Effect of limb cooling on peripheral and global oxygen consumption in neonates

Neonatal somatic oxygenation and perfusion assessment using near-infrared spectroscopy : Part of the series on near-infrared spectroscopy by the European Society of Paediatric Research Special Interest Group "Near-Infrared Spectroscopy"

In this narrative review, we summarize the current knowledge and applications of somatic near-infrared spectroscopy (NIRS), with a focus on intestinal, renal, limb, and multi-site applications in neonates. Assessing somatic oxygenation at various body locations in neonates may aid in the understanding of underlying pathophysiology of organ injury. Considering cerebral autoregulation may be active to protect the brain during systemic circulatory failure, peripheral somatic oxygenation may potentially provide an early indication of neonatal cardiovascular failure and ultimate hypoxemic injury to vital organs including the brain. Certain intestinal oxygenation patterns appear to be associated with the onset and course of necrotizing enterocolitis, whereas impaired renal oxygenation may indicate the onset of acute kidney injury after various types of hypoxic events. Peripheral muscle oxygenation measured at a limb may be particularly effective in the early prediction of shock in neonates. Using multi-site NIRS may complement current approaches and clinical investigations to alert for neonatal tissue hypoxemia, and potentially even guide management. However, somatic NIRS has its inherent limitations in regard to accuracy. Interpretation of organ-specific values can also be challenging. Last, currently there are limited prospective intervention studies, and clinical benefits need to be examined further, after the clarification of critical threshold-values. IMPACT: The assessment of somatic oxygenation using NIRS may contribute to the prediction of specific diseases in hemodynamically challenged neonates. Furthermore, it may give early warning signs for impending cardiovascular failure, and impaired cerebral circulation and oxygenation. We present a comprehensive overview of the literature on applications of NIRS to various somatic areas, with a focus on its potential clinical applicability, including future research directions. This paper will enable prospective standardized studies, and multicenter collaboration to obtain statistical power, likely to advance the field.

Peripheral fractional oxygen extraction measured with near-infrared spectroscopy in neonates-A systematic qualitative review

BACKGROUND

Peripheral fractional oxygen extraction (pFOE) measured with near-infrared spectroscopy (NIRS) in combination with venous occlusion is of increasing interest in term and preterm neonates.

OBJECTIVE

The aim was to perform a systematic qualitative review of literature on the clinical use of pFOE in term and preterm neonates and on the changes in pFOE values over time.

METHODS

A systematic search of PubMed, Embase and Medline was performed using following terms: newborn, infant, neonate, preterm, term, near-infrared spectroscopy, NIRS, oximetry, spectroscopy, tissue, muscle, peripheral, arm, calf, pFOE, OE, oxygen extraction, fractional oxygen extraction, peripheral perfusion and peripheral oxygenation. Additional articles were identified by manual search of cited references. Only studies in human neonates were included.

RESULTS

Nineteen studies were identified describing pFOE measured with NIRS in combination with venous occlusion. Nine studies described pFOE measured on the forearm and calf at different time points after birth, both in stable preterm and term neonates without medical/respiratory support or any pathological findings. Nine studies described pFOE measured at different time points in sick preterm and term neonates presenting with signs of infection/inflammation, anemia, arterial hypotension, patent ductus arteriosus, asphyxia or prenatal tobacco exposure. One study described pFOE both, in neonates with and without pathological findings.

CONCLUSION

This systematic review demonstrates that pFOE may provide additional insight into peripheral perfusion and oxygenation, as well as into disturbances of microcirculation caused by centralization in preterm and term neonates with different pathological findings.

SYSTEMATIC REVIEW REGISTRATION

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42021249235].

The Predictive Value of Pulse Oximeters for Pulse Improvement after Angiography in Infants and Children

Background

Information from pulse oximeter waves confirms the presence of a pulse and helps obtain waves from tissue when the supplying artery is not readily accessible.

Objectives

This study determined the predictive value of pulse oximeters for detecting improved arterial pulses after angiography.

Patients and Methods

This cross-sectional, multi-center study included 467 4-day-old to 12-year-old patients and was conducted from January 2012 to January 2016. Angiographies were performed on 12-year-old or younger children for various medical reasons using venous, arterial, or both types of paths. The posterior malleolar or dorsalis pedis were palpated in punctured lower extremities. In the absence of a pulse, pulse oximetry was performed to identify pulse curves at 1 hour, 6 hours, and 12 hours after each angiography.

Results

Pulse oximetry displayed the pulses of 319 patients immediately following each angiography. Of these, 262 patients had palpable pulses at 6 hours after angiography (P < 0.0001), while 57 patients had no palpable pulse. Of these 57 patients, 15 had no palpable pulse at 12 hours after angiography (P < 0.0001). The odds of pulse improvement in children 6 hours after catheter angiography were 76% for the arterial path, 90% for the venous path, and 83.2% for both paths. At 12 hours after catheter angiography, these values increased to 91.6% for the arterial path, 100% for the venous path, and 95.9% for both paths.

Conclusions

The pulse oximeter can display the pulse curve immediately (1 hour) after angiography and indicate pulse improvement at 12 hours maximally following an angiography. In this case, heparin alone may be used instead of thrombolytic agents.

Peripheral Muscle Near-Infrared Spectroscopy in Neonates: Ready for Clinical Use? A Systematic Qualitative Review of the Literature

BACKGROUND

Peripheral muscle near-infrared spectroscopy (NIRS) measurements are of increasing interest especially in the care of critically ill patients.

OBJECTIVE

The aim was to perform a systematic qualitative review on peripheral muscle NIRS measurements in the clinical care of term and preterm neonates.

METHODS

A systematic search of PubMed and Ovid Embase was performed using the following terms: neonate, neonates, newborn, newborns, infant, infants, near-infrared spectroscopy, NIRS, oxygenation, perfusion, oxygen extraction, peripheral, tissue, muscle, calf, forearm and thigh. Additional articles were identified by a manual search of the cited references. Only human studies were included.

RESULTS

Twenty-one studies were identified to use peripheral muscle NIRS measurements as a single method, 17 studies combined cerebral and peripheral muscle NIRS measurements and 1 study used multi-site NIRS measurements in human neonates. Two randomized studies were identified. Two additional publications were included because they provided important general information about peripheral muscle NIRS measurements.

CONCLUSION

In the care of critically ill neonates peripheral muscle NIRS measurements alone or in combination with cerebral or multi-site NIRS measurements provide useful additional information about peripheral circulation and oxygenation. This method is a promising tool in the recognition of early states of centralization (compensated shock) in this vulnerable group of patients. However, before this method can be used in the clinical routine it has to be tested as monitoring to guide interventions in further studies.

The influence of perinatal asphyxia on peripheral oxygenation and perfusion in neonates

BACKGROUND

Perinatal asphyxia influences peripheral oxygenation and perfusion in neonates.

OBJECTIVES

The aim was to investigate the influence of perinatal asphyxia on peripheral oxygenation and perfusion in neonates by using near-infrared spectroscopy (NIRS).

METHODS

Prospective observational study. Neonates with gestational age >34 weeks and birth weight >2000 g without infection or congenital malformations were included. Peripheral muscle NIRS measurements in combination with venous occlusion were performed once in the first 48 h of life. Tissue oxygenation index (TOI), mixed venous oxygenation (SvO2), fractional oxygen extraction (FOE), haemoglobin flow (Hbflow), oxygen delivery (DO2) and oxygen consumption (VO2) were assessed. Furthermore arterial oxygen saturation, heart rate, blood pressure and temperatures were measured. Neonates with a UapH≤7.15 and an Apgar 5≤6 were compared to neonates with a UapH≥7.15, an Apgar 5≥7 (control group) and a UapH was correlated to NIRS parameters.

RESULTS

8 asphyxiated neonates were compared to 30 neonates in the control group. TOI (67.7±5.5%) and DO2 (29.0±14.2 μmol/100 mL/min) were significantly lower in asphyxiated neonates compared to the controls (TOI 71.8±4.9%, p=0.045; DO2 43.9±16.9 μmol/100 mL/min, p=0.028) and FOE was significantly higher (0.33±0.05) compared to the controls (0.28±0.06, p=0.028). Furthermore significant correlations between UapH and DO2 (r=0.78, p=0.022), VO2 (r=0.80, p=0.018) and FOE (r=-0.75, p=0.034) in the asphyxiated group were found.

CONCLUSION

Peripheral oxygenation and perfusion measured with NIRS are compromised in neonates with perinatal asphyxia with worsening of parameters and degree of acidosis in the umbilical cord blood.

Peripheral blood flow and oxygen extraction in the sick, newborn very low birth weight infant shortly after birth

This study examined the relationship between blood pressure, peripheral blood flow (PBF), and peripheral fractional oxygen extraction (FOE). Variables that may influence PBF and peripheral FOE were also measured. Measurements of PBF by near infrared spectroscopy and fractional shortening by echocardiography were made within 12 h of birth in 24 infants less than 32 wk gestation. Blood gases, Hb, temperature, and blood pressure were also measured. PBF was significantly correlated with fractional shortening (r = 0.56, p = 0.005), Po2 (r = -0.5, p = 0.01), and peripheral temperature (r = 0.52, p = 0.01). Peripheral FOE was significantly correlated with fractional shortening (r = -0.48, p = 0.02), Po2 (r = 0.52, p = 0.02), and Pco2 (r = -0.53, p = 0.008), but not with peripheral temperature. There was no significant correlation between blood pressure and either PBF or peripheral FOE. These results indicate the importance of several physiologic variables, but not blood pressure, in determining peripheral tissue oxygen delivery in sick preterm infants receiving intensive care. It adds weight to the idea that blood pressure should not be considered a surrogate for peripheral blood flow and oxygen delivery.

Early versus late cord clamping: effects on peripheral blood flow and cardiac function in term infants

BACKGROUND

In the debate on the best cord clamping time in newborn infants, we hypothesized that late cord clamping enables an increased volemia due to blood transfer to the newborn from the placenta.

AIM

To assess whether clamping time can affect limb perfusion and heart hemodynamics in a group of 22 healthy term newborn infants.

STUDY DESIGN

A case-control study.

SUBJECTS

Eleven early-clamped (at 30 s) vaginally-delivered newborn infants were compared with eleven late-clamped (at 4 min) newborns.

OUTCOME MEASURES

The two groups were studied using near-infrared spectroscopy and M-mode echocardiography.

RESULTS

Late cord clamping coincided with a higher hematocrit (median 62% versus 54%) and hemoglobin concentration (median 17.2 versus 15 g/dL), whilst there were no changes in bilirubin level. Echocardiography showed a larger end-diastolic left ventricle diameter (1.7 cm median value versus 1.5) coupled with unvaried shortening and ejection fraction values. There were no changes in calf blood flow, oxygen delivery, oxygen consumption or fractional oxygen extraction calculated from the NIRS measurements, or in foot perfusion index.

CONCLUSIONS

Our results demonstrated that late cord clamping coincides with an increased placental transfusion, expressed by higher hematocrit and hemoglobin values, and larger left ventricle diameter at the end of the diastole, with no changes in peripheral perfusion or oxygen metabolism.

Impact of smoking during pregnancy on peripheral tissue oxygenation in term neonates

BACKGROUND

Smoking during pregnancy is associated with higher blood pressure in neonates.

OBJECTIVE

To analyze whether smoking during pregnancy has an influence on peripheral tissue oxygenation in healthy term neonates within the first days after delivery.

METHODS

In a prospective cohort study, 15 healthy term neonates of mothers who had smoked during pregnancy (smoking group) were matched for gestational age, actual weight and postnatal age to 15 healthy term neonates of mothers who had not smoked during pregnancy (non-smoking group). Peripheral oxygenation was measured by near-infrared spectroscopy in combination with the venous occlusion method on the left forearm. Measurements were performed within the first 2 days after delivery. Tissue oxygenation index (TOI), fractional oxygen extraction (FOE), oxygen delivery (DO(2)) and oxygen consumption (VO(2)) were analyzed.

RESULTS

In neonates measured within the first day after delivery, TOI was significantly lower and FOE was significantly higher (63.5 +/- 5.5; 0.37 +/- 0.04) in the smoking group compared to the non-smoking group (69.2 +/- 2.9; 0.30 +/- 0.04). DO(2) tended to be lower and VO(2) tended to be higher in the smoking group. In neonates measured on the second day after delivery, no significant differences were observed between the groups.

CONCLUSIONS

Smoking during pregnancy reduced TOI and increased FOE in otherwise healthy neonates on the first day of life with normalization on the second day of life.

Forearm oxygen consumption and forearm blood flow in healthy children and adolescents measured by near infrared spectroscopy

The assessment of forearm oxygen consumption (VO(2)) and forearm blood flow (FBF) by means of near infrared spectroscopy has become widespread in adults, whereas in children and adolescents no data are available. The aim of the present study was to analyze VO(2) and FBF in healthy children and adolescents.

METHODS

In a prospective cohort study, 20 male and 20 female healthy children and adolescents were investigated. The measurements of VO(2) and FBF were performed by means of near infrared spectroscopy in combination with the venous occlusion method.

RESULTS

Mean VO(2) was 0.08 +/- 0.04 ml 100 g(-1) min(-1) in male and 0.09 +/- 0.05 ml 100 g(-1) min(-1) in female subjects. Mean FBF was 1.95 +/- 1.25 ml 100 g(-1) min(-1) in male and 1.82 +/- 0.98 ml 100 g(-1) min(-1) in female subjects. No significant difference was found between male and female subjects. A significant negative correlation of VO(2) and FBF to age was observed in both groups.

CONCLUSION

In the present study we were able to show that VO(2) and FBF decreased with increasing age in children and adolescents without significant differences between male and female subjects.

Foot pulse oximeter perfusion index correlates with calf muscle perfusion measured by near-infrared spectroscopy in healthy neonates

OBJECTIVE

In critically ill neonates, peripheral perfusion and oxygenation assessment may provide indirect information on the circulatory failure of vital organs during circulatory shock. The development of pulse oximetry has recently made it possible to calculate the perfusion index (PI), obtained from the ratio between the pulsatile and nonpulsatile signals of absorbed light. The main goals of this study were: (1) to study foot PI; and (2) to evaluate the relationship between foot PI, obtained continuously by pulse oximetry, and a number of variables, i.e. blood flow (BF), oxygen delivery (DO(2)), oxygen consumption (VO(2)), and fractional oxygen extraction (FOE), measured indirectly by near-infrared spectroscopy (NIRS) on the calf in 43 healthy term neonates (weight 3474.6 +/- 466.9 g; gestational age 39.1 +/- 1.4 weeks).

STUDY DESIGN

Calf BF, DO(2) and VO(2) were assessed by NIRS on short-lived venous and arterial occlusion maneuvers. PI was measured on the contralateral foot.

RESULTS

Foot PI was 1.26 +/- 0.39. There was a positive correlation between foot PI and both calf BF (r = 0.32, p = 0.03) and DO(2) (r = 0.32, p = 0.03), but no correlation was found between foot PI and calf FOE and between foot PI and VO(2).

CONCLUSIONS

In the neonatal intensive care unit, continuously measuring foot PI by pulse oximetry seems clinically more feasible for peripheral perfusion monitoring than spot measurements of the calf BF and/or VO(2) by indirect NIRS.