Systemic changes in the elderly patient and their anaesthetic implications

Pharmacokinetics and intramuscular bioavailability of a single dose of butorphanol in Asian elephants (Elephas maximus)

Captive Asian elephants (Elephas maximus) are susceptible to lameness resulting from foot and joint pain, including chronic arthritis. In the past, opioid analgesics, such as butorphanol, have been used clinically for pain management. However, dosages used in treating elephants were often extrapolated from data in horses, with no pharmacokinetic information on the specific agents used in elephant species. In this pharmacokinetic study, six adult captive Asian elephants (5 female, 1 male castrate) were administered a 0.015 mg/kg dose of butorphanol by both i.v. and i.m. routes. A complete crossover design was used with a 3-wk washout period between treatments. Serial blood samples were collected immediately prior to butorphanol administration and at 5, 10, 20, and 40 min and 1, 1.5, 2, 3, 4, 5, 6, 8, 10, and 24 h after administration. The butorphanol analysis was performed using a validated liquid chromatography-mass spectrophotometric assay with a limit of quantitation of 0.025 ng/ml. The mean Cmax after i.m. administration was 7.9 ng/ml, with a corresponding Tmax, of 40 min and t(1/3), of 7.1 h. After i.v. administration, the mean Vd(ss) was 1.4 L/kg and the mean Cl(p) was 0.26 L/kg/h. Mean i.m. bioavailability was 37%. The results indicate that butorphanol used at 0.015 mg/kg i.m. or i.v. could be useful in elephants when given for pain control.

Clinical comparison of spontaneous respiration versus controlled ventilation general anaesthesia using isoflurane for intraocular surgery: intraoperative, recovery and postoperative effects

A prospective randomized study was undertaken on elderly patients undergoing intraocular, predominantly cataract, surgery to compare the intraoperative, recovery and postoperative features associated with general anaesthesia employing either the spontaneous (SV) or controlled ventilation (IPPV) techniques of respiration using isoflurane, nitrous oxide and a constant FiO2 of 0.33. SV patients received isoflurane 0.97% (mean). IPPV patients were intubated with atracurium alone, and received isoflurane 0.60% (mean). Heart rates were lower intraoperatively with IPPV, and blood pressures were lower with SV. Intraocular pressure measurement identified three subgroups of patients within each respiratory group: a large subgroup (70% of SV, 64% of IPPV patients) with a high-normal initial mean intraocular pressure which fell intraoperatively; a small subgroup (25% of SV, 24% of IPPV patients) with a low normal initial mean intraocular pressure which rose intraoperatively; and a small subgroup (5% of SV and 11% of IPPV patients) in whom the intraocular pressure remained unchanged. A satisfactory operative field was reported by surgeons in 87% of SV and in 86% of IPPV patients. SV patients had a lower mean end-operative SaO2 than IPPV patients (SV 95.0%; IPPV 96.7%), and were extubated sooner at the end of anaesthesia. In the recovery ward the times to awakening, vomiting incidences, analgesic usages and recovery times were similar, and patients were similarly restful. Postoperatively, the incidences of vomiting, headache, fever, sore throat and myalgia were similar, but SV patients required more analgesia for headache. We conclude that both technique properly performed are similarly satisfactory for cataract surgery in elderly patients.

Nonsurgical control of upper gastrointestinal hemorrhage in old age patients: intragastric norepinephrine and endoscopic alcoholization of lesions

Of 28 consecutive patients over 64 years old, in whom endoscopy revealed gastro-duodenal ulcers with signs of recent hemorrhage (active bleeding, non-bleeding vessel or adherent clot), 14 were randomly assigned to receive endoscopic alcoholization of the lesions preceded by intragastric instillation of norepinephrine, while as controls 14 received antacids. After the applied treatment the bleeding stopped in all cases (100%) in the study group and one patient died (7.1%) after hemostasis was achieved. In the control group bleeding stopped in 12 patients (85.7%). Two patients continued to bleed and needed emergency surgery. Another patient had a major rebleed successfully treated by alcoholization. There were 4 deaths (28%): 2 patients died postoperatively and the other 2 from acute porphyria and bronchopneumonia respectively. The transfusion requirements after the entry into trial were significantly lower in the study group compared to controls (mean no. of blood units 0.79 vs. 1.71). No complications were seen with the treatment applied. These results suggest that endoscopic alcoholization of the lesions preceded by intragastric instillation of norepinephrine is an effective and safe emergency therapy for bleeding from peptic ulcers in old age patients.