Níveis plasmáticos de cafeína no cordão umbilical e apneia da prematuridade / Serum levels of caffeine in umbilical cord and apnea of prematurity

OBJETIVO: Determinar a influência da presença de cafeína no sangue de cordão umbilical na ocorrência de apneia. MÉTODOS: Estudo de coorte prospectivo de recém-nascidos pré-termo com peso de nascimento menor que 2.000 g. Os critérios de exclusão foram: mães que receberam opioides; ventilação mecânica durante os primeiros 4 dias de vida; malformações cerebrais e cardíacas maiores; asfixia perinatal; hemorragia peri-intraventricular grave; exsanguineotransfusão antes do quarto dia de vida; e uso de metilxantina antes da extubação. Os recém-nascidos foram divididos em com e sem cafeína detectável no sangue de cordão umbilical, sendo acompanhados nos primeiros 4 dias para verificar ocorrência de apneia. RESULTADOS: Oitenta e sete recém-nascidos com e 40 sem cafeína detectável no sangue de cordão umbilical foram estudados. A mediana da concentração de cafeína dos 87 pacientes com cafeína detectável no sangue de cordão umbilical foi 2,3 µg/mL (0,2-9,4 µg/mL). Não houve associação entre ocorrência de apneia e presença de cafeína no sangue de cordão umbilical. Recém-nascidos com cafeína detectável no cordão umbilical tiveram tendência a apresentar apneia mais tardiamente (66,3±4,14 horas) do que aqueles com níveis indetectáveis (54,2±6,26 horas). CONCLUSÃO: A detecção de níveis de cafeína no sangue de cordão umbilical não diminuiu a ocorrência de apneia da prematuridade, mas teve um efeito limítrofe atrasando sua ocorrência, o que sugere que mesmo um nível baixo de cafeína no sangue de cordão umbilical pode retardar a ocorrência de apneia.

OBJECTIVE: To determine the influence of presence of caffeine in umbilical cord blood on apnea occurrence. METHODS: A prospective cohort study with preterm newborns with birth weight lower than 2,000 g was undertaken. Exclusion criteria were: mothers who received opioids; mechanical ventilation during the first 4 days of life; cerebral and major cardiac malformations; perinatal asphyxia; severe periintraventricular hemorrhage; exchange transfusion before the fourth day of life; and those who received methylxantine prior to extubation. Neonates were divided into detectable and undetectable caffeine in umbilical cord blood. Newborns were followed for the first 4 days for occurrence of apnea spells. RESULTS: Eighty-seven newborns with and 40 without detectable caffeine in umbilical cord blood were studied. Median caffeine concentration of the 87 patients with detectable caffeine in umbilical blood was 2.3 µg/mL (0.2-9.4 µg/mL). There was no association between occurrence of apnea spells and presence of caffeine in umbilical cord blood. Neonates with detectable caffeine in umbilical blood had borderline later apnea (66.3±4.14 hours) than those with undetectable levels (54.2±6.26 hours). CONCLUSION: Detected levels of caffeine in umbilical cord blood did not decrease occurrence of apnea of prematurity, but it had a borderline effect delaying its occurrence, suggesting that even a low level of caffeine in umbilical cord blood might delay occurrence of apnea spells.

Prophylactic theophylline infusion for prevention of apnea of prematurity.

To assess if there was any advantage in the prophylactic use of theophylline to prevent apnea in preterms, we treated 56 preterms (Group A) < 34 weeks gestation with theophylline infusion and compared these with 25 age and weight matched preterms (Group B) who received no therapy. Aminophylline (25 mg/ml) was infused from admission in all neonates (group A) at rates ranging 0.2 to 0.38 mg/kg/h and blood levels estimated on an Abbots TDX analyser by Fluorescence Polarization Immunoassay, after 5 days infusion. All neonates (Groups A + B) were monitored on a Corometric 505 neonatal monitor. In Group A, 1/48 developed primary apnea while in Group B, 4-21 had primary apnea (p < 0.05). Serum theophylline ranged from 2.3 to 39.5 micrograms/ml with a mean of 12.7 micrograms/ml. The mean serum level of theophylline in 4 cases who exhibited clinical evidences of toxicity was 30.1 micrograms/ml. A statistically significant difference (p < 0.05) was noted in birth weight and serum level inspite of similar infusion rates of theophylline. A linear correlation r = 0.65 was noted between serum level and infusion rate. Multivariate regression analysis, between birth weight and gestational age to serum level, showed a linear correlationship only between birth weight and serum level (r = 0.45).

Breath holding spells: an analysis of 50 cases.

Of 50 preschool children having breath holding spells (M:F::3:1) (BHS), 80.0% were less than 18 months of age (mean age 16 +/- 5 mo). More children came from a lower social class (70.0%) and a nuclear family (64.0%). Seventy four per cent cases had onset of BHS within 12 months of age (mean 9.6 mo) and the commonest frequency was 1 to 3 spells per week (56.0%). Cyanosis and tonic-clonic spasms were seen in 96.0 and 84.0% cases, respectively. Anger and frustration were the common triggering factors in 90.0% cases. No ante-, peri- and postnatal factors were significantly associated with the study group as compared to the control cases. The mean scores on Behaviour Screening Questionnaire measuring child's habits related to feeding, toilet and sleep were not significantly different in the study and control groups but the difference was significant (p less than 0.05) for behaviour measuring child's social habits. Parental attitudes, measured on Attitude Screening Questionnaires, were also not significantly different in the study and control groups. Mean hemoglobin and percentage transferrin saturation were significantly lower in the study group as compared to the controls (p less than 0.001). There was a significant decrease in severity and frequency of spells with oral iron therapy.