Evaluation of indirect blood pressure monitoring in awake and anesthetized red-tailed hawks (Buteo jamaicensis): effects of cuff size, cuff placement, and monitoring equipment

ObjectiveTo compare Doppler and oscillometric methods of indirect arterial blood pressure (IBP) with direct arterial measurements in anesthetized and awake red-tailed hawks.Study designProspective, randomized, blinded study.AnimalsSix, sex unknown, adult red-tailed hawks.MethodsBirds were anesthetized and IBP measurements were obtained by oscillometry (IBP-O) and Doppler (IBP-D) on the pectoral and pelvic limbs using three cuffs of different width based on limb circumference: cuff 1 (20–30% of circumference), cuff 2 (30–40%), and cuff 3 (40–50%). Direct arterial pressure measurements were obtained from the contralateral superficial ulnar artery. Indirect blood pressure measurements were compared to direct systolic arterial pressure (SAP) and mean arterial pressure (MAP) during normotension and induced states of hypotension and hypertension. Measurements were also obtained in awake, restrained birds. Three-way anova, linear regression and Bland–Altman analyses were used to evaluate the IBP-D data. Results are reported as mean bias (95% confidence intervals).ResultsThe IBP-O monitor reported errors during 54% of the measurements. Indirect blood pressure Doppler measurements were most accurate with cuff 3 and were comparable to MAP with a bias of 2 (?9, 13 mmHg). However, this cuff consistently underestimated SAP with a bias of 33 (19, 48 mmHg). Variability in the readings within and among birds was high. There was no significant difference between sites of cuff placement. Awake birds had SAP, MAP and diastolic arterial pressure that were 56, 43, and 38 mmHg higher than anesthetized birds.Conclusions and clinical relevanceIndirect blood pressure (oscillometric) measurements were unreliable in red-tailed hawks. Indirect blood pressure (Doppler) measurements were closer to MAP measurements than SAP measurements. There was slightly better agreement with the use of cuff 3 on either the pectoral or pelvic limbs. Awake, restrained birds have significantly higher arterial pressures than those under sevoflurane anesthesia.     

A study of cardiovascular function under controlled and spontaneous ventilation in isoflurane–medetomidine anaesthetized horses

Objective To determine, in mildly hypercapnic horses under isoflurane–medetomidine balanced anaesthesia, whether there is a difference in cardiovascular function between spontaneous ventilation (SV) and intermittent positive pressure ventilation (IPPV). Study design Prospective randomized clinical study. Animals Sixty horses, undergoing elective surgical procedures under general anaesthesia: ASA classification I or II. Methods Horses were sedated with medetomidine and anaesthesia was induced with ketamine and diazepam. Anaesthesia was maintained with isoflurane and a constant rate infusion of medetomidine. Horses were assigned to either SV or IPPV for the duration of anaesthesia. Horses in group IPPV were maintained mildly hypercapnic (arterial partial pressure of carbon dioxide (PaCO₂) 50–60 mmHg, 6.7–8 kPa). Mean arterial blood pressure (MAP) was maintained above 70 mmHg by an infusion of dobutamine administered to effect. Heart rate (HR), respiratory rate (f_R), arterial blood pressure and inspiratory and expiratory gases were monitored continuously. A bolus of ketamine was administered when horses showed nystagmus. Cardiac output was measured using lithium dilution. Arterial blood‐gas analysis was performed regularly. Recovery time was noted and recovery quality scored. Results There were no differences between groups concerning age, weight, body position during anaesthesia and anaesthetic duration. Respiratory rate was significantly higher in group IPPV. Significantly more horses in group IPPV received supplemental ketamine. There were no other significant differences between groups. All horses recovered from anaesthesia without complications. Conclusions There was no difference in cardiovascular function in horses undergoing elective surgery during isoflurane–medetomidine anaesthesia with SV in comparison with IPPV, provided the horses are maintained slightly hypercapnic. Clinical relevance In horses with health status ASA I and II, cardiovascular function under general anaesthesia is equal with or without IPPV if the PaCO₂ is maintained at 50–60 mmHg.     

Partitioning soil carbon responses to warming: Model-derived guidance for data interpretation

Parallel incubation at different temperatures combined with ¹³CO₂ efflux has been used to distinguish the temperature sensitivity of labile soil carbon (young soil carbon derived from newly-introduced vegetation) from that of resistant soil carbon (old, native vegetation-derived soil carbon). But we believe that this approach to assessing relative temperature sensitivities is confounded by differential rates of depletion of labile and resistant soil carbon at different temperatures. Here we employ a simple decomposition model to demonstrate potential pitfalls in interpreting ¹³CO₂ efflux data that inevitably, and potentially erroneously, lead to the conclusion that decomposition of resistant soil carbon pools is more temperature sensitive than labile pools. We conclude by offering a new approach for interpreting these data that eliminates this potential bias.     

Influence of swab material on the detection of Mycoplasma gallisepticum and Mycoplasma synoviae by real-time PCR

Recent reports have shown an increased recovery of cells from flocked nylon swabs which may improve the specimen quality and the real sensitivity of diagnostic tests in a clinical setting. In this study, the detection of Mycoplasma gallisepticum (MG) and M. synoviae (MS), using dry swabs of different materials (nylon flocked, cotton, and polyester), was investigated using real-time TaqMan PCR protocols. Different types of samples, including dilutions of pure broth cultures of MG and MS as well as swabs from tracheas of experimentally infected chickens and field cases of infection, were analyzed. There were no statistical differences in real-time PCR results among the different swab types (P < 0.05), indicating that this is not likely to be a significant factor in MG and MS detection by this method.     

An open clinical trial on the efficacy of cetirizine hydrochloride in the management of allergic pruritus in cats

Cetirizine hydrochloride was administered orally at 5 mg/cat, q24h, to 32 cats with allergic skin disease. Pruritus was reduced in 41% (13/32) of the cats. The antipruritic effect was repeatable and sustainable. There was no significant association between patient age, disease severity, or cutaneous reaction pattern and improvement during cetirizine administration. No adverse side effects were reported.     

Characterization of the mutations causing hemophilia B in 2 domestic cats

The purpose of the present study was to determine the normal sequence for the gene encoding factor IX in cats and to characterize the genetic basis for hemophilia B in 2 unrelated male, domestic, mixed-breed cats. Genomic DNA sequence for the entire coding region of the factor IX gene was determined in the affected cats and compared to the sequence obtained from a healthy cat. The factor IX gene in cats encodes a mature protein consisting of 420 amino acids, unlike genes in humans and dogs that encode 415 and 413 amino acid proteins, respectively. Affected cat 1 had a single nucleotide change in exon 8 at the 1st nucleotide position of the codon encoding an arginine (CGA to TGA) at amino acid position 338. This mutation would be predicted to result in the appearance of a premature stop codon in the portion of the gene encoding much of the catalytic domain of the protein. Affected cat 2 had a single nucleotide change in exon 4 at the 2nd nucleotide position of the codon encoding amino acid 82 (TGT to TAT), which would be predicted to result in the substitution of a tyrosine for a cysteine. This substitution would likely result in disruption of a disulfide bond crucial to normal protein structure and function. This study represents the 1st time hemophilia B has been characterized at the molecular level in cats.