Anesthesia and analgesia
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Anesthesia and analgesia · Dec 2001
Randomized Controlled Trial Comparative Study Clinical TrialA dose response study of clonidine with local anesthetic mixture for peribulbar block: a comparison of three doses.
Clonidine prolongs anesthesia and analgesia of local anesthetics in various neural blocks as well as the duration of retrobulbar block. We assessed the dose-response relationship of clonidine added to lidocaine in peribulbar block. Sixty patients undergoing cataract surgery were given peribulbar block with 7 mL of 2% lidocaine and hyaluronidase with either saline (Control) or clonidine in 0.5-microg/kg (0.5 Clon), 1.0-microg/kg (1.0 Clon), or 1.5-microg/kg (1.5 Clon) doses. The onset and duration of lid and globe akinesia, globe anesthesia and analgesia, postoperative analgesic requirement, and adverse effects (hypotension, bradycardia, hypoxia, sedation, and dizziness) were recorded. The success rate and onset of block were comparable in all groups. The duration of lid and globe akinesia, globe anesthesia and analgesia was significantly (P < 0.01) prolonged in patients receiving 1.0 and 1.5 microg/kg clonidine as compared with the Control group. Perioperative pain scores and analgesic requirement were significantly less in these groups. 0.5 microg/kg clonidine did not increase the duration of anesthesia and analgesia significantly. Hypotension and dizziness were observed more in patients receiving 1.5 microg/kg clonidine as compared with other groups. We conclude that 1.0 microg/kg clonidine with a mixture of lidocaine (2%) significantly prolonged the duration of anesthesia and analgesia after peribulbar block with limited side effects. ⋯ We studied the effect of the addition of 0.5, 1.0 and 1.5 microg/kg clonidine to a lidocaine-hyaluronidase mixture on the onset and duration of peribulbar block and perioperative analgesia. A dose of 1.0 microg/kg produced a significant increase in duration of anesthesia and analgesia with minimal side effects.
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Anesthesia and analgesia · Dec 2001
Case ReportsHemostatic analysis of a patient with hereditary angioedema undergoing coronary artery bypass grafting.
Hereditary angioedema is a disease associated with acute complement-mediated inflammation and swelling of the airway and other vital organs. This case describes the impact of hereditary angioedema and cardiopulmonary bypass on hemostasis as assessed by thrombelastography.
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Anesthesia and analgesia · Dec 2001
The impact of longer-than-average anesthesia times on the billing of academic anesthesiology departments.
Academic anesthesiology departments provide clinical services for surgical procedures that have longer-than-average surgical times and correspondingly increased anesthesia times. We examined the financial impact of these longer times in three ways: 1) the estimated loss in revenue if billing were done on a flat-fee system by using industry-averaged anesthesia times; 2) the estimation of incremental operating room (OR) sites necessitated by longer anesthesia times; and 3) the estimated potential gain in billed units if the hours of productivity of current anesthesia time were applied to surgical cases of average duration. Health Care Financing Administration average times per anesthesia procedure code were used as industry averages. Billing data were collected from four academic anesthesiology departments for 1 yr. Each claim billed with ASA units was included except for obstetric anesthesia care. All clinical sites that do not bill with ASA units were excluded. Base units were determined for each anesthesia procedure code. The mean commercial conversion factor (US$45 per ASA unit) for reimbursement was used to estimate the impact in dollar amounts. In all four groups, anesthesia times exceeded the Health Care Financing Administration average. The loss per group in billed ASA units if a flat-fee billing system were used ranged from 18,194 to 31,079 units per group, representing a 5% to 15% decrease (estimated billing decrease of US$818,719 to US$1,398,536 per group). The number of excess OR sites necessitated by longer surgical and anesthesia times ranged from 1.95 to 4.57 OR sites per group. The potential gain in billed units if the hours of productivity of current anesthesia time were applied to surgical cases of average duration was estimated to be from 13,273 to 21,368 ASA units. Longer-than-average anesthesia and surgical times result in extra hours or additional OR sites to be staffed and loss of potential reimbursement for the four academic anesthesiology departments. A flat-fee system would adversely affect academic anesthesiology departments. ⋯ We examined the economic impact of longer-than-average anesthesia times on four academic anesthesiology departments in three ways: the estimated loss in revenue under a flat-fee system, the excess operating room sites staffed, and the potential gain in revenue if the surgeries were of average length. These results should be considered both in productivity measurements and strategies for operating room management.
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Anesthesia and analgesia · Dec 2001
Randomized Controlled Trial Comparative Study Clinical TrialThe 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 (> or =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. ⋯ Desflurane was associated with a faster early recovery than sevoflurane after general anesthesia in elderly patients. However, recovery of cognitive function was similar with both volatile anesthetics.
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Anesthesia and analgesia · Dec 2001
Multicenter Study Clinical TrialA dose-determining trial of heparinase-I (Neutralase) for heparin neutralization in coronary artery surgery.
Heparinase-I, a specific heparin-degrading enzyme, may represent an alternative to protamine. We explored the dose of heparinase-I for efficacy and safety in patients undergoing coronary artery surgery. At the conclusion of cardiopulmonary bypass, subjects received 5, 7, or 10 microg/kg of open-label heparinase-I instead of protamine. Activated clotting time (ACT) and its difference from a contemporaneous heparin-free sample (DeltaACT) at 3 min before and 3, 6, and 9 min after heparinase-I determined reversal efficacy. After surgery, we recorded hourly chest tube drainage. Systemic and pulmonary arterial blood pressure and cardiac output measurements before and immediately after heparinase-I were used to evaluate hemodynamic safety. Coagulation measurements included anti-factor Xa and anti-factor IIa activities. Forty-nine patients from seven institutions participated: 12 received 5 microg/kg, 21 received 7 microg/kg, 4 received two doses of 7 microg/kg, 8 received 10 microg/kg, and 4 received two doses of 10 microg/kg. Treatment groups did not differ demographically. Median DeltaACT 9 min later was 11, 7, and 4 s for the 5, 7, and 10 microg/kg groups, respectively. No adverse hemodynamic changes occurred with heparinase-I administration. The authors conclude that heparinase-I effectively restored the ACT after cardiopulmonary bypass. This effect appeared to be dose dependent. ⋯ Heparinase-I (Neutralase(TM)) successfully restored activated coagulation time with no adverse hemodynamic events in patients undergoing coronary artery surgery with cardiopulmonary bypass in an open-label dose-determining trial.