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SUMMARY

End-tidal carbon dioxide tension (Pet CO2 ) and arterial carbon dioxide tension (PaCO2 ) were determined and compared in isoflurane-anesthetized spontaneously breathing equine neonates. End-tidal carbon dioxide and PaCO2 values increased with respect to time. Difference between values of Pet CO2 and PaCO2 increased over time. End-tidal carbon dioxide tension was useful to predict changes in and was more closely correlated with PaCO2 early in the anesthetic period (T ≤ 60 minutes). The dead space volume to tidal volume (Vd/Vt) ratio increased with respect to time, indicating increase in physiologic dead space in isoflurane-anesthetized foals. The data indicate that the increased difference between widening of the Pet CO2 and PaCO2 values over time may have been attributable to hypoventilation and decreased pulmonary capillary perfusion of alveoli.

Free access
in American Journal of Veterinary Research

Abstract

Objectives

To determine whether high PaCO2 reduced apparent efficiency of IgG absorption (AEA) in calves and whether assisted ventilation of calves with high PaCO2 increased AEA.

Animals

48 Holstein calves.

Procedures

Arterial and venous blood samples were collected 1, 13, and 25 hours after birth; an additional venous sample was collected at 37 hours after birth. Arterial samples were analyzed for PaCO2 , PaO2 , pH, and bicarbonate and base excess concentrations; venous samples were analyzed for plasma IgG concentrations. On the basis of 1-hour PaCO2 , calves were assigned to nonrespiratory acidosis (PaCO2 < 50 mm Hg; n = 19) or respiratory acidosis (PaCO2 ≥ 50 mm Hg; 29) groups. Calves in the respiratory acidosis group were assigned randomly to receive no further treatment (n = 17) or to be given 5 minutes of assisted ventilation (12). All calves received between 1.8 and 2 L of colostrum 2, 14, 26, and 38 hours after birth. Plasma volume and AEA were determined 25 hours after birth.

Results

1-hour PaCO2 had no effect on AEA or on plasma IgG concentrations determined 13, 25, or 37 hours after birth. Artificial ventilation had no effect on plasma IgG concentration or AEA.

Conclusions and Clinical Relevance

Lack of effect of 1-hour PaCO2 on AEA and IgG concentration indicated that calves compensated for moderate acidbase imbalances associated with birth. Calves born with high PaCO2 achieved adequate plasma IgG concentrations if fed an adequate amount of high-quality colostrum early in life. The effect of artificial ventilation on PaCO2 was temporary and did not increase AEA. (Am J Vet Res 1999;60:609–614)

Free access
in American Journal of Veterinary Research

Summary

Total protein (tp), albumin, and IgG concentrations were measured in csf from the atlanto-occipital (ao) and lumbosacral (ls) sites and in serum of 15 clinically normal neonatal foals ≤ 10 days old (mean, 7.0 days). The albumin quotient (aq; csf albumin/serum albumin × 100) and IgG index ([csf IgG/serum IgG] × [serum albumin/csf albumin]), indicators of blood-brain barrier permeability and intrathecal IgG production, respectively, were then calculated.

Mean ± sd values obtained from the foals of this study were: serum albumin, 2,900 ± 240 mg/dl; serum IgG, 1,325 ± 686 mg/dl; ao csf total protein (tp), 82.8 ± 19.2 mg/dl; ls csf tp, 83.6 ± 16.1 mg/dl; ao csf albumin, 52.0 ± 8.6 mg/dl; ls csf albumin, 53.8 ± 15.7 mg/dl; ao csf IgG, 10.2 ± 5.5 mg/dl; ls csf IgG, 9.9 ± 5.7 mg/dl; ao aq, 1.86 ± 0.29; ls aq, 1.85 ± 0.51, ao IgG index, 0.52 ± 0.28; and ls IgG index, 0.48 ± 0.27. Significant difference between values for the ao and ls sites was not found. A csf albumin concentration > 85.2 mg/dl or aq > 2.4, as determined by mean ± 2 sd, may indicate increased blood-brain barrier permeability. An IgG index value >1.0 may indicate intrathecal IgG production.

Values obtained for foals of this study should serve as baseline for comparison in the evaluation of blood-brain barrier permeability and intrathecal IgG production in neonatal foals with neurologic disease.

Free access
in American Journal of Veterinary Research

Summary

Packed cell volume and plasma total protein (tp), serum albumin (Alb) and globulin (Glb), and plasma ionized calcium (PCa) concentrations, blood viscosity ( bv ), and plasma viscosity (pv) were measured in 42 horses at rest and after the cross country jumping phase of a horse trial competition. The bv and pv were determined at 6 shear rates (230, 115, 46, 23, 11.5, 5.75 s−1), using a digital rotational cone and plate microviscometer. A paired t-test was used to determine differences between pcv, tp, Alb, Glb and PCa values at rest and after exercise. The pcv, tp, Alb, and Glb values increased (P < 0.05) in horses after exercise. The PCa concentration decreased (P < 0.05) in horses after exercise. Mean bv and pv in the 42 horses at rest and after exercise were fitted to an asymptotic function. Significant (P < 0.05) correlation at all shear rates was seen between bv at rest and pcv, tp, Alb, Glb, and PCa values at rest; and between bv after exercise and pcv, tp, Alb, Glb, and PCa values after exercise. Significant correlation was not seen between pv at rest and tp, Alb, Glb, and PCa at rest, or between pv after exercise and tp, Alb, Glb, and PCa concentrations after exercise at any shear rate.

Free access
in American Journal of Veterinary Research

Summary

Body weight of 48 horses competing in a 3-day event was measured the day before the event (baseline), following the dressage phase of the event (day 1), after the endurance phases of the event (day 2), and 18 to 24 hours after the endurance phases (day 3). Plasma sodium and potassium concentrations were measured the evening before, immediately after, and 10 minutes after the endurance phases. Total body water, water loss, and net exchangeable cation loss were then calculated.

Body weight and total body water were significantly decreased, compared with baseline values, at all times during the event, and significant water loss was detected. The largest changes were recorded after the endurance phases of the event. Water deficits were still detected 18 to 24 hours after the endurance phases of the event.

Mean plasma sodium concentration was significantly increased immediately after the endurance phases of the event, compared with concentration measured the evening before, and remained increased after the 10-minute recovery period, presumably because of dehydration. Mean plasma potassium concentration was significantly increased immediately after the endurance phases of the event, compared with concentration measured the evening before, but was not increased after the 10-minute recovery period.

Free access
in Journal of the American Veterinary Medical Association