Growth, Development and Hearing in Premature Infants Who Received Phototherapy

Abstract

Blood flow was s t u d i e d hy venous occlusion plethysmoeraphy i n 1 3 i n f a n t s r g q u i r i n g e i t h e r continuous p o s i t i v e airwhy p r e s s u r e (CPAP) o r a s s i s t e d v e n t i l a t i o n f o r hyaline vembrhne d i s e a s e .I n f a t s were s t u d i e d a t one t o 5 days of age. Ind i v i d u a l i n f a n t s were s t u d i e d on up t o 4 d i f f e r e n t days. The system used c o n s i s t e d of a blood pressure cuff a p p l i e d t o t h e t h i g h and a mercury strxain gauge a p p l i e d c i r c u m f e r e n t i a l l y t o t h e mid-calf (Kidd e t a l , 1966). A r t e r i a l blooc pressure (EP) was measured d i r e c t l y . Venous occlusion was accomplished ky i n f l a t i n g t h e c u f f t o a pressure below t h a t of t h e d i a s t o l i c BP. Blood flow ranged from 3.8 t o 14.2 r n l / l C O gnl of t i s s u e / minute. For each i n f a n t , values were reproducikle on a giver. day, but l a b i l e from day t o day. The observed values were h i g h e r t h a n t h o s e r e p o r t e d by Kidd e t a l , p o s s i b l y becduse of changing p r a c t i c e s regarding intravencus f l u i d s and blood t r a n s f u s i o n . Changes i n blood flow could not be p r e d i c t e d from changes i n BP, c e n t r a l h e c a t o c r i t , o r volume of blood withdrawn f o r l a b o r a t o r y s t u d i e s . Blood l a c t a t e , base d e f i c i t o r requirements f o r intravenous bicarbonate could not be pred i c t e d from bloo6 flow. CPAP a t p r e s s u r e s up t o 6 cm Hz0 d i d not s i g n i f i c a n t l y reduce blood flow. A low blood flow i n t h e f i r s t 24 hours suggested t h a t blooC t r a n s f u s i o n wasmorelrkely t o be r e q u i r e d subsequently during t h e course of t h e ?isease.PULMONARY BLOOD FLOW (PBF) I N LAMBS WITH HYALINE MEMBRANE DISEASE (HMD). Alexander C. Allen, Dora A . Stinson, Hugh M. MacDonald and Paul M. Taylor. Univ. of P i t t s b u r g h Sch. of Med. Maaee-Womens Hosp., Dept. of P e d i a t r i c s , P i t t s b u r g h , Pa.-~f f e c t i v e P B F '~~ lo" during t h e course of HMD (~h u e t a l , P e d i a t r i c s , s : 7 3 3 , 1965). I t i s not known whether t h i s change i s c e n t r a l i n t h e e t i o l o g i c chain of events o r simply a secondary phenomenon. T o t a l PBF was measured during t h e f i r s t 4 h r of l i f e i n lambs with and without HMD.At 129-133 days' g e s t a t i o n a pre-calibrated electromagnetic flow transducer w i t h non-occlusive zero was implanted on the p o s t d u c t a l port i o n of t h e comnon pulmonary a r t e r y of 8 f e t a l lambs which were r e t u r n e d t o t h e amniotic c a v i t y f o r 7 days and then del i v e r e d by C-section a t 136-140 days' g e s t a t i o n . A f t e r b i r t h a Swan-Ganz c a t h e t e r was f l o a t e d i n t o a branch pulmonary a rt e r y f o r pressure measurements. By c l i n i c a l and blood gas c r it e r i a , 4 lambs had no d i s t r e s s o r developed mild HMD; 4 developed moderate o r s e v e r e HMD. PBF increa...