ABSTRACT
OBJECTIVE: To investigate the effect of caffeine infusion on superior mesenteric artery (SMA) blood flow velocities (BFV) in preterm infants. METHODS: Prospective observational study on 38 preterm neonates 28-33+6 weeks gestation, who developed apnea on their first day of life, and caffeine citrate infusion was initiated at a loading dose of 20 mg/kg, followed by a maintenance dose of 5-10 mg/kg/day. Duplex ultrasound measurements of SMA BFV were recorded: peak systolic velocity (PSV), end diastolic velocity (EDV) and resistive index (RI), at 15 min before, 1-, 2- and 6-h after caffeine loading dose, and 2 h after two maintenance doses. RESULTS: There was a significant reduction in PSV 1-h (p = .008), a significant decrease in EDV 1- and 2-h (p = .000 and p = .005, respectively) and a significant increase in RI 1- and 2-h (p = .003 and p = .005, respectively) following caffeine loading dose, as compared to values before caffeine infusion. No significant effect of caffeine maintenance doses on SMA BFV was observed (p > .05). CONCLUSION: Blood flow in SMA is significantly reduced after caffeine citrate infusion at a loading dose of 20 mg/kg. This effect continues for at least 2 h. Meanwhile, SMA BFV seems not affected by maintenance doses.
Subject(s)
Blood Flow Velocity/drug effects , Caffeine/pharmacology , Infant, Premature/physiology , Mesenteric Artery, Superior/drug effects , Regional Blood Flow/drug effects , Caffeine/therapeutic use , Citrates/pharmacology , Citrates/therapeutic use , Female , Gestational Age , Hemodynamics/drug effects , Humans , Infant, Newborn , Male , Mesenteric Artery, Superior/diagnostic imaging , Mesenteric Artery, Superior/physiology , Pregnancy , Premature Birth/drug therapy , Premature Birth/physiopathology , Ultrasonography, Doppler, DuplexABSTRACT
AIM: The aim of this study was to evaluate the effectiveness of meperidine, administered during the first stage of labor in patients with uterine dystocia, on the duration of labor and neonatal acid-base status at birth. MATERIAL AND METHODS: We randomly assigned 240 nulliparous women with a singleton pregnancy at term who were diagnosed with uterine dystocia in labor at 4-6-cm cervical dilatation to receive either a single dose of 50 mg meperidine in 10 mL of saline (slow intravenous injection over 2 min) or 10 mL of isotonic saline (control group). The primary outcome measures were duration of labor (from the time of beginning of the intervention to the time of the expulsion of the fetal head) and umbilical cord arterial acid-base status. RESULTS: The evidence revealed no statistically significant difference between the two groups in length of labor (188.2 ± 92.3 min in the meperidine group compared to 205.4 ± 96.1 min in the placebo group, P = 0.159). The pH of the umbilical cord arterial samples was lower in the meperidine group than in the control group, although the difference was not statistically significant (P = 0.089). CONCLUSION: Because of the absence of any beneficial effect of meperidine on uterine dystocia, its use in labor should be limited to pain relief in the absence of epidural analgesia.
