Pre-induction hypokalaemic phenomenon in Nigerian adult population.
BACKGROUND
Anaesthesia in the perioperative period is characterized by acute changes in plasma potassium (K+) which may be caused by anxiety. Anxiety leads to an intracellular shift of potassium which may lead to hypokalaemia. These fluctuations in plasma potassium may sometimes induce arrhythmias. This study was designed to determine the acute changes in plasma potassium levels in the immediate pre-induction period in a sample of Nigerian patients and to determine the incidence of arrhythmias correlating with these changes.


METHODS
Sixty ASA I and II adults aged 14 to 70 years, both genders, undergoing elective surgery under general anaesthesia at the Lagos University Teaching Hospital were prospectively and consecutively recruited. Preoperative plasma potassium level was determined 1-3 days before surgery. Premedication was with oral diazepam 10-20 mg given nocte and on the morning of surgery. Pre-induction plasma potassium level was determined within 5 minutes before induction of anaesthesia.


RESULTS
Mean preoperative K+ was 3.98 +/- 0.38 mEq.L(-1) (range of 3.5 - 4.9 mEqL(-1)). The mean pre-induction plasma K+ level was 3.01 +/- 0.35 mEq.L(-1) (range of 2.1 - 3.6). This represented a fall of 24% (0.97 +/- 0.39 mEq.L(-1)) which was significantly different (p < 0.001). More than 80% of the patients exhibited some fall in plasma K+. No arrhythmias were recorded during the study period.


CONCLUSIONS
Pre-induction hypokalaemia occurred frequently despite the administration of anxiolysis with diazepam. There is a need to consider this phenomenon and measure K+ levels immediately pre-induction especially in patients with existing borderline normal K+ levels.
Dada
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Department of Anaesthesia, College of Medicine, University of Lagos/Lagos University Teaching Hospital, Lagos, Nigeria. femmy_d2002@yahoo.com
Desalu
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Kushimo
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D000293:Adolescent; D000328:Adult; D000368:Aged; D014151:Anti-Anxiety Agents / Q000008:administration & dosage*; D001007:Anxiety / Q000517:prevention & control; D001145:Arrhythmias, Cardiac / Q000209:etiology; D044383:Black People; D003975:Diazepam / Q000008:administration & dosage*; D005260:Female; D006784:Hospitals, Teaching; D006785:Hospitals, University; D006801:Humans; D007008:Hypokalemia / Q000209:etiology* / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D009549:Nigeria; D011188:Potassium / Q000097:blood*; D011229:Preanesthetic Medication; D011300:Preoperative Care; D011446:Prospective Studies; D013514:Surgical Procedures, Operative / Q000523:psychology
D014151:Anti-Anxiety Agents; D003975:Diazepam; D011188:Potassium