Results:
Out of the total 6007 admissions, 434 (7%) neonates had meconium stained liquor and respiratory distress at birth. The respiratory distress settled within 24 hours in 40 neonates. In the remaining 384 neonates, 347 were discharged home and were enrolled for the study. A total of 10 neonates died, 24 were categorised as Leave against medical advice (LAMA) and 3 were repatriated to the referral hospitals for the continuation of care and outcome data were not available. The mortality including the neonates sent LAMA with grave outcomes was 23 (5.9%). The flow of the patients is summarized in figure 1.
About 35% of neonates required resuscitation at birth. At admission, 163 (47%) neonates had significant distress, evidenced by Downes score ≥4. 184 (53%) were stabilized on CPAP as primary respiratory support. The neonates in the cohort had associated morbidities of HIE stage 2 or 3 in 67 (19%), surfactant requirement 94 (27%), PPHN in 80 (23%). The median length of hospital stay (IQR) was 10 (7-14) days. The baseline characteristics of enrolled neonates are outlined in table 1.
Amongst 347 neonates, 103 (29%) were discharged before 7 days and remaining 244 (71%) had prolonged stay. On univariate comparison of short stay versus long stay (table 2), Positive pressure ventilation (PPV) at birth (27% vs 38%, p=0.05), intubation at birth (2% vs 19%, p<0.001), HIE stage 2 or 3 (2% vs 27%, p<0.001), Fio2 at 1hr>30% (45% vs 87%, p<0.001), Downe’s score at admission ≥4 (64% vs 90%, p<0.001), primary support beyond O2 (CPAP or MV) (42% vs 83%, p<0.001), CPAP as primary support after admission (36% vs 60%, p<0.001), invasive mechanical ventilation (6% vs 23%, p<0.001), surfactant requirement (1% vs 38%, p<0.001), moderate-severe PPHN (3% vs 31%, p<0.001) were statistically significant factors seen in the prolong stay group. Although CPAP as primary support was seen as a statistically significant risk factor in the prolonged stay, CPAP initiation was delayed by a mean difference of 21 hrs (-32 to -10) in the prolonged stay group compared to short stay.
On multivariate analysis, 4 parameters, namely primary support beyond oxygen, FiO2 more than 30% one hour post admission, presence of moderate-severe PPHN, HIE stage 2 or 3, were found to be independent predictors of prolonged stay in hospital (Table 3). These 4 variables were used to devise a scoring system predictive of prolonged stay in MAS. The beta coefficients obtained from the logistic regression were used to calculate the weights of these parameters. The final weighted score is as follows: 9 (Primary support beyond oxygen) + 15 (FiO2 more than 30% 1hour after admission) + 20 (moderate-severe PPHN) + 29 (HIE stage 2 or 3), with each variable being assigned a value as ‘1’ if present and ‘0’ if absent. The ROC curve was plotted to evaluate the predictive ability of the weighted score. The Area under curve (AUC) was 82% (95% CI 78-87%), p<0.001 and thus had excellent model discriminatory power. Based on the distribution of the neonates in both the groups for the weighted score and ROC curve analysis (Table 3) (figure 2), the optimal cutoff for prolonged stay was determined. The optimal cutoff was \(\geq\) 21 had sensitivity, specificity, positive predictive value and negative predictive value of 83%, 68%, 86% and 62%, respectively. The positive and negative likelihood ratios were 2.6 and 0.25, respectively.