Surgery Within 24 Hours Reduces Mortality and General Complication Rates in Patients Who Have Periprosthetic Femoral Fractures at the Hip

BACKGROUND

In patients who have hip fractures, treatment within 24 hours reduces mortality and complication rates. A similar relationship can be assumed for patients who have hip periprosthetic femoral fractures (PPFs) owing to the similar baseline characteristics of the patient populations. This monocentric retrospective study aimed to compare the complication and mortality rates in patients who had hip PPF treated within and after 24 hours.

METHODS

In total, 350 consecutive patients who had hip PPF in a maximum-care arthroplasty and trauma center between 2006 and 2020 were retrospectively evaluated. The cases were divided into 2 groups using a time to surgery (TTS) of 24 hours as the cutoff value. The primary outcome variables were operative and general complications as well as mortalities within 1 year.

RESULTS

Overall, the mean TTS was 1.4 days, and the 1-year mortality was 14.6%. The TTS ≤ 24 hours (n = 166) and TTS > 24 hours (n = 184) groups were comparable in terms of baseline characteristics and comorbidities. Surgical complications were equally frequent in the 2 groups (16.3 versus 15.2%, P = .883). General complications occurred significantly more often in the late patient care group (11.4 versus 28.3%, P < .001). In addition, the 30-day mortality (0.6 versus 5.5%, P = .012), and 1-year mortality (8.3 versus 20.5%, P = .003) rates significantly increased in patients who had TTS > 24 hours. Cox regression analysis yielded a hazard ratio of 4.385 (P < .001) for the TTS > 24 hours group.

CONCLUSIONS

Prompt treatment is required for patients who have hip PPF to reduce mortality and overall complications.

A simple machine learning model for the prediction of acute kidney injury following noncardiac surgery in geriatric patients: a prospective cohort study

BACKGROUND

Surgery in geriatric patients often poses risk of major postoperative complications. Acute kidney injury (AKI) is a common complication following noncardiac surgery and is associated with increased mortality. Early identification of geriatric patients at high risk of AKI could facilitate preventive measures and improve patient prognosis. This study used machine learning methods to identify important features and predict AKI following noncardiac surgery in geriatric patients.

METHODS

The data for this study were obtained from a prospective cohort. Patients aged ≥ 65 years who received noncardiac surgery from June 2019 to December 2021 were enrolled. Data were split into training set (from June 2019 to March 2021) and internal validation set (from April 2021 to December 2021) by time. The least absolute shrinkage and selection operator (LASSO) regularization algorithm and the random forest recursive feature elimination algorithm (RF-RFE) were used to screen important predictors. Models were trained through extreme gradient boosting (XGBoost), random forest, and LASSO. The SHapley Additive exPlanations (SHAP) package was used to interpret the machine learning model.

RESULTS

The training set included 6753 geriatric patients. Of these, 250 (3.70%) patients developed AKI. The XGBoost model with RF-RFE selected features outperformed other models with an area under the precision-recall curve (AUPRC) of 0.505 (95% confidence interval [CI]: 0.369-0.626) and an area under the receiver operating characteristic curve (AUROC) of 0.806 (95%CI: 0.733-0.875). The model incorporated ten predictors, including operation site and hypertension. The internal validation set included 3808 geriatric patients, and 96 (2.52%) patients developed AKI. The model maintained good predictive performance with an AUPRC of 0.431 (95%CI: 0.331-0.524) and an AUROC of 0.845 (95%CI: 0.796-0.888) in the internal validation.

CONCLUSIONS

This study developed a simple machine learning model and a web calculator for predicting AKI following noncardiac surgery in geriatric patients. This model may be a valuable tool for guiding preventive measures and improving patient prognosis.

TRIAL REGISTRATION

The protocol of this study was approved by the Committee of Ethics from West China Hospital of Sichuan University (2019-473) with a waiver of informed consent and registered at www.chictr.org.cn (ChiCTR1900025160, 15/08/2019).

Dexmedetomidine Attenuates Inflammation in Elderly Patients Following Major Hepatobiliary and Pancreatic Surgery: A Randomized Clinical Trial

Background

Dexmedetomidine (Dex) may have anti-inflammatory properties and potentially reduce the incidence of postoperative organ injury.

Objective

To investigate whether Dex protects pulmonary and renal function via its anti-inflammatory effects in elderly patients undergoing prolonged major hepatobiliary and pancreatic surgery.

Design and Setting

Between October 2019 and December 2020, this randomized controlled trial was carried out at a tertiary hospital in Chongqing, China.

Patients

86 patients aged 60-75 who underwent long-duration (> 4 hrs) hepatobiliary and pancreatic surgery without significant comorbidities were enrolled and randomly assigned into two groups at a 1:1 ratio.

Interventions

Patients were given either Dex or an equivalent volume of 0.9% saline (Placebo) with a loading dose of 1 μg kg-1 for 10 min, followed by 0.5 μg kg-1 hr-1 for maintenance until the end of surgery.

Main Outcome Measures

The changes in serum concentrations of interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) were primary outcomes.

Results

At one hour postoperatively, serum IL-6 displayed a nine-fold increase (P<0.05) in the Placebo group. Administration of Dex decreased IL-6 to 278.09 ± 45.43 pg/mL (95% CI: 187.75 to 368.43) compared to the Placebo group (P=0.019; 432.16 ± 45.43 pg/mL, 95% CI: 341.82 to 522.50). However, no significant differences in TNF-α were observed between the two groups. The incidence of postoperative acute kidney injury was twice as high in the Placebo group (9.30%) compared to the Dex group (4.65%), and the incidence of postoperative acute lung injury was 23.26% in the Dex group, lower than that in the Placebo group (30.23%), although there was no statistical significance between the two groups.

Conclusion

Dex administration in elderly patients undergoing major hepatobiliary and pancreatic surgery reduces inflammation and potentially protects kidneys and lungs.

Registration

Chinese Clinical Trials Registry, identifier: ChiCTR1900024162, on 28 June 2019.

Sarcopenia, a Risk Predictor of Postoperative Acute Kidney Injury in Elderly Patients after Hip Fracture Surgery: A Retrospective Analysis

Background and Objectives: Hip fracture surgery, which affects quality of life, can be a major challenge in geriatric populations. Although sarcopenia is known to be associated with postoperative outcomes, there are few studies on the association between sarcopenia and postoperative acute kidney injury (AKI) in this population. We investigated the association between sarcopenia and postoperative AKI in elderly patients following hip fracture surgery. Materials and Methods: We retrospectively reviewed the records of patients who underwent hip fracture surgery at our institution from March 2019 to December 2021. Patients under the age of 65, patients with no preoperative computed tomography (CT) scans and patients with inappropriate cross-sectional images for measurement were excluded. The psoas-lumbar vertebral index (PLVI), which is the ratio of the average area of both psoas muscles to the area of the fourth lumbar vertebral body, was measured from preoperative CT scans. Sarcopenia was defined as a PLVI within the lowest 25% for each sex, and patients were categorized into sarcopenic and nonsarcopenic groups. The occurrence of AKI was determined based on the serum creatinine level within postoperative day 7 using the Kidney Disease Improving Global Outcomes (KDIGO) guidelines. Univariate and multivariate logistic regression analyses were performed to evaluate the associations between clinical variables and the occurrence of AKI. Results: Among the 348 enrolled patients, 92 patients were excluded, and 256 patients were analyzed. The PLVI cutoff values for defining sarcopenia lower than 25% for male and female patients were 0.57 and 0.43, respectively. The overall incidence of AKI was 18.4% (47 patients), and AKI occurred more frequently in sarcopenic patients than in nonsarcopenic patients (29.7% vs. 14.6%, p = 0.007). According to the multivariate logistic regression, which included all variables with a p value < 0.05 in the univariate analysis and adjusted for age, body mass index (BMI) and American Society of Anesthesiologists (ASA) physical status, sarcopenia was revealed to be an independent predictor of postoperative AKI (odds ratio = 5.10, 95% confidence interval = 1.77-14.77; p = 0.003). Conclusions: Preoperative sarcopenia, which corresponds to the lowest quartile of PLVI values, is associated with postoperative AKI among elderly patients who underwent hip fracture surgery.

Improving Patient Outcomes in Abdominal Surgery

Post-operative acute kidney injury (PO-AKI) is a frequent complication described in 15% of non-cardiac surgeries, 30% of cardiac surgeries, and 52% of patients requiring intensive post-operative care [...].

Preliminary investigation of the effect of non-cardiac surgery on intraoperative islet and renal function: a single-center prospective cohort study

Background

The effect of different non-cardiac surgical methods on islet and renal function remains unclear. We conducted a preliminary investigation to determine whether different surgical methods affect islet function or cause further damage to renal function.

Methods

In this prospective cohort study, the clinical data of 63 adult patients who underwent non-cardiac surgery under general anesthesia were evaluated from February 2019 to January 2020. Patients were divided into the abdominal surgery group, the laparoscopic surgery group, and the breast cancer surgery group. The primary outcome was the difference between the effects of different surgical methods on renal function.

Results

Islet and renal function were not significantly different between the groups. The correlation analysis showed that hematocrit (HCT) and hemoglobin (HB) were negatively correlated with fasting plasma glucose (FPG) (p < 0.05), MAP was positively correlated with C-peptide (p < 0.05), and HCT and Hb were positively correlated with serum creatinine (SCr) (p < 0.05). Fasting insulin (FINS) and C-peptide were negatively correlated with SCr (p < 0.05), and the homeostatic model assessment of insulin resistance (HOMA-IR) was positively correlated with SCr (p < 0.05). FINS, C-peptide, HOMA-IR, and the homeostatic model assessment of β-cell function (HOMA-β) were positively correlated with cystatin C (Cys C) (p < 0.05).

Conclusion

FINS, C-peptide, and HOMA-IR had positive effects on beta-2-microglobulin (β2-MG). FINS, C-peptide, and HOMA-IR were positively correlated with Cys C and β2-Mg. While FINS and C-peptide were negatively correlated with SCr, HOMA-IR was positively correlated with SCr.

High Intraoperative Serum Lactate Level is Associated with Acute Kidney Injury after Brain Tumor Resection

BACKGROUND

Postoperative acute kidney injury (AKI) is associated with poor clinical outcomes. Identification of risk factors for postoperative AKI is clinically important. Serum lactate can increase in situations of inadequate oxygen delivery and is widely used to assess a patient's clinical course. We investigated the association between intraoperative serum lactate levels and AKI after brain tumor resection.

METHODS

Demographics, medical and surgical history, tumor characteristics, surgery, anesthesia, preoperative and intraoperative blood test results, and postoperative clinical outcomes were retrospectively collected from 4131 patients who had undergone brain tumor resection. Patients were divided into high (n=1078) and low (n=3053) lactate groups based on an intraoperative maximum serum lactate level of 3.35 mmol/L. After propensity score matching, 1005 patients were included per group. AKI was diagnosed using the Kidney Disease Improving Global Outcomes criteria, based on serum creatinine levels within 7 days after surgery.

RESULTS

Postoperative AKI was observed in 53 (1.3%) patients and was more frequent in those with high lactate both before (3.2% [n=35] vs. 0.6% [n=18]; P < 0.001) and after (3.3% [n=33] vs. 0.6% [n=6]; P < 0.001) propensity score matching. Intraoperative predictors of postoperative AKI were maximum serum lactate levels > 3.35 mmol/L (odds ratio [95% confidence interval], 3.57 [1.45-8.74], P = 0.005), minimum blood pH (odds ratio per 1 unit, 0.01 [0.00-0.24], P = 0.004), minimum hematocrit (odds ratio per 1%, 0.91 [0.84-1.00], P = 0.037), and mean serum glucose levels > 200 mg/dL (odds ratio, 6.22 [1.75-22.16], P = 0.005).

CONCLUSION

High intraoperative serum lactate levels were associated with AKI after brain tumor resection.

Persistent Acute Kidney Injury is Associated with Poor Outcomes and Increased Hospital Cost in Vascular Surgery

BACKGROUND

Postoperative acute kidney injury (AKI) is common after major surgery and is associated with increased morbidity, mortality, and cost. Additionally, there are recent studies demonstrating that time to renal recovery may have a substantial impact on clinical outcomes. We hypothesized that patients with delayed renal recovery after major vascular surgery will have increased complications, mortality, and hospital cost.

METHODS

A single-center retrospective cohort of patients undergoing nonemergent major vascular surgery between 6/1/2014 and 10/1/2020 was analyzed. Development of postoperative AKI (defined using Kidney Disease Improving Global Outcomes (KDIGO) criteria: >50% or > 0.3 mg/dl absolute increase in serum creatinine relative to reference after surgery and before discharge) was evaluated. Patients were divided into 3 groups: no AKI, rapidly reversed AKI (<48 hours), and persistent AKI (≥48 hours). Multivariable generalized linear models were used to evaluate the association between AKI groups and postoperative complications, 90-day mortality, and hospital cost.

RESULTS

A total of 1,881 patients undergoing 1,980 vascular procedures were included. Thirty five percent of patients developed postoperative AKI. Patients with persistent AKI had longer intensive care unit and hospital stays, as well as more mechanical ventilation days. In multivariable logistic regression analysis, persistent AKI was a major predictor of 90-day mortality (odds ratio 4.1, 95% confidence interval 2.4-7.1). Adjusted average cost was higher for patients with any type of AKI. The incremental cost of having any AKI ranged from $3,700 to $9,100, even after adjustment for comorbidities and other postoperative complications. The adjusted average cost for patients stratified by type of AKI was higher among patients with persistent AKI compared to those with no or rapidly reversed AKI.

CONCLUSIONS

Persistent AKI after vascular surgery is associated with increased complications, mortality, and cost. Strategies to prevent and aggressively treat AKI, specifically persistent AKI, in the perioperative setting are imperative to optimize care for this population.

Perioperative acute kidney injury: Current knowledge and the role of anaesthesiologists

Background

Among the different types of perioperative organ injury, acute kidney injury (AKI) occurs frequently and is consistently associated with increased rates of mortality and mortality. Despite development of many clinical trials to assess perioperative interventions, reliable means to prevent or reverse AKI are still lacking.

Objectives

This narrative review discusses recent literature on modifiable risk factors, current approaches to prevention and potential directions for future research.

Methods

A Pubmed search with the relevant keywords was done for articles published in the last 10 years.

Results

New insights into preoperative identification and optimisation, intraoperative strategies, including the choice of anaesthetic, haemodynamic and fluid management, have been made, with the aim of preventing perioperative AKI.

Conclusion

A patient-centric multidisciplinary approach is essential to protect kidney function of patients going for surgery. Much can be done by anaesthesiologists perioperatively, to reduce the risk of development of AKI, especially in susceptible patients. There is a need for further multicentred trials to enhance the currently generic perioperative recommendations.

Bibliometric and visual analysis of intraoperative hypotension from 2004 to 2022

Background

Intraoperative hypotension (IOH) is a common complication occurring in surgical practice. This study aims to comprehensively review the collaboration and impact of countries, institutions, authors, journals, keywords, and critical papers on intraoperative hypotension from the perspective of bibliometric, and to evaluate the evolution of knowledge structure clustering and identify research hotspots and emerging topics.

Methods

Articles and reviews related to IOH published from 2004 to 2022 were retrieved from the Web of Science Core Collection. Bibliometric analyses and visualization were conducted on Excel, CiteSpace, VOSviewer, and Bibliometrix (R-Tool of R-Studio).

Results

A total of 1,784 articles and reviews were included from 2004 to 2022. The number of articles on IOH gradually increased in the past few years, and peaked in 2021. These publications were chiefly from 1,938 institutions in 40 countries, led by America and China in publications. Sessler Daniel I published the most papers and enjoyed the highest number of citations. Analysis of the journals with the most outputs showed that most journals concentrated on perioperative medicine and clinical anesthesiology. Delirium, acute kidney injury and vasoconstrictor agents are the current and developing research hotspots. The keywords "Acute kidney injury", "postoperative complication", "machine learning", "risk factors" and "hemodynamic instability" may also become new trends and focuses of the near future research.

Conclusion

This study uses bibliometrics and visualization methods to comprehensively review the research on intraoperative hypotension, which is helpful for scholars to better understand the dynamic evolution of IOH and provide directions for future research.

Cardiac damage following renal ischemia reperfusion injury increased with excessive consumption of high fat diet but enhanced the cardiac resistance to reperfusion stress in rat

Renal ischemia-reperfusion (IR) injury inflicts remote cardiac dysfunction. Studies on rats fed with a high-fat diet (HD) showed contradictory results: some demonstrated increased sensitivity of the heart and kidney to IR injury, while others reported resistance. In this study, we examined cardiac dysfunction and compromised cardiac tolerance associated with renal IR in HD and standard diet (SD) fed rats. Male Wistar rats fed with HD or SD diet for 16 weeks were subjected to either renal sham or IR protocol (bilateral clamping for 45 min and reperfusion for 24 h). The hearts isolated from these rats were further subjected to normal perfusion or IR procedure to study cardiac response. Renal IR surgery negatively affected cardiac function with substantial changes in the cardiac tissues, like mitochondrial dysfunction, elevated oxidative stress, and inflammation. HD-fed rat hearts exhibited hypertrophy at the end of 16 weeks, and the consequential impact on the heart was higher in the animals underwent renal IR surgery than with sham surgery. However, the IR induction in the isolated heart from renal sham or renal IR operation showed significant tissue injury resistance and better physiological recovery in HD-fed rats. However, in SD-fed rats, only hearts from renal IR-operated rats showed resistance to cardiac IR, whereas hearts from renal sham-operated rats were more susceptible to IR damage. The augmented IR resistance in the heart with prior renal surgery was due to preserved mitochondrial bioenergetics function, reduced oxidative stress, and activation of the PI3K/AKT signaling axis.

A comprehensive analysis of intraoperative factors associated with acute-on-chronic kidney injury in elderly trauma patients: blood loss as a key predictor

BACKGROUND

Postoperative acute kidney injury (AKI) is a critical issue in geriatric patients with pre-existing chronic kidney disease (CKD) undergoing orthopedic trauma surgery. The goal of this study was to investigate modifiable intraoperative risk factors for AKI.

METHODS

A retrospective study was conducted on 206 geriatric patients with CKD, who underwent orthopedic trauma surgery. Several variables, including intraoperative blood loss, postoperative hypoalbuminemia, intraoperative blood pressure and long-term use of potentially nephrotoxic drugs, were analyzed.

RESULTS

Postoperative AKI (KIDGO) was observed in 25.2% of the patients. The 1-year mortality rate increased significantly from 26.7% to 30.8% in patients who developed AKI. Primary risk factors for AKI were blood loss (p < 0.001), postoperative hypoalbuminemia (p = 0.050), and potentially nephrotoxic drugs prior to admission (angiotensin-converting enzyme inhibitors, angiotensin-II receptor antagonists, diuretics, antibiotics, NSAIDs) (p = 0.003). Furthermore, the AKI stage negatively correlated with propofol dose per body weight (p = 0.001) and there was a significant association between AKI and the use of cement (p = 0.027). No significant association between intraoperative hypotension and AKI was observed in any statistical test. Femur fracture surgeries showed the greatest blood loss (524mL ± 357mL, p = 0.005), particularly intramedullary nailing at the proximal femur (598mL ± 395mL) and revision surgery (769mL ± 436mL).

CONCLUSION

In geriatric trauma patients with pre-existing CKD, intraoperative blood loss, postoperative hypoalbuminemia, and pre-admission use of potentially nephrotoxic drugs are associated with postoperative AKI. The findings highlight the necessity to mitigate intraoperative blood loss and promote ortho-geriatric co-management to reduce the incidence and subsequent mortality in this high-risk population.

Future Directions in Optimizing Anesthesia to Reduce Perioperative Acute Kidney Injury

BACKGROUND

Perioperative acute kidney injury (AKI) is common in surgical patients and is associated with high morbidity and mortality. There are currently few options for AKI prevention and treatment. Due to its complex pathophysiology, there is no efficient medication therapy to stop the onset of the injury or repair the damage already done. Certain anesthetics, however, have been demonstrated to affect the risk of perioperative AKI in some studies. The impact of anesthetics on renal function is particularly important as it is closely related to the prognosis of patients. Some anesthetics can induce anti-inflammatory, anti-necrotic, and anti-apoptotic effects. Propofol, sevoflurane, and dexmedetomidine are a few examples of anesthetics that have protective association with AKI in the perioperative period.

SUMMARY

In this study, we reviewed the clinical characteristics, risk factors, and pathogenesis of AKI. Subsequently, the protective effects of various anesthetic agents against perioperative AKI and the latest research are introduced.

KEY MESSAGE

This work demonstrates that a thorough understanding of the reciprocal effects of anesthetic drugs and AKI is crucial for safe perioperative care and prognosis of patients. However, more complete mechanisms and pathophysiological processes still need to be further studied.

Incidence, associated factors, and outcomes of acute kidney injury following placement of antibiotic bone cement spacers in two-stage exchange for periprosthetic joint infection: a comprehensive study

Background

Two-stage exchange with placement of antibiotic cement spacer (ACS) is the gold standard for the treatment of chronic periprosthetic joint infection (PJI), but it could cause a high prevalence of acute kidney injury (AKI). However, the results of the current evidence on this topic are too mixed to effectively guide clinical practice.

Methods

We retrospectively identified 340 chronic PJI patients who underwent the first-stage exchange with placement of ACS. The Kidney Disease Improving Global Outcomes guideline was used to define postoperative AKI. Multivariate logistic analysis was performed to determine the potential factors associated with AKI. Furthermore, a systematic review and meta-analysis on this topic were conducted to summarize the knowledge in the current literature further.

Results

In our cohort, the incidence of AKI following first-stage exchange was 12.1%. Older age (per 10 years, OR= 1.509) and preoperative hypoalbuminemia (OR= 3.593) were independent predictors for postoperative AKI. Eight AKI patients progressed to chronic kidney disease after 90 days. A meta-analysis including a total of 2525 PJI patients showed the incidence of AKI was 16.6%, and AKI requiring acute dialysis was 1.4%. Besides, host characteristics, poor baseline liver function, factors contributing to acute renal blood flow injury, and the use of nephrotoxic drugs may be associated with the development of AKI. However, only a few studies supported an association between antibiotic dose and AKI.

Conclusion

AKI occurs in approximately one out of every six PJI patients undergoing first-stage exchange. The pathogenesis of AKI is multifactorial, with hypoalbuminemia could be an overlooked associated factor. Although the need for acute dialysis is uncommon, the fact that some AKI patients will develop CKD still needs to be taken into consideration.

Elevated serum albumin-to-creatinine ratio as a protective factor on outcomes after heart transplantation

Background

The purpose of this study was to investigate the prognostic significance of serum albumin to creatinine ratio (ACR) in patients receiving heart transplantation of end-stage heart failure.

Methods

From January 2015 to December 2020, a total of 460 patients who underwent heart transplantation were included in this retrospective analysis. According to the maximum Youden index, the optimal cut-off value was identified. Kaplan-Meier methods were used to describe survival rates, and multivariable analyses were conducted with Cox proportional hazard models. Meanwhile, logistic regression analysis was applied to evaluate predictors for postoperative complications. The accuracy of risk prediction was evaluated by using the concordance index (C-index) and calibration plots.

Results

The optimal cut-off value was 37.54 for ACR. Univariable analysis indicated that recipient age, IABP, RAAS, BB, Hb, urea nitrogen, D-dimer, troponin, TG, and ACR were significant prognostic factors of overall survival (OS). Multivariate analysis showed that preoperative ACR (HR: 0.504, 95% = 0.352-0.722, P < 0.001) was still an independent prognostic factor of OS. The nomogram for predicting 1-year and 5-year OS in patients who underwent heart transplantation without ACR (C-index = 0.631) and with ACR (C-index = 0.671). Besides, preoperative ACR level was a significant independent predictor of postoperative respiratory complications, renal complications, liver injury, infection and in-hospital death. Moreover, the calibration plot showed good consistency between the predictions by the nomogram for OS and the actual outcomes.

Conclusion

Our research showed that ACR is a favorable prognostic indicator in patients of heart transplantation.

Development of a Machine Learning Model of Postoperative Acute Kidney Injury Using Non-Invasive Time-Sensitive Intraoperative Predictors

Acute kidney injury (AKI) is a major postoperative complication that lacks established intraoperative predictors. Our objective was to develop a prediction model using preoperative and high-frequency intraoperative data for postoperative AKI. In this retrospective cohort study, we evaluated 77,428 operative cases at a single academic center between 2016 and 2022. A total of 11,212 cases with serum creatinine (sCr) data were included in the analysis. Then, 8519 cases were randomly assigned to the training set and the remainder to the validation set. Fourteen preoperative and twenty intraoperative variables were evaluated using elastic net followed by hierarchical group least absolute shrinkage and selection operator (LASSO) regression. The training set was 56% male and had a median [IQR] age of 62 (51-72) and a 6% AKI rate. Retained model variables were preoperative sCr values, the number of minutes meeting cutoffs for urine output, heart rate, perfusion index intraoperatively, and the total estimated blood loss. The area under the receiver operator characteristic curve was 0.81 (95% CI, 0.77-0.85). At a score threshold of 0.767, specificity was 77% and sensitivity was 74%. A web application that calculates the model score is available online. Our findings demonstrate the utility of intraoperative time series data for prediction problems, including a new potential use of the perfusion index. Further research is needed to evaluate the model in clinical settings.

Impact of Intraoperative Fluid Balance and Norepinephrine on Postoperative Acute Kidney Injury after Cystectomy and Urinary Diversion over Two Decades: A Retrospective Observational Cohort Study

The use of norepinephrine and the restriction of intraoperative hydration have gained increasing acceptance over the last few decades. Recently, there have been concerns regarding the impact of this approach on renal function. The objective of this study was to examine the influence of norepinephrine, intraoperative fluid administration and their interaction on acute kidney injury (AKI) after cystectomy. In our cohort of 1488 consecutive patients scheduled for cystectomies and urinary diversions, the overall incidence of AKI was 21.6% (95%-CI: 19.6% to 23.8%) and increased by an average of 0.6% (95%-CI: 0.1% to 1.1%, p = 0.025) per year since 2000. The fluid and vasopressor regimes were characterized by an annual decrease in fluid balance (-0.24 mL·kg^-1·h^-1, 95%-CI: -0.26 to -0.22, p < 0.001) and an annual increase in the amount of norepinephrine of 0.002 µg·kg^-1·min^-1 (95%-CI: 0.0016 to 0.0024, p < 0.001). The interaction between the fluid balance and norepinephrine levels resulted in a U-shaped association with the risk of AKI; however, the magnitude and shape depended on the reference categories of confounders (age and BMI). We conclude that decreased intraoperative fluid balance combined with increased norepinephrine administration was associated with an increased risk of AKI. However, other potential drivers of the observed increase in AKI incidence need to be further investigated in the future.

Intraoperative serum lactate levels as a prognostic predictor of outcome for emergency abdominal surgery: a retrospective study

BACKGROUND

The relationship between intraoperative lactate levels and prognosis after emergency gastrointestinal surgery remains unclear. The purpose of this study was to investigate the prognostic value of intraoperative lactate levels for predicting in-hospital mortality, and to examine intraoperative hemodynamic managements.

METHODS

We conducted a retrospective observational study of emergency GI surgeries performed at our institution between 2011 and 2020. The study group comprised patients admitted to intensive care units postoperatively, and whose intraoperative and postoperative lactate levels were available. Intraoperative peak lactate levels (intra-LACs) were selected for analysis, and in-hospital mortality was set as the primary outcome. The prognostic value of intra-LAC was assessed using logistic regression and receiver operating characteristic (ROC) curve analysis.

RESULTS

Of the 551 patients included in the study, 120 died postoperatively. Intra-LAC in the group who survived and the group that died was 1.80 [interquartile range [IQR], 1.19-3.01] mmol/L and 4.22 [IQR, 2.15-7.13] mmol/L (P < 0.001), respectively. Patients who died had larger volumes of red blood cell (RBC) transfusions and fluid administration, and were administered higher doses of vasoactive drugs. Logistic regression analysis showed that intra-LAC was an independent predictor of postoperative mortality (odds ratio [OR] 1.210, 95% CI 1.070 -1.360, P = 0.002). The volume of RBCs, fluids transfused, and the amount of vasoactive agents administered were not independent predictors. The area under the curve (AUC) of the ROC curve for intra-LAC for in-hospital mortality was 0.762 (95% confidence interval [CI], 0.711-0.812), with a cutoff value of 3.68 mmol/L by Youden index.

CONCLUSIONS

Intraoperative lactate levels, but not hemodynamic management, were independently associated with increased in-hospital mortality after emergency GI surgery.

Clinical Considerations for Patients Experiencing Acute Kidney Injury Following Percutaneous Nephrolithotomy

Acute kidney injury (AKI) is a common postoperative outcome in urology patients undergoing surgery for nephrolithiasis. The objective of this study was to determine the prevalence of postoperative AKI and its degrees of severity, identify risk factors, and understand the resultant outcomes of AKI in patients with nephrolithiasis undergoing percutaneous nephrolithotomy (PCNL). A cohort of patients admitted between 2012 and 2019 to a single tertiary-care institution who had undergone PCNL was retrospectively analyzed. Among 417 (n = 326 patients) encounters, 24.9% (n = 104) had AKI. Approximately one-quarter of AKI patients (n = 18) progressed to Stage 2 or higher AKI. Hypertension, peripheral vascular disease, chronic kidney disease, and chronic anemia were significant risk factors of post-PCNL AKI. Corticosteroids and antifungals were associated with increased odds of AKI. Cardiovascular, neurologic complications, sepsis, and prolonged intensive care unit (ICU) stay percentages were higher in AKI patients. Hospital and ICU length of stay was greater in the AKI group. Provided the limited literature regarding postoperative AKI following PCNL, and the detriment that AKI can have on clinical outcomes, it is important to continue studying this topic to better understand how to optimize patient care to address patient- and procedure-specific risk factors.

Intraoperative hypotension when using hypotension prediction index software during major noncardiac surgery: a European multicentre prospective observational registry (EU HYPROTECT)

Background

Intraoperative hypotension is associated with organ injury. Current intraoperative arterial pressure management is mainly reactive. Predictive haemodynamic monitoring may help clinicians reduce intraoperative hypotension. The Acumen™ Hypotension Prediction Index software (HPI-software) (Edwards Lifesciences, Irvine, CA, USA) was developed to predict hypotension. We built up the European multicentre, prospective, observational EU HYPROTECT Registry to describe the incidence, duration, and severity of intraoperative hypotension when using HPI-software monitoring in patients having noncardiac surgery.

Methods

We enrolled 749 patients having elective major noncardiac surgery in 12 medical centres in five European countries. Patients were monitored using the HPI-software. We quantified hypotension using the time-weighted average MAP <65 mm Hg (primary endpoint), the proportion of patients with at least one ≥1 min episode of a MAP <65 mm Hg, the number of ≥1 min episodes of a MAP <65 mm Hg, and duration patients spent below a MAP of 65 mm Hg.

Results

We included 702 patients in the final analysis. The median time-weighted average MAP <65 mm Hg was 0.03 (0.00-0.20) mm Hg. In addition, 285 patients (41%) had no ≥1 min episode of a MAP <65 mm Hg; 417 patients (59%) had at least one. The median number of ≥1 min episodes of a MAP <65 mm Hg was 1 (0-3). Patients spent a median of 2 (0-9) min below a MAP of 65 mm Hg.

Conclusions

The median time-weighted average MAP <65 mm Hg was very low in patients in this registry. This suggests that using HPI-software monitoring may help reduce the duration and severity of intraoperative hypotension in patients having noncardiac surgery.

Incidence, risk factors and outcomes of acute kidney injury in surgical intensive care unit octogenarians at the Jordan University Hospital

BACKGROUND

Acute kidney damage (AKI) is among the most severe consequences observed in surgical intensive care units (SICUs). We aim to observe the incidence, risk factors, and outcomes of acute kidney injury in SICU octogenarians.

METHODS

A cross-sectional retrospective study was conducted at the SICU of Jordan University Hospital (JUH), a tertiary teaching hospital in a developing country, between January 2018 and December 2019. Patients who were 80 years or older at the time of data collection were included. The definition of AKI was based on Kidney Disease Improving Global Outcomes (KDIGO) criteria. Demographic, clinical, and laboratory data were reviewed.

RESULTS

A total number of 168 patients were included. The mean age was 84.0 ± 3.8 years, and 54.8% of the participants were women. Of those, 115 (68.5%) had surgery before or during ICU stay, and 28.7% of the patients' surgeries were an emergency surgery. Also, 47.8% of surgeries were considered by anesthesia to be high-risk surgeries. A total of 55 patients (32.7%) developed AKI during their SICU stay. The factors that were significantly associated with AKI in the ICU patients included use of beta blocker [AOR: 3.7; 95% CI: 1.2-11.8; p = 0.025], and inotropes [AOR:4.0; 95% CI: 1.2-13.3; p = 0.03]. The factors that were significantly associated with mortality in the ICU included using mechanical ventilation [AOR:18.7; 95% CI: 2.4-141.9; p = 0.005] and inotropes use [AOR: 12.3; 95% CI: 1.2-120.7; p = 0.031].

CONCLUSIONS

The incidence of AKI during SICU stay in this study was 32.7% and it was significantly associated with the use of beta blockers, mechanical ventilation, and inotropes. The mortality rate among octogenarians who developed AKI during SICU stay was 36.4%. Further studies are needed globally to assess the incidence of AKI in octogenarian surgical patients and identify risk factors to provide preventative measurements and strategies.

Optimization of central venous pressure during the perioperative period is associated with improved prognosis of high-risk operation patients

Background

While central venous pressure (CVP) measurement is used to guide fluid management for high-risk surgical patients during the perioperative period, its relationship to patient prognosis is unknown.

Methods

This single-center, retrospective observational study enrolled patients undergoing high-risk surgery from February 1, 2014 to November 31, 2020, who were admitted to the surgical intensive care unit (ICU) directly after surgery. Patients were divided into the following three groups according to the first CVP measurement (CVP1) after admission to the ICU: low, CVP1 <8 mmHg; moderate, 8 mmHg≤ CVP1 ≤ 12 mmHg; and high, CVP1 >12 mmHg. Perioperative fluid balance, 28-day mortality, length of stay in the ICU, and hospitalization and surgical complications were compared across groups.

Results

Of the 775 high-risk surgical patients enrolled in the study, 228 were included in the analysis. Median (interquartile range) positive fluid balance during surgery was lowest in the low CVP1 group and highest in the high CVP1 group (low CVP1: 770 [410, 1205] mL; moderate CVP1: 1070 [685, 1500] mL; high CVP1: 1570 [1008, 2000] mL; all P <0.001). The volume of positive fluid balance during the perioperative period was correlated with CVP1 (r=0.336, P <0.001). The partial arterial pressure of oxygen(PaO₂)/fraction of inspired oxygen(FiO₂) ratio was significantly lower in the high CVP1 group than in the low and moderate CVP1 groups (low CVP1: 400.0 [299.5, 443.3] mmHg; moderate CVP1: 362.5 [330.0, 434.9] mmHg; high CVP1: 335.3 [254.0, 363.5] mmHg; all P <0.001). The incidence of postoperative acute kidney injury (AKI) was lowest in the moderate CVP1 group (low CVP1: 9.2%; moderate CVP1: 2.7%; high CVP1: 16.0%; P=0.007). The proportion of patients receiving renal replacement therapy was highest in the high CVP1 group (low CVP1: 1.5%; moderate CVP1: 0.9%; high CVP1: 10.0%; P=0.014). Logistic regression analysis showed that intraoperative hypotension and CVP1 >12 mmHg were risk factors for AKI within 72 h after surgery (adjusted odds ratio[aOR]=3.875, 95% confidence interval[CI]: 1.378-10.900, P=0.010 and aOR=1.147, 95%CI: 1.006-1.309, P=0.041).

Conclusions

CVP that is either too high or too low increases the incidence of postoperative AKI. Sequential fluid therapy based on CVP after patients are transferred to the ICU post-surgery does not reduce the risk of organ dysfunction caused by an excessive amount of intraoperative fluid. However, CVP can be used as a safety limit indicator for perioperative fluid management in high-risk surgical patients.

Preoperative renal insufficiency predicts postoperative adverse outcomes in a mixed surgical population: a retrospective matched cohort study using the NSQIP database

BACKGROUND

The incidence of chronic kidney disease is increasing, but most cases are not diagnosed until the accidental finding of abnormal laboratory data or the presentation of severe symptoms. Patients with chronic kidney disease are reported to have an increased risk of postoperative mortality and morbidities, but previous studies mainly targeted populations undergoing cardiovascular surgery. The authors aimed to evaluate the risk of postoperative mortality and complications in a surgical population with preoperative renal insufficiency (RI).

MATERIALS AND METHODS

This retrospective cohort study used data from the National Surgical Quality Improvement Program database between 2013 and 2018 to evaluate the risk of postoperative morbidity and mortality in the surgical population. Patients with estimated glomerular filtration rate less than 60 ml/min/1.73 m 2 were defined as the RI group. Propensity score matching methods and multivariate logistic regression were used to calculate the risk of postoperative morbidity and mortality.

RESULTS

After propensity score matching, 502 281 patients were included in the RI and non-RI groups. The RI group had a higher risk of 30-day in-hospital mortality (odds ratio: 1.54, 95% CI: 1.49-1.58) than the non-RI group. The RI group was associated with a higher risk of postoperative complications, including myocardial infarction, stroke, pneumonia, septic shock, and postoperative bleeding. The RI group was also associated with an increased risk of prolonged ventilator use for over 48 h, readmission, and reoperation.

CONCLUSION

Patients with preoperative RI have an increased risk of postoperative 30-day mortality and complications. RI group patients with current dialysis, estimated glomerular filtration rate less than or equal to 30 ml/min/1.73 m 2 or concomitant anemia had an elevated risk of postoperative mortality.

Goal-directed perfusion for reducing acute kidney injury in cardiac surgery: A systematic review and meta-analysis

BACKGROUND

Acute kidney injury (AKI) is a common complication following cardiopulmonary bypass (CPB) which can affect morbidity and mortality. Goal-directed perfusion (GDP) intended to avoid the nadir oxygen delivery index below the critical value is associated with reduced postoperative AKI. However, current studies suggested that GDP can only decrease the incidence of AKI stage 1 but showed no effects on AKI stages 2-3 and mortality. The objective of the present meta-analysis is to deter the effects of GDP on postoperative AKI in any stage and mortality following cardiac surgery.

METHODS

MEDLINE, Embase, and the Cochrane Library were searched to identify all clinical trials comparing GDP with control (standard care) during cardiopulmonary bypass conducting in adults undergoing cardiac surgery. The primary outcome was postoperative acute kidney injury. Secondary outcomes included postoperative mortality and length of ICU stay. Data synthesis was obtained by using risk ratio with 95% confidence interval by a random-effects model.

RESULT

From 1094 potential studies, 3 trials enrolling 777 patients were included. Meta-analysis suggested the GDP strategy based on DO₂i reduced postoperative AKI compared with standard CPB management (RR = 0.52; 95% CI: 0.38-0.70; p < .0001), especially in AKI stage I (RR = 0.47; 95% CI: 0.33-0.66; p < .0001). But the GDP strategy did not reduce the incidence of severe AKI (stages 2-3) and postoperative mortality.

CONCLUSION

The GDP strategy based on DO₂i during CPB obviously reduces AKI stage 1 and thus reduces overall AKI incidence. But it shows no effects on severe AKI (stages 2-3) and mortality.

Analysis of factors associated with postoperative acute kidney injury in patients with colorectal cancer and the development of a risk prediction model: a retrospective study

BACKGROUND

To investigate the factors associated with acute kidney injury (AKI) in postoperative colorectal cancer (CRC) patients and develop a risk prediction model.

METHODS

The clinical data of 389 CRC patients were retrospectively analyzed. The patients were divided into AKI (n = 30) and non-AKI groups (n = 359) according to KDIGO diagnostic criteria. Demographic data, the presence of underlying diseases, perioperative conditions and related examination results were compared between the two groups. Binary logistic regression was used to analyze the independent risk factors for postoperative AKI, and a risk prediction model was established. And a verification group (94 patients) was used to verify the model.

RESULTS

30 patients (7.71%) with CRC had postoperative AKI. Binary logistic regression analysis showed that preoperative combined hypertension, preoperative anemia, inadequate intraoperative crystalloid infusion, low intraoperative minimum mean arterial pressure (MAP) and moderate to severe postoperative decline in hemoglobin (Hb) levels were independent risk factors. The risk prediction model developed was expressed as Logit P = - 0.853 + 1.228 * preoperative combined hypertension + 1.275 *preoperative anemia - 0.002 * intraoperative crystalloid infusion (ml) - 0.091 * intraoperative minimum MAP (mmHg) + 1.482 * moderate to severe postoperative decline in Hb levels. In Hosmer-Lemeshow test, χ² = 8.157, P = 0.718 showed that the fitting effect was good. The area under ROC curve was 0.776 (95% CI 0.682-0.871, P < 0.001), with a prediction threshold of 1.570, a sensitivity of 63.3% and a specificity of 88.9%. The sensitivity and specificity of the verification group were 65.8% and 86.1%.

CONCLUSIONS

Preoperative combined hypertension, preoperative anemia, inadequate intraoperative crystalloid infusion, low intraoperative minimum MAP, and moderate to severe postoperative decline in Hb levels were independent risk factors for AKI development in CRC patients. The prediction model can effectively predict the occurrence of postoperative AKI in patients with CRC.

Acute Kidney Injury and Renal Replacement Therapy: A Review and Update for the Perioperative Physician

Post-operative acute kidney injury is a devastating complication with significant morbidity and mortality associated with it. The perioperative anesthesiologist is in a unique position to potentially mitigate the risk of postoperative AKI, however, understanding the pathophysiology, risk factors and preventative strategies is paramount. There are also certain clinical scenarios, where renal replacement therapy may be indicated intraoperatively including severe electrolyte abnormalities, metabolic acidosis and massive volume overload. A multidisciplinary approach including the nephrologist, critical care physician, surgeon and anesthesiologist is necessary to determine the optimal management of these critically ill patients.

Acute kidney injury as an independent predicting factor for stage 3 or higher chronic kidney disease after nephrectomy

BACKGROUND

The association between postoperative acute kidney injury (AKI) and long-term renal function after nephrectomy has not been fully explored, with accurate prognostic models in which AKI is an independent predicting variable still being absent.

METHODS

We conducted a retrospective study of 528 patients who underwent unilateral radical nephrectomy or partial nephrectomy owing to renal cell carcinoma between January 2013 and December 2016. Postoperative AKI was defined as an absolute increase in serum creatinine level by 0.3 mg/dl or ≥5 0% increase from the preoperative value within 48 hours after surgery. The endpoint was the time to the incident stage 3 or higher chronic kidney disease (defined as eGFR<60 ml/min/1.73m²), or any claim for initiation of dialysis. Cox proportional hazards regression analysis was conducted to construct the final model. Internal validation was performed using 10-fold cross-validation. The model was evaluated in discrimination by Harrell's C-index and area under curve (AUC) values, and calibration by calibration plots.

RESULTS

Five hundred twenty-eight patients were finally enrolled in the study cohort, and the median follow-up period was 38 months. Among 528 admitted patients, 232 (43.9%) developed AKI, and stage 3 or higher CKD occurred in 47 (8.9%) patients during the follow-up time, with 33 in 47 patients (70.2%) having postoperative AKI. AKI was significantly correlated with poor prognosis of renal function (HR = 3.079, P < 0.001). After the adjustment of conventional predictors, AKI was still independently related to kidney function deterioration, and the correlation was influenced by the severity of AKI. Five variables were selected to establish the prognostic model, including age, surgery type, preoperative estimated glomerular filtration rate, preoperative blood urea nitrogen, and postoperative AKI. The model had good discrimination, with the Harrell's C-index of 0.92 (95% CI 0.89-0.95), and AUC values varying from 87.7 to 95.7 at different time points.

CONCLUSIONS

AKI during the perioperative period is an independent predicting factor of stage 3 or higher CKD after nephrectomy.

Intraoperative mean arterial pressure and acute kidney injury after robot-assisted laparoscopic prostatectomy: a retrospective study

Intraoperative hemodynamics can affect postoperative kidney function. We aimed to investigate the effect of intraoperative mean arterial pressure (MAP) as well as other risk factors on the occurrence of acute kidney injury (AKI) after robot-assisted laparoscopic prostatectomy (RALP). We retrospectively evaluated the medical records of 750 patients who underwent RALP. The average real variability (ARV)-MAP, standard deviation (SD)-MAP, time-weighted average (TWA)-MAP, area under threshold (AUT)-65 mmHg, and area above threshold (AAT)-120 mmHg were calculated using MAPs collected within a 10-s interval. Eighteen (2.4%) patients developed postoperative AKI. There were some univariable associations between TWA-MAP, AUT-65 mmHg, and AKI occurrence; however, multivariable analysis found no association. Alternatively, American Society of Anesthesiologists physical status ≥ III and the low intraoperative urine output were independently associated with AKI occurrence. Moreover, none of the five MAP parameters could predict postoperative AKI, with the area under the receiver operating characteristic curve values for ARV-MAP, SD-MAP, TWA-MAP, AUT-65 mmHg, and AAT-120 mmHg being 0.561 (95% confidence interval [CI], 0.424-0.697), 0.561 (95% CI, 0.417-0.704), 0.584 (95% CI, 0.458-0.709), 0.590 (95% CI, 0.462-0.718), and 0.626 (95% CI, 0.499-0.753), respectively. Therefore, intraoperative MAP changes may not be a determining factor for AKI after RALP.

Pneumoperitoneum and Acute Kidney Injury-An Integrative Clinical Concept Review

An increased intraabdominal pressure, particularly when occurring during periods of hemodynamic instability or fluid overload, is regarded as a major contributor to acute kidney injury (AKI) in intensive care units. During abdominal laparoscopic procedures, intraoperative insufflation pressures up to 15 mmHg are applied, to enable visualization and surgical manipulation but with the potential to compromise net renal perfusion. Despite the widely acknowledged renal arterial autoregulation, net arterial perfusion pressure is known to be narrow, and the effective renal medullary perfusion is disproportionately impacted by venous and lymphatic congestion. At present, the potential risk factors, mitigators and risk-stratification of AKI during surgical pneumoperitoneum formation received relatively limited attention among nephrologists and represent an opportunity to look beyond mere blood pressure and intake-output balances. Careful charting and reporting duration and extent of surgical pneumoperitoneum represents an opportunity for anesthesia teams to better communicate intraoperative factors affecting renal outcomes for the postoperative clinical teams. In this current article, the authors are integrating preclinical data and clinical experience to provide a better understanding to optimize renal perfusion during surgeries. Future studies should carefully consider intrabdominal insufflation pressure as a key variable when assessing outcomes and blood pressure goals in these settings.

Acute Pain Management Pearls: A Focused Review for the Hospital Clinician

Acute pain management is a challenging area encountered by inpatient clinicians every day. While patient care is increasingly complex and costly in this realm, the availability of applicable specialists is waning. This narrative review seeks to support diverse hospital-based healthcare providers in refining and updating their acute pain management knowledge base through clinical pearls and point-of-care resources. Practical guidance is provided for the design and adjustment of inpatient multimodal analgesic regimens, including conventional and burgeoning non-opioid and opioid therapies. The importance of customized care plans for patients with preexisting opioid tolerance, chronic pain, or opioid use disorder is emphasized, and current recommendations for inpatient management of associated chronic therapies are discussed. References to best available guidelines and literature are offered for further exploration. Improved clinician attention and more developed skill sets related to acute pain management could significantly benefit hospitalized patient outcomes and healthcare resource utilization.

Risk factors for and prognostic values of postoperative acute kidney injury after pancreaticoduodenectomy for pancreatic ductal adenocarcinoma: A retrospective, propensity score‐matched cohort study of 1312 patients

BACKGROUND

While an association between postoperative acute kidney injury (AKI) and adverse events exists, the incidence and impact of postoperative AKI after pancreaticoduodenectomy for pancreatic ductal adenocarcinoma remain unclear. This study aimed to diagnose AKI and investigate the risk factors for and prognostic value of postoperative AKI.

METHODS

Clinical characteristics of patients who underwent pancreaticoduodenectomy between 2013 and 2020 at a high-volume centre were collected retrospectively. The Kidney Disease Improving Global Outcomes criteria were used to diagnose AKI. A 1:2 propensity score matching (PSM) was used to minimise bias between the AKI and non-AKI groups. Short-term surgical and long-term survival outcomes were compared between groups. Multivariate logistic regression analysis assessed the independent risk factors for AKI development, major complications, and 30-day mortality.

RESULTS

Postoperative AKI occurred in 10.7% of 1312 patients. Total bilirubin level > 250 μmol/L (odds ratio [OR]: 3.24; p < 0.001), estimated glomerular filtration rate < 60 ml/min/1.73 m² (OR: 2.30; p = 0.048), and intraoperative estimated blood loss >1000 ml (OR: 2.96; p = 0.001) were independent risk factors for postoperative AKI. After PSM, higher incidences of major complications (p < 0.001) and 30-day mortality (p < 0.001) were observed in the AKI group than in the non-AKI group. There was no difference in long-term overall survival outcomes between both groups (p = 0.535). AKI was an independent predictor of major complications (OR: 3.06; p < 0.001) and 30-day mortality (OR: 2.87; p = 0.034).

CONCLUSIONS

Postoperative AKI is common after pancreaticoduodenectomy for pancreatic ductal adenocarcinoma and has a predictive effect on major complications and 30-day mortality. Therefore, prevention and proper management of postoperative AKI are required in clinical practice.

Association between intraoperative oliguria and postoperative acute kidney injury in non-cardiac surgical patients: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to evaluate the association between intraoperative oliguria and the risk of postoperative acute kidney injury (AKI) in patients undergoing non-cardiac surgery.

METHODS

The MEDLINE and EMBASE databases were searched up to August 2022 for studies in adult patients undergoing non-cardiac surgery, where the association between intraoperative urine output and the risk of postoperative AKI was assessed. Both randomised and non-randomised studies were eligible for inclusion. Study selection and risk of bias assessment were independently performed by two investigators. The risk of bias was evaluated using the Newcastle-Ottawa scale. We performed meta-analysis of the reported multivariate adjusted odds ratios for the association between intraoperative oliguria (defined as urine output < 0.5 mL/kg/hr) and the risk of postoperative AKI using the inverse-variance method with random effects models. We conducted sensitivity analyses using varying definitions of oliguria as well as by pooling unadjusted odds ratios to establish the robustness of the primary meta-analysis. We also conducted subgroup analyses according to surgery type and definition of AKI to explore potential sources of clinical or methodological heterogeneity.

RESULTS

Eleven studies (total 49,252 patients from 11 observational studies including a post hoc analysis of a randomised controlled trial) met the selection criteria. Seven of these studies contributed data from a total 17,148 patients to the primary meta-analysis. Intraoperative oliguria was associated with a significantly elevated risk of postoperative AKI (pooled adjusted odds ratio [OR] 1.74; 95% confidence interval [CI] 1.36-2.23, p < 0.0001, 8 studies). Sensitivity analyses supported the robustness of the primary meta-analysis. There was no evidence of any significant subgroup differences according to surgery type or definition of AKI.

CONCLUSIONS

This study demonstrated a significant association between intraoperative oliguria and the risk of postoperative AKI, regardless of the definitions of oliguria or AKI used. Further prospective and multi-centre studies using standardised definitions of intraoperative oliguria are required to define the thresholds of oliguria and establish strategies to minimise the risk of AKI.

Postoperative central venous pressure is associated with acute kidney injury in patients undergoing coronary artery bypass grafting

Objective

The present study aimed to investigate the association of postoperative central venous pressure (CVP) with acute kidney injury (AKI) and mortality in patients undergoing coronary artery bypass grafting (CABG).

Method

Patients who underwent CABG in the MIMIC-III database were included and divided into two groups according to the optimal cutoff value of CVP for postoperative AKI determined by the receiver operating characteristic (ROC) curves. The association of CVP with AKI and mortality was determined by multivariate regression models. A 1:1 propensity score matching (PSM) was performed to balance the influence of potential confounding factors.

Results

A total of 3,564 patients were included and divided into High CVP group (CVP ≥ 10.9 mmHg) and Low CVP group (CVP &lt; 10.9 mmHg) according to the ROC analysis. Patients in High CVP group presented with higher AKI incidence (420 (28.2%) vs. 349 (16.8), p &lt; 0.001), in-hospital mortality (28 (1.9%) vs. 6 (0.3%), p &lt; 0.001) and 4-year mortality (149 (15.8%) vs. 162 (11.1%), p = 0.001). Multivariate regression model showed that CVP was an independent risk factor for the postoperative AKI (OR: 1.071 (1.035, 1.109), p &lt; 0.001), in-hospital mortality (OR: 1.187 (1.026, 1.373), p = 0.021) and 4-year mortality (HR: 1.049 (1.003, 1.096), p = 0.035). A CVP above 10.9 mmHg was significantly associated with about 50% higher risk of AKI (OR: 1.499 (1.231, 1.824), p &lt; 0.001). After PSM, 1004 pairs of score-matched patients were generated. The multivariate logistic model showed that patients with CVP ≥ 10.9 mmHg had a significantly higher risk of AKI (OR: 1.600 (1.268, 2.018), p &lt; 0.001) in the PSM subset. However, CVP, as a continuous or a dichotomic variable, was not independently associated with in-hospital mortality (OR: 1.202 (0.882, 1.637), p = 0.244; OR: 2.636 (0.399, 17.410), p = 0.314) and 4-year mortality (HR: 1.030 (0.974, 1.090), p = 0.297; HR: 1.262 (0.911, 1.749), p = 0.162) in the PSM dataset.

Conclusion

A mean CVP ≥ 10.9 mmHg within the first 24 h after CABG was independently associated with a higher risk of postoperative AKI.

Hypotension Prediction Index Software to Prevent Intraoperative Hypotension during Major Non-Cardiac Surgery: Protocol for a European Multicenter Prospective Observational Registry (EU-HYPROTECT)

Background: Intraoperative hypotension is common in patients having non-cardiac surgery and associated with postoperative acute myocardial injury, acute kidney injury, and mortality. Avoiding intraoperative hypotension is a complex task for anesthesiologists. Using artificial intelligence to predict hypotension from clinical and hemodynamic data is an innovative and intriguing approach. The AcumenTM Hypotension Prediction Index (HPI) software (Edwards Lifesciences; Irvine, CA, USA) was developed using artificial intelligence—specifically machine learning—and predicts hypotension from blood pressure waveform features. We aimed to describe the incidence, duration, severity, and causes of intraoperative hypotension when using HPI monitoring in patients having elective major non-cardiac surgery. Methods: We built up a European, multicenter, prospective, observational registry including at least 700 evaluable patients from five European countries. The registry includes consenting adults (≥18 years) who were scheduled for elective major non-cardiac surgery under general anesthesia that was expected to last at least 120 min and in whom arterial catheter placement and HPI monitoring was planned. The major objectives are to quantify and characterize intraoperative hypotension (defined as a mean arterial pressure [MAP] < 65 mmHg) when using HPI monitoring. This includes the time-weighted average (TWA) MAP < 65 mmHg, area under a MAP of 65 mmHg, the number of episodes of a MAP < 65 mmHg, the proportion of patients with at least one episode (1 min or more) of a MAP < 65 mmHg, and the absolute maximum decrease below a MAP of 65 mmHg. In addition, we will assess causes of intraoperative hypotension and investigate associations between intraoperative hypotension and postoperative outcomes. Discussion: There are only sparse data on the effect of using HPI monitoring on intraoperative hypotension in patients having elective major non-cardiac surgery. Therefore, we built up a European, multicenter, prospective, observational registry to describe the incidence, duration, severity, and causes of intraoperative hypotension when using HPI monitoring in patients having elective major non-cardiac surgery.

Microvascular Changes of the Non-surgical Eye after General Anesthesia in Optical Coherence Tomography Angiography

Purpose: To investigate chorioretinal vascular changes in the non-surgical eyes of patients who underwent vitreoretinal surgery under general anesthesia using optical coherence tomography angiography (OCTA).Methods: Data from 40 patients who underwent retinal surgery were retrospectively analyzed. Ophthalmologic examinations (including OCTA) were performed in the morning before and after surgery. The presence of intraoperative hypotension (IOH; mean arterial pressure <70 mmHg) was determined based on medical records. The vessel density of superficial and deep retinal capillary plexus layers, choriocapillaris void features, and thickness of the choroid and retina were quantified after image processing. Associations between retinal OCTA parameters and anesthesia profiles were also assessed.Results: DCP vessel density was increased after general anesthesia (p < 0.05). Among the patients who experienced IOH, there was no statistical difference in chorioretinal vessel parameters before and after general anesthesia. Also, we did not observe a difference in chorioretinal vessel parameters after general anesthesia between healthy patients and patients with chronic disease, including hypertension and diabetes (p > 0.05). The duration of anesthesia and average size of the choriocapillaris void (p < 0.05, r = -0.32), and the intraoperative mean arterial pressure (MAP) fluctuation and DCP, showed statistically significant negative linear correlations (p < 0.05, r = -0.38). The choriocapillaris void size and intraoperative MAP fluctuation also displayed a significant negative correlation (p < 0.05, r = -0.37), while the average size signal void showed a weak positive linear correlation (p < 0.01, r = 0.41; and p < 0.01, r = 0.44, respectively).Conclusions: This is the first study to assess the effects of general anesthesia on chorioretinal vessels using OCTA. The Vessel density of the DCP was significantly increased in the non-surgical eye after total vitrectomy under general anesthesia. Furthermore, we found a correlation between MAP fluctuation and choriocapillaris void features. More studies are needed to confirm and expand on these observations.

Postoperative physiological parameters associated with severe acute kidney injury after pediatric heart transplant

BACKGROUND

The primary objective was to evaluate associations between perioperative clinical variables and postoperative hemodynamic indices after HT with the development of severe AKI. The secondary objective was to evaluate associations between UOP or creatinine as AKI indicators and morbidity after HT.

METHODS

Retrospective study of all patients who underwent HT 1/2016-11/2019 at a quaternary pediatric institution. Severe AKI was defined as KDIGO stage 2 or higher.

RESULTS

Of 94 HT patients, 73 met inclusion criteria; 45% of patients developed severe AKI. In univariate analysis, non-Hispanic Black race, preoperative AKI, longer CPB duration, lower weight, and peak lactate within 12 h post-HT were associated with severe AKI. CVP ≤12 h post-HT had a quadratic relationship, rather than linear, with severe AKI. PPV >18% was significantly associated with severe AKI but equated to noncontiguous 10 min of high variation over a 12-h period, and thus was deemed not clinically significant. In multivariate analysis, Black race, longer CPB duration, and higher CVP remained associated with severe AKI (c: 0.84, 95% CI 0.73-0.92). Severe AKI per creatinine, but not UOP criteria, was associated with longer duration of ventilation (p = .012) and longer intensive care unit length of stay (p = .003).

CONCLUSIONS

In pediatric HT patients, non-Hispanic Black race, longer CPB time, and higher postoperative CVP ≤12 h post-HT were associated with severe AKI. AKI based on creatinine, not UOP, was associated with postoperative HT morbidity.

Perioperative hypotension: causes and remedies

Background

Arterial hypotension is common in patients during surgery and those admitted to the intensive care unit (ICU) postoperatively. Perioperative arterial hypotension reportedly significantly affects surgical patients’ outcomes. Blood pressure level is the most crucial factor that influences organ perfusion. Hypoperfusion and organ dysfunction are correlated based on their severity associated with hypotension. As several factors can cause intraoperative hypotension, anesthetists must promptly identify the etiology for appropriate treatment and revert the patient’s hemodynamic profile.

Objectives

This review discusses the concept of perioperative hypotension, identifies its effects in clinical situations, and provides remedies and techniques to predict and avoid its significant consequences.

Conclusions

The primary determinant of organ perfusion is blood pressure. On the other hand, profound hypotension is common in surgical patients and is connected to hypoperfusion and organ failure. Currently, hypotension is addressed once low blood pressure levels are recorded. Early detection of oncoming hypotension or its clinical prediction is of paramount importance in allowing the clinician to treat hypotension and reduce the incidence and length of hypotensive episodes promptly and aggressively.

Perioperative acute kidney injury: impact and recent update

PURPOSE OF REVIEW

Acute kidney injury (AKI) is common in hospitalized patients and is a major risk factor for increased length of stay, morbidity, and mortality in postoperative patients. There are multiple barriers to reducing perioperative AKI - the etiology is multi-factorial and the diagnosis is fraught with issues. We review the recent literature on perioperative AKI and some considerations for anesthesiologists that examine the far-reaching effects of AKI on multiple organ systems.

RECENT FINDINGS

This review will discuss recent literature that addresses the epidemiology, use of novel biomarkers in risk stratification, and therapeutic modalities for AKI in burn, pediatrics, sepsis, trauma, cardiac, and liver disease, contrast-induced AKI, as well as the evidence assessing goal-directed fluid therapy.

SUMMARY

Recent studies address the use of risk stratification models and biomarkers, more sensitive than creatinine, in the preoperative identification of patients at risk for AKI. Although exciting, these scores and models need validation. There is a need for research assessing whether early AKI detection improves outcomes. Enhanced recovery after surgery utilizing goal-directed fluid therapy has not been shown to make an appreciable difference in the incidence of AKI. Reducing perioperative AKI requires a multi-pronged and possibly disease-specific approach.

Complications and Mortality after Surgeries in Patients with Prior Stroke Who Received General and Neuraxial Anesthesia: A Propensity-Score Matched Study

Patients who previously suffered a stroke have increased risks of mortality and complications after surgeries, but the optimal anesthesia method is not fully understood. We aimed to compare the outcomes after surgeries for stroke patients who received general anesthesia (GA) and neuraxial anesthesia (NA). Using health insurance research data, we identified 36,149 stroke patients who underwent surgeries from 1 January 2008 to 31 December 2013. For balancing baseline covariates, the propensity-score-matching procedure was used to select adequate surgical patients who received GA and NA at a case–control ratio of 1:1. Multiple logistic regressions were applied to calculate adjusted odds ratios (ORs) with 95% confidence intervals (CIs) for postoperative mortality and complications between surgical patients with prior stroke who received GA and NA. Among the 4903 matched pairs with prior stroke, patients with GA had higher risks of pneumonia (OR 2.00, 95% CI 1.62–2.46), pulmonary embolism (OR 3.30, 95% CI 1.07–10.2), acute renal failure (OR 3.51, 95% CI 1.13–2.10), intensive care unit stay (OR 3.74, 95% CI 3.17–4.41), and in-hospital mortality (OR 2.02, 95% CI 1.16–3.51) than those who received NA. Postoperative adverse events were associated with GA in patients aged more than 60 years and those who received digestive surgery (OR 3.11, 95% CI 2.08–4.66). We found that stroke patients undergoing GA had increased postoperative complications and mortality after surgery compared with those who received NA. However, these findings need more validation and evaluation by clinical trials.

Validation of the OAKS prognostic model for acute kidney injury after gastrointestinal surgery

Background

Postoperative acute kidney injury (AKI) is a common complication of major gastrointestinal surgery with an impact on short- and long-term survival. No validated system for risk stratification exists for this patient group. This study aimed to validate externally a prognostic model for AKI after major gastrointestinal surgery in two multicentre cohort studies.

Methods

The Outcomes After Kidney injury in Surgery (OAKS) prognostic model was developed to predict risk of AKI in the 7 days after surgery using six routine datapoints (age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker). Validation was performed within two independent cohorts: a prospective multicentre, international study (‘IMAGINE’) of patients undergoing elective colorectal surgery (2018); and a retrospective regional cohort study (‘Tayside’) in major abdominal surgery (2011–2015). Multivariable logistic regression was used to predict risk of AKI, with multiple imputation used to account for data missing at random. Prognostic accuracy was assessed for patients at high risk (greater than 20 per cent) of postoperative AKI.

Results

In the validation cohorts, 12.9 per cent of patients (661 of 5106) in IMAGINE and 14.7 per cent (106 of 719 patients) in Tayside developed 7-day postoperative AKI. Using the OAKS model, 558 patients (9.6 per cent) were classified as high risk. Less than 10 per cent of patients classified as low-risk developed AKI in either cohort (negative predictive value greater than 0.9). Upon external validation, the OAKS model retained an area under the receiver operating characteristic (AUC) curve of range 0.655–0.681 (Tayside 95 per cent c.i. 0.596 to 0.714; IMAGINE 95 per cent c.i. 0.659 to 0.703), sensitivity values range 0.323–0.352 (IMAGINE 95 per cent c.i. 0.281 to 0.368; Tayside 95 per cent c.i. 0.253 to 0.461), and specificity range 0.881–0.890 (Tayside 95 per cent c.i. 0.853 to 0.905; IMAGINE 95 per cent c.i. 0.881 to 0.899).

Conclusion

The OAKS prognostic model can identify patients who are not at high risk of postoperative AKI after gastrointestinal surgery with high specificity.

Presented to Association of Surgeons in Training (ASiT) International Conference 2018 (Edinburgh, UK), European Society of Coloproctology (ESCP) International Conference 2018 (Nice, France), SARS (Society of Academic and Research Surgery) 2020 (Virtual, UK).

Mortality and associated risk factors in perioperative acute kidney injury treated with continuous renal replacement therapy

Background

Perioperative acute kidney injury (AKI) is associated with multiple postoperative complications leading to prolonged hospital stay and higher costs. AKI requiring continuous renal replacement therapy (CRRT) after surgery has an incidence of 2–6% and mortality approximates 40–60%. Previous studies examining mortality in perioperative AKI patients managed with CRRT have concentrated on cardiac surgery patients and there are very limited data on broad surgical patient populations requiring CRRT. We examined long-term mortality and factors associated with poor outcome in a broad surgical population requiring CRRT for perioperative AKI during a 10-year period.

Methods

Surgical patients admitted to the intensive care unit (ICU) of academic tertiary hospital requiring CRRT between years 2010–2019 were included. CRRT was performed using regional citrate-calcium-anticoagulation. Extracted data included patient demographics, comorbidities, and clinical parameters at ICU admission and at the initiation of CRRT. Creatinine and estimated glomerular filtration rate (eGFR) were measured at 1 year after ICU admission.

Results

A total of 157 patients were included in the study. ICU mortality was 42.7%, 90-day mortality 58.0% and 1-year mortality 62.4%. Blood lactate at ICU admission and CRRT initiation were independently associated with mortality in the multivariate models. Patients with lactate > 4 mmol/l had higher mortality than patients with normal lactate (77% vs. 21%) (p < 0.001). Creatinine (p = 0.004) and eGFR (p < 0.001) remained significantly altered at 1 year of follow-up compared to baseline.

Conclusions

Patients undergoing surgery and requiring perioperative CRRT in the ICU have a high risk of mortality. Mortality appears to be independently associated with lactate levels.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13741-021-00227-y.

Association between intraoperative hyperglycemia and postoperative end-organ dysfunctions after cardiac surgery: a retrospective observational study

PURPOSE

Hyperglycemia has been associated with postoperative morbidity in patients who undergo cardiac surgery. However, it remains unclear whether the duration of hyperglycemia is as important as its magnitude in the development of postoperative end-organ dysfunction (PEOD). This retrospective study investigated the hypothesis that the intraoperative blood glucose (BG) exposure index (GE index), calculated by the product of the magnitude and duration of BG concentration ≥ 180 mg/dL, which is an integration of the severity and duration of hyperglycemia, is associated with the incidence of PEOD in patients undergoing cardiac surgery with cardiopulmonary bypass.

METHODS

The primary outcome in this study was PEOD within 72 h of surgery, which was defined as a composite of postoperative acute kidney injury, delirium, myocardial injury, and prolonged mechanical ventilation. The GE index (the magnitude of BG concentration deviation ≥ 180 mg/dL [Formula: see text] duration of BG concentration ≥ 180 mg/dL) of each patient was calculated based on the intraoperative BG concentration. The relationship between the GE index and the primary outcome was examined via logistic regression model with adjustment for potential confounders.

RESULTS

Within 72 h of surgery, 301 patients (54.5%) developed PEOD. PEOD was more common in patients with greater GE index quartiles (first versus third quartile; adjusted odds ratio, 5.65, 95% confidence interval (95% CI), 2.94-10.90; P < 0.001; first versus forth quartile, adjusted odds ratio, 20.80; 95% CI, 8.01-54.00; P < 0.001).

CONCLUSION

In patients undergoing cardiac surgery with cardiopulmonary bypass, the GE index was an independent predictor of PEOD.

High risk of acute kidney injury in Malawian trauma patients: a prospective observational cohort study

Background

Trauma is a common cause of acute kidney injury (AKI). Yet little data exist regarding trauma-related-AKI in low-resourced settings, where the majority of deaths from AKI and trauma occur. We prospectively evaluated epidemiology of AKI in hospitalized Malawian trauma patients.

Methods

AKI was defined by creatinine-only Kidney Disease Improving Global Outcomes (KDIGO) criteria. Those with AKI were followed up 3–6 months later to determine persistent kidney abnormalities. We calculated univariate statistics with Wilcoxon rank sum tests, Fisher’s exact, and chi-square tests to compare those with and without AKI. Multivariate log-risk regression modelling was used to determine risk ratios (RR) and 95% confidence intervals (CI) for AKI development.

Results

Of 223 participants, 14.4% (n = 32) developed AKI. Most patients were young (median age 32) males (n = 193, 86.5%) involved in road traffic injuries (n = 120, 53.8%). After adjusting for confounders, those with severe anemia during their admission were 1.4 times (RR 1.4, 95% CI 1.1–1.8) more likely to develop AKI than those without. Overall mortality was 7.6% (n = 17), and those who developed AKI were more likely to die than those who did not (18.8% vs 5.6%, p-value = 0.02). Almost half of those with AKI (n = 32) either died (n = 6) or had persistent kidney dysfunction at follow-up (n = 8).

Conclusion

In one of the few African studies on trauma-related AKI, we found a high incidence of AKI (14.4%) in Malawian trauma patients with associated poor outcomes. Given AKI’s association with increased mortality and potential ramifications on long-term morbidity, urgent attention is needed to improve AKI-related outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02564-y.

Acute Kidney Injury within an Enhanced Recovery after Surgery (ERAS) Program for Colorectal Surgery

BACKGROUND

We aimed to determine the prevalence, risk factors, and outcomes of acute kidney injury (AKI) within an ERAS program for colorectal surgery (CRS).

METHODS

This is a retrospective case-control study conducted from March 2016 to September 2018 at a single tertiary hospital in Singapore. All adult patients requiring CRS within our ERAS program were considered eligible. Exclusions were stage 5 chronic kidney disease or patients requiring a synchronous liver resection. The primary outcome was AKI as defined by the Kidney Disease Improving Global Outcomes (KDIGO) Acute Kidney Injury Work Group. Secondary outcomes included mortality, major complications, and hospital length of stay. Patient, surgical, and anaesthesia-related data were analysed to determine factors associated with AKI.

RESULTS

A total of 575 patients were eligible for the study. Twenty patients were excluded from the study leaving 555 patients for analysis. Mean age was 67.8 (SD 11.4) years. Seventy-four patients met the criteria for AKI (13.4%: stage 1-11.2%, stage 2-2.0%, stage 3-0.2%). One patient required renal replacement therapy (RRT). Patients with AKI had a longer length of stay (median [IQR], 11.0 [5.0-17.0] days vs 6.0 [4.0-8.0] days; P < .001), more major complications (OR, 6.55; 95% CI, 3.00-14.35, P < .001), and a trend towards higher mortality at one year (OR, 1.44; 95% CI 0.48-4.30; p = 0.511. After multivariable regression analysis, factors associated with AKI were preoperative creatinine (OR, 1.01 per 10 µmol/l; 95% CI, 1.03-1.22; P = 0.01), robotic surgery vs open surgery (OR, 0.15; 95% CI, 0.06-0.39; P < 0.001), anaesthesia duration (OR, 1.38 per hour; 95% CI, 1.22-1.55; P < 0.001), and major complications (OR, 5.55; 95% CI, 2.63-11.70; P < 0.001).

CONCLUSIONS

Within the present cohort, the implementation of an ERAS program for CRS was associated with a low prevalence of moderate to severe AKI despite a balanced intravenous fluid regimen. Patients having open surgery, longer procedures, and major complications are at increased risk of AKI.

Acute kidney injury detection using refined and physiological-feature augmented urine output

Acute kidney injury (AKI) is common in the intensive care unit, where it is associated with increased mortality. AKI is often defined using creatinine and urine output criteria. The creatinine-based definition is more reliable but less expedient, whereas the urine output based definition is rapid but less reliable. Our goal is to examine the urine output criterion and augment it with physiological features for better agreement with creatinine-based definitions of AKI. The objectives are threefold: (1) to characterize the baseline agreement of urine output and creatinine definitions of AKI; (2) to refine the urine output criteria to identify the thresholds that best agree with the creatinine-based definition; and (3) to build generalized estimating equation (GEE) and generalized linear mixed-effects (GLME) models with static and time-varying features to improve the accuracy of a near-real-time marker for AKI. We performed a retrospective observational study using data from two independent critical care databases, MIMIC-III and eICU, for critically ill patients who developed AKI in intensive care units. We found that the conventional urine output criterion (6 hr, 0.5 ml/kg/h) has specificity and sensitivity of 0.49 and 0.54 for MIMIC-III database; and specificity and sensitivity of 0.38 and 0.56 for eICU. Secondly, urine output thresholds of 12 hours and 0.6 ml/kg/h have specificity and sensitivity of 0.58 and 0.48 for MIMIC-III; and urine output thresholds of 10 hours and 0.6 ml/kg/h have specificity and sensitivity of 0.49 and 0.48 for eICU. Thirdly, the GEE model of four hours duration augmented with static and time-varying features can achieve a specificity and sensitivity of 0.66 and 0.61 for MIMIC-III; and specificity and sensitivity of 0.66 and 0.64 for eICU. The GLME model of four hours duration augmented with static and time-varying features can achieve a specificity and sensitivity of 0.71 and 0.55 for MIMIC-III; and specificity and sensitivity of 0.66 and 0.60 for eICU. The GEE model has greater performance than the GLME model, however, the GLME model is more reflective of the variables as fixed effects or random effects. The significant improvement in performance, relative to current definitions, when augmenting with patient features, suggest the need of incorporating these features when detecting disease onset and modeling at window-level rather than patient-level.

Perioperative acute kidney injury and urine output in lower limb arthroplasties

BACKGROUND

This study aimed to evaluate the occurrence and perioperative risk factors of acute kidney injury (AKI) in primary elective hip and knee and emergency hip arthroplasty patients. We also aimed to assess the effect of urine output (UOP) as a diagnostic criterion in addition to serum creatinine (sCr) levels. We hypothesized that emergency arthroplasties are prone to AKI and that UOP is an underrated marker of AKI.

METHODS

This retrospective, register-based study assessed 731 patients who underwent primary elective knee or hip arthroplasty and 170 patients who underwent emergency hip arthroplasty at Oulu University Hospital, Finland, between January 2016 and February 2017.

RESULTS

Of the elective patients, 18 (2.5%) developed AKI. The 1-year mortality rate was 1.5% in elective patients without AKI and 11.1% in those with AKI (P = .038). Of the emergency patients, 24 (14.1%) developed AKI. The mortality rate was 16.4% and 37.5% in emergency patients without and with AKI, respectively (P = .024). In an AKI subgroup analysis of the combined elective and emergency patients, the mortality rate was 31.3% (n = 5) in the sCr group (n = 16), 23.5% (n = 4) in the UOP group (n = 17), and 22.2% (n = 2) in AKI patients who met both the sCr and UOP criteria (n = 9).

CONCLUSION

Emergency hip arthroplasty is associated with an increased risk of AKI. Since AKI increases mortality in both elective and emergency arthroplasty, perioperative oliguria should also be considered as a diagnostic criterion for AKI. Focusing solely on sCr may overlook many cases of AKI.