Speed of induction of anaesthesia in dogs administered halothane, isoflurane, sevoflurane or propofol in a clinical setting.

OBJECTIVE: To compare the speed and quality of induction of general anaesthesia using three different inhalant agents and one intravenous agent, in healthy dogs undergoing desexing surgery. MATERIALS AND METHODS: Less excitable dogs were not premedicated; others were premedicated with intramuscular acepromazine and morphine. Anaesthesia induction protocol was randomly assigned, with halothane, isoflurane or sevoflurane delivered by mask, or propofol delivered intravenously. Maximum vaporiser settings were used for inhalant inductions. Induction of anaesthesia was considered complete at the time of endotracheal intubation. Quality of induction was scored by the administering veterinarian. RESULTS: Seventy-one dogs were enrolled. Twenty-four received no premedication and 47 received premedication. Isoflurane inductions were significantly faster than halothane inductions (2.86 +/- 0.25 vs 3.71 +/- 0.22 min; mean +/- SE, P = 0.013). Sevoflurane inductions (3.29 +/- 0.24 min) were not significantly different from either halothane (3.71 +/- 0.22 min, P = 0.202) or isoflurane inductions (2.86 +/- 0.25 min, P = 0.217). Induction with propofol (1.43 +/- 0.13 min) was significantly faster than inhalant induction (P < 0.001 in each case). Premedication decreased the dose requirement and time to induction for dogs induced with propofol, but did not significantly change the time to intubation for inhalant inductions. Dogs administered propofol and/or premedication were significantly more likely to have an excellent quality of induction, but there was no difference between inhalant agents in terms of induction quality. CONCLUSION: Sevoflurane possesses chemical properties that should produce a more rapid induction of anaesthesia in comparison to halothane or isoflurane. However, in clinical practice patient related factors outweigh this improvement.

Effect of hypothermia on recovery from general anaesthesia in the dog.

OBJECTIVE: To discern the effects of anaesthesia protocols and decreasing core body temperature on time to recovery from general anaesthesia. MATERIALS AND METHODS: Healthy adult dogs undergoing desexing surgery were enrolled. More excitable dogs were premedicated with intramuscular acepromazine and morphine; calmer dogs were not premedicated. Anaesthesia was induced using halothane, isoflurane or sevoflurane delivered by mask, or by intravenous propofol, and maintained in standard fashion using one of the three inhalant agents. Thermostat controlled heat mats were used during surgical preparation and surgery. Oesophageal temperature was recorded throughout surgery. The time from cessation of anaesthetic administration until the dog successfully raised itself to sternal recumbency was considered the time of recovery. RESULTS: Sixty-nine dogs completed the study, 42 males anaesthetised for 60.4 +/- 20.5 min, and 27 females anaesthetised for 85.4 +/- 33.2 min. Oesophageal temperature at the end of surgery was 36.8 +/- 0.80 degrees C. Oesophageal temperature had a significant effect on recovery time, with lower temperatures contributing to slower recoveries. Premedication significantly lengthened recovery times. The choice of induction or maintenance anaesthetic agent had no effect on recovery time. DISCUSSION: Hypothermia is a common complication of general anaesthesia and surgery. Amongst other deleterious effects, it is associated with slower recovery from anaesthesia, likely due to a number of different mechanisms.

Anuric renal failure in a dog after red-bellied black snake (Pseudechis porphyriacus) envenomation.

A case of Red-bellied Black snake envenomation resulting in intravascular haemolytic anaemia, rhabdomyolysis and anuric renal failure is described in the dog. A 12-year-old female desexed Golden Retriever was presented with a 15 hour history of profuse salivation, progressive lethargy, obtundence, inappetence and collapse. Significant findings on clinical examination were pallor, icterus, tachypnoea and dyspnoea with increased respiratory sounds and crackles in all lung fields. Generalised abdominal and muscular pain was apparent and dark red-brown urine was present around the perineal region. A diagnosis of Red-bellied Black snake (Pseudechis porphyriacus) envenomation was made and the dog was treated with intravenous fluid therapy, Tiger/Brown snake antivenom, packed red cell transfusions and Intermittent Positive Pressure Ventilation. Continued clinical deterioration occurred and a diagnosis of acute renal failure secondary to myohaemoglobinuric pigmenturia was made 12 hours after admission. Intensive treatment was attempted with diuresis and volume expansion. Oliguria and subsequent anuria ensued and the dog was euthanased due to a grave prognosis and lack of clinical response to treatment. Necropsy examination revealed muscular necrosis, accumulation of fluid in the thoracic and peritoneal cavities, and marked renal tubular necrosis with intraluminal occlusion secondary to pigmentary casts.

Reconstruction of the penis using a radial forearm free flap. A case report.

The total reconstruction of a penis using an innervated radial forearm osteofasciocutaneous free flap is described. Essentially, this procedure is completed in a single stage and satisfies all criteria for good penis reconstruction: the urethra opens at the distal end of the shaft allowing normal micturition; and sensory innervation of the flap, together with the inclusion of vascularised autogenous bone as a stiffener, facilitates normal sexual function.

Experimental reclamping of free-flap pedicles: the effect of prolonged stasis on the anastomoses and clamp sites.

The effect of static blood in direct contact with areas of microvascular anastomoses and previous clamp application for prolonged periods of time has been investigated. The free groin flap was used as a model in 27 white rabbits. The flap pedicle vessels were reclamped proximal to the anastomoses and areas of previous clamp application for periods of time varying between 30 minutes and 4 hours after 15 minutes of blood flow over these areas. A 100 percent patency rate was achieved despite the long periods of reclamping. Histologically, minor intimal damage was visible in the immediate period following anastomoses and clamping of the vessels. After 2 weeks, despite a thickened myofibroblastic intimal lesion, an intact endothelial layer was observed. No evidence of thrombosis could be demonstrated in either period. We postulate that vessels carefully treated and with technically well-performed anastomoses can be regarded as "normal" vessels after 15 minutes of blood flow over the anastomoses and clamp sites. We suggest that when required, microvascular clamps may then be reapplied without risk for prolonged periods of time despite static blood being in contact with these areas.