Anesthesia and analgesia
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Anesthesia and analgesia · Dec 1999
Randomized Controlled Trial Comparative Study Clinical TrialPharmacokinetics and pharmacodynamics of ropivacaine 2 mg/mL, 5 mg/mL, or 7.5 mg/mL after ilioinguinal blockade for inguinal hernia repair in adults.
The aim of our study was to evaluate the pharmacokinetics and pharmacodynamics of ropivacaine in ilioinguinal-iliohypogastric blocks (IIB). After ethics committee approval and informed consent, 80 male adults scheduled for inguinal hernia repair were enrolled and randomized into four groups. After induction of general anesthesia, an IIB was performed double blinded in Groups 1, 2, and 3 with 0.25 mL/kg ropivacaine 2 mg/mL, 5 mg/mL, or 7.5 mg/mL and with saline in the Control group. Plasma concentration of ropivacaine was determined in venous blood using reversed-phase high-performance liquid chromatography. IIB with ropivacaine resulted in peak plasma concentrations of 0.3+/-0.15 microg/mL (Group 1) (mean +/- SD), 0.75+/-0.45 microg/mL (Group 2), or 1.57+/-0.82 microg/mL (Group 3). These concentrations occurred after 30 (15-60) min, median (range), 30 (10-60) min, and 45 (15-60) min, in the respective groups. Three of 19 patients in Group 1, 6 of 18 in Group 2, and 5 of 20 in Group 3 did not need any additional analgesics within 24 h postoperatively, but all 20 control patients did. Time to the first demand for analgesia was significantly shorter in the Control group (median 0.3 h [range 0-2.8]) compared with 1.5 h (0.5-24 h), 2 h (0.5-24 h), and 2 h (1.0-24 h) in Groups 1, 2, and 3, respectively. Three patients in Group 3 had a postoperative motor block of the femoral nerve. In conclusion, a ropivacaine dose of 0.25 mL/kg of 5 mg/mL seems adequate for IIB accompanying general anesthesia for postoperative pain relief. However, the pharmacokinetic results obtained suggest that even larger doses (0.25 mL/kg of 7.5 mg/mL ropivacaine) for IIB do not result in plasma concentrations in a toxic range. ⋯ Ropivacaine, a new local anesthetic, proved to be effective for pain relief after hernia repair in ilioinguinal blocks accompanying general anesthesia. Plasma concentrations peaked after 30-45 min, and were within safe limits after application of 0.25 mL/kg of 2, 5, or 7.5 mg/mL ropivacaine.
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Anesthesia and analgesia · Dec 1999
Randomized Controlled Trial Comparative Study Clinical TrialThe safety and efficacy of prophylactic ondansetron in patients undergoing modified radical mastectomy.
We aimed to evaluate the antiemetic efficacy, safety, and clinical utility of prophylactic ondansetron administered at the end of the surgery for the prevention of postoperative nausea and vomiting (PONV) in a homogenous population of 54 women undergoing modified radical mastectomy (MRM). A standard general anesthetic and perioperative analgesic technique were used. After surgery, patients received either saline placebo or ondansetron 4 mg IV. Episodes of PONV, as well as rescue antiemetic requirements, were recorded for the first 24 h after surgery. The 24-h incidence of PONV (33.3% vs 81.5%; P = 0.0010) was significantly lower in the ondansetron group. The severity of PONV, evaluated by the number of emetic episodes per patient (1.59+/-1.90 vs 0.29+/-0.66; P = 0.0029), and the rescue antiemetic requirement (59.2% vs 14.8%; P = 0.0019) was significantly lower, in the ondansetron group. Patient satisfaction scores and number needed to prevent PONV (2.07) were significantly better and therapeutically more favorable in the ondansetron group. The incidence of adverse events such as headache, dizziness, and increased liver enzyme levels (number needed to harm = infinity) was similar in both groups. Administered at the end of the surgery in adult female patients undergoing general anesthesia for MRM, ondansetron 4 mg is effective and safe in preventing PONV. We recommend the clinical practice of routine prophylactic ondansetron to prevent PONV after MRM, as it significantly improves perioperative patient satisfaction and outcome. ⋯ We evaluated the antiemetic efficacy, safety, and routine use of prophylactic ondansetron, a "gold standard" antiemetic, in women undergoing radical breast surgery who were at a high risk of postoperative vomiting. We analyzed more meaningful "true" and "therapeutic" outcome measures, and we conclude that prophylactic ondansetron is safe and effective and that its routine use is justified.
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Anesthesia and analgesia · Dec 1999
Comparative Study Clinical TrialPreoperative anxiety and intraoperative anesthetic requirements.
The purpose of this study was to determine whether larger doses of anesthetics are required in the anxious patient to establish and maintain a clinically sufficient hypnotic component of the anesthetic state. Fifty-seven women undergoing bilateral laparoscopic tubal ligation with a propofol-based anesthetic regimen were enrolled in this cross-sectional study. Trait (baseline) and state (situational) anxiety were assessed in all patients immediately before surgery, and the propofol doses required for the induction and maintenance of anesthesia were recorded. A bispectral index monitor was used to assure that the hypnotic component of the anesthetic state was the same in all patients. We found that patients with high trait anxiety required more propofol for both the induction (2.1+/-0.4 vs 1.8+/-0.3 mg/kg; P = 0.01) and maintenance of anesthesia (170+/-70 vs 110+/-20 microg x kg(-1) x min(-1); P = 0.02), compared with patients with low trait anxiety. State anxiety, however, was not found to affect the propofol doses required for the induction or maintenance of anesthesia. Multiple regression models confirmed that Trait anxiety is an independent predictor for intraoperative propofol requirements (P = 0.02). We conclude that increased baseline (i.e., trait) anxiety is associated with increased intraoperative anesthetic requirements. Thus, we suggest that the initial dose of anesthetic administered by an anesthesiologist should be modified based on the anxiety level exhibited by the patient. ⋯ The goal of this study was to assess the relationship between preoperative anxiety and intraoperative anesthetic requirements. We found that high baseline anxiety predicts increased intraoperative anesthetic requirements. We suggest that anesthesiologists should modify the initial induction dose based on the anxiety level exhibited by the patient.