title: Effect of different intra-abdominal pressure levels on QT dispersion in patients undergoing laparoscopic cholecystectomy.
abstract: BACKGROUND
  Hemodynamic changes caused by carbon dioxide (CO(2)) insufflation occur frequently in patients who undergo laparoscopic surgery. One indicator of these changes is corrected QT dispersion (QTcd), an index of myocardial function. Prolongation of QTcd has been associated with cardiovascular morbidity and mortality. We compared the effects of high-pressure (15 mmHg) and low-pressure (7 mmHg) CO(2) pneumoperitoneums on the QT interval, the rate-corrected QT interval (QTc), the QT dispersion (QTd), and the corrected QT dispersion (QTcd) during laparoscopic cholecystectomy.
  
  
  METHODS
  Twenty consecutive patients were in a low-pressure pneumoperitoneum group and 32 were in a high-pressure pneumoperitoneum group. A 12-lead electrocardiogram was used to monitor cardiac variables. In all patients, serial electrocardiograms were recorded before anesthesia induction (baseline), immediately after the pneumoperitoneum had been created, every 15 minutes during CO(2) insufflation, and 5 minutes after deflation. Two observers measured the QT intervals independently, and the QTcd was calculated using Bazett's formula.
  
  
  RESULTS
  The QT interval and the QTc interval did not change significantly during the study in either group. The QTd and QTcd in the high-pressure pneumoperitoneum group increased significantly during CO(2) insufflation and were significantly higher in the high-pressure pneumoperitoneum group compared with the low-pressure pneumoperitoneum group. Changes caused by CO(2) insufflation were reversible.
  
  
  CONCLUSIONS
  Statistically significant increases of QTd and QTcd, which are associated with an increased risk of arrhythmias and cardiac events, occur during CO(2) insufflation in both high-pressure and low-pressure pneumoperitoneums. QTd and QTcd were significantly higher in the high-pressure pneumoperitoneum group than they were in the low-pressure pneumoperitoneum group. QT interval changes were not related to anesthetic agents, surgical stress, hypercapnia, or duration of CO(2) insufflation. Increased intra-abdominal pressure may have caused these changes.
authors.affiliation: Department of General Surgery, Baskent University, 1. Cad. No:77 Kat:4 Bahcelievler, 06490, Ankara, Turkey. dryahyaekici@gmail.com
authors.forename: Yahya
authors.initials: Y
authors.lastname: Ekici
authors.forename: Huseyin
authors.initials: H
authors.lastname: Bozbas
authors.forename: Feza
authors.initials: F
authors.lastname: Karakayali
authors.forename: Ebru
authors.initials: E
authors.lastname: Salman
authors.forename: Gokhan
authors.initials: G
authors.lastname: Moray
authors.forename: Hamdi
authors.initials: H
authors.lastname: Karakayali
authors.forename: Mehmet
authors.initials: M
authors.lastname: Haberal
mesh_terms: D034841:Abdominal Cavity; D000328:Adult; D000704:Analysis of Variance; D001795:Blood Pressure Determination; D002245:Carbon Dioxide / Q000494:pharmacology; D017081:Cholecystectomy, Laparoscopic / Q000009:adverse effects / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008133:Long QT Syndrome / Q000175:diagnosis* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods; D011028:Pneumoperitoneum, Artificial / Q000009:adverse effects / Q000379:methods*; D011312:Pressure; D011336:Probability; D018570:Risk Assessment; D016896:Treatment Outcome
chemical_list: D002245:Carbon Dioxide