Which Korotkoff sound? CMAJ 1998;158:297 See response from: M.E. Helewa The work presented in the "Report of the Canadian Hypertension Society Consensus Conference: 1. Definitions, evaluation and classification of hypertensive disorders in pregnancy (CMAJ 1997;157(6):715-25 [full text / résumé] is commendable. The recommendations are evidence driven, clear and clinically relevant. I believe, however, that the recommendation to use the fourth Korotkoff sound to mark the diastolic blood pressure and "for instituting clinical investigation and management" is unfounded. Phase IV of the Korotkoff sounds is not reproducible among clinicans, whereas phase V is.1 Furthermore, current clinical trials of hypertension during pregnancy have adopted the fifth Korotkoff sound in defining outcomes and guiding therapy,2 which raises the issue of external validity if Canadians define hypertension during pregnancy according to different criteria. The recommendation to measure both the fourth and fifth sounds is confusing for the average physician, nurse or midwife, especially if they are encouraged to act upon only the fourth sound. We should agree to standardize blood pressure measurement — during pregnancy and otherwise — by having the rested patient sit upright, supporting her arm, applying the correct size cuff and relying on the first and fifth Korotkoff sounds to denote the systolic and diastolic pressures respectively. Joel G. Ray, MD Clinical Fellow Obsterical Medicine Department of Medicine University of Toronto Toronto, Ont. rayjg@fhs.csu.McMaster.CA References Shennan A, Gupta M, Halligan A, Taylor D, DeSwiet M. Lack of reproducibility in pregnancy of Korotkoff phase IV as measured by mercury sphygmomanometry. Lancet 1996;347:139-42. Levine RJ, Hauth JC, Curet LB, Sibai BM, Catalano PM, Morris CD, et al. Trial of calcium to prevent preeclampsia. N Engl J Med 1997;337:69-76. Send a letter to the editor responding to this letter Envoyez une lettre à la rédaction au sujet de cette lettre | CMAJ February 10, 1998 (vol 158, no 3) / JAMC le 10 février 1998 (vol 158, no 3) |