Ann Bingham 11/24

 Not a policy  A safety tip  Intended to be a useful reference  Collaborative effort by anesthesiology, nephrology, vascular surgery

 First/second/third degree heart block, bradycardia, asystole  Ventricular tachycardia, ventricular fibrillation  Decreased myocardial contractility  Extracardiac effects: muscle weakness  Respiratory depression

 Dialysis dependent pts or those presenting for dialysis access placement should have K+ checked on the am of surgery Chemistry panel with AM labs VBG in preop drawn by anesth or RN and run by AT K+ verified to be acceptable before starting any regional or general anesthesia (part of block pause) Check more frequently if a temporizing measure was instituted

 Normal plasma potassium level = mmol/L  Max K+ 5.5 mmol/L when starting minor surgery.  Max K+ 5.0 mmol/L when starting major surgical procedures with potential muscle breakdown, hemolysis, or transfusion requirements.

 If K>6.0 despite temporizing measures it is recommended to not proceed to surgery without dialysis

 No difference in cutoff value was chosen for acute vs. chronic hyperkalemia.  While chronic hyperkalemia may be better tolerated in chronic renal failure patients, the degree to which the tolerance to hyperkalemia increases is not known.

 Tight coordination among anesthesia, surgery, nephrology and dialysis services is required Ask operator for nephrology fellow on call Do not page “hemodialysis” pager (that pager sits on the charge RN desk and may not be answered).  Initiate discussion with nephrology when temporizing measures are instituted

 In ESRD patients on dialysis with recently thrombosed AVF a higher max K+ may need to be tolerated for the patient to have a fistula revision to then receive dialysis (i.e. this is potentially an urgent case).  It may be beneficial to avoid placement of temporary dialysis access (i.e. the risk benefit analysis may favor allowing a higher than usual K + in order to avoid morbidity associated with placement of temporary access).  Requires a discussion with surgeon

 Calcium chloride (1 gm) or calcium gluconate (3 gm) Onset of action within 5 minutes. Duration of effect minutes. No effect on K+ but antagonizes effect of hyperkalemia on myocardium.  Insulin + Glucose. Commonly used dose is 10 units regular insulin with 25 gm D50 followed by D5 infusion. Consider insulin infusion. Onset of effect approx. 15 minutes. Duration approx 60 minutes. CBG should be checked frequently after administration of any insulin bolus or infusion.  Correction of any acidosis (sodium bicarbonate for patients with metabolic acidosis, hyperventilation or at least avoidance of hypoventilation). The utility of bicarbonate in patients who are not acidotic is questionable.  β 2 -Adrenergic Stimulation (eg. Albuterol). Note that the inhaled albuterol dose for the management of hyperkalemia is significantly higher than that used for the management of bronchospasm (nebulized: mg vs 5 mg, MDI: approx mcg vs 100 mcg). Onset of effect within 10 minutes. Duration of effect up to 2 hours. K+ should be rechecked frequently. When temporizing measures are discontinued expect a rebound in plasma potassium level.

 narrowing and peaking of T waves,  shortening of the QT interval,  widening of the QRS complex,  low P wave amplitude,  AV nodal block, and  ventricular tachycardia.  severe hyperkalemia: sine wave pattern of ventricular flutter occurs, followed by asystole.  Disclaimer: ECG is insensitive and non-specific for severe hyperkalemia, so absence of ECG signs cannot be taken as reassurance that the patient will not experience a life threatening arrhythmia. The clinical course is unpredictable and sudden death can occur in the absence of sentinel ECG changes.  In patients with preexisting ECG abnormalities the presenting ECG sign of hyperkalemia may be normalization of the ECG.

 Patients with ECG signs of hyperkalemia are at risk for life-threatening arrhythmias and should not undergo surgery.  Consider administering IV calcium.  If a life threatening arrhythmia or conduction disturbance develops, such as VT, VF, heart block, prolonged PR interval or widened QRS then IV calcium is immediately indicated. Caution: Blood pressure should be monitored and additional measures may be needed to avoid hypertension resulting from calcium chloride administration or hypotension from calcium gluconate administration.

 Remove K+ from the body if possible (Note: furosemide will not be effective in anuric or very oliguric patients).  Kayexalate is not considered helpful in the intraoperative period (oral or rectal).  Succinylcholine is expected to increase the potassium concentration by mmol/L and should be avoided.  Fasting patients with CKD suppress insulin and tend to become hyperkalemic. Non-diabetic patients at risk for hyperkalemia should receive glucose containing fluids during their NPO time.  Continuous cardiac monitoring is indicated

 Special thanks to Robert Shangraw, Ryan Anderson, Andy Neice, Jennifer Shatzer  Nephrology (especially Richard Parker)  Vascular Surgery  6A nurses  Anesthesia Techs  Michele Noles & Quality Team  Anesthesia leadership