanesthesia care unit (213 ± 66 min versus 241 ± 87 min). However, there were no significant differences between the Desflurane and the Sevoflurane groups when the MMS scores were compared preoperatively, and postoperatively at 1, 3, 6, and 24 h. Compared with the preoperative (baseline) MMS scores, the values were significantly decreased at 1 h postoperatively (27.8 ± 1.7 versus 29.5 ± 0.5 in the Desflurane group, and 27.4 ± 1.7 versus 29.2 ± 1.0 in the Sevoflurane group, respectively). However, the MMS scores returned to preoperative baseline levels within 6 h after surgery. At 1 h and 3 h after surgery, 51% and 11% (versus 57% and 9%) of patients in the Desflurane (versus Sevoflurane) Group experienced cognitive impairment. In conclusion, desflurane is associated with a faster early recovery than sevoflurane after general anesthesia in elderly patients. However, recovery of cognitive function was similar after desflurane and sevoflurane-based anesthesia.

Effect of Parecoxib, A Novel Intravenous Cyclooxygenase Type-2 Inhibitor, on the Postoperative Opioid Requirement and Quality of Pain Control

Background The analgesic efficacy and side effect profile of intravenous parecoxib, a novel cyclooxygenase type-2 (COX-2) inhibitor, was assessed in a double-blinded, placebo-controlled study involving patients undergoing major gynecologic surgical procedures. Methods After Institutional Review Board approval, 60 consenting women, American Society of Anesthesiologists (ASA) physical status I–III, undergoing lower abdominal surgery with a standardized general anesthetic technique were randomly assigned to receive one of three study medications: group 1 (control) received normal saline; group 2 received intravenous parecoxib, 20 mg; and group 3 received intravenous parecoxib, 40 mg. The initial dose of study medication was administered when the patient first requested pain medication after surgery. All patients had access to patient-controlled analgesia (PCA) with intravenous morphine, 1 or 2 mg, with a 6-min lockout period. Subsequent doses of the same study medication were administered at 12-h and 24-h intervals after the initial dose. The postoperative opioid analgesic requirement (PCA morphine usage), pain scores, pain relief scores, side effects, and need for supplemental medications (e.g., antiemetics, antipruritics, laxatives) were recorded. Results Compared with saline, intravenous parecoxib, 20 mg and 40 mg every 12 h, significantly decreased the PCA morphine usage during the first 6 h postoperatively (group 1, 25 ± 13 mg; group 2, 16 ± 11 mg; group 3, 17 ± 10 mg) and at 12 h (group 1, 34 ± 18 mg; group 2, 24 ± 14 mg; group 3, 23 ± 13 mg) and 24 h (group 1, 51 ± 27 mg; group 2, 34 ± 20 mg; group 3, 33 ± 21 mg) after surgery. However, there were no significant differences in the patients’ global evaluation of the study medications at 12 h and 24 h between those who received intravenous parecoxib (20 or 40 mg) and saline. Moreover, the postoperative pain scores and side effect profiles were similar in the three treatment groups. Conclusion Intravenous parecoxib (20 or 40 mg) was effective in decreasing the PCA opioid requirement after lower abdominal surgical procedures. However, it failed to improve pain management or reduce opioid-related side effects in the early postoperative period.

Does the Use of Electroencephalographic Bispectral Index or Auditory Evoked Potential Index Monitoring Facilitate Recovery after Desflurane Anesthesia in the Ambulatory Setting

BackgroundAnalogous to the Bispectral Index® (BIS®) monitor, the auditory evoked potential monitor provides an electroencephalographic-derived index (AAI), which is alleged to correlate with the central nervous system depressant effects of anesthetic drugs. This clinical study was designed to test the hypothesis that intraoperative cerebral monitoring guided by either the BIS or the AAI value would facilitate recovery from general anesthesia compared with standard clinical monitoring practices alone in the ambulatory setting. MethodsSixty consenting outpatients undergoing gynecologic laparoscopic surgery were randomly assigned to one of three study groups: (1) control (standard practice), (2) BIS guided, or (3) AAI guided. Anesthesia was induced with 1.5–2.5 mg/kg propofol and 1–1.5 &mgr;g/kg fentanyl given intravenously. Desflurane, 3%, in combination with 60% nitrous oxide in oxygen was administered for maintenance of general anesthesia. In the control group, the inspired desflurane concentration was varied based on standard clinical signs. In the BIS- and AAI-guided groups, the inspired desflurane concentrations were titrated to maintain BIS and AAI values in targeted ranges of 50–60 and 15–25, respectively. BIS and AAI values, hemodynamic variables, and the end-tidal desflurane concentration were recorded at 5-min intervals during the maintenance period. The emergence times and recovery times to achieve specific clinical endpoints were recorded at 1- to 10-min intervals. The White fast-track and modified Aldrete recovery scores were assessed on arrival in the PACU, and the quality of recovery score was evaluated at the time of discharge home. ResultsA positive correlation was found between the AAI and BIS values during the maintenance period. The average BIS and AAI values (mean ± SD) during the maintenance period were significantly lower in the control group (BIS, 41 ± 10; AAI, 11 ± 6) compared with the BIS-guided (BIS, 57 ± 14; AAI, 18 ± 11) and AAI-guided (BIS, 55 ± 12; AAI, 20 ± 10) groups. The end-tidal desflurane concentration was significantly reduced in the BIS-guided (2.7 ± 0.9%) and AAI-guided (2.6 ± 0.9%) groups compared with the control group (3.6 ± 1.5%). The awakening (eye-opening) and discharge times were significantly shorter in the BIS-guided (7 ± 3 and 132 ± 39 min, respectively) and AAI-guided (6 ± 2 and 128 ± 39 min, respectively) groups compared with the control group (9 ± 4 and 195 ± 57 min, respectively). More importantly, the median [range] quality of recovery scores was significantly higher in the BIS-guided (18 [17–18]) and AAI-guided (18 [17–18]) groups when compared with the control group (16 [10–18]). ConclusionCompared with standard anesthesia monitoring practice, adjunctive use of auditory evoked potential and BIS monitoring can improve titration of desflurane during general anesthesia, leading to an improved recovery profile after ambulatory surgery.

Substance P (Neurokinin-1) antagonist prevents postoperative vomiting after abdominal hysterectomy procedures.

BackgroundThe safety and antiemetic efficacy of CP-122,721, a novel neurokinin-1 antagonist, was evaluated when administered alone or in combination with ondansetron. MethodsUsing a randomized, double-blind, placebo-controlled study design, CP-122,721 was initially compared with placebo and subsequently to ondansetron alone and in combination for prophylaxis against postoperative nausea and vomiting in 243 women undergoing abdominal hysterectomy. In the dose-ranging studies (n = 86), patients received either CP-122,721 100 mg (vs. placebo) or 200 mg (vs. placebo) orally 60–90 min before induction of anesthesia. In the interaction study (n = 157), patients received CP-122,721 200 mg or placebo 60–90 min before induction of anesthesia, and ondansetron 4 mg or saline 2 ml intravenously 15–30 min before the end of surgery. Patients assessed their level of nausea and pain on arrival in the postanesthesia care unit and at 0.5-, 1-, 1.5-, 2-, 4-, 8-, 12-, and 24-h intervals postoperatively. Emetic episodes, need for rescue antiemetic–antinausea medication, postoperative complications, and patient satisfaction were recorded. ResultsIn the initial dose-ranging study, only 10% of the patients experienced emesis within the first 8 h after surgery with CP-122,721 200 mg compared with 50% in the placebo group. CP-122,721 200 mg also decreased the need for rescue medication (25%vs. 48%). CP-122,721 100 mg was less effective than 200 mg in decreasing the incidence of repeated episodes of emesis. In the interaction study, 6% of the patients receiving CP-122,721 200 mg orally experienced emesis less than 2 h after surgery compared with 17% with ondansetron alone. With combined therapy, only 2% experienced emesis. In addition, the median times for 75% of patients to remain free from postoperative nausea and vomiting were 82, 75, and 362 min in the ondansetron, CP-122,721, and combination groups, respectively. ConclusionsOral CP-122,721 200 mg decreased emetic episodes compared with ondansetron (4 mg intravenously) during the first 24 h after gynecologic surgery; however, there was no difference in patient satisfaction.

The effect of intraoperative use of esmolol and nicardipine on recovery after ambulatory surgery

There is controversy regarding the optimal technique for maintaining hemodynamic stability during anesthesia. We designed this prospective, randomized, double-blinded study to test the hypothesis that the technique used for maintaining hemodynamic stability during general anesthesia can influence recovery after ambulatory surgery. Forty-five healthy consenting women undergoing gynecologic laparoscopy procedures were randomly assigned to 1 of 3 treatment groups: Group 1 (control, n = 15) received normal saline 5 mL and 1 mL, followed by a saline infusion at a rate of 0.005 mL · kg−1 · min−1; Group 2 (n = 15) received esmolol 50 mg and saline 1 mL, followed by an esmolol infusion 5 &mgr;g · kg−1 · min−1; and Group 3 (n = 15) received esmolol 50 mg and nicardipine 1 mg, followed by an esmolol infusion 5 &mgr;g · kg−1 · min−1. The study drugs were administered after the induction of anesthesia with fentanyl 1.5 &mgr;g/kg, and propofol 2 mg/kg IV. Tracheal intubation was facilitated with vecuronium 0.12 mg/kg IV. Anesthesia was initially maintained with desflurane 2% end-tidal and N2O 67% in oxygen in all 3 groups. During surgery, the mean arterial blood pressure (MAP) was maintained within ±15% of the baseline value by varying the study drug infusion rate and the inspired concentration of desflurane. In addition to MAP and heart rate values, electroencephalogram bispectral index values were recorded throughout the perioperative period. Recovery times and postoperative side effects were assessed. Compared with the control group, adjunctive use of esmolol and nicardipine attenuated the increase in heart rate (in Group 2) and MAP (in Group 3) after tracheal intubation. Furthermore, the use of an esmolol infusion as an adjunct to desflurane to control the acute autonomic responses during the maintenance period significantly decreased emergence times (4 ± 2 versus 7 ± 4 min), decreased the need for postoperative opioid analgesics (43% versus 80%), and reduced the time to discharge (209 ± 89 versus 269 ± 100 min). We conclude that the adjunctive use of esmolol alone or in combination with nicardipine during the induction of anesthesia reduced the hemodynamic response to tracheal intubation. Furthermore, use of an esmolol infusion as an adjuvant to desflurane-N2O anesthesia for controlling the acute hemodynamic responses during the maintenance period improved the recovery profile after outpatient laparoscopic surgery.

Desflurane versus sevoflurane for maintenance of outpatient anesthesia: the effect on early versus late recovery and perioperative coughing.

BACKGROUND: There is controversy regarding the relative perioperative benefits of desflurane versus sevoflurane when used for maintenance of anesthesia in the ambulatory setting. Although studies have consistently demonstrated a faster emergence with desflurane (versus sevoflurane), the impact of this difference on the later recovery end points has not been definitively established. Furthermore, the effect of desflurane (versus sevoflurane) on the incidence of coughing is also controversial. METHODS: We randomized 130 outpatients undergoing superficial surgical procedures requiring general anesthesia to one of two maintenance anesthetic treatment groups. All patients were induced with propofol, 2 mg/kg IV, and after placement of a laryngeal mask airway, anesthesia was maintained with either sevoflurane 1%–3% or desflurane 3%–8% in an air/oxygen mixture. The inspired concentration of the volatile anesthetic was varied to maintain hemodynamic stability and a Bispectral Index value of 50–60. Analgesia was provided with local anesthetic infiltration and ketorolac (30 mg IV). Antiemetic prophylaxis consisted of a combination of ondansetron (4 mg), dexamethasone (4 mg), and metoclopramide (10 mg) at the end of surgery. Assessments included recovery times to eye opening, response to commands, orientation, fast-track score of 14, first oral intake, sitting, standing, ambulating unassisted, and actual discharge. Patient satisfaction with anesthesia, the ability to resume normal activities on the first postoperative day, adverse side effects (e.g., coughing, purposeful movement, oxygen desaturation <90%, sore throat, postoperative nausea, and vomiting), and the requirement for postoperative analgesic and antiemetic drugs were recorded in the early postoperative period and during the initial 24-h period after discharge. RESULTS: The two study groups had comparable demographic characteristics. Although the overall incidence of coughing during the perioperative period was higher in the desflurane group (60% versus 32% in the sevoflurane group, P < 0.05), the incidences of coughing during the actual administration of the volatile anesthetics (i.e., the maintenance period) did not differ between the two groups. Emergence from anesthesia was more rapid after desflurane; however, all patients achieved fast-track recovery criteria (fast-track score ≥12) before leaving the operating room. Finally, the time to discharge home (90 ± 31 min in sevoflurane and 98 ± 35 min in desflurane, respectively) and the percentage of patients able to resume normal activities on the first postoperative day (sevoflurane 48% and desflurane 60%) did not differ significantly between the two anesthetic groups. CONCLUSIONS: Use of desflurane for maintenance of anesthesia was associated with a faster emergence and a higher incidence of coughing. Despite the faster initial recovery with desflurane, no significant differences were found between the two volatile anesthetics in the later recovery period. Both volatile anesthetics should be available for ambulatory anesthesia.

The impact of current antiemetic practices on patient outcomes: a prospective study on high-risk patients.

BACKGROUND: In this prospective, multicenter, observational study, we evaluated the incidence and time course of postoperative nausea and vomiting (PONV), assessed prophylactic and rescue antiemetic use in high-risk patients, and determined population-based effectiveness of antiemetics, including the impact of American Society of Anesthesiologists (ASA) and American Society of Perianesthesia Nurses (ASPAN) guideline compliance. METHODS: Eligible patients undergoing elective laparoscopic or major plastic surgery possessed two or more of the following Apfel PONV risk factors: female gender, history of PONV or motion sickness, and nonsmoking status. Antiemetic use, emetic episodes, severity of nausea, and functional interference due to PONV were documented during the first 72 h after surgery. Complete response (CR) was defined as no emesis or rescue medication use, and complete control was defined as CR and no moderate-severe nausea. The effect of compliance (versus noncompliance) with ASA and ASPAN guidelines on PONV outcomes was also analyzed. RESULTS: The proportion of patients experiencing postoperative emesis ranged from 18% to 40% depending on the number of antiemetics administered. The rate of rescue medication (45%) was similar to the reported incidences of moderate-to-severe nausea (47%) and functional interference due to emetic symptoms (44%). The administration of three or more antiemetics produced better patient outcomes overall compared to <1 prophylactic antiemetic. CR rates were <70% despite adherence to current organizational PONV management guidelines (ASA: 69%; ASPAN: 63%). The complete control rates were 10% lower than CR rates over the 3 day study period. CONCLUSIONS: Administration of three or more prophylactic antiemetics had the most positive impact on emetic outcomes over 72 hrs in patients at risk of developing PONV. Although compliance with organizational PONV management guidelines improved patient outcomes, postoperative emetic symptoms and interference with patient functioning still occurred in more than 30% of these high-risk patients.

Fast-Track office based anesthesia : a comparison of propofol versus desflurane with antiemetic prophylaxis in spontaneously breathing patients

IMPLICATIONS Compared to propofol, maintenance of anesthesia with desflurane provided significantly better intraoperative conditions during office-based surgery. In addition, desflurane with routine antiemetic prophylaxis was associated with a faster early recovery and similar incidence of postoperative side effects.

A Comparison of Patient State Index and Bispectral Index Values During the Perioperative Period

The patient state index (PSI), a quantitative electroencephalographic index, has been recently introduced into clinical practice as a monitor for assessing consciousness during sedation and general anesthesia. We designed this observational study to compare the sensitivity and specificity of the PSI with that of the bispectral index (BIS) with respect to their ability to predict the loss of consciousness and emergence from anesthesia, as well as to assess changes in IV (propofol) and inhaled (desflurane) anesthetics during the maintenance period. Twenty consenting patients scheduled for elective laparoscopic surgical procedures were enrolled in this prospective clinical study. Anesthesia was induced with propofol 2 mg/kg IV and fentanyl 1 &mgr;g/kg IV, and tracheal intubation was facilitated with cisatracurium 0.3 mg/kg IV. Desflurane 4% in combination with nitrous oxide 60% in oxygen was administered for the maintenance of anesthesia. Comparative PSI and BIS values were obtained at specific time intervals during the induction, maintenance, and emergence periods. The changes in these indices were recorded after the administration of propofol (20 mg IV) or with 2% increases or decreases in the inspired concentration of desflurane during the maintenance period. With logistic regression models, both the BIS and PSI were found to be effective as predictors of unconsciousness (i.e., failed to respond to verbal stimuli) (P < 0.01). The PSI also correlated with the BIS during both the induction of (r = 0.78) and emergence from (r = 0.73) general anesthesia. However, the area under the receiver operating characteristic curve for detection of consciousness indicated a better performance with the PSI (0.95 ± 0.04) than the BIS (0.79 ± 0.04). During the maintenance period, the PSI values were comparable to the BIS in response to changes in propofol and desflurane but displayed greater interpatient variability. Finally, the PSI (versus BIS) values were less interfered with by the electrocautery unit during surgery (16% versus 65%, respectively). In conclusion, the PSI may prove to be a viable alternative to the BIS for evaluating consciousness during the induction of and emergence from general anesthesia, as well as for titrating the administration of propofol and desflurane during the maintenance period. However, further studies with the PSA device are needed to determine its role in anesthesia.