title: The effect of patient-controlled intravenous analgesia on postoperative hypokalemia in patients undergoing laparoscopic cholecystectomy.
abstract: OBJECTIVE
  We investigated whether hypokalemia developed during the postoperative period and whether the use of intravenous patient-controlled analgesia (IV-PCA) could decrease the incidence of postoperative hypokalemia in patients who underwent laparoscopic cholecystectomy.
  
  
  METHODS
  Sixty patients undergoing laparoscopic cholecystectomy were randomly assigned to either IV-PCA (n = 30) or control (n = 30) groups. We measured serum potassium concentration at the outpatient department (T1), at 8:00 a.m. on the day of surgery (T2), at 6 h after the end of surgery (T3), and at 8:00 a.m. on the first (T4), second (T5), and third (T6) postoperative days. Serum potassium concentration, incidence of hypokalemia, mean blood pressure, heart rate, respiratory rate, and the patient-reported visual analogue scale score were compared within each group and between groups at each time point.
  
  
  RESULTS
  Serum potassium concentrations in all patients showed a significant decrease at T2-T4 compared to the preoperative concentration (T1). Serum potassium concentrations at T3 and T4 in the IV-PCA group were significantly higher than those in the control group. Also, the incidence of hypokalemia at T3 and T4 was significantly lower in the IV-PCA group. Mean blood pressure and heart rate were significantly lower in the IV-PCA group than in controls at T3 and T4.
  
  
  CONCLUSIONS
  The results show that hypokalemia developed during the perioperative period and the use of IV-PCA in patients undergoing laparoscopic cholecystectomy effectively decreased the degree and incidence of postoperative hypokalemia on the day of the operation and postoperative day one.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Samsung Seoul Hospital, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-Dong, Kangnam-Gu, Seoul, 135-710, Republic of Korea.
authors.forename: Won Ho
authors.initials: WH
authors.lastname: Kim
authors.forename: Jong Hwan
authors.initials: JH
authors.lastname: Lee
authors.forename: Justin Sangwook
authors.initials: JS
authors.lastname: Ko
authors.forename: Tae Soo
authors.initials: TS
authors.lastname: Hahm
authors.forename: Sangmin M
authors.initials: SM
authors.lastname: Lee
authors.forename: Hyun Sung
authors.initials: HS
authors.lastname: Cho
mesh_terms: D016058:Analgesia, Patient-Controlled / Q000379:methods*; D001794:Blood Pressure / Q000187:drug effects; D017081:Cholecystectomy, Laparoscopic / Q000009:adverse effects* / Q000379:methods; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007008:Hypokalemia / Q000188:drug therapy / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000188:drug therapy / Q000517:prevention & control; D011183:Postoperative Complications / Q000188:drug therapy / Q000517:prevention & control; D011184:Postoperative Period; D011188:Potassium / Q000097:blood; D011446:Prospective Studies; D056152:Respiratory Rate / Q000187:drug effects
chemical_list: D011188:Potassium