Effect of dopamine on peripheral perfusion in very-low-birth-weight infants during the transitional period.

INTRODUCTION: Dopamine is one of the most frequently used inotropic drugs in neonatal intensive care units (NICUs); however, it does not seem to improve outcomes in premature infants. Given that the ultimate aim of cardiovascular management is to stabilize and maintain organ perfusion, an understanding of dopamine's effects on organ blood flow will help in judging when to use dopamine and how to titrate the dosage. Such an approach can lead to improved outcomes. This study aimed to evaluate the effects of dopamine on peripheral perfusion in very-low-birth-weight (VLBW) infants within 72 h of birth. METHODS: This prospective observational study identified and sampled 44 instances of initiation of dopamine treatment or increase in dopamine dose in 29 VLBW infants. Blood pressure, heart rate, and skin and subcutaneous blood flow were measured and compared before and after each instance. RESULTS: Blood pressure and skin and subcutaneous blood flow in the lower limbs increased after initiation of dopamine treatment or after dose increase. DISCUSSION: Dopamine increases blood pressure as well as skin and subcutaneous blood flow in VLBW infants despite its supposed vasoconstrictive action, indicating that it increases both perfusion pressure and blood flow and is devoid of overwhelming peripheral vasoconstrictive effects.

Prophylactic probiotics reduce cow's milk protein intolerance in neonates after small intestine surgery and antibiotic treatment presenting symptoms that mimics postoperative infection.

BACKGROUND: To examine occurrence of cow's milk protein intolerance (CMPI) in newborns that underwent small intestine surgery and the clinical profiles of those newborns with postoperative CMPI, and to evaluate the preventive effects of probiotics on CMPI. METHODS: We retrospectively reviewed from 2000 to 2009, a total of 30 newborns required surgery on their small intestines. All of these patients had received antibiotics to prevent postoperative infection. Since 2005 we adopted a protocol of targeted probiotic therapy prophylaxis. RESULTS: Eighteen patients received probiotic therapy, while twelve did not. One infant among those eighteen patients and eight patients among those twelve developed CMPI, a significantly lower rate for the group with probiotic therapy than that without it (p < 0.001). Patients with positive cultures for gram positive and gram negative organisms increased in number before and after surgery but then decreased after probiotics treatment. Poor weight gain, gastrointestinal symptoms, and rise in C reactive protein (CRP) levels were observed in all of those nine CMPI patients. Specific IgE antibodies were elevated in four of the nine subjects, and total IgE levels were elevated in seven of them. All CMPI patients had increased level of CRP without proven infections. CONCLUSIONS: CMPI was induced in newborns after surgery on their small intestines and antibiotics treatment with presentation of symptoms that mimic postoperative infection. Development of CMPI in this population possibly involves disruption of intestinal flora. Administration of probiotics can reduce the incidence of CMPI after small intestine surgery. The elevated CRP level may be useful in the diagnosis of CMPI.

Changes in skin and subcutaneous perfusion in very-low-birth-weight infants during the transitional period.

BACKGROUND: Conventional parameters of circulation that are routinely used in neonatal intensive care units, including blood pressure, have been reported to be inadequate in improving prognosis of very-low-birth-weight (VLBW) infants. Recently, the importance of evaluating the blood flow to each organ, including both vital and nonvital organs, has been increasingly recognized. OBJECTIVES: To study the changes in peripheral perfusion occurring in VLBW infants of less than 32 weeks' gestation during the extrauterine transitional period. METHODS: In 32 VLBW infants of less than 32 weeks' gestation, forehead blood flow (FBF) and lower-limb blood flow (LBF) were measured for 48 h after birth using a novel laser Doppler flowmeter, and the indices of vascular resistance were estimated. Superior vena cava (SVC) blood flow was measured by echocardiography. Changes in these variables of circulation as well as the correlations were evaluated. RESULTS: Both FBF and LBF significantly increased at 24 h, while the SVC flow remained unchanged over the same period. Both forehead and lower-limb vascular resistance indices significantly decreased at 24 h. LBF was negatively and positively correlated with estimated upper body vascular resistance and SVC flow, respectively. CONCLUSIONS: The increase in the peripheral blood flow along with the decrease in the peripheral vascular resistance indices, without an increase in the systemic blood flow at 24 h of age, indicated vasodilation in skin and subcutaneous tissue during the transitional period in VLBW infants. FBF and LBF can be useful parameters as indicators of both peripheral and systemic circulation.

Resuscitation of preterm infants with reduced oxygen results in less oxidative stress than resuscitation with 100% oxygen.

The objective of this study was to determine the effects of the level of inhaled oxygen during resuscitation on the levels of free radicals and anti-oxidative capacity in the heparinized venous blood of preterm infants. Forty four preterm infants <35 weeks of gestation with mild to moderate neonatal asphyxia were randomized into two groups. The first group of infants were resuscitated with 100% oxygen (100% O(2) group), while in the other group (reduced O(2) group), the oxygen concentration was titrated according to pulse oximeter readings. We measured total hydroperoxide (TH) and redox potential (RP) in the plasma within 60 min of birth. The integrated excessive oxygen ( summation operator(FiO(2)-0.21) x Time(min)) was higher in the 100% O(2) group than in the reduced O(2) group (p<0.0001). TH was higher in the 100% O(2) group than in the reduced O(2) group (p<0.0001). RP was not different between the 100% O(2) and reduced O(2) groups (p = 0.399). RP/TH ratio was lower in the 100% O(2) group than in the reduced O(2) group (p<0.01). We conclude that in the resuscitation of preterm infants with mild to moderate asphyxia, oxidative stress can be reduced by lowering the inspired oxygen concentration using a pulse oximeter.

Levels of catecholamines, arginine vasopressin and atrial natriuretic peptide in hypotensive extremely low birth weight infants in the first 24 hours after birth.

BACKGROUND: Extremely low birth weight infants (ELBWI) often suffer from severe hypotension in the early neonatal period. However, few previous studies have ever revealed plasma levels of vasoactive substances which regulate the cardiovascular system in ELBWI. OBJECTIVE: To study plasma levels of vasoactive substances in ELBWI with hypotension during the first 24 h of life. METHODS: 22 ELBWI with hypotension (gestational age 26.4 +/- 1.9 weeks; birth weight 751 +/- 135 g) were involved in the study. After initial volume therapy, the infants were arbitrarily divided into two groups depending on requirement of dopamine dosage: severe hypotension group (SH; dopamine >10 microg/kg/min, n = 9) and mild hypotension group (MH; dopamine

Association between Total Antioxidant Capacity in Breast Milk and Postnatal Age in Days in Premature Infants.

This study aimed to consider the significance of breast milk in preventing oxidative stress by comparing total antioxidant capacity (TAC) in breast milk and formula milk for premature infants, demonstrating the relationship between TAC in breast milk and postnatal age in days. We used the biological anti-oxidant potential test, a new method to measure TAC in breast milk. Breast milk for premature infants were stored at -20 degrees C and thawed within 48 h of collection. We measured TAC in two types of formula milk in the same way. TAC was clearly higher in breast milk than formula milk. Although a negative correlation was observed between TAC in breast milk and age when collected, TAC was always higher than the average TAC in formula milk. TAC in breast milk is higher than TAC in formula milk. We suggest the importance of breast milk for preventing oxidative stress and starting breastfeeding early.