The value of oxygen index and base excess in predicting the outcome of neonatal acute respiratory distress syndrome

Correlation and Prediction of Oxygen Index from Oxygen Saturation Index in Neonates with Acute Respiratory Failure

OBJECTIVE

 The aim of this article was to evaluate the correlation between the oxygen index (OI) and the oxygen saturation index (OSI, measured by pulse oximetry and noninvasively) in neonates with acute respiratory failure and to predict the OI from the OSI.

STUDY DESIGN

 A retrospective cohort study was conducted in neonates requiring invasive mechanical ventilation who had arterial blood gas between 2018 and 2019 at a neonatal intensive care unit. The correlation between OI and OSI was analyzed by using the Pearson correlation coefficient.

RESULTS

 A total of 636 measurements from 68 neonates (35 preterm and 33 terms) were recruited into the study. There was a strong correlation between the OI and the OSI (r = 0.90) in all neonates. The correlation between the OI and the OSI in persistent pulmonary hypertension of the newborn, congenital cyanotic heart disease, and other causes of respiratory failure also showed a strong correlation (r = 0.88, 0.93, and 0.88, respectively). The correlation was strong in neonates with an oxygen saturation less than 85% (r = 0.88), those with oxygen saturation ranging from 85 to 95% (r = 0.87), and also in preterm and term infants (gestational age < 28, 28 - 34, 34 - 36, and ≥37 weeks, r = 0.87, 0.92, 0.89, and 0.90, respectively). There were strong accuracy measures of the OI for OI cutoffs of 5, 10, 15, and 20 (area under the curve > 0.85). The equation relating the OI and OSI was represented by: OI = (2.3 × OSI) - 4.

CONCLUSION

 The OSI has a strong correlation with the OI, is a reliable assessor of the severity of respiratory failure in neonates without arterial sampling, and has high accuracy when the OI is less than 40.

KEY POINTS

· OSI is calculated as (FiO2 × mean airway pressure × 100)/SpO2.. · OSI is as effective tool as OI for assessing the severity of pediatric acute respiratory distress syndrome.. · OSI has a strong correlation with OI in neonatal respiratory failure..

Expression and prognostic value of MIP-1α in neonatal acute respiratory distress syndrome

OBJECTIVE

To investigate the expression and prognostic value of macrophage inflammatory protein 1α (MIP-1α) in neonatal acute respiratory distress syndrome (NRDS).

METHODS

In this retrospective analysis, 96 newborns with NRDS in Affiliated Lianyungang Hospital of Xuzhou Medical University from January 2018 to June 2021 were included in the experimental group (EG), while the other 60 normal neonates were included as the control group (CG). The concentration of MIP-1α in umbilical cord blood was tested by Elisa method. The clinical value of MIP-1α in diagnosing NRDS was assessed via receiver operating characteristic (ROC) curve. According to the 28-day survival data, children were divided into a survival group and a death group. The prognostic factors were assessed by Cox regression analysis. The correlation between MIP-1α and IL-1β, IL-6, TNF-α, SNAPPE-II scores were evaluated by Pearson test. The relationship between the MIP-1α level and the severity of the disease was assessed.

RESULTS

The MIF-1α level in cord blood of children in the EG was dramatically higher than that in the CG (P<0.05). Besides, ROC curve further found that the area of MIF-1α under the curve of diagnosing NRSD was 0.949. MIF-1α was positively correlated with the levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor α (TNF-α) and SNAPPE-II score (P<0.001). With the increase of NRDS, the serum MIF-1α level increased, showing a positive association (P<0.05). Cox regression analysis revealed that the severity and MIF-1α level were independent prognostic factors of survival (P<0.001). The survival rate of children with MIF-1α <281.58 pg/mL as well as children with I-II grade was higher than those with MIF-1α >281.58 pg/mL as well as children with III-IV grade (P<0.05).

CONCLUSION

The increase of serum MIP-1α level is relevant to the condition and prognosis of NRDS children. The level of cord blood MIP-1α level is expected to become a potential outcome measure.

A prediction nomogram for neonatal acute respiratory distress syndrome in late-preterm infants and full-term infants: A retrospective study

BACKGROUND

Neonatal acute respiratory distress syndrome (ARDS) is a critical clinical disease with high disability and mortality rates. Early identification and treatment of neonatal ARDS is critical. This study aimed to build a perinatal prediction nomogram for early prediction of neonatal ARDS.

METHODS

A prediction model was built including 243 late-preterm and full-term infants from Daping Hospital in Chongqing, China, hospitalised between Jan 1, 2018 and Dec 31, 2019. 80 patients from the Children's Hospital in Chongqing, China, hospitalised between Jan 1, 2018 and June 30, 2018 were considered for external validation. Multivariate logistic regression was performed to identify independent predictors and establish a nomogram to predict the occurrence of neonatal ARDS. Both discrimination and calibration were assessed by bootstrapping with 1000 resamples.

FINDINGS

Multivariate logistic regression demonstrated that mother's education level (odds ratio [OR] 0·478, 95% confidence interval [CI] 0·324-0·704), premature rupture of membrane (OR 0·296, 95% CI 0·133-0·655), infectious disease within 7 days before delivery (OR 0·275, 95% CI 0·083-0·909), hospital level (OR 2·479, 95% CI 1·260-4·877), and Apgar 5-min score (OR 0·717, 95% CI 0·563-0·913) were independent predictors for neonatal ARDS in late-preterm and full-term infants, who experienced dyspnoea within 24 h after birth and required mechanical ventilation. The area under the curve and concordance index of the nomogram constructed from the above five factors were 0·760 and 0·757, respectively. The Hosmer-Lemeshow test showed that the model was a good fit (P = 0.320). The calibration curve of the nomogram was close to the ideal diagonal line. Furthermore, the decision curve analysis demonstrated significantly better net benefit in the model. The external validation proved the reliability of the prediction nomogram.

INTERPRETATION

A nomogram based on perinatal factors was developed to predict the occurrence of neonatal ARDS in late-preterm and full-term infants who experienced dyspnoea within 24 h after birth and required mechanical ventilation. It provided clinicians with an accurate and effective tool for the early prediction and timely management of neonatal ARDS.

FUNDING

No funding was associated with this study.

Association Between Base Excess and Mortality Among Patients in ICU With Acute Kidney Injury

Objective: This study aimed to explore the association between base excess (BE) and the risk of 30-day mortality among patients with acute kidney injury (AKI) in the intensive care unit (ICU). Methods: This retrospective study included patients with AKI from the Medical Information Mart for Intensive Care (MIMIC)-IV database. We used a multivariate Cox proportional-hazards model to obtain the hazard ratio (HR) for the risk of 30-day mortality among patients with AKI. Furthermore, we utilized a Cox proportional-hazard model with restricted cubic splines (RCS) to explore the potential non-linear associations. Results: Among the 14,238 ICU patients with AKI, BE showed a U-shaped relationship with risk of 30-day mortality for patients with AKI, and higher or lower BE values could increase the risk. Compared with normal base excess (-3~3 mEq/L), patients in different groups (BE ≤ -9 mEq/L, -9 mEq/L < BE ≤ -3 mEq/L, 3 mEq/L < BE ≤ 9 mEq/L, and BE > 9 mEq/L) had different HRs for mortality: 1.57 (1.40, 1.76), 1.26 (1.14, 1.39), 0.97 (0.83, 1.12), 1.53 (1.17, 2.02), respectively. The RCS analyses also showed a U-shaped curve between BE and the 30-day mortality risk. Conclusion: Our results suggest that higher and lower BE in patients with AKI would increase the risk of 30-day mortality. BE measured at administration could be a critical prognostic indicator for ICU patients with AKI and provide guidance for clinicians.