Maternal pulse oximetry perfusion index as a predictor of early adverse respiratory neonatal outcome after elective cesarean delivery

Effect of Norepinephrine on Peripheral Perfusion Index and Its Association With the Prognosis of Patients With Sepsis

Background: To evaluate whether the use of norepinephrine during the management of patients with sepsis affects the perfusion index (PI) and patient outcomes. Methods: We retrospectively studied patients with septic shock between January 2014 and December 2018 who had undergone Pulse index Continuous Cardiac Output-Plus cardiac output monitoring and received norepinephrine during the management. We collected data regarding basic clinical characteristics. Hemodynamic parameters, including lactate, PI, and norepinephrine dose at T0 and 24 h after Pulse index Continuous Cardiac Output catheterization (T24) were obtained. Results: The PI of the nonsurvivor group (n  =  44) was significantly lower than that of the survivor group (n  =  144) at T24, and the lactate level of the nonsurvivor group was significantly higher than that of the survivor group. The multiple logistic regression analysis suggested that the norepinephrine dose and PI were the most independent risk and protective factors, respectively, for intensive care unit mortality. The area under the curve for a poor prognosis was 0.847 (95% confidence interval, 0.782-0.912). The optimal cutoff value of the PI at T24 to predict intensive care unit mortality was 0.6, with a sensitivity of 77.1% and a specificity of 80%. Based on this optimal cutoff value, we divided patients into groups with PI ≥ 0.6 (n  =  125) and PI < 0.6 (n  =  59). The lactate level of the PI < 0.6 group was higher than that of the PI ≥ 0.6 group at T24. The PI < 0.6 group showed a significantly higher sublingual dose of norepinephrine indicators than the PI ≥ 0.6 group. The PI showed a strong negative correlation with norepinephrine dose (r  =  -0.344, P < .001) and lactate (r  =  -0.291, P < .001). Conclusions: A higher PI is a protective factor, and a higher dose of norepinephrine is a risk factor for the prognosis of critically ill patients with septic shock. A lower PI was associated with a higher dose of norepinephrine.

Peripheral perfusion index percentiles for healthy newborns by gestational age and sex in China

Peripheral perfusion index (PPI) percentiles for newborns serve as an important observation tool in clinical practice, but research pertaining to reference ranges are lacking. The aim of this study was to establish PPI percentiles for healthy newborns by gestational age and sex at 24-48 hours of life. We conducted an observational study and examined PPI values at 24-48 hours of life in 3814 asymptomatic newborns born between 35 and 41 weeks gestation who did not need medical treatment from June 1, 2016 to May 31, 2017 at two maternity hospitals in Shanghai. Linear regression analysis was carried out on the associations between PPI values and variables such as gestational age, sex, and birthweight. Pre-ductal PPI values linearly increased with gestational age (β: 0.072; 95% CI: 0.037, 0.107; P = 0.000). Post-ductal PPI values were also mainly related to gestational age (β: 0.051; 95% CI: 0.018, 0.085; P = 0.003). Smoothed reference curves for pre- and post-ductal PPI values by gestational age and sex were derived from LMS Chart Maker. Our study is the first study to establish PPI percentiles curves for healthy newborns by gestational age and sex at 24-48 hours of life. Further research is required for the implementation of PPI curves into clinical practice.

[Risks factors of cesarean delivery after 3hours of delayed pushing]

OBJECTIVES

Identify the factors associated with caesarean delivery for unengaged fetal head beyond 3hours of passive second stage of labor, among primiparous patients.

METHODS

A case-control study conducted in level III universitary center between October 2012 and September 2015. Only primiparous at term, with a singleton, cephalic fetus and a passive second stage of labor prolonged over 3hours before pushing were included. During the second stage of labor, patients who had caesarean for abnormal fetal heart rate were excluded. Risk factors of cesarean were analyzed with univariate analysis and after statistical adjustment using multivariate logistic regression.

RESULTS

The mean passive second stage duration was significantly longer among patients who had a caesarean (3h37±21min vs 3h13±19min [P=0,0001]). After multivariate logistic regression, factors associated with a risk of caesarean were body mass index higher than 30kg/m² (OR=25.9 [3.1-215.9]). fetal macrosomia suspected by 3rd trimester ultrasound (OR=4.4 [1.2-16.4]), induction by prostaglandins (OR=5.7 [2.1-15.5]), a stagnation of cervical dilatation during the 1st stage (OR=[1.3-6.8]), and fetal occiput posterior position beyond 3hours (OR=30.7 [3.3-280.9]).

CONCLUSIONS

Risk of caesarean delivery for unengaged fetal head beyond 3hours of passive second stage of labor is associated with maternal, fetal and obstetrical factors. Those factors might be taken into account before accept or not a 3rd hour at full cervical dilation.

Continuous noninvasive monitoring in the neonatal ICU

PURPOSE OF REVIEW

Standard hemodynamic monitoring such as heart rate and systemic blood pressure may only provide a crude estimation of organ perfusion during neonatal intensive care. Pulse oximetry monitoring allows for continuous noninvasive monitoring of hemoglobin oxygenation and thus provides estimation of end-organ oxygenation. This review aims to provide an overview of pulse oximetry and discuss its current and potential clinical use during neonatal intensive care.

RECENT FINDINGS

Technological advances in continuous assessment of dynamic changes in systemic oxygenation with pulse oximetry during transition to extrauterine life and beyond provide additional details about physiological interactions among the key hemodynamic factors regulating systemic blood flow distribution along with the subtle changes that are frequently transient and undetectable with standard monitoring.

SUMMARY

Noninvasive real-time continuous systemic oxygen monitoring has the potential to serve as biomarkers for early-organ dysfunction, to predict adverse short-term and long-term outcomes in critically ill neonates, and to optimize outcomes. Further studies are needed to establish values predicting adverse outcomes and to validate targeted interventions to normalize abnormal values to improve outcomes.

Reference values of perfusion indices in hemodynamically stable newborns during the early neonatal period

We aimed to determine reference values of perfusion index (PI) in healthy newborns during the early neonatal period. Preductal (right hand) and postductal (foot) PI values were assessed during the first 5 days of life by using a new generation pulse oximetry. A total of 241 newborn infants (196 [81.3 %] term and 45 [18.7 %] preterm) were enrolled to the study. On the first day, in term infants, the median (interquartile range [IQR]) preductal and postductal PI were 1.35 (1.02-1.91) and 0.88 (0.62-1.22), respectively (p = 0.001). These values were 0.88 (0.60-1.26) and 0.61 (0.35-0.92) in preterm infants, with the same respect (p = 0.001). From the first to third days, preductal PI remained significantly higher than the postductal PI (p < 0.001, for all comparisons). Both preductal and postductal PI of term newborns were significantly higher than those of preterm infants (p < 0.001, for both comparisons). These differences in PI disappeared on the fifth day of life. Conclusion PI values which reflect peripheral perfusion seem to reach to a steady state on the fifth day of life following physiological maturation.

Perfusion index in newborn infants: a noninvasive tool for neonatal monitoring

AIM

To review the utility of perfusion index (PI) in the evaluation of neonatal clinical conditions. Twenty-five manuscripts were reviewed. PI provides information about haemodynamic stability, illness severity, early neonatal respiratory outcome, low superior vena cava flow and subclinical chorioamnionitis.

CONCLUSION

PI is a valuable tool to assess the newborn's health condition and could become a standardised measure in clinical evaluation. Different study designs are necessary to provide further validation to this method.

The peripheral perfusion index and transcutaneous oxygen challenge test are predictive of mortality in septic patients after resuscitation

Introduction

The peripheral perfusion index (PI) is a noninvasive numerical value of peripheral perfusion, and the transcutaneous oxygen challenge test (OCT) is defined as the degree of transcutaneous partial pressure of oxygen (PtcO₂) response to 1.0 FiO_2. The value of noninvasive monitoring peripheral perfusion to predict outcome remains to be established in septic patients after resuscitation. Moreover, the prognostic value of PI has not been investigated in septic patients.

Methods

Forty-six septic patients, who were receiving PiCCO-Plus cardiac output monitoring, were included in the study group. Twenty stable postoperative patients were studied as a control group. All the patients inspired 1.0 of FiO₂ for 10 minutes during the OCT. Global hemodynamic variables, traditional metabolic variables, PI and OCT related-variables were measured simultaneously at 24 hours after PiCCO catheter insertion. We obtained the 10min-OCT ((PtcO₂ after 10 minutes on inspired 1.0 oxygen) - (baseline PtcO₂)), and the oxygen challenge index ((10min-OCT)/(PaO₂ on inspired 1.0 oxygen - baseline PaO₂)) during the OCT.

Results

The PI was significantly correlated with baseline PtcO₂, 10min-OCT and oxygen challenge index (OCI) in all the patients. The control group had a higher baseline PtcO₂, 10min-OCT and PI than the septic shock group. In the sepsis group, the macro hemodynamic parameters and ScvO₂ showed no differences between survivors and nonsurvivors. The nonsurvivors had a significantly lower PI, 10min-OCT and OCI, and higher arterial lactate level. The PI, 10min-OCT and OCI predicted the ICU mortality with an accuracy that was similar to arterial lactate level. A PI <0.2 and a 10min-OCT <66mmHg were related to poor outcome after resuscitation.

Conclusions

The PI and OCT are predictive of mortality for septic patients after resuscitation. Further investigations are required to determine whether the correction of an impaired level of peripheral perfusion may improve the outcome of septic shock patients.

Noninvasive monitoring by photoplethysmography

The photoplethysmogram (PPG) is a noninvasive circulatory signal related to the pulsatile volume in tissue and is displayed by many pulse oximeters. The PPG is similar in appearance to the invasive arterial waveform, but is noninvasive and ubiquitous in hospitals. There is increasing interest in seeking circulatory information from the PPG and developing techniques for a wide variety of novel applications. This article addresses the basic physics of photoplethysmography, physiologic principles behind pulse oximetry operation, and recent technological advances in the usefulness of the PPG waveform to assess microcirculation and intravascular fluid volume monitoring during intensive care.

First day of life reference values for pleth variability index in spontaneously breathing term newborns

BACKGROUND

The perfusion index (PI), derived from the pulse oximetry signal, has been shown to be an accurate predictor for identifying high illness severity in neonates. The plethysmographic variability index (PVI) is a measure of the dynamic change in PI occurring during a complete respiratory cycle.

OBJECTIVES

The aim of this study was to establish the reference range of PVI in spontaneously breathing term newborns.

METHODS

PI and PVI values were assessed in 242 term newborns during the first day of life.

RESULTS

The median PVI value on the first day of life was 20% [95% confidence interval (CI) for the mean 19-20%; inter-quartile range 15 (95% CI 15-16) - 24 (95% CI 23-24)]. The 10th and 90th percentile cutoff values were 12% (95% CI 11-12) and 28% (95% CI 27-29), respectively, with the 97.5th percentile of 35% (95% CI 34-38). PVI was also significantly influenced by the behavioral status of the newborn, and was positively correlated with PI and pulse rate, while it was inversely correlated with oxygen saturation (p < 0.0001).

CONCLUSIONS

Our findings suggest: (1) evaluation of PVI values is an easily applicable, noninvasive procedure for monitoring early postnatal respiratory changes in newborns, and (2) the feasibility of a noninvasive pulse-oximeter postnatal screening for early identification of adverse neonatal cardiorespiratory outcomes.