Agreement between arterial partial pressure of carbon dioxide and saturation of hemoglobin with oxygen values obtained by direct arterial blood measurements versus noninvasive methods in conscious healthy and ill foals

Objective—To determine agreement between indirect measurements of end-tidal partial pressure of carbon dioxide (Petco2) and saturation of hemoglobin with oxygen as measured by pulse oximetry (Spo2) with direct measurements of Paco2 and calculated saturation of hemoglobin with oxygen in arterial blood (Sao2) in conscious healthy and ill foals. Design—Validation study. Animals—10 healthy and 21 ill neonatal foals. Procedures—Arterial blood gas analysis was performed on healthy and ill foals examined at a veterinary teaching hospital to determine direct measurements of Paco2 and Pao2 along with Sao2. Concurrently, Petco2 was measured with a capnograph inserted into a naris, and Spo2 was measured with a reflectance probe placed at the base of the tail. Paired values were compared by use of Pearson correlation coefficients, and level of agreement was assessed with the Bland-Altman method. Results—Mean ± SD difference between Paco2 and Petco2 was 0.1 ± 5.0 mm Hg. There was significant strong correlation (r = 0.779) and good agreement between Paco2 and Petco2. Mean ± SD difference between Sao2 and Spo2 was 2.5 ± 3.5%. There was significant moderate correlation (r = 0.499) and acceptable agreement between Sao2 and Spo2. Conclusions and Clinical Relevance—Both Petco2 obtained by use of nasal capnography and Spo2 obtained with a reflectance probe are clinically applicable and accurate indirect methods of estimating and monitoring Paco2 and Sao2 in neonatal foals. Indirect methods should not replace periodic direct measurement of corresponding parameters

Effects of intravenous administration of polymyxin B in neonatal foals with experimental endotoxemia

Objective—To evaluate the effect of IV administration of polymyxin B on clinical and serum biochemical variables in foals with experimental endotoxemia. Design—Prospective experimental study. Animals—14 healthy neonatal foals. Procedures—Foals were randomly assigned to a treatment or control group and were administered a single dose of lipopolysaccharide (0.5 μg/kg [0.23 μg/lb]) IV over 30 minutes. The treatment group received polymyxin B (6,000 U/kg [2,727 U/lb], IV) immediately after completion of lipopolysaccharide infusion; the control group was administered an equal volume of saline (0.9% NaCl) solution. Subsequent doses of polymyxin B or saline solution were administered IV at 8 and 16 hours. Blood was collected at various time points, and outcome variables, including heart rate, respiratory rate, rectal temperature, attitude score, WBC count, neutrophil count, lymphocyte count, monocyte count, platelet count, Hct, blood lactate concentration, blood glucose concentration, serum tumor necrosis factor-α concentration, and plasma thromboxane B2 concentration, were measured. Urine was collected prior to and after experimentation to determine whether nephrotoxicosis was associated with treatment. Results—The treatment group had significantly lower blood lactate concentration and serum tumor necrosis factor-α and plasma thromboxane B2 concentrations and had higher blood glucose concentrations and better attitude scores, compared with the control group, at various time points during the study. No other significant differences and no evidence of overt nephrotoxicosis were detected. Conclusions and Clinical Relevance—Administration of polymyxin B IV in healthy neonatal foals challenged with lipopolysaccharide attenuated some clinical and serum biochemical derangements associated with endotoxemia

Clinical and Immunomodulating Effects of Ketamine in Horses with Experimental Endotoxemia

Background:  Ketamine has immunomodulating effects both in vitro and in vivo during experimental endotoxemia in humans, rodents, and dogs. Hypothesis:  Subanesthetic doses of ketamine will attenuate the clinical and immunologic responses to experimental endotoxemia in horses. Animals:  Nineteen healthy mares of various breeds. Methods:  Experimental study. Horses were randomized into 2 groups: ketamine-treated horses (KET; n = 9) and saline-treated horses (SAL; n = 10). Both groups received 30 ng/kg of lipopolysaccharide (LPS, Escherichia coli, O55:B5) 1 hour after the start of a continuous rate infusion (CRI) of racemic ketamine (KET) or physiologic saline (SAL). Clinical and hematological responses were documented and plasma concentrations of tumor necrosis factor-α (TNF-α) and thromboxane B2 (TXB2) were quantified. Results:  All horses safely completed the study. The KET group exhibited transient excitation during the ketamine loading infusion (P \u3c .05) and 1 hour after discontinuation of administration (P \u3c .05). Neutrophilic leukocytosis was greater in the KET group 8 and 24 hours after administration of LPS (P \u3c .05). Minor perturbations of plasma biochemistry results were considered clinically insignificant. Plasma TNF-α and TXB2 production peaked 1.5 and 1 hours, respectively, after administration of LPS in both groups, but a significant difference between treatment groups was not demonstrated. Conclusions and Clinical Importance:  A subanesthetic ketamine CRI is well tolerated by horses. A significant effect on the clinical or immunologic response to LPS administration, as assessed by clinical observation, hematological parameters, and TNF-α and TXB2production, was not identified in healthy horses with the subanesthetic dose of racemic ketamine utilized in this study

Factors associated with recovery from paraplegia in dogs with loss of pain perception in the pelvic limbs following intervertebral disk herniation

Abstract OBJECTIVE To investigate associations between recovery of locomotion and putative prognostic factors in dogs with loss of deep pain perception in the pelvic limbs caused by intervertebral disk herniation (IVDH). DESIGN Prospective cohort study. ANIMALS 78 client-owned dogs evaluated for IVDH that underwent spinal decompression surgery. PROCEDURES Dogs with complete loss of deep pain perception in the pelvic limbs and tail underwent routine examinations, advanced imaging, and spinal decompression surgery in accordance with standards of practice and owner consent. For each dog, information was prospectively collected on duration of clinical signs prior to onset of paraplegia; delay between onset of paraplegia and initial referral evaluation; date of recovery of locomotion, death, or euthanasia (3-month follow-up period); and whether dogs had received corticosteroid drugs before surgery. Severity of spinal cord compression at the lesion epicenter was measured via CT or MRI. RESULTS 45 of 78 (58%) of dogs recovered the ability to ambulate independently within 3 months after spinal decompression surgery. No evidence of prognostic value was identified for any of the investigated factors; importantly, a greater delay between onset of paraplegia and referral evaluation was not associated with a poorer prognosis. CONCLUSIONS AND CLINICAL RELEVANCE In this group of dogs with IVDH, immediacy of surgical treatment had no apparent association with outcome. The prognosis for recovery may instead be strongly influenced by the precise nature of the initiating injury.</jats:p

Effects of intravenous administration of polymyxin B in neonatal foals with experimental endotoxemia

Objective—To evaluate the effect of IV administration of polymyxin B on clinical and serum biochemical variables in foals with experimental endotoxemia. Design—Prospective experimental study. Animals—14 healthy neonatal foals. Procedures—Foals were randomly assigned to a treatment or control group and were administered a single dose of lipopolysaccharide (0.5 μg/kg [0.23 μg/lb]) IV over 30 minutes. The treatment group received polymyxin B (6,000 U/kg [2,727 U/lb], IV) immediately after completion of lipopolysaccharide infusion; the control group was administered an equal volume of saline (0.9% NaCl) solution. Subsequent doses of polymyxin B or saline solution were administered IV at 8 and 16 hours. Blood was collected at various time points, and outcome variables, including heart rate, respiratory rate, rectal temperature, attitude score, WBC count, neutrophil count, lymphocyte count, monocyte count, platelet count, Hct, blood lactate concentration, blood glucose concentration, serum tumor necrosis factor-α concentration, and plasma thromboxane B2 concentration, were measured. Urine was collected prior to and after experimentation to determine whether nephrotoxicosis was associated with treatment. Results—The treatment group had significantly lower blood lactate concentration and serum tumor necrosis factor-α and plasma thromboxane B2 concentrations and had higher blood glucose concentrations and better attitude scores, compared with the control group, at various time points during the study. No other significant differences and no evidence of overt nephrotoxicosis were detected. Conclusions and Clinical Relevance—Administration of polymyxin B IV in healthy neonatal foals challenged with lipopolysaccharide attenuated some clinical and serum biochemical derangements associated with endotoxemia.This article is from Journal of the American Veterinary Medical Association 243 (2013): 874, doi: 10.2460/javma.243.6.874. Posted with permission.</p

Agreement between arterial partial pressure of carbon dioxide and saturation of hemoglobin with oxygen values obtained by direct arterial blood measurements versus noninvasive methods in conscious healthy and ill foals

Objective—To determine agreement between indirect measurements of end-tidal partial pressure of carbon dioxide (Petco2) and saturation of hemoglobin with oxygen as measured by pulse oximetry (Spo2) with direct measurements of Paco2 and calculated saturation of hemoglobin with oxygen in arterial blood (Sao2) in conscious healthy and ill foals. Design—Validation study. Animals—10 healthy and 21 ill neonatal foals. Procedures—Arterial blood gas analysis was performed on healthy and ill foals examined at a veterinary teaching hospital to determine direct measurements of Paco2 and Pao2 along with Sao2. Concurrently, Petco2 was measured with a capnograph inserted into a naris, and Spo2 was measured with a reflectance probe placed at the base of the tail. Paired values were compared by use of Pearson correlation coefficients, and level of agreement was assessed with the Bland-Altman method. Results—Mean ± SD difference between Paco2 and Petco2 was 0.1 ± 5.0 mm Hg. There was significant strong correlation (r = 0.779) and good agreement between Paco2 and Petco2. Mean ± SD difference between Sao2 and Spo2 was 2.5 ± 3.5%. There was significant moderate correlation (r = 0.499) and acceptable agreement between Sao2 and Spo2. Conclusions and Clinical Relevance—Both Petco2 obtained by use of nasal capnography and Spo2 obtained with a reflectance probe are clinically applicable and accurate indirect methods of estimating and monitoring Paco2 and Sao2 in neonatal foals. Indirect methods should not replace periodic direct measurement of corresponding parameters.This article is from Journal of the American Veterinary Medical Association 239 (2011): 1341, doi: 10.2460/javma.239.10.1341. Posted with permission.</p

Renal Replacement Therapy in Healthy Adult Horses

Background Renal replacement therapy (RRT) has been implemented extensively in people to facilitate recovery from acute renal failure (ARF). RRT has not been explored in horses, but might provide a further treatment option in horses with ARF. Objective To investigate efficacy and safety of RRT in horses. Animals Five healthy adult horses. Methods A prospective study was performed on horses restrained in stocks and intravenously connected to a commercial RRT machine to allow continuous venovenous hemodiafiltration to be performed for 6 hours. The RRT machine was set at the following flow rates: blood flow rate 250 mL/min; dialysate rate 3,000 mL/h; prefilter replacement pump 3,000 mL/h; and postfilter replacement pump rate 2,000 mL/h. Balanced electrolyte solution was used as dialysate and replacement fluid. Heart rate, respiratory rate, body temperature, direct arterial blood pressure, urine output, and various clinicopathologic parameters were measured over the study period. Results Renal replacement therapy was successfully performed in horses, resulting in a mean creatinine clearance of 0.127 mL/kg/min (68.9 mL/min) and urea reduction ratio of 24%. No adverse effects were detected although a significant decrease in rectal temperature was observed (P ≤ .007). A significant increase in serum phosphorus (P ≤ .001) and decrease in BUN (P P P P ≤ .04). Conclusions and Clinical Importance Renal replacement therapy can safely and effectively be used in adult horses.This article is from Journal of Veterinary Internal Medicine 27 (2013); 308, doi: 10.1111/jvim.12049. Posted with permission.</p

Physiologic effects of nasopharyngeal administration of supplemental oxygen at various flow rates in healthy neonatal foals

Objective—To evaluate the effects of various flow rates of oxygen administered via 1 or 2 nasal cannulae on the fraction of inspired oxygen concentration (Fio2) and other arterial blood gas variables in healthy neonatal foals. Animals—9 healthy neonatal (3- to 4-day-old) foals. Procedures—In each foal, a nasal cannula was introduced into each naris and passed into the nasopharynx to the level of the medial canthus of each eye; oxygen was administered at 4 flow rates through either 1 or both cannulae (8 treatments/foal). Intratracheal Fio2, intratracheal end-tidal partial pressure of carbon dioxide, and arterial blood gas variables were measured before (baseline) and during unilateral and bilateral nasopharyngeal delivery of 50, 100, 150, and 200 mL of oxygen/kg/min. Results—No adverse reactions were associated with administration of supplemental oxygen except at the highest flow rate, at which the foals became agitated. At individual flow rates, significant and dose-dependent increases in Fio2, Pao2, and oxygen saturation of hemoglobin (Sao2) were detected, compared with baseline values. Comparison of unilateral and bilateral delivery of oxygen at similar cumulative flow rates revealed no differences in evaluated variables. Conclusions and Clinical Relevance—Results indicated that administration of supplemental oxygen via nasal cannulae appeared to be a highly effective means of increasing Fio2, Pao2, and Sao2 in neonatal foals. These findings may provide guidance for implementation of oxygen treatment in hypoxemic neonatal foals.This article is from American Journal of Veterinary Research 71 (2010): 1081, doi: 10.2460/ajvr.71.9.1081. Posted with permission.</p