A prospective assessment of renal oxygenation in children undergoing laparoscopy using near-infrared spectroscopy

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.

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

BACKGROUND

Acute 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.

AIMS

Dynamic 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.

METHODS

This 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.

RESULTS

Postoperative 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".

CONCLUSIONS

Older 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.

Effect of retropneumoperitoneum on cerebral and renal oxygen saturation during retroperitoneal robotic-assisted laparoscopic pyeloplasty (R-RALP) in a pediatric population: Preliminary results of a prospective observational study using a dedicated anesthetic protocol and Near-InfraRed Spectroscopy

BACKGROUND

Retroperitoneal robotic-assisted laparoscopic pyeloplasty (R-RALP) for ureteropelvic junction obstruction (UPJO) has gained growing acceptance among pediatric urologists, and is increasingly performed as day-case surgery, involving smaller children and infants. However, retroperitoneal CO2 insufflation may cause hemodynamic derangements, respiratory changes, and hypercapnia, whose consequences are poorly investigated. We, therefore, decided to prospectively study its effect on regional tissue perfusion and oxygenation in a cohort of pediatric patients undergoing R-RALP, using a dedicated anesthetic protocol and cerebral and renal Near InfraRed Spectroscopy (NIRS).

MATERIAL AND METHODS

Between January 2021 and September 2022, a cohort of 21 consecutive children [12 males (9 females), mean age of 7.1 ± 3.8 years and mean body weight of 25.7 ± 12.3 kg] underwent their first elective pyeloplasty for UPJO by R-RALP. The surgical procedure followed a previously described standardized technique and a dedicated anesthetic protocol. In conjunction with the minimal expected standard monitoring, cerebral and renal NIRS were added. Standard monitoring parameters and NIRS values were recorded at preset points throughout the procedures.

RESULTS

Standard monitoring and NIRS measurements during R-RALP were not adversely affected by CO2 insufflation, pending a significant increase in respiratory rate, aimed to avoid hypercapnia, while keeping the ventilation pressure within the safety range, preventing lung injury.

CONCLUSIONS

R-RALP, using a constant retroperitoneal CO2 insufflation pressure of 12 mmHg with a 5 L.min-1 flow, does not adversely affect respiratory and hemodynamics parameters, pending the implementation of a specifically designed anesthetic protocol aimed to prevent hypercapnia, the most threatening effect of retroperitoneal CO2 insufflation.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03274050.

Retroperitoneoscopic Surgery in Children Does Not Cause Pathological Desaturation in Cerebral/Renal Oxygenation on Near-Infrared Spectroscopy Compared with Laparoscopic and Thoracoscopic Surgery

Introduction: Cerebral and renal regional oxygen saturation (C-rSO₂ and R-rSO₂, respectively) were monitored using near-infrared spectroscopy in pediatric patients (range: 0.3-14.3 years) during minimally invasive surgery (MIS) taking at least 3 hours performed by laparoscopy (Lap), thoracoscopy (Tho), or retroperitoneoscopy (Ret) from January 2019 to December 2021. Materials and Methods: Criteria compared were operative time, preoperative/intraoperative hemoglobin, blood loss, mean arterial pressure, arterial partial pressure of carbon dioxide (PaCO₂), peripheral oxygen saturation (SpO₂), C-rSO₂, and R-rSO₂. Pathological desaturation (PD) was defined as >20% decrease from baseline, and statistical significance as P < .05. Results: Subjects (n = 79) were similar for gender, age, and body mass index. MIS procedures were: Lap = 45, Tho = 20, Ret = 14; one Lap case required conversion for severe adhesions, not PD. Intraoperative PaCO₂ (mmHg) was significantly higher in Tho (maximum: 59.5 ± 17.0, minimum: 39.9 ± 7.5) versus Lap (maximum: 39.9 ± 5.1, minimum: 34.6 ± 3.9) and Ret (maximum: 37.8 ± 4.2, minimum: 35.0 ± 3.3); P < .0001 (maximum), P = .0013 (minimum). Minimum intraoperative SpO₂ was significantly lower in Tho (P < .0001). Mean operative times were significantly shorter in Tho (259 ± 114 minutes) versus Lap (433 ± 154 minutes) and Ret (342 ± 100 minutes); P < .0001, respectively. PD was absent during Ret (C-rSO₂: 0/14 = 0% and R-rSO₂: 0/14 = 0%). Differences in PD for Lap (C-rSO₂: 7/45 = 15.6% and R-rSO₂: 10/45 = 22.2%) and Tho (C-rSO₂: 9/20 = 45.0%, and R-rSO₂: 7/20 = 35.0%) were significant; P = .0028 for C-rSO₂ and P = .0497 for R-rSO₂. Hemoglobin and blood loss were similar. Conclusions: PD was absent during Ret, despite longer operative times. If Ret is indicated for a procedure, neurodevelopmental sequelae of MIS could be minimized.

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

BACKGROUND

: 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.

METHODS

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".

RESULTS

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.

DISCUSSION

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.

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

INTRODUCTION

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.

MATERIALS AND METHODS

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 3 h (MOp; MMI). Pathological desaturation (PD) was defined as > 20% deterioration in rSO₂.

RESULTS

Mean ages at surgery were N: 5.2 ± 8.2 days, MOp: 2.4 ± 2.9 years, and MMI: 3.8 ± 4.3 years. Despite significantly shorter operative times in N (169 ± 94 min; 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.

Evaluation of visible diffuse reflectance spectroscopy in liver tissue: validation of tissue saturations using extracorporeal circulation

SIGNIFICANCE

Real-time information about oxygen delivery to the hepatic graft is important to direct care and diagnose vascular compromise in the immediate post-transplant period.

AIM

The current study was designed to determine the utility of visible diffuse reflectance spectroscopy (vis-DRS) for measuring liver tissue saturation in vivo.

APPROACH

A custom-built vis-DRS probe was calibrated using phantoms with hemoglobin (Hb) and polystyrene microspheres. Ex vivo (extracorporeal circulation) and in vivo protocols were used in a swine model (n  =  15) with validation via blood gas analysis.

RESULTS

In vivo absorption and scattering measured by vis-DRS with and without biliverdin correction correlated closely between analyses. Lin's concordance correlation coefficients are 0.991 for μa and 0.959 for μs  '  . Hb measured by blood test and vis-DRS with (R2  =  0.81) and without (R2  =  0.85) biliverdin correction were compared. Vis-DRS data obtained from the ex vivo protocol plotted against the PO2 derived from blood gas analysis showed a good fit for a Hill coefficient of 1.67 and P50  =  34  mmHg (R2  =  0.81). A conversion formula was developed to account for the systematic deviation, which resulted in a goodness-of-fit R2  =  0.76 with the expected oxygen dissociation curve.

CONCLUSIONS

We show that vis-DRS allows for real-time measurement of liver tissue saturation, an indicator for liver perfusion and oxygen delivery.

Effects of Pneumoperitoneum on Splanchnic Oxygenation during Abdominal Laparoscopic Surgery in Paediatric Patients: A prospective, Observational Study

Objective

Pneumoperitoneum can cause disruption in splanchnic perfusion. This study aims to investigate effects of pneumoperitoneum on splanchnic oxygenation during abdominal laparoscopic surgery in paediatric patients with NIRS (Near-Infrared Spectroscopy).

Material and methods

A total of 45 patients between 1 and 4 years of age with ASA physical status I–II and scheduled to undergo abdominal laparoscopic surgery under general anaesthesia were enrolled in this prospective, observational surgery. No premedication was used. Standard monitoring and regional splanchnic saturation (rSPcO₂), regional cerebral oxygen saturation (rScO₂) with NIRS were established before anaesthesia. Anaesthesia was induced with an inhalational agent and maintained with an oxygen/air mixture and sevoflurane. Peripheral oxygen saturation (SPO₂), rSPcO₂, rScO₂, heart rate (HR), mean arterial pressure (MAP), end tidal CO₂ (Et-CO₂), and insufflation pressure (IP) were continuously monitored during administration of anaesthesia and recorded. After intubation (baseline T0); before CO₂ insufflation induced pneumoperitoneum (PP) (T1); CO₂ PP insufflation (T2); 5 minutes after PP insufflation (T3); 10 minutes after PP insufflation (T4); 15 minutes after PP insufflation (T5); 20 minutes after PP insufflation (T6); 30 minutes after PP insufflation (T7), 60 minutes after PP insufflation (T8), and after desufflation (T9). Bradycardia and hypotension were recorded. Paracetamol IV 10 mg kg⁻¹ was applied for post-operative analgesia. p<0.05 wasconsidered significant.

Results

HR, rScO₂, and rSPcO₂ decreased at all measured time intervals when compared to T0 (p<0.01) MAP decreased at T1 compared to T0 (p<0.001). Et-CO₂ increased at T3-T4-T5-T6 compared to T0 (p<0.001).

Conclusion

We found that pneumoperitoneum reduced splanchnic oxygenation during laparoscopic abdominal surgery in paediatric patients, which was measured using NIRS.

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

PURPOSE

Increased intraabdominal pressure IAP may 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.

METHODS

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 5 min intervals up to 60 min and at post-extubation.

RESULTS

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.

CONCLUSION

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.

Renal Tissue Oxygenation Monitoring-An Opportunity to Improve Kidney Outcomes in the Vulnerable Neonatal Population

Adequate oxygenation of the kidney is of critical importance in the neonate. Non-invasive monitoring of renal tissue oxygenation using near-infrared spectroscopy (NIRS) is a promising bedside strategy for early detection of circulatory impairment as well as recognition of specific renal injury. As a diagnostic tool, renal NIRS monitoring may allow for earlier interventions to prevent or reduce injury in various clinical scenarios in the neonatal intensive care unit. Multiple studies utilizing NIRS monitoring in preterm and term infants have provided renal tissue oxygenation values at different time points during neonatal hospitalization, and have correlated measures with ultrasound and Doppler flow data. With the establishment of normal values, studies have utilized renal tissue oxygenation monitoring in preterm neonates to predict a hemodynamically significant patent ductus arteriosus, to assess response to potentially nephrotoxic medications, to identify infants with sepsis, and to describe changes after red blood cell transfusions. Other neonatal populations being investigated with renal NIRS monitoring include growth restricted infants, those requiring delivery room resuscitation, infants with congenital heart disease, and neonates undergoing extracorporeal membrane oxygenation. Furthermore, as the recognition of acute kidney injury (AKI) and its associated morbidity and mortality in neonates has increased over the last decade, alternative methods are being investigated to diagnose AKI before changes in serum creatinine or urine output occur. Studies have utilized renal NIRS monitoring to diagnose AKI in specific populations, including neonates with hypoxic ischemic encephalopathy after birth asphyxia and in infants after cardiac bypass surgery. The use of renal tissue oxygenation monitoring to improve renal outcomes has yet to be established, but results of studies published to date suggest that it holds significant promise to function as a real time, early indicator of poor renal perfusion that may help with development of specific treatment protocols to prevent or decrease the severity of AKI.

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 ± 10 days and weight of 4.0 ± 0.6 kg. IAP at the beginning of laparoscopy was 10 ± 2 mmHg (range 7-15 mmHg). 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.

Use of renal near-infrared spectroscopy measurements in congenital diaphragmatic hernia patients on ECMO

INTRODUCTION

This study tests the hypothesis that renal tissue oxygen saturation as measured by Near Infrared Spectroscopy (NIRS) would correlate with urine output in neonates with congenital diaphragmatic hernia (CDH) on extracorporeal membrane oxygenation (ECMO).

METHODS

Between 2012 and 2015, neonates with CDH were enrolled as part of a comprehensive study that provided renal/cerebral/abdominal NIRS monitoring for the duration of ECMO support. Continuous NIRS measurements, mean arterial pressure, and urine output were recorded. Periods of anuria (NU), adequate urine output >1ml/kg/h (AU), and low urine output <1ml/kg/h (LU) were noted and analyzed.

RESULTS

Over 1500h of continuous renal NIRS were obtained from six neonates. NIRS values were significantly different during periods of AU, LU, and anuria (84±6%, 76±3%, and 67±6%, p<0.01). ROC curves identified NIRS >76% as highly predictive of adequate urine output (AUC=0.96). MAP was significantly lower only in anuric patients, 36.42±10.26, compared to patients with AU and LU - 42.99±5.25 and 42.85±7.4, respectively (p<0.001).

CONCLUSION

Renal NIRS measurements correlate with urine production. Lower values are noted as urine output declines and precedes a decline in MAP. Renal NIRS may have promise as a non-invasive means of determining adequacy of renal perfusion and urine output in neonates with complex fluid shifts.

LEVEL OF EVIDENCE

IIb.

A systematic review of the quality of conduct and reporting of systematic reviews and meta-analyses in paediatric surgery

OBJECTIVE

Our objective was to evaluate quality of conduct and reporting of published systematic reviews and meta-analyses in paediatric surgery. We also aimed to identify characteristics predictive of review quality.

BACKGROUND

Systematic reviews summarise evidence by combining sources, but are potentially prone to bias. To counter this, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was published to aid in reporting. Similarly, the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) measurement tool was designed to appraise methodology. The paediatric surgical literature has seen an increasing number of reviews over the past decade, but quality has not been evaluated.

METHODS

Adhering to PRISMA guidelines, we performed a systematic review with a priori design to identify systematic reviews and meta-analyses of interventions in paediatric surgery. From 01/2010 to 06/2016, we searched: MEDLINE, EMBASE, Cochrane, Centre for Reviews and Dissemination, Web of Science, Google Scholar, reference lists and journals. Two reviewers independently selected studies and extracted data. We assessed conduct and reporting using AMSTAR and PRISMA. Scores were calculated as the sum of reported items. We also extracted author, journal and article characteristics, and used them in exploratory analysis to determine which variables predict quality.

RESULTS

112 articles fulfilled eligibility criteria (53 systematic reviews; 59 meta-analyses). Overall, 68% AMSTAR and 56.8% PRISMA items were reported adequately. Poorest scores were identified with regards a priori design, inclusion of structured summaries, including the grey literature, citing excluded articles and evaluating bias. 13 reviews were pre-registered and 6 in PRISMA-endorsing journals. The following predicted quality in univariate analysis:, word count, Cochrane review, journal h-index, impact factor, journal endorses PRISMA, PRISMA adherence suggested in author guidance, article mentions PRISMA, review includes comparison of interventions and review registration. The latter three variables were significant in multivariate regression.

CONCLUSIONS

There are gaps in the conduct and reporting of systematic reviews in paediatric surgery. More endorsement by journals of the PRISMA guideline may improve review quality, and the dissemination of reliable evidence to paediatric clinicians.

Laparoscopy in children and its impact on brain oxygenation during routine inguinal hernia repair

BACKGROUND

The systemic impact of intra-abdominal pressure (IAP) and/or changes in carbon dioxide (CO2) during laparoscopy are not yet well defined. Changes in brain oxygenation have been reported as a possible cause of cerebral hypotension and perfusion. The side effects of anaesthesia could also be involved in these changes, especially in children. To date, no data have been reported on brain oxygenation during routine laparoscopy in paediatric patients.

PATIENTS AND METHODS

Brain and peripheral oxygenation were investigated in 10 children (8 male, 2 female) who underwent elective minimally invasive surgery for inguinal hernia repair. Intraoperative transcranial near-infrared spectroscopy to assess regional cerebral oxygen saturation (rScO2), peripheral oxygen saturation using pulse oximetry and heart rate (HR) were monitored at five surgical intervals: Induction of anaesthesia (baseline T1); before CO2insufflation induced pneumoperitoneum (PP) (T2); CO2PP insufflation (T3); cessation of CO2PP (T4); before extubation (T5).

RESULTS

rScO2decreases were recorded immediately after T1 and became significant after insufflation (P = 0.006; rScO2decreased 3.6 ± 0.38%); restoration of rScO2was achieved after PP cessation (P = 0.007). The changes in rScO2were primarily due to IAP increases (P = 0.06). The HR changes were correlated to PP pressure (P < 0.001) and CO2flow rate (P = 0.001). No significant peripheral effects were noted.

CONCLUSIONS

The increase in IAP is a critical determinant in cerebral oxygenation stability during laparoscopic procedures. However, the impact of anaesthesia on adaptive changes should not be underestimated. Close monitoring and close collaboration between the members of the multidisciplinary paediatric team are essential to guarantee the patient's safety during minimally invasive surgical procedures.

Monitoring Cerebral and Renal Oxygenation Status during Neonatal Digestive Surgeries Using Near Infrared Spectroscopy

BACKGROUND

Depending on the initial pathology, hypovolemia, intra-abdominal hypertension, and sepsis are often encountered in neonatal digestive surgery. Accurate newborn monitoring during and after surgery is essential to adapt resuscitation protocols. Near infrared spectroscopy (NIRS) is non-invasive and can detect hypoperfusion which indicates a low circulatory blood flow, regardless of the cause.

OBJECTIVE

Evaluating changes in cerebral and renal regional oxygen saturation during neonatal digestive surgeries, conducted according to normal practices, with commonly used monitoring parameters. Analyzing retrospectively the inter-relationships between NIRS values and mean arterial pressure (MAP) values as well as pre-ductal SpO₂.

METHODS

Prospective, descriptive, monocentric study. All neonates referred for surgery were included. NIRS allows the measurement of cerebral and renal oxygenation fluctuations, as well as calculating difference in intraoperative and postoperative values.

RESULTS

Nineteen patients were included. Cerebral regional oxygen saturation (C rSO₂) values were stable while renal regional oxygen saturation (R rSO₂) values tended to decrease with time during surgery. Indeed, 72% of rSO₂ decline episodes occurred after the first 30 min of surgery, without any significant statistical differences for the next 90 min of surgery. After surgery, the lowest average C and R rSO₂ values were evidenced during the first 6 h, with 60% of C rSO₂ and R rSO₂ anomalies occurring in that time frame. There was no significant statistical difference observed in the following 18 h. There was a significant correlation between R rSO₂ and SpO₂ values (p < 0.01), but not with C rSO₂ values. There was no correlation with the MAP either for the C rSO₂ values or R rSO₂ ones.

CONCLUSION

NIRS is a promising non-invasive bedside tool to monitor cerebral and tissue perfusion, analyzing tissue microcirculation. NIRS has its interest to guide neonatal digestive surgeries (bowel manipulation, viscera reduction) and may represent an early warning for identifying patients requiring resuscitation during or after these surgeries.

Can transcutaneous near infrared spectroscopy detect severe hepatic ischemia: a juvenile porcine model

BACKGROUND

Vascular complications following pediatric liver transplantation occur in 8-10% of cases, and no continuous, non-invasive monitoring for this problem exists. Near infrared spectroscopy (NIRS) allows non-invasive, continuous, transcutaneous assessment of hemoglobin oxygenation (StO₂ ) 1-4 cm below the skin surface.

AIMS

We hypothesized that transcutaneous NIRS would be able to detect severe hepatic ischemia, and tested this in an animal model using 15-20 kg and 5-7 kg juvenile pigs.

MATERIALS AND METHODS

Direct liver surface and transcutaneous hepatic tissue hemoglobin oxygen saturation (StO₂ ) were measured during occlusions of the hepatic artery and portal vein. Changes in hepatic delivery of oxygen (HepDO₂ ) were calculated for each ischemic challenge and compared to changes in direct liver surface (DirHepStO₂ ) and transcutaneous liver StO₂ measurements (CutHepStO₂ ).

RESULTS

In the 15-20 kg animals during complete occlusion, CutHepStO₂ decreased by 6.0(±4.9)%, whilst DirHepStO₂ decreased by 83.7(±7.2)%. In the 5-7 kg animals during complete occlusion, CutHepStO₂ decreased by 27.4(±8.5)%, whilst DirHepStO₂ decreased by 82.8(±4.6)%.

CONCLUSION

Transcutaneous hepatic StO₂ monitoring cannot reliably detect severe hepatic ischemia in a juvenile porcine model, although a stronger and potentially useful signal is seen in 5-7 kg pigs. Trials of this technology should be currently restricted to situations where the organ is less than 1 cm from the skin surface, corresponding to infants of <10 kg.