Getting the best of both worlds--clinical excellence at a peripheral unit.

Audit of hospital practice in remote areas and military practice indicates that it is possible to provide a high degree of patient safety with the advantages of care close to home in a small hospital with less than 100 beds. However such an approach requires strict attention to training and retraining, good clinical networking, attention to quality control and a well defined system for identifying those patients who need to be transferred to a specialist centre.

Comparison of intra-articular and epidural morphine for analgesia following stifle arthrotomy in dogs.

We prospectively studied 18 dogs that presented for exploratory stifle arthrotomy, with or without meniscectomy, and lateral extracapsular stabilization as a result of cranial cruciate ligament rupture. Dogs were premedicated with acepromazine, induced with thiopental, and maintained with halothane in oxygen. Preoperatively, dogs were assigned to one of three groups. Group 1 (n = 6) received intra-articular morphine (0.1 mg/kg diluted in 1 mL/10 kg body weight of saline) and epidural saline (1 mL/5 kg body weight saline plus the volume of saline representing 0.1 mg/kg of morphine). Group 2 (n = 6) received intra-articular saline (1 mL/10 kg body weight of saline plus the volume of saline representing 0.1 mg/kg of morphine) and epidural saline (1 mL/5 kg body weight saline plus the volume of saline representing 0.1 mg/kg of morphine). Group 3 (n = 6) received intra-articular saline (1 mL/10 kg body weight of saline plus the volume of saline representing 0.1 mg/kg of morphine) and epidural morphine (0.1 mg/kg of morphine diluted in 1 mL/5 kg body weight saline). The efficacy of each analgesia regimen was evaluated for 6 hours postoperatively with a pain score based on subjective and objective variables. Serum cortisol and blood glucose concentrations were measured. Butorphanol was used to provide analgesia as needed based on a predetermined maximum pain score. Supplemental analgesics were required postoperatively every 2 to 3 hours for 6 hours in all dogs that did not initially receive analgesics (group 2). Pain scores were significantly lower in dogs administered morphine intra-articularly (group 1) and epidurally (group 3) at 30 minutes and 30, 120, and 360 minutes, respectively, compared with dogs that did not initially receive analgesics (group 2). One dog in group 1 and one dog in group 3 required supplemental analgesia with butorphanol. There was no difference between analgesia produced by intra-articular morphine compared with that of epidural morphine. Side effects after intra-articular or epidural morphine were not observed. Intra-articular administration of morphine can produce effective analgesia in dogs comparable with that produced by epidural administration of morphine.

Blood gas values during intermittent positive pressure ventilation and spontaneous ventilation in 160 anesthetized horses positioned in lateral or dorsal recumbency.

One hundred sixty horses were anesthetized with xylazine, guaifenesin, thiamylal, and halothane for elective soft tissue and orthopedic procedures. Horses were randomly assigned to one of four groups. Group 1 (n = 40): Horses positioned in lateral (LRG1; n = 20) or dorsal (DRG1; n = 20) recumbency breathed spontaneously throughout anesthesia. Group 2 (n = 40): Intermittent positive pressure ventilation (IPPV) was instituted throughout anesthesia in horses positioned in lateral (LRG2; n = 20) or dorsal (DRG2; n = 20) recumbency. Group 3 (n = 40): Horses positioned in lateral (LRG3; n = 20) or dorsal (DRG3; n = 20) recumbency breathed spontaneously for the first half of anesthesia and intermittent positive pressure ventilation was instituted for the second half of anesthesia. Group 4 (n = 40): Intermittent positive pressure ventilation was instituted for the first half of anesthesia in horses positioned in lateral (LRG4; n = 20) or dorsal (DRG4; n = 20) recumbency. Spontaneous ventilation (SV) occured for the second half of anesthesia. The mean time of anesthesia was not significantly different within or between groups. The mean time of SV and IPPV was not significantly different in groups 3 and 4. Variables analyzed included pH, PaCO2, PaO2, and P(A-a)O2 (calculated). Spontaneous ventilation resulted in significantly higher PaCO2 and P(A-a)O2 values and significantly lower PaO2 values in LRG1 and DRG1 horses compared with LRG2 and DRG2 horses. Intermittent positive pressure ventilation resulted in normocarbia and significantly lower P(A-a)O2 values in LRG2 and DRG2 horses. In LRG2 the PaO2 values significantly increased from 20 minutes after induction to the end of anesthesia. The PaO2 and P(A-a)O2 values were not significantly different from the beginning of anesthesia after IPPV in DRG2 or DRG3. The PaO2 values significantly decreased and the P(A-a)O2 values significantly increased after return to SV in horses in LRG4 and DRG4. The PaO2 values were lowest and the P(A-a)O2 values were highest in all horses positioned in dorsal recumbency compared with lateral recumbency and in SV horses compared with IPPV horses. The pH changes paralleled the changes in PaCO2. Blood gas values during right versus left lateral recumbency in all groups were also evaluated. The PaO2 values were significantly lower and the P(A-a)O2 values were significantly higher during SV in horses positioned in left lateral (LRLG1) compared with right lateral (LRRG1) recumbency.(ABSTRACT TRUNCATED AT 400 WORDS)

The effects of consecutive day propofol anesthesia on feline red blood cells.

This study investigated the potential for multiple exposures of propofol to induce oxidative injury, in the form of Heinz body production, to feline red blood cells. Anesthesia was induced in six healthy cats with propofol (6 mg/kg, intravenous [IV]) and maintained for 30 minutes with a propofol infusion (0.20 to 0.30 mg/kg/min, IV). The initial protocol was designed for each cat to receive 10 consecutive days of propofol anesthesia. All cats spontaneously breathed room air. Heart rate, respiratory rate, and indirect blood pressure were measured and recorded before and during anesthesia. Time to complete recovery after each infusion was measured and recorded. Heinz body analysis was performed before and after each day of propofol anesthesia. Based on predetermined criteria for discontinuing daily infusions, the mean number of consecutive days of propofol anesthesia was six and propofol administration did not continue beyond 7 days in any cat. Heart rate, respiratory rate, and indirect blood pressure did not change significantly during propofol anesthesia compared with awake values. Following the third consecutive day of propofol anesthesia, there was a significant increase from baseline in the mean percentage of Heinz bodies. Hemolysis was not detected in any cat. Recovery time significantly increased after the second consecutive day of propofol anesthesia compared with the first day. Five of six cats developed generalized malaise, anorexia, and diarrhea on day 5, 6, or 7, and two cats developed facial edema.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of halothane, enflurane, and isoflurane on supraventricular and ventricular rate in dogs with complete atrioventricular block.

Complete atrioventricular (AV) block was produced in 32 chloralose-anesthetized autonomically intact dogs to determine the effects of halothane, enflurane, and isoflurane on supraventricular and ventricular rate. Halothane (n = 17), enflurane (n = 6), and isoflurane (n = 9) were administered in three separate experiments in sequential minimum alveolar concentration (MAC) multiples of 0.5, 1.0, 1.5, 2.0, 1.5, and 1.0. Supraventricular rate, ventricular rate, and mean arterial blood pressure (MAP) were measured and recorded at baseline and after a 20-minute equilibration period of each inhalation anesthetic at each MAC multiple. Increasing concentrations of enflurane and isoflurane significantly decreased supraventricular rate (P < .05). Ventricular rate was not significantly changed by sequential MAC multiples of halothane, enflurane, and isoflurane. Increasing concentrations of halothane, enflurane, and isoflurane significantly decreased MAP with enflurane producing the most significant decrease (P < .05). Ventricular arrhythmias occurred in 5 of 17 dogs anesthetized with halothane and 1 of 9 dogs anesthetized with isoflurane. Inhalation anesthesia can significantly decrease supraventricular rate and MAP, does not alter ventricular rate, and can produce ventricular arrhythmias in dogs with complete AV block.

The pharmacology of local anesthetics.

Understanding of the pharmacology of local anesthesia is important for selection of a local anesthetic for use in equine standing surgery. In general, the action potential is inhibited by local anesthetics by preventing the influx of sodium ions across the axonal membrane. The physicochemical properties of each local anesthetic determine the onset of action, potency, and duration of action. Procaine, chlorprocaine, lidocaine, and mepivacaine are the local anesthetics still used clinically in horses; lidocaine is the most widely used. The future of equine local anesthesia may see the introduction of longer acting, more potent drugs currently used clinically in humans and dogs as well as drugs not classified as local anesthetics--alpha-2 agonists and opioids--for use in epidural anesthesia.

Variability of heparin levels and bleeding with low-dose heparin prophylaxis following transurethral resection of the prostate.

Plasma heparin levels and operative/postoperative bleeding were assessed in 16 patients of varying body weights who received subcutaneous low-dose heparin prophylaxis for deep vein thrombosis during and after transurethral resection for benign prostatic hypertrophy. The concentration of heparin in the blood at operation and subsequently was found to vary widely but did not correlate with the extent of blood loss. When adjusted for body weight, plasma heparin concentration showed significantly less variation from patient to patient. In this respect, body weight was a more effective parameter than lean body mass or surface area. Adjustment of heparin dosage by body weight may be advisable when using low-dose heparin prophylaxis.

Obstructing/perforated carcinoma of the left colon treated by resection and the formation of a double colostomy.

Forty patients presenting with obstructing left colon tumours between 1975 and 1980 were treated by a modified Paul-Mikulicz resection. The hospital mortality was 5 per cent. Subsequent mortality was largely related to the stage of the tumour at presentation and was not higher than that to be expected after an elective resection. In 21 patients the procedure was palliative and 16 of these patients later died. The quality of palliation was reasonable in 80 per cent and poor in 20 per cent. Despite the need for a second hospital stay to close the colostomy, time in hospital accounted, on average, for less than one-tenth of the remaining lifespan in those having a palliative resection.

Controlled trial of prophylactic antibiotics in minor wounds requiring suture.

Minor wounds presenting in the accident department requiring suture were randomly allocated to one of three treatment groups: an intramuscular injection of 1-25 megaunits of penicillin as a long-acting depot preparation, local wound irrigation with 100mg of tetracycline in solution, or no antibiotics. All wounds had a standard surgical toilet and were closed under aseptic conditions. Wound infections were noted five to seven days after suture, and in the two groups receiving antibiotics 23% of the wounds were infected whilst in the control group the frequency was 7%. The wisdom of using routine antibiotic prophylaxis in minor wounds is questioned.