RESUMO
BACKGROUND: To investigate the relationship between the OPRM1 gene A118G polymorphism and intracranial hemorrhage (ICH) in premature infants and identify the relevant genes in disease occurrence. METHODS: In the present case study analysis, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to detect the genotype and allele frequencies of the OPRM1 gene All8G single nucleotide polymorphism (SNP) in a case group of premature infants with ICH (n=167) and a control group of premature infants (n=163) without ICH. RESULTS: In the case group, 73 (43.7%) wild type A118 homozygous (A/A), 82 (49.1%) mutant heterozygous (A/G), and 12 (7.2%) mutant G118 homozygous (G/G) individuals were observed. The frequencies of A and G alleles were 68.3% and 31.7% respectively. In the control group, 89 (54.6%) wild type A118 homozygous (A/A), 68 (41.7%) mutant heterozygous (A/G), and 6 (3.7%) mutant G118 homozygous (G/G) individuals were observed. The frequencies of A and G alleles were 75.5% and 24.5% respectively. There was no significant difference in the frequency distribution of the OPRM1 gene A118G polymorphism between the two groups (χ2=4.839, P=0.089). There was a significant difference in the positive rate of wild-type AA and mutant-type (A/G + G/G) between the two groups (χ2=3.913, P=0.048). Carrying the G allele of the individual was 1.5 times more frequent suffering from the risk of ICH than carrying the A allele [odds ratio (OR): 1.549; 95% confidence interval (CI): 1.003-2.391], indicating that the OPRM1 118G allele was positively correlated with ICH and can increase the risk of ICH occurrence. CONCLUSIONS: The OPRM1 gene A118G polymorphism is associated with ICH in premature infants. The OPRM1 gene A118G may play a critical role in the occurrence of ICH.
RESUMO
OBJECTIVE: To evaluate the value of N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels along with spontaneous breathing trial (SBT) in the prediction of ventilator weaning outcome among respiratory distress syndrome (RDS) preterm infants ready to wean. METHODS: NT-proBNP along with plasma albumin concentration, serum sodium, serum potassium, and hematocrit were measured immediately before SBT in preterm infants (≤32 weeks) mechanically ventilated due to RDS. Extubation was considered successful if infants remained extubated >48 hr. Either SBT failure or extubation failure was considered weaning failure. RESULTS: Sixty-three of 88 infants passed the SBT and were subsequently extubated. Of these, two (3.2%) cases rapidly developed laryngeal dyspnea imposing reintubation (excluded from analysis). Of the remaining 61 infants, 45 (73.8%) cases had successful extubation, and 16 (26.2%) cases were reintubated. Infants who failed weaning had lower gestational age, birth weight, and plasma albumin concentrations, higher NT-proBNP, doses of surfactant, occurrence of ventilator-associated pneumonia, and occurrence of pulmonary arterial hypertension than those who did not. NT-proBNP was the only independent factor that could predict weaning failure (OR = 1.872; P = 0.044). The ROC-AUC for NT-proBNP to predict weaning failure was 0.977 (95% CI 0.918-0.997; P < 0.001). The cut-off of NT-proBNP level 18,500 pg/ml to predict weaning failure had a positive likelihood ratio of 25.180. The addition of NT-proBNP to SBT in prediction of weaning failure significantly improved the net reclassification improvement (NRI = 0.224; P = 0.034). CONCLUSION: NT-proBNP is an independent factor that could predict weaning failure. Measurement of NT-proBNP prior to SBT may be helpful in promoting successful ventilator weaning along with SBT.
