| Premature infants are different in physiology and pathology from full - term newborns. It is important to deal with early tolerance to en-teral feed and to prevent efficiently necrotising enterocolitis (NEC) in premature infants. Gut ischaemia, undoubtly, plays a key role in the changes mentioned above.Blood supply to gastrointestine is largely from the superior mesen-teric artery ( SMA ) and celiac artery ( CA) . The SMA supplies blood to the small and large bowel as far as the midtransverse colon. The CA supplies the liver, spleen, pancreas and stomach. Blood flow velocities of these two vessels represent the changes of gut haemodynamics.Doppler ultrasound provides a noninvasive technique for studying the adaption process of circulation in newborn. From 1990s, some foreign reports concerned with assessment of the SMA and CA blood flow with Doppler ultrasound have been noted. However, as to the certain related factors and variations of the gut blood flow, these reports did not agree with each other, especially in premature infants. In China , there have been only two reports about ultrasonographic assessment of the gut blood flow in newborns who were full - term and suffering from birth asphyxia. The reports about Doppler ultrasonographic assessment of the gut blood flow in premature infants are rare.The aims of our study are to assess the SMA and CA blood flow ofpremature infants, furthermore, study the intestinal heamodynamics in adaptation after birth and search a save and noninvasive method to measure the gut blood flow in premature infants.MATERIALS AND METHODSSubjectsPremature groups: Thirteen premature infants ( examined 20 times totally) were divided into Premature 1, Premature 2 and Premature 3 groups. Premature 1 (n =9) was examined in the first day of life, Premature 2 ( n = 9 ) was examined in the third day of life and Premature 3 (n =2) was examined in the seventh day of life. Premature 3 was not included into stastics analysis because its sample size was too small.Control groups; Twenty - six full - term infants ( examined 27 times totally) were divided into Control 1, Control 2 and Control 3 groups. The controls were examined as the same schedule as the premature groups of matched age respectively. Control 3 was not included into statistics analysis because the same reason as Premature 3.MethodsA color Doppler ultrasound machine was used to interrogate the splanchnic vessels. A 10 MHz probe was held just below the xiphister-num to visualize the SMA and CA in the sagittal plane. The angle of insonation was kept between 0 - 15. Once an adequate image of the vessels had been achieved and with the aid of the auditory Doppler signal, a Doppler pulse that insonated the complete cross - sectional area of the vessel was used to obtain velocity spectra from a point just 3 mm distal to the origin of each vessel. The blood flow velocity wave-forms as the mean of three waves were calculated. These included peak systolic flow velocity (Vps) , end diastolic flow velocity (Ved) , mean time velocity ( Vtam) , pulsatility index ( PI) and resistant index (RI).In all neonates, the same investigator performed Doppler sono-graphic measurements of the SMA and CA immediately before feeding and when the infants were quiet in beds.Data AnalysisAll data were input in SPSS software. Parameters of blood flow were showed by x @ Sx. The statistical differences in blood flow parameters between each group were evaluated with independent t - test and relations between parameters were analyzed with Spearman's correlation.RESULTIn the SMA, Vps and Ved of Premature 1 were significantly lower than Control 1; RI of Premature 1 was significantly higher than the Control ( P < 0. 05 , respectively) .In the SMA, Vps and Ved of Premature 2 were significantly lower than Control 2. Vps and Vtam of Premature 2 were significantly lower than Control 2 in the CA (P <0. 05 , respectively) .Compared with Premature 1, PI and RI of Premature 2 in the SMA significantly decreased, and RI in the... |
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