Vet Times

Tag: Potassium

  • Blood gas analysis, pt 5: metabolic acidosis and alkalosis

    Blood gas analysis, pt 5: metabolic acidosis and alkalosis

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    Base excess (BE) and bicarbonate (HCO3-) represent the metabolic components of the acid base equation. In general, both components will change in the same direction. Decreased HCO3– and BE indicate either a primary metabolic acidosis or a metabolic compensation for a chronic respiratory alkalosis. Elevated HCO3– and BE indicate either a primary metabolic alkalosis or…

  • Blood gas analysis, pt 2: acid-base disturbances

    Blood gas analysis, pt 2: acid-base disturbances

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    Acid-base disturbances are common in critical patients. These changes must be identified, as even minor deviations from the normal range can lead to significant abnormal body functions. Acidaemia and alkalaemia Acidaemia, which occurs when blood pH falls below 7.35, will lead to: impedance of cardiac output reduced cardiac contractility a blunted response to catecholamine manifesting…

  • Hyperkalaemia, pt 2: treatment

    Hyperkalaemia, pt 2: treatment

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    Treatment of hyperkalaemia is based on its severity. Mild to moderate elevations Mild to moderate elevations exist when the serum potassium concentration is between 5.5mmol/L and 6.5mmol/L. Treatment options are: IV crystalloids, which correct volume and dehydration deficits. Fluid therapy – the primary treatment, with the aim of: diluting serum potassium, by increasing the intravascular…

  • Hyperkalaemia, pt 1: clinical signs and causes

    Hyperkalaemia, pt 1: clinical signs and causes

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    Hyperkalaemia is a relatively common electrolyte abnormality encountered in the clinic and always requires immediate attention, as myocardial toxicity can occur when serum potassium concentration gets sufficiently high (exceeding 5.5mmol/L). Hyperkalaemia causes clinical signs due to its effect on the resting membrane potential. The increase in potassium causes depolarisation of this potential, which, in effect,…

  • Lipaemia – the bane of biochemistry

    Lipaemia – the bane of biochemistry

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    Last week we covered haemolysed samples – this week we’re looking at lipaemic samples. Lipaemic samples are caused by an excess of lipoproteins in the blood, creating a milky/turbid appearance that interferes with multiple biochemical tests and can even cause haemolysis of red blood cells. Lipaemia can follow recent ingestion of a meal – especially…

  • PCV/total solids interpretation: serum colour

    PCV/total solids interpretation: serum colour

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    When interpreting the often misinterpreted and underused PCV and total solids test, it is important to take note of the serum colour as this may give clues into the diagnosis. The most common abnormalities seen in clinic are icteric, haemolysed and lipaemic serum. Clear serum can also be of importance – especially when you interpret…

  • Focus on GDV, part 4: the recovery

    Focus on GDV, part 4: the recovery

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    Postoperatively, gastric dilatation-volvulus (GDV) patients remain in our intensive care unit for at least two to three days. Monitoring includes standard general physical examination parameters, invasive arterial blood pressures, ECG, urine output via urinary catheter and pain scoring. I repeat PCV/total protein, lactate, blood gas and activated clotting times (ACT) immediately postoperatively and then every…

  • Maintenance fluids

    Maintenance fluids

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    A while ago we discussed the components of a fluid therapy plan and talked about hydration deficits. This week I want to touch on maintenance fluids. Maintenance rates are typically calculated using the following formulae: ml/day = 80 × bodyweight (kg)0.75 (cats) ml/day = 132 × bodyweight (kg)0.75 (dogs) or ml/day = 30 × bodyweight…

  • Making sense of effusions (part 1): is your patient septic?

    Making sense of effusions (part 1): is your patient septic?

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    Interpreting effusion samples can be confusing, so try to think of effusions as if you were collecting a blood sample. Many of the in-clinic diagnostic tests that apply to blood samples also apply to effusions, such as: PCV/total protein smears glucose lactate potassium creatinine bilirubin It’s not enough to only check the protein concentration of…

  • SNAP cortisol test

    SNAP cortisol test

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    While hyperadrenocorticism is not an uncommon incidental finding in patients presenting to our emergency clinic, hypoadrenocorticism is a lot less common. Or, possibly, more frequently underdiagnosed. Textbook clinical presentations combined with haematology and biochemicial changes can make diagnosis straightforward, but not all patients will present with all the classic signs. To complicate things further, hypoadrenocorticism…