Clinic for Ruminants with Ambulatory and Herd Health Services at the Centre for Clinical Veterinary Medicine, LMU Munich, Sonnenstraße 16, 85764 Oberschleißheim, Germany.
Vet J. 2013 Mar;195(3):350-6. doi: 10.1016/j.tvjl.2012.07.002. Epub 2012 Sep 8.
One hundred and twenty-four calves with neonatal diarrhoea were investigated in order to assess the prevalence of hyperkalaemia and the associated clinical signs. Hyperkalaemia (potassium concentration >5.8mmol/L) was recognized in 42 (34%) calves and was more closely associated with dehydration than with decreases in base excess or venous blood pH. In 75 calves with normal blood concentrations of D-lactate (i.e. ⩽3.96mmol/L), K concentrations were moderately correlated with base excess values (r=-0.48, P<0.001). In contrast, no significant correlation was observed in 49 calves with elevated D-lactate. Only three hyperkalaemic calves had bradycardia and a weak positive correlation was found between heart rate and K concentrations (r=0.22, P=0.014). Ten of the 124 calves had cardiac arrhythmia and of these seven had hyperkalaemia indicating that cardiac arrhythmia had a low sensitivity (17%) but a high specificity (96%) as a predictor of hyperkalaemia. In a subset of 34 calves with base excess values ⩽-5mmol/L and D-lactate concentrations <5mmol/L (of which 22 had hyperkalaemia), changes in posture/ability to stand could be mainly explained by elevations of K concentrations (P<0.001) and to a lesser extent by increases in L-lactate concentrations (P=0.024). Skeletal muscle weakness due to hyperkalaemia alongside hypovolaemia may produce a clinical picture that is similar to that in calves with marked D-lactic acidosis. However, since reductions in the strength of the palpebral reflex are closely correlated with D-lactate concentrations, a prompt palpebral reflex can assist the clinical prediction of hyperkalaemia in calves presenting with a distinct impairment in their ability to stand (specificity 99%, sensitivity 29%).
为了评估高钾血症的流行情况和相关临床症状，对 124 头患有新生期腹泻的犊牛进行了研究。在 42 头（34%）犊牛中发现了高钾血症（钾浓度>5.8mmol/L），与脱水的相关性比与基础碱缺失或静脉血 pH 值降低的相关性更密切。在 75 头血 D-乳酸浓度正常（即 ⩽3.96mmol/L）的犊牛中，K 浓度与基础碱缺失值中度相关（r=-0.48，P<0.001）。相比之下，在 49 头 D-乳酸升高的犊牛中，没有观察到显著相关性。只有 3 头高钾血症犊牛有心动过缓，并且发现心率与 K 浓度之间存在弱正相关（r=0.22，P=0.014）。124 头犊牛中有 10 头有心律失常，其中 7 头有高钾血症，这表明心律失常作为高钾血症的预测指标具有较低的敏感性（17%），但较高的特异性（96%）。在一组 34 头基础碱缺失值 ⩽-5mmol/L 和 D-乳酸浓度<5mmol/L 的犊牛中（其中 22 头有高钾血症），姿势/站立能力的变化主要可以由 K 浓度升高（P<0.001）来解释，而在较小程度上可以由 L-乳酸浓度升高来解释（P=0.024）。由于低钾血症引起的骨骼肌无力可能导致与具有明显 D-乳酸性酸中毒的犊牛相似的临床症状。然而，由于上睑反射强度的降低与 D-乳酸浓度密切相关，因此及时的上睑反射可以协助预测具有明显站立能力障碍的犊牛发生高钾血症（特异性 99%，敏感性 29%）。
