Renal rSO2 Research Articles

Changes in regional tissue oxygen saturation values during the first week of life in stable preterm infants.

Near infrared spectroscopy (NIRS) is a non-invasive method for monitoring regional tissue oxygen saturation (rSO2). The purpose of this study is to investigate the changes that occur in cerebral, splanchnic, and renal rSO2 and fractional tissue oxygen extraction (FTOE) in stable preterm infants in the first week of life. Prospective observational study of infants born 30-34weeks gestation at NYU Langone Health between November 2017 and November 2018. Cerebral, renal, and splanchnic rSO2 were monitored from 12 to 72 h of life, andatseven days. Subjects were divided into gestational age(GA) cohorts. Average rSO2, splanchnic cerebral oxygen ratio(SCOR), FTOE, and regional intra-subject variability was calculated at each location at five different time intervals: 0-12 h, 12-24 h, 24-48 h, 48-72 h, and one week of life. Twenty subjects were enrolled. The average cerebral rSO2 ranged from 76.8 to 92.8 %, renal rSO2 from 65.1 to91.1 %, and splanchnic rSO2 from 36.1 to 76.3 %. The SCOR ranged from 0.45 to 0.94. The strongest correlation between the GA cohorts was in the cerebral region (R2=0.94) and weakest correlation was in the splanchnic region (R2=0.81). The FTOE increased in all three locations over time. Intra-subject variability was lowest in the cerebral region (1.3 % (±1.9)). The cerebral region showed the strongest correlation between GA cohorts and lowest intra-subject variability, making it the most suitable for clinical use whenmonitoring for tissue hypoxia. Further studies are needed to further examine rSO2 in preterm infants.

The relationship between trajectories of renal oxygen saturation and acute kidney injury: a prospective cohort study with a secondary analysis

BackgroundAcute kidney injury (AKI) is a major postoperative consequence, affecting prognosis of older patients. Effective prediction or intervention to predict or prevent the incidence of AKI is currently unavailable.AimsDynamic changes of renal tissue oxygen saturation (RSO2) during surgery process are understudied and we intended to explore the distinct trajectories and associations with postoperative AKI.MethodsThis was a secondary analysis including data for older patients who underwent open hepatectomy surgery with informed consent. Latent class mixed models (LCMM) method was conducted to generate trajectories of intraoperative renal tissue RSO2 through different time points. The primary outcome was postoperative 7-day AKI. The univariate and multivariate regression analysis were performed to identify the relationship between distinct trajectories of renal tissue RSO2 and the risk of AKI. Meanwhile, the prediction efficacy of renal tissue RSO2 at different time points was compared to find potential intervention timing.ResultsPostoperative AKI occurred in 14 (15.2%) of 92 patients. There are two distinct renal tissue RSO2 trajectories, with 44.6% generating "high-downwards" trajectory and 55.4% generating "consistently-high" trajectory. Patients with "high-downwards" trajectory had significantly higher risk of postoperative AKI than another group (Unadjusted OR [Odds Ratio] = 3.790, 95% CI [Confidence Interval]: 1.091–13.164, p = 0.036; Adjusted OR = 3.973, 95% CI 1.020–15.478, p = 0.047, respectively). Predictive performance was 71.4% sensitivity and 60.3% specificity for "high-downwards" trajectory of renal tissue RSO2 to identify AKI. Furthermore, the renal tissue RSO2 exhibited the lowest level and the best results in terms of the sensitivity during the hepatic occlusion period, may be considered as a "time of concern".ConclusionsOlder patients undergoing hepatectomy may show high-downwards trajectory of renal tissue RSO2, indicating a higher risk of AKI, and the lowest level was identified during the hepatic occlusion period. These findings may help to provide potential candidates for future early recognition of deterioration of kidney function and guide interventions.

Abstract 185: Regional Oxygen Saturation and Capnography Monitoring During Resuscitation After Cardiac Arrest in a Swine Pediatric ARDS Model

Introduction: Survival and outcomes after cardiac arrest (CA) depend largely on the effectiveness of cardiopulmonary resuscitation (CPR). Traditional invasive methods of monitoring CPR can be challenging out-of-hospital and are lacking in more than 50% of in-hospital pediatric CA. Regional oxygen saturation (rSO 2 ) monitoring with Near Infrared Spectroscopy (NIRS) and volumetric capnography offers a noninvasive approach that could potentially overcome these challenges. Aim: To determine the feasibility and effectiveness of NIRS and volumetric capnography monitoring in a swine model of pediatric hypoxia induced CA. Approach: Juvenile pigs were sedated and mechanically ventilated. Mild to moderate Acute Respiratory Distress Syndrome (ARDS) was induced by continuous oleic acid infusion. Respiratory and hemodynamic variables were monitored using invasive and noninvasive (NIRS and capnography) monitoring to assess efficacy of CPR. Animals were randomized into one of the two groups: High-quality CPR (hqCPR) to achieve coronary perfusion pressure of 25-30 mmHg and low-quality CPR (lqCPR) to achieve coronary perfusion pressure of 10-15 mmHg. Trajectories over time were analyzed using regression analyses. The discriminatory ability to distinguish between groups based on trajectories were analyzed using receiver operating characteristics curve (ROC) analysis. Results: 39 animals (23±3 kg) were included in our study. In the hqCPR group, there are generally higher values for cerebral and renal rSO 2 , ETCO 2 , volume of CO 2 elimination (VCO 2 ), and carotid blood flow, compared to the lqCPR group (p<0.0001). Cerebral and renal rSO 2 values increase over time, while ETCO 2 , VCO 2 , and carotid flow values decrease in the hqCPR group. Cerebral rSO2 had a ROC AUC of 0.76 (95% CI: 0.58-0.94), whereas renal rSO2 had a ROC AUC of 0.54 (95% CI: 0.22-0.87) representing nearly no discrimination ability. ETCO 2 had a ROC AUC of 0.66 (95% CI: 0.49-0.84), whereas VCO 2 had a ROC AUC of 0.62 (95% CI: 0.38-0.85). Conclusions: Higher mean cerebral rSO2 values during CPR might be used to assess quality of CPR effectiveness and provide real-time adjustments as needed. This could guide healthcare providers in optimizing CPR quality and improving outcomes for cardiac arrest patients.

Use of Renal Near-Infrared Spectroscopy and Urinary Neutrophil Gelatinase-Associated Lipocalin Monitoring as Indicators of Acute Kidney Injury in Pediatric Cardiac Surgery.

Acute kidney injury (AKI) is a common complication following cardiac surgery under cardiopulmonary bypass (CPB) in children. A prospective study for examining urinary neutrophil gelatinase-associated lipocalin (NGAL) and renal near-infrared spectroscopy (NIRS) trends during AKI was conducted among pediatric patients undergoing cardiac surgery with CPB. Urinary NGAL showed a significant difference between intensive care unit admission (0 h) and 2 h post-admission (p < 0.001) and remained significant up to 4 h (p < 0.05). The renal NIRS in the AKI group showed a significant rate of decrease and lower values during the intraoperative period (p < 0.05). The cumulative median saturation of renal regional saturation of oxygen (rSO2) during CPB was 1637.5% min in the AKI group and 943.0% min in the non-AKI group. The median renal rSO2 scores at a reduction of 20% and 25% were significantly higher (p < 0.001) in the AKI group. Our results suggest that monitoring renal rSO2 scores and limiting their decline might be useful in preventing AKI. The combination of NGAL, renal rSO2, and renal rSO2 scores might be useful in the early diagnosis of AKI during pediatric cardiac surgery.

Evaluation of renal oxygenation by near-infrared spectroscopy during endoscopic injection of bulking agents in children with vesicoureteral reflux.

Near infrared spectroscopy (NIRS) is the measuring of regional tissue oxygenation (rSO2) by interpreting oxyhemoglobin and deoxyhemoglobin signals that come back by transmitting near infrared light to tissues. The effect of endourological interventions on renal perfusion in children is largely unknown. To evaluate the effects of endoscopic injection of bulking agents (EIBA) for vesicoureteral reflux (VUR) on renal oxygenation (RO) using renal NIRS monitoring, which shows renal perfusion and oxygenation changes. Case-control study. Group I had bilateral inguinal surgery, Group II cystoscopy, and Group III, EIBA for VUR with 30 patients in each group. During the operation, vital signs, peripheral oxygen saturation, end-tidal carbon dioxide, and renal regional oxygen saturation index (rSO2) values by bilateral renal NIRS monitoring were recorded. NIRS values before induction (T0) to postoperative (Tend) were determined. A 20% or more reduction in renal rSO2 (%20↓rSO2) was considered significant. Group III was also evaluated as subgroup III-A (not having "%20↓rSO2") and subgroup III-B ("%20↓rSO2"). The rSO2 decrease was observed in the first 5min for both sides in group III. The most significant drop was at T30 for the right kidney and a significant decrease in rSO2, 20% or more, was observed in 6 renal units of 4 patients having higher SFU grading and renal scar in group III. EIBA may transitionally impair renal oxygenation. Higher SFU grading and renal scar may increase the risk of renal hypoxia during EIBA.

Significant neonatal intraoperative cerebral and renal oxygen desaturation identified with near-infrared spectroscopy.

Near-infrared spectroscopy (NIRS) was used to monitor intraoperative regional oxygen saturation (rSO2) during open (Op) and minimally invasive (MI) surgery performed in neonates (N) and children. NIRS sensors were applied to the forehead and flanks for cerebral rSO2 (C-rSO2) and renal rSO2 (R-rSO2), respectively. MI included laparoscopy (La), retroperitoneoscopy (Re) and thoracoscopy (Th). In children, Op and MI were major operations taking at least 3h (MOp; MMI). Pathological desaturation (PD) was defined as > 20% deterioration in rSO2. Mean ages at surgery were N: 5.2 ± 8.2days, MOp: 2.4 ± 2.9years, and MMI: 3.8 ± 4.3years. Despite significantly shorter operative times in N (169 ± 94min; p < 0.0001), PD was significantly worse; PD(C-rSO2): N = 14/35 (40.0%) versus MOp = 3/36 (8.3%) and MMI = 7/58 (12.1%); p = 0.0006, and PD(R-rSO2): N = 27/35 (77.1%) versus MOp = 6/36 (16.7%) and MMI = 7/58 (12.1%); p < 0.0001, respectively. PD(R-rSO2) occurred immediately with visceral reduction in NOp (Fig.1) and PD was frequent during NMI(Th) (Fig.2). rSO2 was stable throughout MOp and MMI (Fig.3). Fig. 1 Pathological desaturation in renal rSO2 after visceral reduction for gastroschisis. Renal rSO2 deteriorated immediately after viscera were returned to the abdominal cavity rSO2 regional oxygen saturation Fig. 2 Fragility of tissue perfusion during thoracoscopic lung lobectomy in a neonate. Pathological desaturation occurred frequently during neonatal thoracoscopic surgery rSO2 regional oxygen saturation Fig. 3 Changes in cerebral and renal rSO2 according to operative time. Cerebral and renal rSO2 did not appear to change according to operative time during major open and major minimally invasive surgery in children. rSO2 regional oxygen saturation CONCLUSIONS: NIRS is a non-invasive technique for monitoring rSO2 as an indicator of intraoperative stress and vascular perfusion. PD was so significant in neonates that intraoperative NIRS is highly recommended during thoracoscopy and procedures requiring visceral manipulation.

Monitoring renal oxygenation status by near-infrared spectroscopy during ureterorenoscopy in children.

: Near-infrared spectroscopy (NIRS) monitoring demonstrates renal blood flow, perfusion, and oxygenation changes. This study aimed to evaluate the effects of pediatric endourological interventions (PEI) on regional oxygen saturation value (rSO2) usingrenal NIRS monitoring. Patients having bilateral inguinal surgery (group I), cystoscopy (group II), and ureterorenoscopy (group III), 20 patients in each group, were included in the study. NIRS values before induction (T0) and at 5 min (T5), 10 min (T10), 15 min (T15), 20 min (T20), 25 min (T25), 30 min (T30) of the surgical procedure, and at the postextubation (Tend) were determined. The amount of irrigation fluid was recorded in groups II and III. The ureterorenoscopy group was also evaluated as two subgroups, as group III-R with patients having a "20%↓rSO2" and as group III-NoR, not having a "20%↓rSO2". The mean total volume of irrigation was higher in group III, but the difference was not significant between the subgroups III-R and III-NoR. Renal rSO2 decreased significantly in T25, T30, and T-end values in group III. "20%↓rSO2" was seen in 1 patient in group II and 7 patients in group III. In the subgroups III-R, all patients had an obstructive pathology and significant preoperative hydronephrosis with a mean renal pelvis AP diameter of 21.1 ± 16.4 mm. Although rSO2 significantly improves postoperatively, our data may suggest that congenital and acquired obstructive pathologies with hydronephrosis, prolonged operative time with continuous irrigation, and instrument movement in a narrow lumen may increase intrarenal pressure and the risk of renal hypoxia in endourological interventions. Preoperative evaluation of kidney functions and a meticulously well-planned intervention can prevent possible complications.

Intraoperative Near-Infrared Spectroscopy Monitoring of Renal Allograft Reperfusion in Kidney Transplant Recipients: A Feasibility and Proof-of-Concept Study.

Conventional renal function markers are unable to measure renal allograft perfusion intraoperatively, leading to delayed recognition of initial allograft function. A handheld near-infrared spectroscopy (NIRS) device that can provide real-time assessment of renal allograft perfusion by quantifying regional tissue oxygen saturation levels (rSO2) was approved by the FDA. This pilot study evaluated the feasibility of intraoperative NIRS monitoring of allograft reperfusion in renal transplant recipients (RTR). Intraoperative renal allograft rSO2 and perfusion rates were measured in living (LDRT, n = 3) and deceased donor RTR (DDRT, n = 4) during the first 50 min post-reperfusion and correlated with renal function markers 30 days post-transplantation. Intraoperative renal allograft rSO2 for the DDRT group remained significantly lower than the LDRT group throughout the 50 min. Reperfusion rates were significantly faster in the LDRT group during the first 5 min post-reperfusion but remained stable thereafter in both groups. Intraoperative rSO2 were similar among the upper pole, renal hilum, and lower pole, and strongly correlated with allograft function and hemodynamic parameters up to 14 days post-transplantation. NIRS successfully detected differences in intraoperative renal allograft rSO2, warranting future studies to evaluate it as an objective method to measure ischemic injury and perfusion for the optimization of preservation/reperfusion protocols and early prediction of allograft function.

Regional oxygen saturation and acute kidney injury in premature infants

Decreased renal blood flow plays a vital role in the etiology of acute kidney injury (AKI). In this study, we aim to investigate the role of renal regional oxygen saturation (rSO2 ) reductions in predicting AKI in the first 24h of life. One hundred premature babies with a gestational age of ≤32weeks were included. Renal and cerebral rSO2 s were monitored for 24 h by near-infrared spectroscopy. Infants were followed up for the first 7days for the diagnosis of AKI. Infants' median gestational age was 29 (23-32) weeks, and their birthweight was 1,192±355g. It was found that the renal rSO2 values were lower in the first 24h of life in patients who developed AKI, and this decrease was statistically significant in the first 6h of life. The low renal rSO2 values in the early hours of life in premature babies may have a role in predicting AKI.

İntraoperatif Renal Oksijen Saturasyon Değişiminin Postoperatif Akut Böbrek Hasarı İle İlişkisi

Objective: Acute kidney injury seen in 25-30 % of the cases after open heart surgery where cardiopulmonary bypass was performed, is one of the most important factors that affect the success of the on- pump open heart surgery by increasing the rates of postoperative morbidity, and mortality. Near infrared spectroscopy (NIRS) is a noninvasive monitoring that frequently used method that allows correction of imbalances in oxygen supply to the brain and vital organs. We aimed to investigate the relationship between renal oxygen saturation values and postoperative acute kidney injury. Method: Fifty patients who underwent on- pump open heart surgery between July 2020 and January 2021 by using cardiopulmonary bypass were included in the study. Demographic data included age, gender, body mass index (BMI), hypertension, diabetes mellitus, chronic obstructive pulmonary disease, other chronic diseases and left ventricular ejection fraction. The definition of acute kidney injury was defined according to the criteria of KDIGO. At the end of the postoperative 48th hour the relationship between intraoperative renal rSO2 changes in patients with or without acute kidney injury was evaluated. Results: Fifty patients were included in the current study. The median (IQR) age of 50 patients was 62 (54.3-66.5), and mostly male patients constituted the study populatio,. When we evaluated the intraoperative data, there were statistically significant differences in changes in renal rSO2 values in patients who had and had not developed postoperative acute kidney injury (-12%, -3%, respectively) (p: 0.001). In the multivariate logistic regression analysis, the change in rSO2 values in the intraoperative period [(from - 10% to 0.5%), OR: 0.18 (0.04-0.76) p: 0.03] were found to be an independent predictor of postoperative acute kidney injury. Conclusion: We found that the decrease of renal rSO2 measurements during surgery may predict the development of acute kidney injury in the postoperative period. We think that renal oxygen saturation monitoring with NIRS is a very effective method for predicting postoperative renal dysfunction, because it is both noninvasive and reflects simultaneous data.

Near infrared spectroscopy and abdominal compartmental syndrome in neonates

ABSTRACT Background and Aims Abdominal compartmental syndrome considered the most common cause of postoperative mortality in neonates scheduled for surgical repair of congenital abdominal wall defect. This study aimed primarily to observe the renal and cerebral rSO2 variation during and after surgical reduction, while secondarily to analyze correlations with other perfusion markers of intra-abdominal hypertension. Patients and methods A randomized, prospective, cohort study was piloted in a tertiary care pediatric surgery center from February 2017 to march 2021 where 20 neonates scheduled surgical repair of congenital abdominal wall defects. Near-infrared spectroscopy (NIRS) measurements of regional tissue oxygenation (rSO2) fluctuations performed using the two-channel mode, channel 1 for cerebral monitoring (C rSO2) and channel 2 for renal monitoring (R rSO2), and calculating differences intraoperative as well as postoperative. Results Intra-operative C and R ΔrSO2 had a significant positive correlation with an intraoperative post-ductal SPO2 and MABP changes, while a significant negative correlation was noted with serum lactate level and capillary refill time. Postoperative C ΔrSO2 showed a negative correlation with postoperative serum lactate level, whereas postoperative R ΔrSO2 had a positive correlation with postoperative post-ductal SPO2 changes, and negative correlations with postoperative capillary refill time changes. Pathological intraoperative ΔrSO2 had a statistically significant relation with intraoperative post-ductal SPO2, MABP, capillary refill time, serum lactate level, postoperative serum creatinine level, and postoperative vasoactive-ventilation-renal (VVR) score. Conclusion : NIRS is an efficient non-invasive monitor of cerebral and tissue perfusion, evaluating tissue microcirculation, and considered an early warning for detecting abdominal compartment syndrome (ACS) in neonates.

Prenatal Use of Sildenafil in Fetal Growth Restriction and Its Effect on Neonatal Tissue Oxygenation-A Retrospective Analysis of Hemodynamic Data From Participants of the Dutch STRIDER Trial.

Objective: Sildenafil is under investigation as a potential agent to improve uteroplacental perfusion in fetal growth restriction (FGR). However, the STRIDER RCT was halted after interim analysis due to futility and higher rates of persistent pulmonary hypertension and mortality in sildenafil-exposed neonates. This hypothesis-generating study within the Dutch STRIDER trial sought to understand what happened to these neonates by studying their regional tissue oxygen saturation (rSO2) within the first 72 h after birth.Methods: Pregnant women with FGR received 25 mg placebo or sildenafil thrice daily within the Dutch STRIDER trial. We retrospectively analyzed the cerebral and renal rSO2 monitored with near-infrared spectroscopy (NIRS) in a subset of neonates admitted to two participating neonatal intensive care units, in which NIRS is part of standard care. Secondarily, blood pressure and heart rate were analyzed to aid interpretation. Differences in oxygenation levels and interaction with time (slope) between placebo- and sildenafil-exposed groups were tested using mixed effects analyses with multiple comparisons tests.Results: Cerebral rSO2 levels were not different between treatment groups (79 vs. 77%; both n = 14) with comparable slopes. Sildenafil-exposed infants (n = 5) showed lower renal rSO2 than placebo-exposed infants (n = 6) during several time intervals on day one and two. At 69–72 h, however, the sildenafil group showed higher renal rSO2 than the placebo group. Initially, diastolic blood pressure was higher and heart rate lower in the sildenafil than the placebo group, which changed during day two.Conclusions: Although limited by sample size, our data suggest that prenatal sildenafil alters renal but not cerebral oxygenation in FGR neonates during the first 72 post-natal hours. The observed changes in renal oxygenation could reflect a vasoconstrictive rebound from sildenafil. Similar changes observed in accompanying vital parameters support this hypothesis.

Evaluation of renal oxygenization in laparoscopic pediatric surgery by near infrared spectroscopy.

Increased intraabdominal pressure IAPmay reduce renal blood flow (RBF). The study aims to evaluate the pneumoperitoneum effect on RBF by comparing renal regional oxygen saturation index (rSrO2) measured by near-infrared spectroscopy (NIRS) in pediatric patients having laparotomy and laparoscopy. Of 58 patients having laparoscopy and laparotomy, 18 were excluded due to renal pathologies, combined open surgical procedures, and administration of inotropic drugs. Hemodynamic parameters and rSrO2 were recorded in laparoscopy (n = 20) and laparotomy (n = 20) groups before induction and with 5min intervals up to 60min and at post-extubation. Decrease in right renal rSrO2 at 45th and 60th min and 30th, 45th and 60th min in left were significant in the laparoscopy group compared to laparotomy group. In the laparoscopy group, reductions at T25, T30, T45, and T60 were significant in both renal rSrO2. Renal rSO2 increased to normal with desufflation. IAP with pneumoperitoneum may lead to renal hypoxia in children. Renal rSO2 returns to normal with desufflation. Renal NIRS monitorization might be needed in patients with renal parenchymal and vascular pathologies, solitary kidney, and multiorgan pathologies that may affect renal oxygenation.

Correlation of intraoperative renal near infrared spectroscopy with the development of acute kidney injury in adult patients undergoing cardiac surgery using cardiopulmonary bypass

Introduction: The present study aimed to correlate renal oximetry near-infrared spectroscopy (NIRS) values with conventional non-invasive biomarkers for the early detection of acute kidney injury (AKI) in adult patients undergoing cardiac surgery using cardiopulmonary bypass (CPB). Accordingly, renal NIRS can be employed as a trending device for the prevention of AKI development. Materials and methods: After institutional ethical committee approval, a number of 132 adult patients undergoing cardiac surgery with CPB were selected by consecutive consenting sampling method. Emergency surgery and patients with preexistent renal insufficiency were excluded. NIRS sensor was applied on either the right or the left side of the spine at the lower border of L-1 before starting the induction. A renal regional oxygen saturation (rSO2) score was calculated after recording the renal oximetry values intra- and postoperatively. Urine output and serum creatinine were measured at 24, 48, and 72 hours postoperatively. Results: Out of 132 patients, 22 cases (16.66 %) developed AKI according to Acute Kidney Injury Network (Akin) criteria± Risk, Injury, Failure, Loss, and End-stage kidney disease (RIFLE) classification. Among these AKI patients, three cases required dialysis, and one of these three patients died on the 21st day postsurgery. Renal rSO2 scores in the AKI group were measured at 535 and 912 minutes %, in comparison to 162 and 184 minutes % reported in the non-AKI group which was statistically significant (P< 0.05). Conclusion: As evidenced by the obtained results, there is a correlation between intraoperatively measured renal NIRS readings and the occurrence of AKI following adult cardiac surgery using CPB.

Renal Near-Infrared Spectroscopy for Assessment of Renal Oxygenation in Adults Undergoing Cardiac Surgery: A Method Validation Study

To investigate the correlation between invasively measured renal venous oxygen saturation (SrvO2) and tissue oxygenation (rSO2) measured with near-infrared spectroscopy (NIRS) in adult patients undergoing cardiac surgery. Prospective observational study. Single cardiac surgery center at a university hospital. Thirteen adult patients with skin- to- kidney distance ≤4 cm undergoing open cardiac surgery with cardiopulmonary bypass (CPB). All patients received renal vein catheters for invasive measurement of SrvO2, and NIRS electrodes for assessment of renal rSO2 were placed over the kidney using ultrasound guidance. Measurements were made before CPB, during CPB at 3 different flow rates (2.4, 2.7, and 3.0 L/min/m2), and after CPB. Repeated- measures correlation analyses and Bland-Altman plots were used to study the correlation and agreement between rSO2 and SrvO2. For all measurement points, renal rSO2 correlated with SrvO2 (rrm = 0.61, p < 0.001), and the mean difference (bias) between rSO2 and SrvO2 was -2.71 ± 7.22 (p = 0.002), with an error of 17.6%. When measurements during CPB and before and after CPB were studied separately, rSO2 and SrvO2 were correlated (rrm = 0.51, p < 0.007 and rrm = 0.73, p < 0.001, respectively). During CPB, renal rSO2 predicted SrvO2 with a bias of -3.41 ± 7.76 (p = 0.009) and an error of 18.8%. Before and after CPB, the mean difference was -1.93 ± 6.60 (p = 0.092), with an error of 16.2%. Renal rSO2 is correlated to and predicts SrvO2 with a small bias and acceptable agreement. Further studies are needed before renal NIRS can be used as a surrogate marker of renal oxygenation in clinical practice.

Somatic regional oxygen saturation as an early marker of intra-abdominal hypertension in critically ill children: a pilot study

Background/aimIntraabdominal hypertension is a common clinical condition with high mortality and morbidity in pediatric intensive care units. The aim of this study was to test the feasibility of regional tissue oxygenation (rSO2) measurement using near-infrared spectroscopy and to assess the correlation between rSO2 and perfusion markers of intraabdominal hypertension in high-risk pediatric patients.Materials and methods In this prospective observational cohort study in a tertiary pediatric intensive care unit in Çukurova University Faculty of Medicine, a total of 31 patients who were admitted between May 2017 and May 2018 with a risk of intraabdominal hypertension were included. Mesenteric and renal rSO2 measurements were taken and correlations with other tissue perfusion markers including mean arterial pressure, pH, lactate, intraabdominal pressure, abdominal perfusion pressure, mixed venous oxygen saturation, vasoactive inotropic score were assessed. Intraabdominal pressure was measured as ≥10 mmHg in 15 patients (48.3%) and these patients were defined as the group with intraabdominal hypertension.ResultsIn the group with intraabdominal hypertension, mixed venous oxygen saturation was lower (P = 0.024), vasoactive inotropic score was higher (P = 0.024) and the mean abdominal perfusion pressure value was lower (P = 0.014). In the ROC analysis, the mesenteric rSO2 measurement was the best parameter to predict intraabdominal hypertension with area under the curve of 0.812 (P = 0.003) 95% CI [0.652–0.973].ConclusionMonitoring of mesenteric rSO2 is feasible in patients at risk for intraabdominal hypertension. Moreover, both mesenteric regional oxygen and perfusion markers may be used to identify pediatric patients at risk for intraabdominal hypertension.

Changes in cerebral and renal oxygenation during laparoscopic pyloromyotomy

Although a laparoscopic approach may be preferred over open procedures for abdominal surgery, there are limited data on the effect of laparoscopic procedures on cerebral and renal oxygenation in neonates and young infants. Here, we evaluated the effect in neonates and infants. In this two-center prospective observational study, we evaluated changes in cerebral and renal regional oxygen saturation (rSO2) in infants during laparoscopic pyloromyotomy. Intraoperative hemodynamic and respiratory parameters and rSO2 were recorded. For the primary outcome, these parameters were compared at incision and at the end of pneumoperitoneum. The study cohort included 25 infants with a mean age of 40 ± 10days and weight of 4.0 ± 0.6kg. IAP at the beginning of laparoscopy was 10 ± 2mmHg (range 7-15mmHg). Although both cerebral and renal rSO2 decreased from incision compared to the end of laparoscopy, the decrease reached statistical significance only for cerebral rSO2 (81 ± 12 to 76 ± 16, p = 0.033). Similarly, the increase in fractional tissue oxygen extraction (FTOE) was only statistically significant for cerebral FTOE (0.18 ± 0.12 to 0.23 ± 0.16, p = 0.037). No change in hemodynamic or respiratory parameters was found. Although there was a decrease in cerebral rSO2 and increase in cerebral FTOE during pneumoperitoneum, the values did not decrease below those noted before anesthetic induction.

Two-site regional oxygen saturation and capnography monitoring during resuscitation after cardiac arrest in a swine pediatric ventricular fibrillatory arrest model.

AbstarctTo investigate the use of two-site regional oxygen saturations (rSO2) and end tidal carbon dioxide (EtCO2) to assess the effectiveness of resuscitation and return of spontaneous circulation (ROSC). Eight mechanically ventilated juvenile swine underwent 28 ventricular fibrillatory arrests with open cardiac massage. Cardiac massage was administered to achieve target pulmonary blood flow (PBF) as a percentage of pre-cardiac arrest baseline. Non-invasive data, including, EtCO2, cerebral rSO2 (C-rSO2) and renal rSO2 (R-rSO2) were collected continuously. Our data demonstrate the ability to measure both rSO2 and EtCO2 during CPR and after ROSC. During resuscitation EtCO2 had a strong correlation with goal CO with r = 0.83 (p < 0.001) 95% CI [0.67–0.92]. Both C-rSO2 and R-rSO2 had moderate and statistically significant correlation with CO with r = 0.52 (p = 0.003) 95% CI (0.19–0.74) and 0.50 (p = 0.004) 95% CI [0.16–0.73]. The AUCs for sudden increase of EtCO2, C-rSO2, and R-rSO2 at ROSC were 0.86 [95% CI, 0.77–0.94], 0.87 [95% CI, 0.8–0.94], and 0.98 [95% CI, 0.96–1.00] respectively. Measurement of continuous EtCO2 and rSO2 may be used during CPR to ensure effective chest compressions. Moreover, both rSO2 and EtCO2 may be used to detect ROSC in a swine pediatric ventricular fibrillatory arrest model.

Multisite measurement of regional oxygen saturation in Fontan patients with andwithout protein-losing enteropathy at rest and during exercise.

Protein-losing enteropathy (PLE) is a severe complication of Fontan circulation with increased risk of end-organ dysfunction. We evaluated tissue oxygenation via near-infrared spectroscopy (NIRS) at different exercise levels in Fontan patients. Assessment of multisite NIRS during cycle ergometer exercise and daily activities in three groups: Fontan patients with PLE; without PLE; patients with dextro-transposition of the great arteries (d-TGA); comparing univentricular with biventricular circulation and Fontan with/without PLE. Renal threshold analysis (<65%;<55%;<45%) of regional oxygen saturation (rSO2) was performed. Fontan patients showed reduced rSO2 (p < 0.05) in their quadriceps femoris muscle compared with biventricular d-TGA patients at all time points. rSO2 in renal tissue was reduced at baseline (p = 0.002), exercise (p = 0.0062), and daily activities (p = 0.03) in Fontan patients with PLE. Renal threshold analysis identified critically low renal rSO2 (rSO2 < 65%) in Fontan patients with PLE during exercise (95% of monitoring time below threshold) and daily activities (83.7% time below threshold). Fontan circulation is associated with decreased rSO2 values in skeletal muscle and hypoxemia of renal tissue solely in patients with PLE. Reduced rSO2 already during activities of daily life, might contribute to comorbidities in patients with Fontan circulation, including PLE and renal failure.

Preoperative cerebral and renal oxygen saturation and clinical outcomes in pediatric patients with congenital heart disease.

We examined the predictability of preoperative cerebral and renal rSO2 values for outcomes in pediatric patients undergoing cardiac surgery under cardiopulmonary bypass (CPB). Patients who underwent pediatric cardiac surgery under CPB between September 2015 and September 2017 were enrolled in this study. Patients monitored with both cerebral and renal rSO2 at the beginning of surgery were included. The primary outcome was the prediction of outcomes after pediatric cardiac surgery. Outcome was defined as any of: (1) death within 30 days after surgery, or the need for (2) renal replacement therapy or (3) extracorporeal membrane oxygenation, (4) shorten mechanical ventilator-free day,(5) shorten ICU-free survival day. We included 59 patients: cyanotic n = 31; non-cyanotic n = 28. Among all patients, 15 (25%) had poor outcomes, including three deaths. The cerebral and renal rSO2 values were significantly lower in the cyanotic patients with poor outcomes compared to those without poor outcomes (cerebral: 59 ± 11 vs. 50 ± 5, p = 0.021; renal: 59 ± 15 vs. 51 ± 14, p = 0.015) but only the renal rSO2 value was significantly lower in the non-cyanotic patients (77 ± 10 vs. 61 ± 14, p = 0.011). The cut-off value (51%) of cerebral rSO2 were associated with risk of mechanical ventilator-free day and ICU-free survival day [ORs of 22.8 (95% CI 2.21-235.0, p = 0.0087) and 15.8 (95% CI 1.53-164.0, p = 0.0204), respectively] in the cyanotic patients. The cut-off value (66%) of cerebral rSO2 value was associated with risk of mechanical ventilator-free day [OR of 11.3 (95% CI 1.05-25.3, p = 0.0456)] and the cut-off value (66%) of renal rSO2 value was associated with risk of ICU-free survival day [ORs of 33.0 (95% CI 2.25-484.0, p = 0.0107)] in the noncyanotic patients. The preoperative low rSO2 values were associated with outcomes including 30-day mortality and might be reflective of the severity of cardiopulmonary function. Further studies are needed to confirm our results.