Intraoperative Hypotension and Acute Kidney Injury after Noncardiac Surgery in Infants and Children: A Retrospective Cohort Analysis

Perioperative Incidence of Acute Renal Failure in Aortic Arch Reconstruction Using Retrograde Selective Lower Body Perfusion in Neonates and Infants

OBJECTIVE

Examination of the impact of retrograde selective lower body perfusion (SLP) via a femoral arterial catheter on urine output and the incidence of acute kidney injury (AKI) during pediatric aortic arch reconstructions. The secondary objective was if the cannulation of the superficial femoral artery was associated with complications in the perfusion area.

DESIGN

A retrospective study over an 8-year period (January 2015 to December 2023).

SETTING

Pediatric heart center of a tertiary care hospital.

PARTICIPANTS

Neonates and infants (N = 104) undergoing elective aortic arch reconstruction with cardiopulmonary bypass, of whom 45 received retrograde SLP.

INTERVENTIONS

Retrograde SLP via ultrasound-guided, weight-adapted femoral artery catheters for retrograde perfusion during clamping of the descending aorta under surgery, compared to a control group with identical surgical, perfusion, and anesthesiologic management but without SLP.

MEASUREMENTS AND MAIN RESULTS

Perioperative AKI incidence was analyzed using KDIGO criteria at multiple predetermined time points, along with urinary output. The SLP group showed a significantly lower AKI incidence immediately and 6 hours postsurgery (p = 0.001). Higher urine output postoperatively until day 3 (p ≤ 0.045) in the SLP group. No vascular complications were observed until hospital discharge.

CONCLUSIONS

Retrograde SLP is associated with a reduced AKI incidence and increased postoperative urine output, without vascular complications. Further studies are needed to investigate the long-term effects of retrograde SLP on renal function.

Risk factors and mortality of postoperative acute kidney injury (AKI) in newborns across geographical regions, surgical type, and national economic levels: a systematic review and meta-analysis

BACKGROUND

It is noted that postoperative acute kidney injury (AKI) in neonates is known to be associated with adverse outcomes, yet its incidence and risk factors remain incompletely elucidated. The current study aims to improve the understanding of postoperative AKI in neonates by systematically evaluating its incidence, diagnostic criteria, risk factors, and clinical outcomes, with particular attention to variations across geographic regions, surgical types, the span of time, and national economic statuses.

METHODS

A comprehensive search of Pubmed, Embase, OVID, Web of Science (WOS), Medline, and Cochrane Controlled Register of Trials (CENTRAL) was conducted from inception to 30 September 2024. Studies meeting all the following inclusion criteria were enrolled: 1) Population: neonates aged ≤ 30 days; 2) Disease: postoperative AKI diagnosed per KDIGO, pRIFLE, AKIN, nKDIGO, or others; 3) Study design: prospective/retrospective cohort studies or case-control studies; 4) Reporting data on postoperative incidence of AKI. The pooled proportion (along with 95% confidence intervals [CI]) of postoperative AKI was calculated. We also calculated pooled odds ratios (95% CI) for all-cause mortality in neonates with postoperative AKI when compared with those without AKI.

RESULTS

A total of 69 studies (10,519 cases) were included in the meta-analysis. The pooled incidence of postoperative AKI in neonates was 37% (95%CI 32-42, I2 = 96.4%, P<0.01), with a wide variability ranging from 0.0% to 74.8%. Several risk factors were identified, including lower preoperative or intraoperative urinary output, lower preoperative serum creatinine (SCr)/higher maximum postoperative SCr, elevated vasoactive inotrope score (VIS)/hypotension, younger corrected gestational age, prolonged cardiopulmonary bypass (CPB) duration, hypothermia, sepsis, and preoperative ventilation. Furthermore, 28 studies involving 6714 patients reported data on AKI-associated mortality with an overall incidence of 8.2%. Neonates who developed postoperative AKI had 3.3 times higher odds of mortality as compared to those without this complication.

CONCLUSIONS

Postoperative AKI affects one-third of neonates, and AKI-associated mortality remains high. Future efforts should focus on developing earlier and more sensitive detection methods.

SYSTEMATIC REVIEW REGISTRATION NUMBER

This meta-analysis was registered on https://www.crd.york.ac.uk/prospero/ with the registration number CRD 42024602820 on October 29, 2024.

Intraoperative dexmedetomidine and acute kidney injury in paediatric noncardiac surgery: a retrospective propensity score-matched analysis

BACKGROUND

Paediatric acute kidney injury (AKI) is common and linked to longer hospitalisation and mortality. We investigated whether a continuous intraoperative infusion of dexmedetomidine, which increases renal blood flow, was associated with a lower risk of postoperative AKI in paediatric patients undergoing noncardiac surgery.

METHODS

This retrospective cohort study included paediatric patients undergoing noncardiac surgery between January 2019 and July 2021. Propensity score matching, based on the participants' baseline characteristics, was used to minimise the potential bias. The primary outcome was AKI within 7 days after surgery. The secondary outcomes included ICU admission, in-hospital mortality, length of hospitalisation, intraoperative bradycardia, and hypotension. The exposure of interest was continuous intraoperative infusion of dexmedetomidine at any dosage or duration. Multivariable logistic regression and linear regression analyses were further used to adjust for residual imbalanced intraoperative factors in the matched cohort.

RESULTS

After propensity score matching, we identified 1858/4091 paediatric patients who had received intraoperative dexmedetomidine infusion. Intraoperative dexmedetomidine infusion was associated with a lower risk of AKI (1.4% vs 3.2%; odds ratio 0.43, 95% confidence interval 0.27-0.66; P<0.001), postoperative ICU admission (odds ratio 0.35, 95% confidence interval 0.30-0.42; P<0.001), and shorter hospitalisation (7 [5-10] vs 9 [6-13] days; P<0.001). Intraoperative bradycardia, hypotension, and in-hospital mortality were similar between the matched groups.

CONCLUSIONS

This retrospective analysis of a single-centre paediatric noncardiac surgery cohort suggests that intraoperative dexmedetomidine infusion was associated with a lower incidence of AKI within 7 days after surgery.

CLINICAL TRIAL REGISTRATION

ChiCTR2300069115.

Haemodynamic effect of dexmedetomidine during paediatric kidney transplantation

BACKGROUND

Dexmedetomidine is increasingly used for its ability to stabilise haemodynamic status during general anaesthesia. However, there is currently no data on paediatric kidney transplant recipients (pKTR). This study investigates the haemodynamic impact of dexmedetomidine administered perioperatively in pKTR.

METHODS

From 2019 to 2023, a retrospective study was conducted at Nantes University Hospital involving all pKTR under 18 years of age. The study compared intraoperative haemodynamic parameters between patients administered dexmedetomidine during kidney transplantation (DEX group) and those who did not receive it (no-DEX group). Mean arterial pressure (MAP) and heart rate (HR) were monitored throughout the duration of anaesthesia and compared. Graft function was assessed based on creatinine levels and glomerular filtration rate (GFR) at specific intervals. The perioperative use of fluids and vasoactive drugs, as well as their administration within 24 h post-surgery, were analysed.

RESULTS

Thirty-eight patients were enrolled, 10 in the DEX group and 28 in the no-DEX group. Intraoperative HR was similar between the groups; however, MAP was higher in the DEX group (mean difference 9, standard deviation (SD, 1-11) mmHg, p = 0.039). No differences were found regarding the use of fluid and vasoactive drug therapy between groups. GFR at 1 month post-transplantation was significantly elevated in the DEX group (p = 0.009).

CONCLUSIONS

pKTR receiving intraoperative dexmedetomidine exhibited higher perioperative MAP compared to those not administered dexmedetomidine. Additionally, the DEX group demonstrated superior graft function at 1 month. The direct impact of dexmedetomidine on immediate postoperative graft function in pTKR warrants further investigation in a prospective multicentre randomised study.

Intraoperative Hypotension and Postoperative Newly Developed Cerebral Infarction in Patients With Aneurysmal Subarachnoid Hemorrhage: A Retrospective Cohort Study

AIMS

To investigate the association between intraoperative hypotension and newly developed cerebral infarction in patients with aneurysmal subarachnoid hemorrhage (aSAH) undergoing aneurysm clipping or coiling.

METHODS

The patients who had emergent clipping/coiling procedures for aSAH under general anesthesia were included. The major exposure was mean arterial pressure (MAP) below different absolute or relative thresholds characterized by area under curve (AUC), duration, and time-weighted average (TWA) value. The outcome was newly developed cerebral infarction. The associations between MAP and newly developed cerebral infarction were adjusted by other risk factors. Odds ratio and 95% confidence interval were used to present the statistical difference.

RESULTS

A total of 1205 patients were included in the analysis. Of these, 260 patients (21.6%) developed new cerebral infarctions assessed by computed tomography. Patients with newly developed cerebral infarction had higher incidence of modified Fisher Scale (mFS) score 3 to 4 (80.0 vs. 69.1%, p < 0.01) and longer duration of anesthesia (4.3 vs. 3.9 h, p < 0.01). In the multivariate model, the AUC-MAP (adjusted odds ratio: 1.00, 95% CI: 1.000 to 1.000, p = 0.02) and the TWA-MAP (adjusted odds ratio: 1.01, 95% CI: 1.001 to 1.024, p = 0.04) of 20% decrease from baseline were closely associated with the newly developed cerebral infarction.

CONCLUSIONS

Mean arterial pressure decreased 20% from baseline value were independently associated with postoperative newly developed cerebral infarction in patients with aSAH.

Relationship between intra-operative urine output and postoperative acute kidney injury in paediatric cardiac surgery: A retrospective observational study

BACKGROUND

Intra-operative urine output (UO) has been shown to predict postoperative acute kidney injury (AKI) in adults; however, its significance in children undergoing cardiac surgery remains unknown.

OBJECTIVE

To explore the association between intra-operative UO and postoperative AKI in children with congenital heart disease.

DESIGN

A retrospective observational study.

SETTING

A tertiary hospital.

PATIENTS

Children aged >28 days and <6 years who underwent cardiac surgery at Fuwai Hospital from 1 April 2022 to 30 August 2022.

MAIN OUTCOME MEASURES

AKI was identified by the highest serum creatinine value within postoperative 7 days using Kidney Disease Improving Global Outcomes (KDIGO) criteria.

RESULTS

In total, 1184 children were included. The incidence of AKI was 23.1% (273/1184), of which 17.7% (209/1184) were stage 1, 4.2% (50/1184) were stage 2, and others were stage 3 (1.2%, 14/1184). Intra-operative UO was calculated by dividing the total intra-operative urine volume by the duration of surgery and the actual body weight measured before surgery. There was no significant difference in median [IQR] intra-operative UO between the AKI and non-AKI groups (2.6 [1.4 to 5.4] and 2.7 [1.4 to 4.9], respectively, P  = 0.791), and multivariate logistic regression analyses showed that intra-operative UO was not associated with postoperative AKI [adjusted odds ratio (OR) 0.971; 95% confidence interval (CI), 0.930 to 1.014; P  = 0.182]. Regarding the clinical importance of severe forms of AKI, we further explored the association between intra-operative UO and postoperative moderate-to-severe AKI (adjusted OR 0.914; 95% CI, 0.838 to 0.998; P  = 0.046).

CONCLUSIONS

Intra-operative UO was not associated with postoperative AKI during paediatric cardiac surgery. However, we found a significant association between UO and postoperative moderate-to-severe AKI. This suggests that reductions in intra-operative urine output below a specific threshold may be associated with postoperative renal dysfunction.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT05489263.

Outcomes of Acute Kidney Injury After Pediatric Liver Transplantation: A 1-Year Follow-Up

BACKGROUND

Postoperative acute kidney injury (AKI) and chronic kidney disease (CKD) following pediatric liver transplantation (PLT) have not been comprehensively studied. This study aimed to evaluate the correlation between AKI and both 1-year CKD and mortality.

METHODS

This retrospective study included 132 children aged between 3 months and 12 years who underwent PLT between 2017 and 2021. Postoperative AKI and CKD after 1 year were assessed according to KDIGO criteria. AKI was classified as mild, moderate, or severe based on severity as well as transient (≤2 days) and persistent (>2 days) based on duration. CKD occurrence was the primary outcome, whereas all-cause mortality was the secondary outcome.

RESULTS

AKI developed in 45.4% of children, with 40.7% mild, 37.1% moderate, and 22.2% severe. Half of the children with AKI subsequently developed CKD within 1 year, compared to 23.1% without AKI. Multivariate analysis indicated that moderate AKI, severe AKI, and persistent AKI were risk factors for CKD development (moderate AKI, OR = 3.8, 95% CI = 1.2-12.3; severe AKI, OR = 7.4, 95% CI = 1.4-38.3; persistent AKI, OR = 9.7, 95% CI = 2.3-36.4). The overall mortality rate within 1 year after surgery was 9.8%. Children with severe AKI and AKI lasting longer than 2 days exhibited a higher mortality rate than those without AKI.

CONCLUSIONS

The development of postoperative AKI is relatively common after PLT, and the severity and duration of AKI are associated with CKD and mortality within 1 year.

Definition of clinically relevant intraoperative hypotension: A data-driven approach

BACKGROUND

Associations between intraoperative hypotension (IOH) and various postoperative outcomes were shown in retrospective trials using a variety of different definitions of IOH. This complicates the comparability of these trials and makes clinical application difficult. Information about the best performing definitions of IOH regarding 30-day mortality, hospital length of stay (hLOS), and postanesthesia care unit length of stay (PACU-LOS) is missing.

METHODS

A retrospective cohort trial was conducted using data from patients undergoing noncardiothoracic surgery. We split the obtained dataset into two subsets. First, we used one subset to choose the best fitting definitions of IOH for the outcomes 30-day mortality, hLOS, and PACU-LOS. The other subset was used to independently assess the performance of the chosen definitions of IOH.

RESULTS

The final cohort consisted of 65,454 patients. In the shaping subset, nearly all tested definitions of IOH showed associations with the three outcomes, where the risk of adverse outcomes often increased continuously with decreasing MAP. The best fitting definitions were relative time with a MAP (mean arterial pressure) of <80 mmHg for 30-day mortality, lowest MAP for one minute for hLOS, and lowest MAP for one cumulative minute for PACU-LOS. Testing these three definitions of IOH in the independent second subset confirmed the associations of IOH with 30-day mortality, hLOS, and PACU-LOS.

CONCLUSIONS

Using a data-driven approach, we identified the best fitting definitions of IOH for 30-day mortality, hLOS, and PACU-LOS. Our results demonstrate the need for careful selection of IOH definitions. Clinical trial number: n/a, EC #2245/2020.

Comparative Electroencephalographic Profile of a New Anesthetic and Anticonvulsant That Is Selective for the GABA A R Slow Receptor Subtype

BACKGROUND

Anesthetics like propofol increase electroencephalography (EEG) power in delta frequencies (0.1-4 Hz), with a decrease of power in bandwidths >30 Hz. Propofol is nonselective for gamma amino butyric acid type A receptor subtypes (GABA A R) as it enhances all 3 GABA A R subtypes (slow, fast, and tonic). Our newly developed anesthetic class selectively targets GABA A R-slow synapses to depress brain responsiveness. We hypothesized that a selective GABA A R-slow agonist, KSEB 01-S2, would produce a different EEG signature compared to the broad-spectrum GABA A R agonist (propofol), and tested this using rat EEG recordings.

METHODS

Male rats were studied after Institutional Animal Care and Use Committees (IACUC) approval from the US Army Medical Research Institute of Chemical Defense and the University of Michigan. Rats were anesthetized using isoflurane (3%-5% induction, 1%-3% maintenance) with oxygen at 0.5 to 1.0 L/min. Stainless steel screws were placed in the skull and used to record subcranial cortical EEG signals. After recovery, either propofol or KSEB 01-S2 was administered and effects on EEG signals were analyzed.

RESULTS

As previously reported, propofol produced increased power in delta frequencies (0.1-4 Hz) compared to predrug recordings and produced a decrease in EEG power >30 Hz but no significant changes were seen within ±20 seconds of losing the righting reflex. By contrast, KSEB 01-S2 produced a significant increase in theta frequency percent power (median 14.7%, 16.2/13.8, 75/25 confidence interval; to 34.7%, 35/31.8; P < .015) and a significant decrease in low gamma frequency percent power (16.9%, 18.6/15.8; to 5.45%, 5.5/5.39; P < .015) for all rats at ± 20 seconds of loss of consciousness (LOC). Both anesthetics produced a flattening of chaotic attractor plots from nonlinear dynamic analyses, like that produced by volatile and dissociative anesthetics at LOC.

CONCLUSIONS

KSEB 01-S2 produced a markedly different EEG pattern, with a selective increase observed in the theta frequency range. KSEB 01-S2 also differs markedly in its activity at the GABA A R-slow receptor subtype, suggesting a possible mechanistic link between receptor subtype specificity and EEG frequency band signatures. Increased theta together with depressed gamma frequencies is interesting because GABA A R slow synapses have previously been suggested to underlie theta frequency oscillations, while fast synapses control gamma activity. These reciprocal effects support a previous model for theta and nested gamma oscillations based on inhibitory connections between GABA A R fast and slow interneurons. Although each anesthetic produced a unique EEG response, propofol and KSEB 01-S2 both increased slow wave activity and flattened chaotic attractor plots at the point of LOC.

Intraoperative hypotension is associated with decreased long-term survival in older patients after major noncardiac surgery: Secondary analysis of three randomized trials

STUDY OBJECTIVE

To assess the association of intraoperative hypotension with long-term survivals in older patients after major noncardiac surgery mainly for cancer.

DESIGN

A secondary analysis of databases from three randomized trials with long-term follow-up.

SETTING

The underlying trials were conducted in 17 tertiary hospitals in China.

PATIENTS

Patients aged 60 to 90 years who underwent major noncardiac thoracic or abdominal surgeries (≥ 2 h) in a single center were included in this analysis.

EXPOSURES

Restricted cubic spline models were employed to determine the lowest mean arterial pressure (MAP) threshold that was potentially harmful for long-term survivals. Patients were arbitrarily divided into three groups according to the cumulative duration or area under the MAP threshold. The association between intraoperative hypotension exposure and long-term survivals were analyzed with the Cox proportional hazard regression models.

MEASUREMENTS

Our primary endpoint was overall survival. Secondary endpoints included recurrence-free and event-free survivals.

MAIN RESULTS

A total of 2664 patients (mean age 69.0 years, 34.9% female sex, 92.5% cancer surgery) were included in the final analysis. MAP < 60 mmHg was adopted as the threshold of intraoperative hypotension. Patients were divided into three groups according to duration under MAP < 60 mmHg (<1 min, 1-10 min, and > 10 min) or area under MAP <60 mmHg (< 1 mmHg⋅min, 1-30 mmHg⋅min, and > 30 mmHg⋅min). After adjusting confounders, duration under MAP < 60 mmHg for > 10 min was associated with a shortened overall survival when compared with the < 1 min patients (adjusted hazard ratio [HR] 1.31, 95% confidence interval [CI] 1.09 to 1.57, P = 0.004); area under MAP < 60 mmHg for > 30 mmHg⋅min was associated with a shortened overall survival when compared with the < 1 mmHg⋅min patients (adjusted HR 1.40, 95% CI 1.16 to 1.68, P < 0.001). Similar associations exist between duration under MAP < 60 mmHg for > 10 min or area under MAP < 60 mmHg for > 30 mmHg⋅min and recurrence-free or event-free survivals.

CONCLUSIONS

In older patients who underwent major noncardiac surgery mainly for cancer, intraoperative hypotension was associated with worse overall, recurrence-free, and event-free survivals.

Urinary oxygen tension and its role in predicting acute kidney injury: A narrative review

Acute kidney injury occurs frequently in the perioperative setting. The renal medulla often endures hypoxia or hypoperfusion and is susceptible to the imbalance between oxygen supply and demand due to the nature of renal blood flow distribution and metabolic rate in the kidney. The current available evidence demonstrated that the urine oxygen pressure is proportional to the variations of renal medullary tissue oxygen pressure. Thus, urine oxygenation can be a candidate for reflecting the change of oxygen in the renal medulla. In this review, we discuss the basic physiology of acute kidney injury, as well as techniques for monitoring urine oxygen tension, confounding factors affecting the reliable measurement of urine oxygen tension, and its clinical use, highlighting its potential role in early detection and prevention of acute kidney injury.

Ephedrine to treat intraoperative hypotension in infants: what is the target?

Off-label use of medications in paediatric anaesthesia is common practice, owing to the relative paucity of evidence-based dosing regimens in children. Well-performed dose-finding studies, especially in infants, are rare and urgently needed. Unanticipated effects can result when paediatric dosing is based on adult parameters or local traditions. A recent dose-finding study on ephedrine highlights the uniqueness of paediatric dosing in comparison with adult dosing. We discuss the problems of off-label medication use and the lack of evidence for various definitions of hypotension and associated treatment strategies in paediatric anaesthesia. What is the aim of treating hypotension associated with anaesthesia induction: restoring the MAP to awake baseline values or elevating it above a provisional hypotension threshold?

Intraoperative arterial pressure and delayed cerebral ischemia in patients with aneurysmal subarachnoid hemorrhage after surgical clipping: A retrospective cohort study

Background

Delayed cerebral ischemia (DCI) is the major predictor of poor outcomes in patients with aSAH. Previous studies have attempted to assess the relationship between controlling blood pressure and DCI. However, the management of intraoperative blood pressure in reducing the occurrence of DCI still remains inconclusive.

Methods

All patients with aSAH who received general anesthesia for surgical clipping between January 2015 and December 2020 were prospectively reviewed. Patients were divided in the DCI group or the non-DCI group depending on whether DCI occurred or not. Intraoperative arterial pressure was measured every minute and recorded in an electronic anesthesia recording system along with intraoperative medication and other vital signs. The initial neurological function score, aneurysm characteristics, surgical and anesthetic information, and outcomes were compared between the DCI and the non-DCI groups.

Results

Among 534 patients who were enrolled, a total of 164 (30.71%) patients experienced DCI. The baseline characteristics of patients were similar between the groups. The World Federation of Neurosurgical Societies (WFNS) Scale > 3, age ≥ 70 years, and the modified Fisher Scale > 2 were significantly higher in patients with DCI than those without. Though it was the second derivative of the regression analysis, 105 mmHg was adopted as the threshold for intraoperative hypotension and was not associated with DCI.

Conclusions

The threshold of 105 mmHg was adopted as intraoperative hypotension even though it was the second derivative of the regression analysis and could not be proved to be associated with delayed cerebral ischemia adjusted by the baseline severity of aSAH and age.

Mild acute kidney injury after pediatric surgery is not-associated with long-term renal dysfunction: A retrospective cohort study

BACKGROUND AND STUDY OBJECTIVE

Acute kidney injury (AKI) is a sudden deterioration in renal function and is common in pediatric patients undergoing cardiac and non-cardiac surgery. Few studies have investigated the association of postoperative AKI with kidney dysfunction seen long-term and other adverse outcomes in pediatric patients. The study aimed to determine the association between postoperative AKI (mild AKI vs. no AKI and mild AKI vs. moderate-severe AKI) and chronic kidney dysfunction (CKD) seen long-term in pediatric patients undergoing cardiac and non-cardiac major surgery.

DESIGN

Restrospective, cohort study.

SETTING

Tertiary care hospital.

PATIENTS

This retrospective cohort study included patients aged 2-18 years who underwent cardiac and non-cardiac major surgery lasting >2 h at the Cleveland Clinic Main Campus between June 2005 and December 2020.

MEASUREMENTS

Postoperative AKI and CKD seen in long-term were defined and staged according to the Kidney Disease: Improving Global Outcomes criteria.

MAIN RESULTS

Among 10,597 children who had cardiac and non-cardiac major surgery, 1,302 were eligible. A total of 682 patients were excluded for missing variables and baseline kidney dysfunction and 620 patients were included. The mean age was 11 years, and 307 (49.5%) were female. Postoperative mild AKI was detected in 5.8% of the patients, while moderate-severe AKI was detected in 2.4%. There was no significant difference in CKD seen in long-term between patients with and without postoperative AKI, p = 0.83. The CKD seen in long-term developed in 27.7% of patients with postoperative mild AKI and 33.3% of patients with postoperative moderate and severe AKI. Patients without postoperative AKI had an estimated 1.09 times higher odds of having CKD seen in long-term compared with patients who have postoperative mild AKI (odds ratio [95% CI] 1.09 [0.48,2.52]).

CONCLUSION

In contrast to adult patients, the authors did not find any association between postoperative AKI and CKD seen in long-term in pediatric patients.