Anesthesia of captive African wild dogs (Lycaon pictus) using a medetomidine-ketamine-atropine combination

Seven captive male African wild dogs (Lycaon pictus) weighing 25-32 kg each, were anesthetized by i.m. injection via hand syringe with a combination of 1.5 mg/kg ketamine, 40 mu g/kg medetomidine, and 0.05 mg/kg atropine. Following endotracheal intubation, each animal was connected to a bain closed-circuit system that delivered 1.5% isoflurane and 2 L/min oxygen. Atipamezole (0.1 mg/kg i.v.; 0.1 mg/kg i.m.) was given at the end of each procedure (60 min following injection of medetomidine/ketamine/atropine). Time to sternal recumbency was 5-8 min. Times to standing after atipamezole administration were 8-20 min. This anesthetic regimen was repeated on three separate occasions (September 2000, February 2002, and October 2002) on all males to perform electroejaculation procedures. Each procedure was < 80 min from injection to standing. Dogs showed excellent muscle relaxation during the procedures. Arterial blood samples were collected at 10-min intervals for blood gases in one procedure (September 2000). Separate venous samples were taken from each dog during each procedure for hematology and biochemistry. These values were within the normal range for this species. Arterial hemoglobin oxygen saturation (SpO2) and heart rate (HR) were monitored continuously in addition to other anesthesia monitoring procedures (body temperature, respiratory rate [RR], capillary refill time, blink response, pupil position, deep pain perception reflex). All dogs maintained relatively stable SpO2 profiles during monitoring, with a mean (+/- SD) SpO2 of 92% +/- 5.4%. All other physiological variables (HR, RR, body temperature, blood pressure) were within normal limits. Following each procedure, normal behavior was noted in all dogs. All the dogs were reunited into the pack at completion of their anesthetic procedures. An injectable medetomidine-ketamine-atropine combination with maintenance by gaseous isoflurane and oxygen provides an inexpensive, reliable anesthetic for captive African wild dogs.

The clinical implication of the vocal cords-carina distance in anaesthetized Chinese adults during orotracheal intubation

Background. Previous studies have identified no strong correlation between patients' height and tracheal length in anaesthetized patients. We have attempted to compare vocal cords-carina distance (VCD) in Chinese patients with the dimensions of five commonly used tracheal tubes. In addition, we attempted to find a surface anatomy measurement that would identify patients with 'short tracheas'. Methods. We measured VCD in 130 anaesthetized Chinese patients with a fibreoptic bronchoscope. Also measurements were obtained of the distal ends of five commonly used tracheal tubes. We undertook various surface anatomy measurements on the patients' chest and neck region to predict those patients with short tracheas. Results. VCD averaged 12.6 ((SD) 1.4) cm. In seven patients (5%) this distance was particularly short (between 8.8 and 10.4 cm). Many of the commonly used tracheal tubes would be placed close to or beyond the carina when the black intubation guide mark(s) is (are) at the level of the vocal cords. The VCD of

Comparison of the Berman Intubating Airway and the Williams Airway Intubator for fibreoptic orotracheal intubation in anaesthetised patients

Sixty patients with no clinical indicators of a difficult airway were selected to undergo a fibreoptic assessment after induction of general anaesthesia using both the Berman Intubating Airway and the Williams Airway Intubator. The bronchoscopic view and ease of railroading a tracheal tube during fibreoptic orotracheal intubation were studied. The bronchoscopic views obtained by the Berman Airway and the Williams Airway were significantly different (p < 0.008, test of symmetry). The estimated odds ratio of obtaining an obstructed path was 3.06 times higher for the Berman than the Williams Airway. However, if the glottis could be reached with the bronchoscope, there was no significant difference in the degree of ease of intubation between the two airways.

Equine laminitis: loss of hemidesmosomes in hoof secondary epidermal lamellae correlates to dose in an oligofructose induction model: an ultrastructural study

Reasons for performing study: Light microscopical studies show that the key lesion of laminitis is separation at the hoof lamellar dermal-epidermal interface. More precise knowledge of the damage occurring in the lamellar basement membrane zone may result if laminitis affected tissue is examined with the transmission electron microscope. This could lead to better understanding of the pathogenesis of lesions and the means of treatment or prevention. Objectives: To investigate the ultrastructure of acute laminitis as disease of greater severity is induced by increasing oligofructose (OF) dosage. Methods: Three pairs of normal horses, dosed with OF at 7.5, 10 and 12.5 g/kg bwt via nasogastric intubation, developed laminitis 48 h later. Following euthanasia, their forefeet were processed for transmission electron microscopy. Lamellar basal cell hemidesmosome (HD) numbers and the distance between the basal cell plasmalemma and the lamina densa of the basement membrane were estimated and compared to control tissue. Results: Increasing OF dosage caused greater HD loss and more severe laminitis. The characteristic separation of the basement membrane, cytoskeleton failure and rounded basal cell nuclei results from combined HD dysassembly and anchoring filament failure. Conclusions: Without properly assembled HDs, dysadhesion between the lamina densa of the basement membrane (BM) and epidermal basal cells occurs, emphasising the fundamental importance of HDs in maintaining attachment at the lamellar interface. Medical conditions that trigger lamellar matrix metalloproteinase (MMP) activation and/or compromise entry of glucose into lamellar basal cells appear to promote loss and failure of HDs and, therefore, laminitis development. Potential relevance: A correlation between lameness severity and escalating loss of lamellar HDs now exists. Therapy aimed at protecting the lamellar environment from haematogenous delivery of MMP activators or from glucose deprivation may control laminitis development.

Rhythmic variations in pain, stiffness, and manual dexterity in hand osteoarthritis

Objective: To explore circadian variation in pain, stiffness, and manual dexterity inpatients with hand osteoarthritis (OA). Methods: Twenty one patients with hand OA, as defined by ACR criteria (17 women, four men, mean age 62.2 years, range 52-74 years) self rated pain and stiffness on separate 10 cm horizontal visual analogue scales and performed bead intubation coordinometry (BIC) six times each day (on waking up, at bedtime, and every four hours in between) for 10 consecutive days. Each series (using data with the trend removed if there was a significant trend) was analysed for circadian rhythmicity by a cosine. vector technique (single cosinor). With individual data expressed as the percentage of the mean, group rhythm characteristics at period 24 hours were summarised for each variable by population mean cosinor analysis. Results: Individual analyses identified significant circadian rhythms at pless than or equal to0.05 for pain (n=15/21), stiffness (n=16/20), and dexterity (n=18/21), and a significant circadian rhythm on a group basis was identified for pain (p=0.013), stiffness (p

Systematic review of the role of pre-oxygenation for tracheal suctioning in ventilated newborn infants

Pre-oxygenation for endotracheal suctioning for mechanically ventilated infants is routine practice in many neonatal intensive care units. In the present systematic review the evidence to support its use is discussed and the authors conclude that no confident recommendations can be made from the results of this review.

Chronic inflammatory demyelinating polyneuropathy and respiratory failure

Neuromuscular respiratory failure is not considered to be a clinical feature of chronic inflammatory demyelinating polyneuropathy (CIDP). We present 4 patients with CIDP who required respiratory assistance and mechanical ventilation. Two patients needed emergent intubation and one patient lapsed in a stupor from hypercapnia. Respiratory failure in CIDP should be considered exceptional, but more formal studies in CIDP may be needed to assess its prevalence.

Pressure support ventilation with the ProSeal (R) laryngeal mask airway. A comparison of sevoflurane, isoflurane and propofol

Background and objective: There are no data about the influence of anaesthetics on cardiovascular variables during pressure support ventilation of the lungs through the laryngeal mask airway. We compared propofol, sevoflurane and isoflurane for maintenance of anaesthesia with the ProSeal (R) laryngeal mask airway during pressure support ventilation. Methods: Sixty healthy adults undergoing peripheral musculo-skeletal surgery were randomized for maintenance with sevoflurane end-tidal 29%, isoflurane end-tidal 1.1% or propofol 6 mg kg(-1) h(-1) in oxygen 33% and air. Pressure support ventilation comprised positive end-expiratory pressure set at 5 cmH(2)O, and pressure support set 5 cmH(2)O above positive end-expiratory pressure. Pressure support was initiated when inspiration produced a 2 cmH(2)O reduction in airway pressure. A blinded observer recorded cardiorespiratory variables (heart rate, mean blood pressure, oxygen saturation, air-way occlusion pressure, respiratory rate, expired tidal volume, expired minute volume and end-tidal CO2), adverse events and emergence times. Results: Respiratory rate and minute volume were 10-21% lower, and end-tidal CO2 6-11% higher with the propofol group compared with the sevoflurane or isoflurane groups, but otherwise cardiorespiratory variables were similar among groups. No adverse events occurred in any group. Emergence times were longer with the propofol group compared with the sevoflurane or isoflurane groups (10 vs. 7 vs. 7 min). Conclusion: Lung ventilation is less effective and emergence times are longer with propofol than sevoflurane or isoflurane for maintenance of anaesthesia during pressure support ventilation with the ProSeal (R) laryngeal mask airway. However, these differences are small and of doubtful clinical importance.

Double-heater-wire circuits and heat-and-moisture exchangers and the risk of ventilator-associated pneumonia

Objective: To compare the incidence of ventilator-associated pneumonia (VAP) in patients ventilated in intensive care by means of circuits humidified with a hygroscopic heat-and-moisture exchanger with a bacterial viral filter (HME) or hot-water humidification with a heater wire in both inspiratory and expiratory circuit limbs (DHW) or the inspiratory limb only (SHW). Design: A prospective, randomized trial. Setting: A metropolitan teaching hospital's general intensive care unit. Patients: Three hundred eighty-one patients requiring a minimum period of mechanical ventilation of 48 hrs. Interventions: Patients were randomized to humidification with use of an HME (n = 190), SHW (n = 94), or DHW (n = 97). Measurements and Main Results. Study end points were VAP diagnosed on the basis of Clinical Pulmonary Infection Score (CPIS) (1), HME resistance after 24 hrs of use, endotracheal tube resistance, and HME use per patient. VAP occurred with similar frequency in all groups (13%, HME; 14%, DHW; 10%, SHW; p = 0.61) and was predicted only by current smoking (adjusted odds ratio [AOR], 2.1; 95% confidence interval [CI], 1.1-3.9; p =.03) and ventilation days (AOR, 1.05; 95% Cl, 1.0-1.2; p =.001); VAP was less likely for patients with an admission diagnosis of pneumonia (AOR, 0.40; 95% Cl, 0.4-0.2; p =.04). HME resistance after 24 hrs of use measured at a gas flow of 50 L/min was 0.9 cm H2O (0.4-2.9). Endotracheal tube resistance was similar for all three groups (16-19 cm H2O min/L; p =.2), as were suction frequency, secretion thickness, and blood on suctioning (p =.32, p =.06, and p =.34, respectively). The HME use per patient per day was 1.13. Conclusions: Humidification technique does not influence either VAP incidence or secretion characteristics, but HMEs may have air-flow resistance higher than manufacturer specifications after 24 hrs of use.