Splanchnic-cerebral oxygenation ratio associated with packed red blood cell transfusion in preterm infants.

BACKGROUND: Splanchnic-cerebral oxygenation ratio (SCOR), the ratio of splanchnic tissue oxygen (StO2 s) to simultaneously measured cerebral tissue oxygen (StO2 c), has been described as a surrogate to detect impaired splanchnic oxygenation associated with hypoperfusion status such as necrotizing enterocolitis. This concept is based on the presumption that any change in SCOR indicates a corresponding change in splanchnic tissue oxygenation as the numerator, whereas cerebral tissue oxygenation as the denominator remains stable. However, it is questionable to utilise this concept to detect splanchnic oxygenation changes in the context of packed red blood cell transfusion (PRBCT). AIM: The current study examines the contribution of both cerebral and splanchnic oxygenation components to PRBCT-associated SCOR changes in preterm infants. DESIGN: Prospective cohort study. SETTING: Neonatal intensive care. PATIENTS: Hemodynamically stable infants: Gestation <32 weeks; birth weight <1500 g; postmenstrual age <37 weeks: tolerating ≥120 ml/kg/day feed volume. INTERVENTIONS: PRBCT at 15 ml/kg, over 4 h. MAIN OUTCOME MEASURES: Transfusion-associated changes were determined by performing mixed models for repeated measures analysis between the 4-h mean pre-transfusion values (SCOR 0, StO2 s 0, and StO2 c 0) and the post-transfusion hourly mean values for the next 28 h (SCOR 1-28, StO2 s 1-28, and StO2 c 1-28). Dunnett's method was used to adjust for the multiplicity of the p value. RESULTS: Of 30 enrolled infants 14 [46.7%] male; median [IQR] birth weight, 923 [655-1064] g; gestation, 26.4 [25.5-28.1] weeks; enrolment weight, 1549 [1113-1882] g; and postmenstrual age, 33.6 [32.4-35.0] weeks, one infant was excluded because of corrupted NIRS data. With the commencement of PRBCT, SCOR demonstrated a downward trend throughout the study period. This drift was associated with an increasing StO2 c trend, while StO2 s remained unchanged throughout the study period. CONCLUSIONS AND RELEVANCE: PRBCT-associated SCOR decrease suggests improvement in cerebral oxygenation rather than worsening splanchnic oxygenation. Our study underlines that it is necessary to determine individual components of SCOR, namely cerebral and splanchnic StO2 to understand SCOR changes in the context of PRBCT.

Selective bronchial intubation in a preterm infant with congenital cystic adenomatoid malformation and pulmonary air leak syndrome.

A preterm infant with congenital cystic adenomatoid malformation (CCAM) who developed a right-sided pulmonary air leak syndrome (pulmonary interstitial emphysema and bronchopleural fistula) following CCAM resection is reported. The pulmonary air leak syndrome was successfully ameliorated by intubating the right mainstem bronchus using a modified endotracheal tube that allowed selective ventilation of the left lung. The procedure was used successfully as rescue treatment to control the pulmonary air leak and to confirm the functional adequacy of the left lung prior to definitive operative surgery.

Extending total parenteral nutrition hang time in the neonatal intensive care unit: is it safe and cost effective?

AIM: To investigate the effects of prolonging hang time of total parenteral nutrition (TPN) fluid on central line-associated blood stream infection (CLABSI), TPN-related cost and nursing workload. METHODS: A before-after observational study comparing the practice of hanging TPN bags for 48 h (6 February 2009-5 February 2010) versus 24 h (6 February 2008-5 February 2009) in a tertiary neonatal intensive care unit was conducted. The main outcome measures were CLABSI, TPN-related expenses and nursing workload. RESULTS: One hundred thirty-six infants received 24-h TPN bags and 124 received 48-h TPN bags. Median (inter-quartile range) gestation (37 weeks (33,39) vs. 36 weeks (33,39)), mean (±standard deviation) admission weight of 2442 g (±101) versus 2476 g (±104) and TPN duration (9.7 days (±12.7) vs. 9.9 days (±13.4)) were similar (P > 0.05) between the 24- and 48-h TPN groups. There was no increase in CLABSI with longer hang time (0.8 vs. 0.4 per 1000 line days in the 24-h vs. 48-h group; P < 0.05). Annual cost saving using 48-h TPN was AUD 97,603.00. By using 48-h TPN, 68.3% of nurses indicated that their workload decreased and 80.5% indicated that time spent changing TPN reduced. CONCLUSION: Extending TPN hang time from 24 to 48 h did not alter CLABSI rate and was associated with a reduced TPN-related cost and perceived nursing workload. Larger randomised controlled trials are needed to more clearly delineate these effects.

Cerebral and splanchnic near-infrared spectroscopic dataset in premature newborns receiving packed red blood cell transfusion.

This article presents the near-infrared spectroscopy (NIRS) dataset of cerebral (StO2c) and splanchnic (StO2s) oxygenation in 29 stable premature infants admitted to a tertiary neonatal intensive care unit who received elective packed red blood cell transfusion (PRBCT) to treat anemia of prematurity. StO2c and StO2s data were prospectively recorded continuously from at least 4 hours before the beginning of PRBCT until 24 hours after its completion, using a 4-wavelength near-infrared spectroscopy (NIRS) monitor (FORE-SIGHT® absolute cerebral oximeter, CASMED, Branford, Connecticut, 06405 USA). StO2 data were downloaded as an analog output at a sampling rate of 1000Hz and aligned along the time axis in LabChart reader format (.adicht files) using a PowerLab data acquisition system [1] (PowerLab®, ADInstruments, Sydney, Australia). The .adicht files were then converted into .mat file format using a Python script (PythonTM version 3.7.3 [2]) and resampled at 1Hz for faster processing. Data that could not be physiologically explained (e.g., the absence of variability, [3] a 30% step change in StO2 between two subsequent data points for StO2[4]), as well as the data during the period of 'cares' were presumed to be artefactual and were replaced with 'NaN' or 'Not a Number' which is recognised by Matlab [5] (MATLAB 9.3, The MathWorks, Inc., Massachusetts, United States) and ignored for all subsequent processing while maintaining the correct time point of the StO2 signals. The data were then exported into Microsoft Excel format. The splanchnic cerebral oxygenation ratio (SCOR) was calculated as the ratio of StO2s/StO2c. A 4-hour mean pre-transfusion values (StO2s 0, StO2c 0, SCOR 0) and post-transfusion hourly mean values (1-28) were determined. Secondary data were derived from a Mixed Models for Repeated Measures (MMRM) analysis with the time point fitted as a fixed effect and the infant fitted as a random effect. The MMRM was used to perform paired comparisons between pre-transfusion and each of the post-baseline values. This article only provides the NIRS data. The secondary data and demography can be found in the article "Splanchnic-Cerebral Oxygenation Ratio associated with Packed Red Blood Cell Transfusion in preterm infants", published in Transfusion Medicine. [6] The data will be of use to researchers in neonatology, transfusion medicine, and physiology to understand changes in cerebral and splanchnic oxygenation associated with PRBCT. Data collection, processing, and analysis can be remodelled in larger multicentric randomised controlled studies to evaluate the effect of transfusion and feeding on transfusion-associated necrotising enterocolitis. The data are also helpful to explore the autoregulatory behaviour of the brain and gut when the oxygen content of blood is increased by administering PRBCT.

Regional tissue oxygenation and conventional indicators of red blood cell transfusion in anaemic preterm infants.

Background: It is unresolved whether low haemoglobin (Hb) and symptoms of anaemia reflect oxygen delivery-consumption imbalances (fractional tissue oxygen extraction [FTOE]). Here, we test whether pre-transfusion Hb and symptoms of anaemia correlate with pre-transfusion cerebral and splanchnic FTOE. Methods: This prospective cohort study was carried out between Sept 1, 2014 and Nov 30, 2016 at Nepean Hospital, Sydney, Australia. The study enroled haemodynamically stable preterm infants: gestation <32 weeks; birth weight <1500 gs; postmenstrual age <37weeks, who received 15 mL/kg packed red blood cell transfusion (PRBCT) based on low Hb and symptoms of anaemia. FTOE was determined using simultaneous monitoring of near-infrared spectroscopy and pulse oximetry for 4 h before PRBCT. Findings: The study enroled 29 infants born with a median gestation of 26.4 weeks (IQR 25.4-28.1), birth weight 922 g (655-1064), at postmenstrual age 33.6 weeks (31.7-34.9), and weight 1487 g (1110-1785). There was no significant correlation between Hb (median 97 g/L, IQR 87-100) and cerebral FTOE (r=-0.12, 95% CI -0.47 to 0.27; p = 0.54, n = 29) as well as splanchnic FTOE (r=-0.09, 95% CI -0.45 to 0.29; p = 0.64, n = 29). Median cerebral FTOE (p = 0.67) and splanchnic FTOE (p = 0.53) did not differ between symptomatic and asymptomatic groups. Interpretation: Our preliminary findings suggest that pre-transfusion Hb and symptoms of anaemia might not accurately reflect oxygen delivery-consumption imbalances in both the brain and the gut. A lack of correlation with cerebral FTOE might be presumed to be due to the brain-sparing effect. However, the lack of correlation with splanchnic FTOE is more concerning. Hence, these results warrant larger studies incorporating FTOE along with the conventional criteria in the transfusion algorithm. Funding: The study was funded (for the purchase of NIRS sensors) by the Australian Women and Children's Research Foundation.

Hierarchical improvement of regional tissue oxygenation after packed red blood cell transfusion.

BACKGROUND: It is well established that counter-regulation to hypoxia follows a hierarchical pattern, with brain-sparing in preference to peripheral tissues. In contrast, it is unknown if the same hierarchical sequence applies to recovery from hypoxia after correction of anemia with packed red blood cell transfusion (PRBCT). OBJECTIVE: To understand the chronology of cerebral and splanchnic tissue oxygenation resulting after correction of anemia by PRBCT in preterm infants using near-infrared spectroscopy (NIRS). DESIGN: Prospective cohort study. SETTING: Neonatal intensive care. PATIENTS INCLUDED: Haemodynamically stable infants: <32 weeks gestation, <37weeks postmenstrual age, <1500 grams birth weight; and ≥120 mL/kg/day feeds tolerated. INTERVENTION: PRBCT at 15 mL/Kg over 4 hours. MAIN OUTCOME MEASURES: Transfusion-associated changes were determined by comparing the 4-hour mean pre-transfusion cerebral and splanchnic fractional tissue oxygen extraction (FTOEc0; FTOEs0) with hourly means during (FTOEc1-4; FTOEs1-4) and for 24 hours after PRBCT completion (FTOEc5-28; FTOEs5-28). RESULTS: Of 30 enrolled infants, 14[46.7%] male; median[IQR] birth weight, 923[655-1064]g; gestation, 26.4[25.5-28.1]weeks; enrolment weight, 1549[1113-1882]g; and postmenstrual age, 33.6[32.4-35]weeks, 1 infant was excluded because of corrupted NIRS data. FTOEc significantly decreased during and for 24 hours after PRBCT (p < 0.001), indicating prompt improvement in cerebral oxygenation. In contrast, FTOEs showed no significant changes during and after PRBCT (p>0.05), indicating failure of improvement in splanchnic oxygenation. CONCLUSION: Improvement in regional oxygenation after PRBCT follows the same hierarchical pattern with a prompt improvement of cerebral but not splanchnic tissue oxygenation. We hypothesise that this hierarchical recovery may indicate continued splanchnic hypoxia in the immediate post-transfusion period and vulnerability to transfusion-associated necrotizing enterocolitis (TANEC). Our study provides a possible mechanistic underpinning for TANEC and warrants future randomised controlled studies to stratify its prevention.

Furosemide for packed red cell transfusion in preterm infants: a randomized controlled trial.

OBJECTIVE: To assess the effect of furosemide administered with packed red blood cell transfusion on cardiopulmonary variables of hemodynamically stable, electively transfused preterm infants beyond the first week of life. STUDY DESIGN: A randomized, stratified, double-blind, placebo-controlled trial of intravenous furosemide (1 mg/kg) versus placebo (normal saline) just before "top-up" packed red blood cell transfusion (20 mL/kg over 4 hours) in a tertiary neonatal intensive care unit. RESULTS: The primary outcome was a change in fraction of inspired oxygen (FiO(2)) during the 24 hours posttransfusion compared with the 6-hour pretransfusion period. Secondary outcomes were functional echocardiographic and clinical/biochemical variables. Of 51 consecutive preterm infants with mean (± SD) birth weights of 900 g (± 28); enrollment weights of 1342 g (± 432); birth gestation of 27 weeks (± 1); and postmenstrual age of 32 weeks (± 4), 40 completed the study. Pretransfusion variables were comparable between the furosemide (n = 21) and placebo (n = 19) groups. There was a small but significant increase (P < .05) in posttransfusion FiO(2) in placebo (relative increase of 7%, equivalent to an absolute increase from 0.27 to 0.29) compared with the furosemide group. Other variables were similar. No infant received open-label furosemide. CONCLUSIONS: Routine furosemide in electively transfused preterm infants confers minimal clinical benefits. Prevention of a clinically insignificant FiO(2) rise needs to be balanced against potential adverse effects.

The practice of blood volume submitted for culture in a neonatal intensive care unit.

BACKGROUND: Neonatal sepsis is the leading cause of mortality and morbidity in neonatal intensive care units. The volume of blood taken for culture remains one of the most important factors in isolating microorganisms. OBJECTIVES: To evaluate the impact of the intervention on the blood volume submitted for culture and to identify factors influencing the volume as determined by the phlebotomist. METHODS: Blood culture volume was determined by weighing the culture bottle before and immediately after blood inoculation. A 3-month preintervention audit revealed that in 126/130 samples (96.9%), the volume of blood submitted was suboptimal. Multiple intervention measures were instituted, and volume was monitored over the next 9 months. RESULTS: 637 blood culture samples were included in the study, 130 were in preintervention and 507 were in postintervention epochs. Following the intervention, suboptimal volume samples reduced from 96.9% (126/130 samples) to 25% (126/507 samples), p<0.0001 and the median (IQR) sample volume improved from 0.36 (0.23) ml to 0.9 (0.27) ml, p<0.0001. Poor blood flow was identified as the most common reason for an inadequate sample. CONCLUSION: The study underscores the role of educational intervention in improving the blood culture volume in newborn infants. Poor backflow from the cannula is an important cause of inadequate volume collection.

Association of Bolus Feeding With Splanchnic and Cerebral Oxygen Utilization Efficiency Among Premature Infants With Anemia and After Blood Transfusion.

Importance: The pathogenesis of transfusion-associated necrotizing enterocolitis remains elusive. Splanchnic hypoperfusion associated with packed red blood cell transfusion (PRBCT) and feeding has been implicated, but studies of splanchnic tissue oxygenation with respect to feeding plus PRBCT are lacking. Objective: To investigate the oxygen utilization efficiency of preterm gut and brain challenged with bolus feeding during anemia and after transfusion using near-infrared spectroscopy. Design, Setting, and Participants: This prospective cohort study conducted from September 1, 2014, to November 30, 2016, at a tertiary neonatal intensive care unit included 25 hemodynamically stable infants with gestational age less than 32 weeks, birth weight less than 1500 g, and postmenstrual age younger than 37 weeks. Data analysis was performed from August 1, 2017, to October 31, 2018. Exposures: Infants received PRBCT (15 mL/kg for 4 hours) and at least 120 mL/kg daily of second hourly bolus feedings. Main Outcomes and Measures: Splanchnic fractional tissue oxygen extraction (FTOEs) and cerebral fractional tissue oxygen extraction (FTOEc) measures were made during 75-minute feeding cycles that comprised a 15-minute preprandial feeding phase (FP0) and 4 contiguous 15-minute postprandial feeding phases (FP1, FP2, FP3, and FP4; each 15 minutes long). The intraindividual comparisons of feeding-related changes were evaluated during the pretransfusion epoch (TE0: 4 hours before onset of transfusion) and 3 TEs after transfusion (TE1: first 8 hours after PRBCT completion; TE2: 9-16 hours after PRBCT completion; and TE3: 17-24 hours after PRBCT completion). Results: Of 25 enrolled infants (13 [52%] female; median birth weight, 949 g [interquartile range {IQR}, 780-1100 g]; median gestational age, 26.9 weeks [IQR, 25.9-28.6 weeks]; median enrollment weight, 1670 g [IQR, 1357-1937 g]; and median postmenstrual age, 34 weeks [IQR, 32.9-35 weeks]), 1 infant was excluded because of corrupted near-infrared spectroscopy data. No overall association was found between FTOEs and FPs in a multivariable repeated-measures model that accounted for transfusion epochs (primary analysis approach) (FP0: mean estimate, 11.64; 95% CI, 9.55-13.73; FP1: mean estimate, 12.02; 95% CI, 9.92-14.11; FP2: mean estimate, 12.77; 95% CI, 10.68-14.87; FP3: mean estimate, 12.54; 95% CI, 10.45-14.64; FP4: mean estimate, 12.98; 95% CI, 10.89-15.08; P = .16 for the FP association). However exploratory analyses of postprandial changes in FTOEs undertaken for each transfusion epoch separately found evidence of increased postprandial FTOEs during TE1 (mean [SD] FTOEs, 10.55 [5.5] at FP0 vs 13.21 [5.96] at FP4, P = .046). The primary and exploratory analyses found no association between FTOEc and feeding phases, suggesting that cerebral oxygenation may be protected. Conclusions and Relevance: The findings suggest that enteral feeding may be associated with gut ischemia and potentially transfusion-associated necrotizing enterocolitis. The postprandial changes in FTOEs appear to warrant further investigation in larger randomized studies.