Megan L. Buddle

Does gestational hypertension become pre-eclampsia?

Objective To determine the likelihood of progression from gestational hypertension (GH) to pre‐eclampsia (PE) in hypertensive pregnant women and whether this change can be identified in advance by available clinical and laboratory measures.

Is resistant hypertension really resistant

BACKGROUND Managing resistant hypertension is difficult and mostly involves expensive testing seeking an underlying secondary cause. This study was undertaken to determine 1) the extent of the white-coat phenomenon in patients with resistant hypertension, and 2) whether 24-h ambulatory blood pressure (BP) monitoring (ABPM) or having BP recorded by a nurse instead of the referring doctor could clarify how many apparently resistant hypertensives actually have controlled BP. METHODS This study involved 611 patients with BP > or = 140/90 mm Hg who were referred for 24-h ABPM by their specialist or general practitioner, including 277 patients who were taking no antihypertensives (group 1), 216 taking one or two antihypertensive drugs (group 2), and 118 taking at least three antihypertensives in combination (group 3). Each had BP recorded by one of two nurses before 24-h ABPM. Controlled BP was defined as awake ambulatory BP <135/85 mm Hg and the white-coat effect was the difference between the BP recorded by the referring doctor or nurse and the average awake ambulatory BP. RESULTS Those with resistant hypertension (group 3) were older (61 years (12) v group 1: 46 years (14) and group 2: 56 (14) years; P < .001), but were of similar weight, height, and arm circumference to the other groups. Referral systolic, but not diastolic BP was higher in resistant hypertensives (mean 171/95 v 154/95 mm Hg and 164/94 mm Hg, respectively, P < .001 for systolic BP only). Twenty-eight percent of resistant hypertensives and 32% of those taking no antihypertensive drugs had normal awake ambulatory BP and the white-coat effect attributable to the referring doctor was always greater than that due to the nurse (range 16 to 26/12 to 14 mm Hg v 9 to 17/4 mm Hg, P < .001). Nurse recorded BP was highly sensitive (97%) in identifying awake hypertension but lacked specificity (57%) to replace ABPM. CONCLUSION Our results show that approximately one in four patients with apparent resistant hypertension referred for ABPM have controlled BP and one-third of patients referred for initial evaluation of office or clinic hypertension have normal BP using ABPM, ie, white-coat hypertension. Twenty-four-hour ABPM appears an appropriate initial step before further investigating or treating patients with apparently resistant hypertension.

Measuring blood pressure in pregnant women: a comparison of direct and indirect methods.

OBJECTIVES Our goals were to determine (1) whether Korotkoff phase IV or V sound was a more accurate measure of diastolic blood pressure in pregnancy and (2) interobserver variability of mercury sphygmomanometry of pregnant women. STUDY DESIGN Direct (intraarterial) and indirect (mercury sphygmomanometry) blood pressures were compared in 28 pregnant women. Interobserver variability was assessed in a separate study of 86 pregnant women using four highly trained observers. RESULTS (1) Routine sphygmomanometry underestimated direct systolic pressure by 11 (3, 18) mm Hg, p < 0.001 (median, interquartile range of differences). Phase IV Korotkoff sound overestimated direct diastolic pressure by 9 (2, 12) mm Hg (p < 0.001) and phase V by 4 (2, 7) mm Hg (p = 0.04). Phase V-recorded diastolic pressure was closer to direct diastolic pressure significantly more often (75%) than was phase IV-recorded diastolic pressure (21%) (p = 0.003). Mean arterial pressures did not differ significantly according to the method used. (2) Median blood pressures did not differ among the four observers for systolic, diastolic phase IV, or phase V recordings. Maximum difference for blood pressure recording among observers was 4 (2, 6) mm Hg. CONCLUSIONS Auscultatory sphygmomanometry in pregnant women underestimates systolic and overestimates diastolic blood pressure, but the phase V Korotkoff sound is more likely to represent the true diastolic pressure than is the phase IV sound.

Randomised trial of management of hypertensive pregnancies by Korotkoff phase IV or phase V

BACKGROUND There is debate about whether diastolic blood pressure should be recorded as the fourth (muffling, K4) or fifth (disappearance, K5) Korotkoff sound in pregnancy. We compared maternal and fetal outcomes and the likelihood that episodes of severe hypertension would be recorded when hypertensive pregnancies were managed according to either K4 or K5. METHODS 220 pregnant women with diastolic hypertension (K4 > or =90 mm Hg) after the 20th week of gestation were enrolled in a prospective randomised study at two obstetric units in Australia; they were randomly assigned management with K4 (n=103) or K5 (n=117) for the remainder of the pregnancy. Clinical management was according to a uniform department protocol. Analysis was by intention to treat. All the women completed the trial. FINDINGS An episode of severe hypertension (systolic > or =170 mm Hg, diastolic > or =110 mm Hg, or both) was more likely to be recorded with use of K4 than with use of K5 (39 [38%] vs 30 [26%] women, p=0.051), mainly because of a greater likelihood that severe diastolic hypertension would be recorded (34 [33%] vs 20 [17%], p=0.006). The frequency of severe systolic hypertension and simultaneous severe systolic and diastolic hypertension did not differ between groups. Pregnancy was prolonged by an average of 2 weeks in both groups, and there were no significant differences between the groups in laboratory data, requirements for antihypertensive treatment, birthweight, fetal growth retardation, or perinatal mortality. There was no eclampsia or significant maternal morbidity in either group. INTERPRETATION A change from use of K4 to K5 would mean that one fewer case of severe diastolic hypertension would be recorded for every six hypertensive pregnancies, but all other episodes of severe hypertension would be recorded with similar frequency. Since the K4/K5 difference is smaller in hypertensive than in normotensive pregnant women and since K5 is closer to the actual intra-arterial pressure and more reliably detected, universal adoption of K5 to record diastolic blood pressure in hypertensive pregnancy should be considered.

Ambulatory blood pressure monitoring (ABPM) in the normal menstrual cycle and in women using oral contraceptives : Comparison with conventional blood pressure measurement

This study was undertaken to determine if blood pressures (BP) assessed by routine sphygmomanometry and 24 h ambulatory monitoring (ABPM) alter throughout the normal menstrual cycle or in the cycle of women using oral contraceptive pills (OCP), and the interrelationships between urinary sodium (Na) and potassium (K) excretion and ABPM throughout the menstrual cycle. Eleven women with a normal ovulatory cycle (ovulatory) and ten age-matched women taking an oral contraceptive pill (OCP) were studied three times in random order during their menstrual cycle, within days 1 to 5, 13 to 16, and 25 to 28. Twenty-four hour urine Na, K, and creatinine (Cr) excretion and serum Na, K, Cr, cortisol, estradiol, progesterone and plasma renin, angiotensinogen, and aldosterone concentrations were measured. BP was measured by a mercury sphygmomanometer and by 24 h BP (Accutracker II). On days 1 to 5, daytime systolic BP was higher in OCP [mean: 123 mm Hg, 95% confidence interval: 117, 128] than ovulatory women [114 mm Hg (109, 118); P = .011] though daytime diastolic BPs were similar [OCP: 71 (68, 75), ovulatory: 69 (66, 72)]. This difference in daytime systolic BP between groups was also apparent at both of the other stages of the menstrual cycle. Nighttime systolic BPs were significantly higher in OCP users on days 13 to 16 (P < .05) and days 25 to 28 (P < .01). In women taking OCPs, daytime ABPM for days 1 to 5 were higher than their office readings by 15 (7,23)/11 (7,15) mm Hg (P = .001), whereas office and ABPM readings were similar in ovulatory women. This pattern was evident at all three stages. There was no significant change in BP throughout the menstrual cycle within either group, and no correlation between urine Na or K and BP. Systolic BPs are higher throughout the menstrual cycle in women who take OCPs than in ovulatory women but this difference is only detected when ambulatory blood pressure is assessed. Blood pressure does not change subsequently in either ovulatory or OCP-taking women throughout the menstrual cycle.

Ambulatory blood pressure in pregnancy: Comparison of the Spacelabs 90207 and Accutracker II monitors with intraarterial recordings

OBJECTIVE Our purpose was to compare systolic and diastolic blood pressures obtained with the Spacelabs 90207 (Spacelabs Medical Products, Dee Why, Australia) or Accutracker II (Suntech Medical Instruments, Melbourne, Australia) ambulatory blood pressure monitoring devices with intraarterial blood pressures in pregnant women. STUDY DESIGN Direct (intraarterial) and resting blood pressures with the ambulatory blood pressure monitoring device were compared in 39 pregnant women (14 Accutracker II and 25 Spacelabs 90207). RESULTS The Accutracker II device underestimated direct systolic pressure by -9 (-13, -3) mm Hg (median, interquartile range) (p = 0.028) but gave similar diastolic pressure. The Spacelabs 90207 device gave similar systolic pressures but overestimated direct diastolic pressure by 7 (2, 12) mm Hg (p < 0.001). Variability for systolic and diastolic blood pressures within subjects was similar with the two devices. Both received poor gradings by standards of the British Hypertension Society and did not meet criteria of the Association for the Advancement of Medical Instrumentation, with intraarterial recordings used as the reference. CONCLUSIONS The Accutracker II device significantly underestimated resting direct systolic pressure, whereas the Spacelabs 90207 device significantly overestimated resting direct diastolic pressure in pregnant women. Although poor gradings were achieved for both devices when intraarterial pressures were used as the reference, this is similar to comparisons of routine mercury sphygmomanometry with intraarterial recordings and does not mean these devices are unsuitable for use in pregnancy.