Diathermy power settings as a risk factor for hemorrhage after tonsillectomy.

OBJECTIVE: To investigate bipolar diathermy power settings as a risk factor for postoperative hemorrhage following tonsillectomy. STUDY DESIGN AND SETTING: A prospective cohort study was undertaken between July 2003 and September 2004 in National Health Service (NHS) and independent hospitals in England and Northern Ireland. Data were collected on patient characteristics, tonsillectomy technique, and postoperative hemorrhage within 28 days of surgery. RESULTS: Among the 9572 patients who had a tonsillectomy performed with bipolar diathermy dissection and hemostasis, the overall rate of hemorrhage was 4.6 percent and the risk of hemorrhage was not associated with the diathermy power setting. Among the 8465 patients who had tonsillectomy with cold steel dissection and bipolar diathermy hemostasis, the rate of hemorrhage increased from 1.8% in patients with the lowest power settings (6 to 8 watts) to 3.7% in those with settings above 18 watts (P value for trend = 0.005). CONCLUSION: In tonsillectomies using cold steel dissection and bipolar diathermy for hemostasis, the risk of postoperative hemorrhage becomes greater as diathermy power increases.