Title of Guideline (must include the word Guideline Guideline for the Treatment of Hypokalaemia in Adults

Transcription

1 Title of Guideline (must include the word Guideline Guideline for the Treatment of (not protocol, policy, procedure etc) Hypokalaemia in Adults Contact Name and Job Title (author) Emily Snow, Pharmacist NUH Directorate & Speciality Diagnostics and Clinical Support Date of submission October 2015 Date on which guideline must be reviewed (this should February 2019 be one to three years) Explicit definition of patient group to which it applies Guideline for adult patients with (e.g. inclusion and exclusion criteria, diagnosis) exception of those treated on a critical care unit. Version 2 Abstract Key Words Changes from previous guideline Statement of the evidence base of the guideline has the guideline been peer reviewed by colleagues? Evidence base: (1-6) 1 NICE Guidance, Royal College Guideline, SIGN 2a 2b 3a 3b (please state which source). meta analysis of randomised controlled trials at least one randomised controlled trial at least one well-designed controlled study without randomisation at least one other type of well-designed quasiexperimental study 4 well designed non-experimental descriptive studies (i.e. comparative / correlation and case studies) 5 expert committee reports or opinions and / or clinical experiences of respected authorities 6 recommended best practise based on the clinical experience of the guideline developer Consultation Process This guideline describes the management of hypokalaemia in adult inpatients Hypokalaemia, Potassium Formatting and typo correction. Dextrose wording changed to glucose. Re-wording and clarification of the principles and investigation section by Dr Roe. Addition of link to NUH Code of Practice for concentrated potassium. Addition of information for referral to CCOT. Clarification that administration of potassium is always by volumetric pump. 5 expert committee reports or opinions and / or clinical experiences of respected authorities Plus national advice in BNF Drugs & Therapeutics Committee Clinical Chemistry Renal Dr Simon Roe (Consultant Nephrologist) Target audience Nursing, pharmacy & medical staff This guideline has been registered with the trust. However, clinical guidelines are guidelines only. The interpretation and application of clinical guidelines will remain the responsibility of the individual clinician. If in doubt contact a senior colleague or expert. Caution is advised when using guidelines after the review date. Page 1 of 10

2 GUIDELINE FOR THE TREATMENT OF HYPOKALAEMIA IN ADULTS This guideline has been compiled to give advice to medical and nursing staff caring for patients on non-critical care wards. Alternative regimes using more concentrated potassium solutions are used in specialist areas of the hospital including critical care. Normal adult potassium range = mmol/l Severity of Hypokalaemia Serum Level (mmol/l) Mild Moderate Severe <2.5 In the presence of hypokalaemia AND ECG changes contact Critical Care Outreach Team (CCOT) for advice and support to manage the patient. CCOT QMC Campus Bleep CCOT City Campus Bleep If CCOT is not available (e.g. out of hours) contact the critical care registrar. Nearly 98% of the body s potassium is intracellular. The kidneys determine potassium haemostasis and excess potassium is excreted in the urine. Signs and symptoms of hypokalaemia Cardiovascular Bradycardia or tachycardia, hypotension, arrhythmias, cardiac arrest and palpitations ECG changes (U waves, T wave flattening, ST segment changes) Respiratory Respiratory distress and respiratory failure, hypoventilation Musculoskeletal Cramps, tetany, reduced deep tendon reflexes, reduced muscle strength General Peripheral oedema, lethargy, constipation, nausea, vomiting, abdominal cramping and paraesthesia Page 2 of 10

3 Causes of hypokalaemia -inadequate diet including anorexia, malnutrition, bulimia -high dietary sodium intake -gastrointestinal loss including diarrhoea, vomiting, ileostomy, intestinal fistulae -renal loss including dialysis -urinary loss in congestive heart failure -hypomagnesaemia -endocrine disorders, hyperaldosteronism, Cushing s syndrome -ectopic ACTH production, typically from small cell lung cancer -metabolic acidosis -medication -transcellular shift (movement of potassium from serum into cells) Drugs which can induce hypokalaemia This is not an exhaustive list. Please contact Pharmacy Medicines Information (x64185) for more details. Transcellular potassium shift -beta-agonists, caffeine, theophylline -verapamil or chloroquine overdose -insulin Increased renal potassium loss - diuretics (especially loop diuretics, high dose thiazides, metolazone, indapamide) -mineralocorticoids -hypomagnesaemia-inducing medications: e.g. aminoglycosides, cisplatin, amphotericin B, PPIs -High dose penicillin Excess potassium loss in stool -laxative abuse -liquorice Page 3 of 10

4 Principles and investigations for the treatment of hypokalaemia Remove causes. Assess for underlying cardiac disease. An ECG is strongly recommended in patients with: -severe / symptomatic hypokalaemia -cardiac disease or -renal impairment. Monitor U&Es, bicarbonate, chloride, glucose. Check magnesium levels repletion of magnesium stores will facilitate more rapid correction of hypokalaemia. If the cause is obvious: Treat any underlying cause such as diarrhoea and/or review medication. Consider oral potassium replacement treatment as outlined below. If the cause is unclear: Consider sending a random urine for spot potassium concentration to identify renal loss. A value of >15-20 mmol/l suggests renal loss. Unexplained renal loss, with or without hypertension, should prompt referral to investigate for rarer and complex electrolyte disorders such as Bartter s and Liddle s syndromes. Low urine potassium levels suggest poor intake/ shift into intracellular space or GI loss. Consider referral to Endocrinology to exclude Conn s and Cushing s Syndrome in hypertensive patients. Page 4 of 10

5 Treatment Gradual replacement of potassium, via the oral route, is preferred if clinically appropriate. Oral potassium should be taken with plenty of fluid, with or after meals. A drop in serum potassium level of 1 mmol/l represents a loss of about mmol of potassium from body stores. For serum levels between 2-3 mmol/l: o a maximum oral daily dose of mmol K + should be considered. For serum levels between 3-4 mmol/l, o a maximum oral daily dose of mmol K + should be considered. Use IV route in patients with severe nausea, vomiting, abdominal distress or when the oral or enteral route is not available or will not achieve the required increase of serum potassium within a clinically acceptable time. Use pre-mixed IV infusions. Sodium Chloride 0.9% is the preferred infusion fluid as Glucose 5% may cause trans-cellular shift of potassium into cells. Before a patient is transferred any prescriptions for solutions containing potassium infusions must be reviewed to ensure that the treatment can be continued on the receiving ward (see NUH Medicines Code of Practice). Renal impairment Potassium must be replaced cautiously in patients with renal impairment (risk of hyperkalaemia secondary to impaired potassium excretion). Contact the renal team if patient is on dialysis or has severe renal impairment i.e. CKD stage 4/5 (GFR<30) or AKI stage 2/3. Page 5 of 10

6 Potassium plasma level mmol/l Dosing and Administration Oral replacement: Sando K Effervescent Tablets contains potassium 12mmols per tablet 2 tablets taken three times a day (=72mmol/day) Sando K dissolves in water and may be given via feeding tubes. If not tolerated: Potassium chloride syrup (Kay-Cee-L ) contains potassium 5mmols in 5mL 25mL taken three times a day (=75 mmol/day) Monitor serum potassium daily continue treatment until potassium is in range (about 3 days) The patient may also be receiving addition sources of potassium, such as those in IV fluids or TPN and these should be included in calculations. Liaise with the nutrition team as necessary. Slow K 600mg MR Tablets (potassium chloride MR) contains potassium 8mmols per tablet and should only be used if Sando K or Kay-Cee-L are inappropriate. Slow K should be swallowed whole, with fluid, during meals, whilst the patient is sitting upright. It is associated with intestinal ulceration. Consider IV route if patient cannot tolerate oral treatment. Potassium plasma level mmol/l Dosing and Administration If patient is symptomatic consider IV route and contacting CCOT as advised above (see page 2). For IV dosing see below: potassium level <2.5mmol/L. Oral replacement: Sando K Effervescent Tablets 2 tablets taken four times a day (=96mmol/day) If not tolerated: Potassium chloride syrup (Kay-Cee-L ) contains potassium 5mmols in 5mL 25mL taken four times a day (=100mmol/day) See above for further information. Consider IV route if patient cannot tolerate oral treatment e.g. 20mmol 40mmol potassium chloride infusion, repeated as required. See rate and concentration restrictions below. Page 6 of 10

7 Potassium plasma level mmol/l <2.5 Dosing and Administration In the presence of hypokalaemia AND ECG changes contact Critical Care Outreach Team (CCOT) for advice and support to manage the patient (see page 2). If CCOT is not available (e.g. out of hours) contact the critical care registrar. Intravenous replacement: Dose Give potassium chloride 40mmol by intravenous infusion and repeat as required. It is recommended not to exceed 2-3 mmol K + per kg body weight in 24 hours. Concentration Pre-prepared infusion bags should be used (refer to list of available preprepared infusions on page 9). These can be given peripherally or centrally. Concentrated potassium* (1mmol in 1mL) must only be given in authorised areas and must be administered via the central route only. Concentrated potassium* (20mmol in 20ml and 50mmol in 50ml syringes) must be stored segregated from other injectables and treated as a controlled drug. A separate policy for parenteral concentrated potassium exists. Please follow hyperlink to Medicines Code of Practice below. Route of administration The concentration of the infusion will determine the route of administration. Refer to table below. Rate of administration Refer to table below. Infusion Device A rate controlled infusion pump (volumetric pump or syringe pump) must be used to administer all potassium containing infusions. Monitoring Please see monitoring section below. Information continues on following page: Page 7 of 10

8 Potassium Maximum Rate Maximum Concentration Usual Exceptional Usual Exceptional Peripherally 20mmol/hr 40mmol/hr With ECG monitoring 40mmol/L 80mmol/L only after discussion with senior medical Centrally (authorised areas only for concentrated potassium*) 20mmol/hr 40mmol/hr With ECG monitoring 20mmol in 20ml* 50mmol in 50ml* Syringes are available in restricted areas* staff 20mmol in 20ml* 50mmol in 50ml* Syringes are available in restricted areas* *Please refer to the NUH code of practice for the concentrated potassium policy and list of approved concentrated potassium stock holding areas: Medicines_Code_of_Practice.aspx Monitoring See above section - Principles and Investigations for the treatment of hypokalaemia. Intravenous administration Check potassium level after every 40mmol 80mmol and at least once daily to determine the need for further infusions and to avoid hyperkalaemia. ECG monitoring is required for administration rates over 20mmol/hour Infusion sites should be checked on a 4-hourly basis for signs of redness and inflammation. Extreme care must be taken to avoid extravasation. Oral administration Monitor potassium daily. Adverse effects: Cardiac arrhythmias and sudden cardiac death (those with congestive heart failure, underlying ischaemic heart disease and on digoxin or having aggressive therapy for hyperglycaemia in diabetic ketoacidosis are most vulnerable). Cardiac toxicity is of particular concern after intravenous administration. Intravenous concentrations greater than 40mmol/L are painful and may cause severe phlebitis; give via the largest suitable vein. Rapid intravenous potassium infusion is toxic to the heart. Page 8 of 10

9 Available Potassium Solutions (pre-diluted) if not ward stock obtain from pharmacy Concentration of potassium in Available Solutions mmol/ml already in solution in infusion bag 10mmols/500mL (0.15% w / v ) Sodium chloride 0.9% Glucose 5% Glucose 10% Glucose 5% / Sodium chloride 0.9% Glucose 5% / Sodium chloride 0.45% Glucose 4% / Sodium chloride 0.18% 20mmols/500mL (0.3% w / v ) Sodium chloride 0.9% Glucose 5% Glucose 10% Glucose 5% / Sodium chloride 0.9% Glucose 5% / Sodium chloride 0.45% 40mmols/500mL (0.6% w / v ) (high concentration only use on recommendation of senior medical staff) Sodium chloride 0.9% Glucose 5% 20mmols/1L (0.15% w / v ) Sodium chloride 0.9% Glucose 5% Glucose 4% / Sodium chloride 0.18% Glucose 2.5% / Sodium chloride 0.45% 40mmols/1L (0.3% w / v ) Sodium chloride 0.9% Glucose 5% Glucose 4% / Sodium chloride 0.18% 60mmols/1L (0.45% w / v ) Sodium chloride 0.9% (high concentration only use on recommendation of senior medical staff) A rate controlled infusion pump (volumetric pump or syringe pump) must be used to administer all potassium containing infusions. Page 9 of 10

10 References Joint Formulary Committee. British National Formulary [Ed]. [edition no. 70] London: British Medical Association and Royal Pharmaceutical Society of Great Britain; August 2015]. Accessed via medicines complete 04/09/15 Nottingham University Hospitals NHS IV Guide 2011 Blue pages Accessed via nous_therapy.aspx on [ ] Sando K Effervescent Tablets HK Pharma Limited. Summary of product characteristics [last updated ] on Electronic Medicines Compendium: (accessed on [ ]) via Sterile Potassium Chloride Concentrate 20% hameln pharmaceuticals ltd. Summary of product characteristics [last updated ] on Electronic Medicines Compendium: (accessed on [ ]) via Cohn JN et al. New Guidelines for Potassium Replacement in Clinical Practice. Arch Intern Med Vol 160 Sep NUH Medicines Code of Practice Chapter 25 parenteral concentrated potassium concentrations V6. Review date January Management of Hypokalaemia. Map of Medicine. Review November Accessed Hypokalaemia. Accessed Hypokalaemia in Emergency Medicine. Accessed Guideline for the management of hypokalaemia in adults. Gloucester for the Management of Hypokalaemia in Adults. August 2010 Guidelines for potassium replacement in hypokalaemia. Nottingham City Hospital NHS Trust. V1 Review:October 2007 UKMi Q&A How should intravenous (IV) potassium chloride be administered in adults? Accessed on from: icines%2520q%2520%26%2520a/qa186_3potassium_admin.doc&sa=u&ei=ygauabfnkxs0gwohodadq&ved=0cb0qfjaa&sig2=v8unanqco5_iznypaysrta&usg=afqjcngie1 ygc4uxeslg9vpg4ste7pvzgq Injectable medicines guide (Medusa) Accessed 6/10/15 Page 10 of 10