Dean's Lunchtime Clinical Club - 14 November 2017 - Fernanda Camacho
Fernanda Camacho, Intern in Small Animal Intensive Care, spoke to this week's Clinical Club about 'When Potassium Matters' and how important this is in the ICU. Fernanda began her talk by looking at what potassium is and where it’s found. Potassium is located mainly intracellularly and is responsible for maintaining the resting cell membrane potential; changes in the plasma concentration can therefore be detrimental. Fernanda also looked at potassium regulation, describing intake, excretion and translocation. Her talk was focused on how to apply this to clinical cases, and she emphasised the importance of looking at smaller issues as well as the bigger picture; Fernanda then went through two cases - one of hyperkalaemia and the other a case of hypokalaemia.
The first case discussed involved a 3 year old mini schnauzer called Ben. Ben had been attacked by another dog two days prior to coming to the UCDVH, and his neck wound had been treated with broad spectrum anti-biotics and a non-steroidal anti-inflammatory. Ben was dull, off his food and had experienced one episode of vomiting. His clinical exam was within normal limits and the wound was healing well so the next step was to take bloods. The biochemistry report showed up hyperkalaemia, and a number of other minor issues related to this main problem. Urinalysis showed that there was minimal urine in the bladder and Ben was started on fluids to improve the renal perfusion and urinary excretion of potassium. An ECG was also attached as Fernanda explained that it's important to monitor the heart in these cases; brachycardia and atrial standstill are just two of the potentially fatal issues that can arise. There is an extensive list of the causes of hyperkalaemia, and Fernanda went through the four main ones seen in practice. Ben's diagnosis was acute kidney injury with secondary hyperkalaemia, most likely caused by the anti-inflammatory drug; the hyperkalaemia was caused by a decrease of renal excretion.
The second case Fernanda focused on was Tiggy, a 10 year old DSH, who had vomiting, diarrhoea, anorexia, lethargy and weakness prior to coming to the UCDVH. Her haemotology was unremarkable, and her biochemistry report showed that her glucose was increased, but this can often happen when cats are under stress. Tiggy was also found to have hypokalaemia or low potassium. There are three general causes of this - decreased intake, translocation and increased loss. The consequences can be extensive and in the following areas: metabolic, neuromuscular, renal, cardiac. In such cases, it is important to treat the underlying cause and also to treat with supplementation. Tiggy improved quickly and was discharged with normal appetite and normal potassium values. Her diagnosis was presumptive gastroenteritis. Fernanda outlined the importance of continually measuring potassium levels in a case like Tiggy's to ensure that they don't go up or down too much either way.
This was an informative and engaging talk, and offered fascinating insights for students into the work of the Small Animal ICU unit in the UCDVH.