Effects of Blood Pressure Cuffs on the Circulatory and Respiratory Status of Infants with Persistent Pulonary Hypertension of the Newborn

ABSTRACT

PURPOSE: Vasodilator therapy in infants with persistent pulmonary hypertension of the newborn(PPHN) frequently causes systemic hypotension due to non-selectivity for pulmonary vessels. Blood pressure(BP) cuffs can increase systemic vascular resistance around which they are applied without affecting pulmonary vessels. We studied the effects of BP cuffs on the circulatory and respiratory status of infants with PPHN receiving vasodilator therapy. METHODS: Mechanically ventilated 16 term infants(gestational age of 39.9+ 1.3 weeks and birth weight of 3,533+/-318 gm with PPHN who had right to left shunt on echocardiogram and survived over 5 days were included for the study. All infants received vasodilator(tolazoline)therapy. We applied BP cuffs for neonatal use to four extremities of study infants(n=8) and inflated them to systolic pressure. Those who received vasodilator therapy alone served as control(n=8). We analyzed systolic and mean BP, respiratory parameters, presence of right to left shunt an clinical outcome at 1, 2, 6, 12, 24, 48, 72hr after initiation of vasodilator therapy. RESULTS: Systolic BP increased significantly in study group(from 37+/-11 to 46+/-13 mmHg) from 6 hours after BP cuff application compared to control group(from 39+/-8 to 40+/-13 mmHg), and this effect persisted up to 72 hour(52+/-18 vs. 46+/-16 mmHg)(P<0.05). Mean BP also increased significantly in study group(30 +/-10 to 38+/-12 mmHg) from 6 hours compared to control group(32+/-11 to 33 15 mmHg) and maintained up to 72 hour occurred(43+17 vs. 3715 mmHg)(P<0.05). Reversal of right to left shunt occurred significantly earlier in study group than control group(30+/-10 vs. 52+/-18 hr)(P<0.01). Respiratory parameters such as mean airway pressure, oxygenation index and duration of ventilator care and hospitalization were not different. Four of five infants in the study group and five of eight in control group survived. CONCLUSION: Application of BP cuffs to the infants with PPHN treated with vasodilator resulted in increase innd mean BP and early reversal of right to left shunt. We suggest that application of BP cuffs can play a useful role in the management of infants with PPHN.