Restrictive versus Liberal Fluid Therapy for Major Abdominal Surgery

Progression of chronic kidney disease after non-cardiac surgery: A retrospective cohort study

BACKGROUND

Chronic-kidney-disease (CKD) is prevalent among adults undergoing noncardiac surgery, with surgery-related factors potentially worsening CKD or triggering acute kidney injury (AKI). We hypothesized that CKD patients experience more kidney function decline within one to two years post-surgery than those without CKD, particularly if they develop AKI.

METHODS

We conducted a single-center retrospective cohort study, including noncardiac surgery patients with documented creatinine preoperative and between 1 and 2 years after surgery. The primary outcome was long-term course of kidney function, defined as the change in estimated glomerular filtration rate (eGFR) in mL/min/1.73m2.

RESULTS

Of 58,175 included cases, 17 % had preoperative CKD. Mean eGFR changed from 90.1 ± 16.7 to 92.0 ± 18.8 in non-CKD patients and from 45.6 ± 11.9 to 55.6 ± 20.1 in patients with CKD, with an estimated difference in means of 8.9 (95 % CI: 8.5, 9.3; P < 0.0001). There was a significant interaction between CKD-dependent eGFR change from baseline to follow-up and postoperative AKI (P = 0.001). For cases with preoperative CKD, eGFR increase from baseline to follow-up was 11.7 ± 18.0 with no AKI, 7.7 ± 17.9 with AKI stage 1, 2.4 ± 15.0 with AKI stage 2, and 7.3 ± 25.8 with AKI stage 3. For non-CKD patients, eGFR increased from baseline by 2.3 ± 13.7 with no AKI but decreased by 5.5 ± 19.0 with AKI stage 1, 7.7 ± 21.8 with AKI stage 2, and 9.3 ± 21.3 with AKI stage 3.

CONCLUSIONS

Contrary to expectations, patients with preoperative CKD experienced a significant improvement in eGFR postoperatively. Patients without CKD exhibited minimal change. Postoperative AKI negated the eGFR improvement in CKD patients and exacerbated the decline in non-CKD patients.

A review of gut failure as a cause and consequence of critical illness

In critical illness, all elements of gut function are perturbed. Dysbiosis develops as the gut microbial community loses taxonomic diversity and new virulence factors appear. Intestinal permeability increases, allowing for translocation of bacteria and/or bacterial products. Epithelial function is altered at a cellular level and homeostasis of the epithelial monolayer is compromised by increased intestinal epithelial cell death and decreased proliferation. Gut immunity is impaired with simultaneous activation of maladaptive pro- and anti-inflammatory signals leading to both tissue damage and susceptibility to infections. Additionally, splanchnic vasoconstriction leads to decreased blood flow with local ischemic changes. Together, these interrelated elements of gastrointestinal dysfunction drive and then perpetuate multi-organ dysfunction syndrome. Despite the clear importance of maintaining gut homeostasis, there are very few reliable measures of gut function in critical illness. Further, while multiple therapeutic strategies have been proposed, most have not been shown to conclusively demonstrate benefit, and care is still largely supportive. The key role of the gut in critical illness was the subject of the tenth Perioperative Quality Initiative meeting, a conference to summarize the current state of the literature and identify key knowledge gaps for future study. This review is the product of that conference.

Development and Validation of a Risk Predictive Model for Adverse Postoperative Health Status of Elderly Patients Undergoing Major Abdominal Surgery Using Lasso-Logistic Regression

Background

The postoperative health status of elderly patients has a substantial impact on both the individuals themselves and their families, and this impact became more pronounced with advancing age. The aim of this study was to identify risk factors that can predict the health status of patients aged 80 and over after major abdominal surgery and to establish a nomogram model.

Methods

We conducted a retrospective study of elderly patients (aged 80+) who underwent major abdominal surgery at the First Affiliated Hospital of Soochow University from January 2017 to June 2023. Least absolute shrinkage and selection operator (lasso) regression analysis was employed to identify potential perioperative factors associated with the patients' health status one year post-surgery. Subsequently, logistic regression was then used to refine these factors for the model. The nomogram's performance was assessed through discriminative ability, calibration, and clinical utility in both training and validation datasets.

Results

In total, 576 and 145 individuals were allocated to the training and validation sets, respectively. Lasso regression first identified 10 variables as candidate risk factors. After further screening through univariate and multivariate logistic regression, it was confirmed that seven variables, including tumor, operative duration, left ventricular ejection fraction (LVEF), blood transfusion, direct bilirubin, erythrocyte, and self-care, were included in the final nomogram model. The Hosmer-Lemeshow test, with a P-value of 0.835, indicates that the model was well-fitted. The area under the Receiver Operating Characteristic curve (ROC-AUC) for the model on the training set was 0.81 (95% CI 0.764-0.855), and for the validation set, it was 0.83 (95% CI 0.751-0.91). Additionally, the calibration curves and decision curve analyses in both the training and validation sets demonstrated the accuracy and clinical applicability of the predictive model.

Conclusion

The nomogram has a good predictive ability for the health status of older patients aged 80 years and above after abdominal surgery for one year, which can help clinical doctors develop better treatment plans.

Simplified Enhanced Recovery After Surgery Intraoperative Fluid Management

INTRODUCTION

This study evaluates the efficacy of a simplified intraoperative fluid administration metric within enhanced recovery after surgery (ERAS) pathways. The objective is to optimize fluid management to improve postoperative outcomes, specifically kidney function.

METHODS

A retrospective evaluation was conducted at Massachusetts General Hospital on adult patients who underwent open hysterectomy, colectomy, and gastrectomy as part of ERAS pathways. The proposed fluid metric, set at 500 mL/h, was assessed against traditional methods of fluid administration. Data on serum creatinine (Cr) changes as defined as the difference between the baseline value and the maximum value within 1 week of surgery were collected, and compliance with the metric was monitored. Analysis involved Wilcoxon rank-sum test, Kruskal-Wallis test, and quantile regression.

RESULTS

The study included 1028 patients. Regression analysis indicated that compared to patients who received the optimal fluid quantity, those receiving below the optimal range showed an absolute increase in median Cr levels of 0.03 mg/dl (95% confidence interval = -0.005, 0.05) while those who received above the optimal range demonstrated an absolute increase in median Cr level of 0.01 (95% confidence interval = -0.03, 0.05).

CONCLUSIONS

The new fluid metric demonstrated a balanced approach to fluid administration, reducing the risk of overhydration while maintaining sufficient hydration. Additionally, implementing a simplified fluid metric of 500 mL/h in ERAS pathways is effective in improving postoperative kidney function. This approach facilitates adherence to fluid guidelines and can be applied across various healthcare settings. This metric serves as a practical, evidence-based pathway for fluid administration for most patients undergoing most ERAS procedures.

Perioperative Fluid Management

The medical complexity of the geriatric patients has been steadily rising. Still, as outcomes of surgical procedures in the older adults are improving, centers are pushing boundaries. There is also a growing appreciation of the importance of perioperative fluid management on postoperative outcomes, especially in the older adults. Optimal fluid management in this cohort is challenging due to the combination of age-related physiological changes in organ function, increased comorbid burden, and larger fluid shifts during more complex surgical procedures. The current state-of-the-art approach to fluid management in the perioperative period is outlined.

Postoperative oliguria after intermediate and high-risk surgeries in critical care, A cohort analysis

INTRODUCTION

Oliguria is commonly used as a cutoff for acute kidney injury (AKI), however, a decrease in urine output is common during surgery and may represent an adaptative response in the perioperative setting rather than a reduction in glomerular filtration rate, leading to a possible overestimation of postoperative AKI incidence. Although this dilemma has been addressed in the intraoperative scenario, the incidence and impact of oliguria in the first postoperative day represents a gap in the current literature. Our main goal is to describe the incidence, risk factors and clinical outcomes related to postoperative oliguria.

METHODS

This was a retrospective cohort conducted in four intensive care units (ICUs) across two private Brazilian hospitals, analyzing patients admitted after intermediate and high-risk surgeries between January 1, 2018 and December 31, 2022.

RESULTS

1476 patients were included in the final analysis. Overall, 656 (44,5 %) were males, and the median age was 61,7 years. Oliguria was identified in 508 (34,4 %) patients within the first 24 h after surgery. Vasopressor requirement at admission, non-elective procedures, male sex and baseline serum creatinine were higher among oliguric patients. Among oliguric patients, age and basal serum creatine were higher among those who experienced AKI. Although only 12,4 % of oliguric patients developed AKI according to serum creatinine criterion, this incidence was significantly higher than in non-oliguric group (3,6 %), RR 3.42, IC 95 % 2.3-5.1 (p < 0.01). AKI recovery, RRT, ICU and hospital free days, and mortality were similar between the groups.

CONCLUSIONS

Postoperative oliguria is common after intermediate and high-risk surgical procedures and increases the risk of AKI. However, oliguria was largely unrelated with kidney disfunction measured by serum creatinine (87,6 %), raising doubts on whether diuresis overestimates AKI incidence in the postoperative setting.

Nonsteroidal anti-inflammatory drugs in the perioperative period: current controversies and concerns

Nonsteroidal anti-inflammatory drugs (NSAIDs) and cyclooxygenase (COX)-2-specific inhibitors provide significant analgesic and opioid-sparing benefits. However, these analgesics are commonly avoided owing to concerns of potential adverse effects. The evidence for NSAID-related adverse effects is conflicting and of poor quality, and these analgesics are safer than what has been implied. Thus, it is imperative that NSAIDs or COX-2-specific inhibitors are administered routinely unless there are well-founded contraindications.

Effect of restrictive versus liberal fluid therapy for laparoscopic gastric surgery on postoperative complications: a randomized controlled trial

PURPOSE

Currently, laparoscopic surgery is a standard technique in the field of abdominal surgery. However, the most adequate fluid regimen during laparoscopic surgery remains unclear. The aim of this trial is to compare a restricted fluid therapy with a liberal fluid therapy for laparoscopic abdominal surgery. Our hypothesis was that restrictive fluid therapy would reduce postoperative complications better than liberal fluid therapy.

METHOD

In this randomized controlled trial, patients scheduled for laparoscopic gastric surgery were randomized to either the liberal group (receiving 7-10 ml/kg/h of crystalloid) or the restrictive group (receiving 1-2 ml/kg/h of crystalloid) for each stratum of surgical procedure from April 2017 to March 2019. For both groups, blood loss was replaced by an equal volume of hydroxyethyl starch. The primary endpoint was postoperative complications up to 30 days after surgery, according to the Clavien-Dindo classification.

RESULTS

We enrolled 148 patients, and 140 of these were randomized to either the liberal or the restrictive group after exclusion. As a result, 69 cases were included in the liberal group for analysis, and 67 patients composed the restrictive group. Median fluid administration for the liberal and restrictive groups was 2950 ml and 800 ml, respectively. As well, overall complications in the liberal and restrictive groups were 27.5% and 19.4%, respectively (risk ratio 0.71, 95% confidence interval 0.38-1.31, p value = 0.264).

CONCLUSION

Restricted fluid therapy and liberal fluid therapy did not show any statistical differences in postoperative complications after laparoscopic gastric surgery.

Ten tips on how to reduce iatrogenic acute kidney injury

Acute kidney injury (AKI) is a heterogeneous syndrome associated with worse clinical outcomes. Many treatments and procedures in the hospitalized patient can cause AKI. Hence, the incidence of iatrogenic AKI is expected to be high. In this review we provide 10 practical tips on how to manage and avoid iatrogenic AKI. We cover identification of vulnerable patients by epidemiological data and recommend the usage of renal stress biomarkers for enhanced screening of high-risk patients. Further, we discuss the limitations of current diagnostic criteria of AKI. As a key takeaway, we suggest the implementation of novel damage biomarkers in clinical routine to identify subclinical AKI, which may guide novel clinical management pathways. To further reduce the incidence of procedure-associated AKI, we advocate certain preventive measures. Foremost, this includes improvement of hemodynamics and avoidance of nephrotoxic drugs whenever possible. In cases of severe AKI, we provide tips for the implementation and management of renal replacement therapy and highlight the advantages of regional citrate anticoagulation. The furosemide stress test might be of help in recognizing patients who will require renal replacement therapy. Finally, we discuss the progression of AKI to acute and chronic kidney disease and the management of this growing issue. Both can develop after episodes of AKI and have major implications for patient co-morbidity and long-term renal and non-renal outcomes. Hence, we recommend long-term monitoring of kidney parameters after AKI.

Impact of intraoperative hypotension during laparoscopic liver resection on postoperative complications including acute kidney injury

BACKGROUND

Postoperative acute kidney injury is associated with an increase in hospital length of stay and mortality. Intraoperative hemodynamics and fluid management may contribute to acute kidney injury. The aim of this study is to evaluate the association between intraoperative duration of hypotension with adverse events after laparoscopic liver resection.

METHODS

A prospective cohort including adult patients undergoing laparoscopic liver resection between January 2010 and June 2022. Cumulative time below mean arterial blood pressure thresholds and association with major adverse events composing of postoperative acute kidney injury (≤2 days) and complications (Dindo-Clavien ≥3a) ≤30 days were assessed.

RESULTS

In 360 patients, the median age was 61 years, 206 (57%) were male, median body mass index was 26.3, and 129 (36%) patients had hepatocellular carcinoma. Acute kidney injury was recorded in 3 (0.8%) patients as stage 1, 6 (1.7%) patients as stage 2, and 7 (1.9%) patients as stage 3. Major adverse events occurred in 31 (8.6%) patients, and the median estimated blood loss was 200 mL. On continuous analysis, a threshold <60 mmHg at ≥15 minutes was found for major adverse events. The mean arterial blood pressure <55 mmHg for ≥20 minutes was associated with an increased risk of major adverse events (odds ratio 7.72; P < .001). In patients with >15 minutes of mean arterial blood pressure <60 mmHg, higher intravenous volume was associated with increase in major adverse events (P = .045), whereas adjusted intravenous volume was not associated with major adverse events (P = .657), acute kidney injury (P = .681), or blood loss (P = .875).

CONCLUSIONS

Laparoscopic liver resection is a safe procedure with a low risk of acute kidney injury. After ≥15 minutes at mean arterial blood pressure <60 mmHg, the risk of major adverse events increases. Greater intravenous fluid infusion volume was associated with an observed risk for major adverse events, suggesting that mean arterial blood pressure should be managed by vasoactive agents.

Understanding fluid dynamics and renal perfusion in acute kidney injury management

Acute kidney injury (AKI) is associated with an increased risk of morbidity, mortality, and healthcare expenditure, posing a major challenge in clinical practice, and affecting about 50% of patients in the intensive care unit (ICU), particularly the elderly and those with pre-existing chronic comorbidities. In health, intra-renal blood flow is maintained and auto-regulated within a wide range of renal perfusion pressures (60-100 mmHg), mediated predominantly through changes in pre-glomerular vascular tone of the afferent arteriole in response to changes of the intratubular NaCl concentration, i.e. tubuloglomerular feedback. Several neurohormonal processes contribute to regulation of the renal microcirculation, including the sympathetic nervous system, vasodilators such as nitric oxide and prostaglandin E2, and vasoconstrictors such as endothelin, angiotensin II and adenosine. The most common risk factors for AKI include volume depletion, haemodynamic instability, inflammation, nephrotoxic exposure and mitochondrial dysfunction. Fluid management is an essential component of AKI prevention and management. While traditional approaches emphasize fluid resuscitation to ensure renal perfusion, recent evidence urges caution against excessive fluid administration, given AKI patients' susceptibility to volume overload. This review examines the main characteristics of AKI in ICU patients and provides guidance on fluid management, use of biomarkers, and pharmacological strategies.

Association between intraoperative fluid management and postoperative outcomes in living kidney donors: a retrospective cohort study

Optimal fluid strategy for laparoscopic donor nephrectomy (LDN) remains unclear. LDN has been a domain for liberal fluid management to ensure graft perfusion, but this can result in adverse outcomes due to fluid overload. We compared postoperative outcome of living kidney donors according to the intraoperative fluid management. Five hundred and five LDNs performed over a six-year period at a tertiary hospital were analyzed. Donors were divided into tertiles according to intraoperative crystalloid infusion rate (ml/kg/hr), and associations between the tertile and outcomes were investigated with inverse probability of treatment weighting with entropy balancing. Primary outcome was maximal rise of serum creatinine (sCr). Secondary outcomes were sCr rise meeting Acute Kidney Injury (AKI) criteria, time to reach minimal sCr, and length of hospital stay. The following covariates were used: age, sex, body weight, height, diabetes mellitus, hypertension, preoperative estimated glomerular filtration rate, operation duration, surgeon, nephrectomy side, and estimated blood loss. Median intraoperative crystalloid infusion rate was 3.5, 4.6, and 6.0 ml/kg/hr in the first, second, and third tertile, respectively (group 1, 2, and 3). Maximal rise of sCr did not differ between groups (P = 0.274). Twofold increase in sCr (equivalent to stage 2 AKI) during the first week and prolonged hospitalization were most frequent in group 1 [7.8 vs. 1.1 vs. 1.5%, P = 0.004; 7.9 vs. 3.1 vs. 0.7%, P = 0.003]. Time to reach minimal sCr was longest in group 1. No differences were found in recipient early renal function. Hypovolemia is associated with poor postoperative outcomes after LDN. Efforts to find the optimal fluid management should be continued.

Acute kidney injury

Acute kidney injury (AKI) is a common, heterogeneous, multifactorial condition, which is part of the overarching syndrome of acute kidney diseases and disorders. This condition's incidence highest in low-income and middle-income countries. In the short term, AKI is associated with increased mortality, an increased risk of complications, extended stays in hospital, and high health-care costs. Long-term complications include chronic kidney disease, kidney failure, cardiovascular morbidity, and an increased risk of death. Several strategies are available to prevent and treat AKI in specific clinical contexts. Otherwise, AKI care is primarily supportive, focused on treatment of the underlying cause, prevention of further injury, management of complications, and short-term renal replacement therapy in case of refractory complications. Evidence confirming that AKI subphenotyping is necessary to identify precision-oriented interventions is growing. Long-term follow-up of individuals recovered from AKI is recommended but the most effective models of care remain unclear.

Prevalence and Risk Factors of Acute Kidney Injury After Colorectal Cancer Surgery

PURPOSE

Acute kidney injury is a sentinel event affecting colorectal cancer patients either as a consequence of surgery or systemic chemotherapy. It is highly correlated with both short and long-term adverse outcomes. This work aimed to study the prevalence, risk factors, and impact on survival of postoperative (PO-AKI) and post-chemotherapy (PC-AKI) after colorectal cancer (CRC) surgery in Egyptian patients.

METHODS

Data of the patients with CRC who underwent surgery over the previous 5 years was retrieved from an internet-based medical system. The incidence of PO-AKI and PC-AKI was calculated, the rate and time to resolution of PO-AKI were recorded, and the possible predictors of AKI were assessed using univariate and multivariate analysis; also, the impact of AKI on patients' survival was tested using survival curves.

RESULTS

Five hundred sixty-one cases fulfilled the inclusion criteria and were included in the study. PO-AKI was detected in 10.5% of the patients. Significant risk factors included intraoperative hypotension, sepsis, hypoalbuminemia, amount of intraoperative bleeding, neoadjuvant therapy, and preoperative chronic kidney disease (CKD). However, only neoadjuvant treatment (hazard ratio (HR) 2.2) and CKD (HR 3.3) maintained significant risk in the multivariate analysis. PC-AKI was observed in 18.7% of the patients treated. Significant risk factors were previous CKD and the chemotherapy type, mainly affecting those who received Irinotecan-based therapy. The hazard ratio was 8.5 and 2.4 respectively, in multivariate analysis. The overall survival was significantly worse in those who developed PO- or PC-AKI (p < 0.001).

CONCLUSION

AKI affects more than 25% of CRC patients after surgery and/or chemotherapy. Modifiable risk factors include preoperative hypoalbuminemia, intraoperative bleeding, and/or intraoperative hypotension. While, the more important risk factors were non-modifiable including CKD, neoadjuvant therapy, and Irinotecan-containing regimens. Most kidney injuries are stage I; however, they are associated with shorter overall survival.

How Would We Prevent Our Own Acute Kidney Injury After Cardiac Surgery?

Acute Kidney Injury (AKI) is a common complication after cardiac surgery affecting up to 40% leading to increased morbidity and mortality. To date, there is no specific treatment for AKI, thus, clinical research efforts are focused on preventive measures. The only pharmacological preventive intervention that has demonstrated a beneficial effect on AKI in a high-quality, double-blind, randomized controlled trial is a short perioperative infusion of a balanced mixture of amino acid solution. Amino acid infusion reduced the incidence of AKI by recruiting renal functional reserve and, therefore, increasing the glomerular filtration rate. The beneficial effect of amino acids was further confirmed for severe AKI and applied to patients with chronic kidney disease. Among non-pharmacological interventions, international guidelines on AKI suggest the implementation of a bundle of good clinical practice measures to reduce the incidence of perioperative AKI or to improve renal function whenever AKI occurs. The Kidney Disease Improving Global Outcomes (KDIGO) bundle includes the discontinuation of nephrotoxic agents, volume status and perfusion pressure assessment, renal functional hemodynamic monitoring, serum creatine, and urine output monitoring, and the avoidance of hyperglycemia and radiocontrast procedures. However, pooled data from a meta-analysis did not find a significant reduction in AKI. The aim of this review is to delineate the most appropriate evidence-based approach to prevent AKI in cardiac surgery patients.

Heart failure diagnostic accuracy, intraoperative fluid management, and postoperative acute kidney injury: a single-centre prospective observational study

BACKGROUND

The accurate diagnosis of heart failure (HF) before major noncardiac surgery is frequently challenging. The impact of diagnostic accuracy for HF on intraoperative practice patterns and clinical outcomes remains unknown.

METHODS

We performed an observational study of adult patients undergoing major noncardiac surgery at an academic hospital from 2015 to 2019. A preoperative clinical diagnosis of HF was defined by keywords in the preoperative assessment or a diagnosis code. Medical records of patients with and without HF clinical diagnoses were reviewed by a multispecialty panel of physician experts to develop an adjudicated HF reference standard. The exposure of interest was an adjudicated diagnosis of heart failure. The primary outcome was volume of intraoperative fluid administered. The secondary outcome was postoperative acute kidney injury (AKI).

RESULTS

From 40 659 surgeries, a stratified subsample of 1018 patients were reviewed by a physician panel. Among patients with adjudicated diagnoses of HF, those without a clinical diagnosis (false negatives) more commonly had preserved left ventricular ejection fractions and fewer comorbidities. Compared with false negatives, an accurate diagnosis of HF (true positives) was associated with 470 ml (95% confidence interval: 120-830; P=0.009) lower intraoperative fluid administration and lower risk of AKI (adjusted odds ratio:0.39, 95% confidence interval 0.18-0.89). For patients without adjudicated diagnoses of HF, non-HF was not associated with differences in either fluids administered or AKI.

CONCLUSIONS

An accurate preoperative diagnosis of heart failure before noncardiac surgery is associated with reduced intraoperative fluid administration and less acute kidney injury. Targeted efforts to improve preoperative diagnostic accuracy for heart failure may improve perioperative outcomes.

Perioperative Acute Kidney Injury: Diagnosis, Prediction, Prevention, and Treatment

In this review, the authors define acute kidney injury in the perioperative setting, describe the epidemiologic burden, discuss procedure-specific risk factors, detail principles of management, and highlight areas of ongoing controversy and research.

Relevance of perioperative fluid dynamics in liver transplantation to acute kidney injury and patient outcomes: a cross-sectional survey

Background

Fluid administration is a critical component of perioperative management for liver transplant recipients, and excessive fluid infusion can lead to acute kidney injury (AKI) and poor patient outcomes.

Method

We conducted a cross-sectional survey on the fluid intake and output of adult liver transplant recipients over a 7-day period. The patients were divided into AKI and non-AKI groups. Multivariate logistic regression analyses were used to evaluate the association between fluid balance (FB) and AKI. A Kaplan-Meier survival analysis was performed to determine the survival of the recipient survival at 180 days.

Results

A total of 210 liver transplant recipients were included. The peak FB occurred on the second day after transplantation, which was higher than on the seventh day (0.3 [IQR, -0.2 to 0.8] L vs. -0.4 [IQR, -1.0 to 0.3] L, p < 0.001). The highest incidence of AKI was observed on the second day after transplantation and the lowest on the seventh day (52.4% vs. 15.4%, p < 0.001). Multivariate analysis showed that a cumulative FB > 1 L within the first 2 days postoperatively was an independent risk factor for AKI on the second day after liver transplantation (LT) (OR = 2.66, 95% CI, 1.31-5.41, p = 0.007). Survival analysis indicated significant differences in 180-day survival rates among patients with different grades of AKI [94.0% (grade 1) vs. 91.4% (grade 2) vs. 77.8% (grade 3), χ 2  = 12.93, p < 0.001].

Conclusion

There is a significant correlation between post-LT AKI and perioperative FB. Cumulative FB > 1 L in the first 2 days postoperatively is an independent risk factor for AKI on the second day after LT. AKI after LT is associated with a lower 180-day survival rate in patients.

Goal-directed fluid therapy on the postoperative complications of laparoscopic hepatobiliary or pancreatic surgery: An interventional comparative study

BACKGROUND

Intraoperative fluid balance significantly affects patients' outcomes. Goal-directed fluid therapy (GDFT) has reduced the incidence of major postoperative complications by 20% for 30 days after open abdominal surgery. Little is known about GDFT during laparoscopic surgery.

AIM

We investigated whether GDFT affects the postoperative outcomes in laparoscopic hepatobiliary or pancreatic surgery compared with conventional fluid management.

METHODS

This interventional comparative study with a historical control group was performed in the tertiary care center. Patients were allocated to one of two groups. The GDFT (n = 147) was recruited prospectively and the conventional group (n = 228) retrospectively. In the GDFT group, fluid management was guided by the stroke volume (SV) and cardiac index (CI), whereas it had been performed based on vital signs in the conventional group. Propensity score (PS) matching was performed to reduce selection bias (n = 147 in each group). Postoperative complications were evaluated as primary outcome measures.

RESULTS

The amount of crystalloid used during surgery was less in the GDFT group than in the conventional group (5.1 ± 1.1 vs 6.3 ± 1.8 ml/kg/h, respectively; P <0.001), whereas the amount of colloid was comparable between the two groups. The overall proportion of patients who experienced any adverse events was 57.8% in the GDFT group and 70.1% in the conventional group (P = 0.038), of which the occurrence of pleural effusion was significantly lower in the GDFT group than in the conventional group (9.5% vs. 19.7%; P = 0.024). During the postoperative period, the proportion of patients admitted to the intensive care unit (ICU) was lower in the GDFT group than that in the conventional group after PS matching (4.1% vs 10.2%; P = 0.049).

CONCLUSIONS

GDFT based on SV and CI resulted in a lower net fluid balance than conventional fluid therapy. The overall complication rate in laparoscopic hepatobiliary or pancreatic surgery decreased after GDFT, and the frequency of pleural effusion was the most affected.

The Association Between Fluid Management and Intraoperative Blood Pressure and Patients' Outcome After Complex Spine Surgeries

BACKGROUND

Both intraoperative hypotension and excessive fluid administration can lead to detrimental perioperative complications. However, how much fluid is considered excessive and how is intraoperative hypotension related to major postoperative complications?

METHODS

We conducted a single-center retrospective cohort study in 6243 patients undergoing complex spine surgery at the Cleveland Clinic Foundation between 2012 and 2022 and studied the relationship between intraoperative net fluid administration and intraoperative hypotension with major postoperative complications. The primary outcome was a collapsed composite of postoperative complications including acute kidney injury (AKI), myocardial infarction (MI), stroke, and intensive care unit (ICU) admissions. Secondary outcomes were in-hospital postoperative pulmonary complications, surgical site infections (SSI), and mortality.

RESULTS

The study consisted of 6998 complex spinal surgery cases from 6243 patients. The median net fluid administration was 2100 mL (Interquartile range: 1450 to 3020 mL), and we found a change point in net fluid administration of 1865 mL (95% Confidence Interval: 1228 to 4710 mL). The odds ratio of developing postoperative complications for every 500 mL increase in net fluid administration was 1.16 (95% confidence interval [CI], 1.11-1.21; P < .0001) above and 0.87 (95% CI, 0.77-0.98; P = .026) below the change point. The odds ratio of developing postoperative pulmonary complications was 1.12 (95% CI, 1.07-1.18; P < .0001) for every 500 mL increase in net fluid administration.Intraoperative hypotension was detected in 2052 complex spine surgeries (29%). The odds ratio of developing any postoperative complication was 1.57 (95% CI, 1.37-1.80; P < .0001) and 1.30 (95% CI, 1.04-1.61; P = .019) for postoperative pulmonary complications.

CONCLUSIONS

We discovered a change point in net fluid administration of 1,865mL. Above this change point, higher net fluid administration is associated with increased odds of developing postoperative complications. Intraoperative hypotension in complex spine surgeries was associated with increased postoperative complications.

Cardiac output-guided haemodynamic therapy for patients undergoing major gastrointestinal surgery: OPTIMISE II randomised clinical trial

OBJECTIVES

To evaluate the clinical effectiveness and safety of a perioperative algorithm for cardiac output-guided haemodynamic therapy in patients undergoing major gastrointestinal surgery.

DESIGN

Multicentre randomised controlled trial.

SETTING

Surgical services of 55 hospitals worldwide.

PARTICIPANTS

2498 adults aged ≥65 years with an American Society of Anesthesiologists physical status classification of II or greater and undergoing major elective gastrointestinal surgery, recruited between January 2017 and September 2022.

INTERVENTIONS

Participants were assigned to minimally invasive cardiac output-guided intravenous fluid therapy with low dose inotrope infusion during and four hours after surgery, or to usual care without cardiac output monitoring.

MAIN OUTCOME MEASURES

The primary outcome was postoperative infection within 30 days of randomisation. Safety outcomes were acute cardiac events within 24 hours and 30 days. Secondary outcomes were acute kidney injury within 30 days and mortality within 180 days.

RESULTS

In 2498 patients (mean age 74 (standard deviation 6) years, 57% women), the primary outcome occurred in 289/1247 (23.2%) intervention patients and 283/1247 (22.7%) usual care patients (adjusted odds ratio 1.03 (95% confidence interval 0.84 to 1.25); P=0.81). Acute cardiac events within 24 hours occurred in 38/1250 (3.0%) intervention patients and 21/1247 (1.7%) usual care patients (adjusted odds ratio 1.82 (1.06 to 3.13); P=0.03). This difference was primarily due to an increased incidence of arrhythmias among intervention patients. Acute cardiac events within 30 days occurred in 85/1249 (6.8%) intervention patients and 79/1247 (6.3%) usual care patients (adjusted odds ratio 1.06 (0.77 to 1.47); P=0.71). Other secondary outcomes did not differ.

CONCLUSIONS

This clinical effectiveness trial in patients undergoing major elective gastrointestinal surgery did not provide evidence that cardiac output-guided intravenous fluid therapy with low dose inotrope infusion could reduce the incidence of postoperative infections. The intervention was associated with an increased incidence of acute cardiac events within 24 hours, in particular tachyarrhythmias. Based on these findings, the routine use of this treatment approach in unselected patients is not recommended.

TRIAL REGISTRATION

ISRCTN Registry ISRCTN39653756.

Mitigating Intraoperative Hypotension: A Review and Update on Recent Advances

Intraoperative hypotension (IOH) is a common occurrence during anesthesia administration for various surgical procedures and is linked to postoperative adverse outcomes. Factors contributing to IOH include hypovolemia, vasodilation, and impaired contractility, often combined with patient comorbidities. Strategies for mitigating IOH have been developed and are continually being updated with new research and technological advancements. These strategies include personalized blood pressure thresholds, pharmacologic measures, and the use of predictive tools. However, the management of IOH also requires careful consideration of patient-specific comorbidities and the use of appropriate treatment options.

Intraoperative Fluid Balance and Perioperative Complications in Ovarian Cancer Surgery

BACKGROUND

Fluid overload and hypovolemia promote postoperative complications in patients undergoing cytoreductive surgery for ovarian cancer. In the present study, postoperative complications and anastomotic leakage were investigated before and after implementation of pulse pressure variation-guided fluid management (PPVGFM) during ovarian cancer surgery.

PATIENTS AND METHODS

A total of n = 243 patients with ovarian cancer undergoing cytoreductive surgery at the University Hospital Bonn were retrospectively evaluated. Cohort A (CA; n = 185 patients) was treated before and cohort B (CB; n = 58 patients) after implementation of PPVGFM. Both cohorts were compared regarding postoperative complications.

RESULTS

Ultrasevere complications (G4/G5) were exclusively present in CA (p = 0.0025). No difference between cohorts was observed regarding severe complications (G3-G5) (p = 0.062). Median positive fluid excess was lower in CB (p = 0.001). This was independent of tumor load [peritoneal cancer index] (p = 0.001) and FIGO stage (p = 0.001). Time to first postoperative defecation was shorter in CB (CB: d2 median versus CA: d3 median; p = 0.001). CB had a shorter length of hospital stay (p = 0.003), less requirement of intensive medical care (p = 0.001) and postoperative ventilation (p = 0.001). CB received higher doses of noradrenalin (p = 0.001). In the combined study cohort, there were more severe complications (G3-G5) in the case of a PFE ≥ 3000 ml (p = 0.034) and significantly more anastomotic leakage in the case of a PFE ≥ 4000 ml (p = 0.006).

CONCLUSIONS

Intraoperative fluid reduction in ovarian cancer surgery according to a PPVGFM is safe and significantly reduces ultrasevere postoperative complications. PFEs of ≥ 3000 ml and ≥ 4000 ml were identified as cutoffs for significantly more severe complications and anastomotic leakage, respectively.

Fluid management of acute kidney injury

PURPOSE OF REVIEW

Acute kidney injury (AKI) is commonly encountered in critical care medicine as is intravenous fluid therapy. It is accepted that there is interplay between fluid use and AKI, both potentially positive and negative. An understanding of the physiological rationale for fluid is important to help clinicians when considering fluid therapy in patients with, or at risk for AKI; this includes understanding choice of fluid, method of monitoring, administration and clinical sequelae.

RECENT FINDINGS

There is increasing interest in combining both static and dynamic measures to assess fluid balance, fluid responsiveness effects of fluid therapy, which are areas requiring ongoing study to translate this theory into clinically useful practice at the bedside. Whilst the debate of choice of crystalloid in ICU practice continues, further evidence for benefits for balanced solutions emerges in the form of international guidelines and patient data meta-analysis of previously performed trials.

SUMMARY

This review assesses the physiological rationale for fluid use in ICU cohorts with AKI of various types, as well as a systematic approach for choice of fluid therapy using a number of different variables, which aims to help guide clinicians in managing fluid use and fluid balance in critically ill patients with AKI.

Fluid management in the septic peri-operative patient

PURPOSE OF REVIEW

This review provides insight into recent clinical studies involving septic peri-operative patients and highlights gaps in understanding fluid management. The aim is to enhance the understanding of safe fluid resuscitation to optimize peri-operative outcomes and reduce complications.

RECENT FINDINGS

Recent research shows adverse surgical and clinical outcomes with both under- and over-hydration of peri-operative patients. The kinetic of intravenous fluids varies significantly during surgery, general anaesthesia, and sepsis with damage to endothelial glycocalyx (EG), which increases vascular permeability and interstitial oedema. Among clinical anaesthesia, neuraxial anaesthesia and sevoflurane have less effect on EG. Hypervolemia and the speed and volume of fluid infusion are also linked to EG shedding. Despite improvement in the antisepsis strategies, peri-operative sepsis is not uncommon. Fluid resuscitation is the cornerstone of sepsis management. However, overzealous fluid resuscitation is associated with increased mortality in patients with sepsis and septic shock. Personalized fluid resuscitation based on a careful assessment of intravascular volume status, dynamic haemodynamic variables and fluid tolerance appears to be a safe approach. Balanced solutions (BS) are preferred over 0.9% saline in patients with sepsis and septic shock due to a potential reduction in mortality, when exclusive BS are used and/or large volume of fluids are required for fluid resuscitation. Peri-operative goal-directed fluid therapy (GDFT) using dynamic haemodynamic variables remains an area of interest in reducing postoperative complications and can be considered for sepsis management (Supplementary Digital Content).

SUMMARY

Optimization of peri-operative fluid management is crucial for improving surgical outcomes and reducing postoperative complications in patients with sepsis. Individualized and GDFT using BS is the preferred approach for fluid resuscitation in septic peri-operative patients. Future research should evaluate the interaction between clinical anaesthesia and EG, its implications on fluid resuscitation, and the impact of GDFT in septic peri-operative patients.

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.

Acknowledging acute kidney disease following ureteroscopy and laser lithotripsy: results from a tertiary care referral center

BACKGROUND

Acute kidney disease (AKD) is a recently described syndrome consisting of kidney function abnormalities lasting less than 3 months. Little is known regarding AKD following ureteroscopy (URS) and laser lithotripsy.

OBJECTIVE

To evaluate the occurrence and evolution of AKD in stone patients treated with URS.

MATERIALS AND METHODS

Data from 284 patients treated with URS for urinary stones were retrospectively analyzed. According to the KDIGO 2020 criteria, AKD was defined as postoperative acute kidney injury (AKI) occurrence, estimated glomerular filtration rate (eGFR) decrease ≥ 35%, or serum creatinine (SCr) increase ≥ 50%. AKI was defined as SCr increase ≥ 0.3 mg/dL or ≥ 50%. AKD evolution was evaluated 60 days post-URS. Data were analyzed using descriptive statistics. Univariable (UVA) and multivariable (MVA) logistic regression analyses tested the association of patients' characteristics and perioperative data with the occurrence of AKD.

RESULTS

Overall, postoperative AKD occurred in 32 (11.3%) patients. Recovery from AKD was found in 26 (82%) patients and persistent AKD occurred in 6 (18%) patients. At UVA, age at surgery (p = 0.05), baseline SCr (p = 0.02), baseline CKD category (p = 0.006), Charlson comorbidity index (p = 0.01), operative time (p = 0.04) and postoperative complications (< 0.001) were associated with AKD. At MVA, CKD category (OR 2.99, 95% CI = 1.4-6.3; p = 0.004), operative time (OR 1.01, 95% CI = 1.001-1.018; p = 0.023) and postoperative complications (OR 3.5, 95% CI = 1.46-8.49; p = 0.005) were independent predictors of AKD.

CONCLUSIONS

AKD is a frequent complication in patients treated with URS. Moreover, AKD persists in a non-neglectable percentage of patients at medium-term follow-up. Therefore, nephrological assessment should be considered, especially in high-risk patients. Current findings should be considered for the peri-operative management of stone patients.

Perioperative fluid management: evidence-based consensus recommendations from the international multidisciplinary PeriOperative Quality Initiative

Fluid therapy is an integral component of perioperative management. In light of emerging evidence in this area, the Perioperative Quality Initiative (POQI) convened an international multiprofessional expert meeting to generate evidence-based consensus recommendations for fluid management in patients undergoing surgery. This article provides a summary of the recommendations for perioperative fluid management of surgical patients from the preoperative period until hospital discharge and for all types of elective and emergency surgery, apart from burn injuries and head and neck surgery. Where evidence was lacking, recommendations for future research were generated. Specific recommendations are made for fluid management in elective major noncardiac surgery, cardiopulmonary bypass, thoracic surgery, neurosurgery, minor noncardiac surgery under general anaesthesia, and critical illness. There are ongoing gaps in knowledge resulting in variation in practice and some disagreement with our consensus recommendations. Perioperative fluid management should be individualised, taking into account the type of surgery and important patient factors, including intravascular volume status and acute and chronic comorbidities. Recommendations are made for further research in perioperative fluid management to address important gaps.

Incidence and trajectories of subclinical and KDIGO-defined postoperative acute kidney injury in patients undergoing major abdominal surgery

Background

Postoperative acute kidney injury is a common occurrence among patients undergoing major abdominal surgery and is associated with adverse outcomes. The effect of an incremental increase in serum creatinine concentration not meeting the KDIGO criteria for acute kidney injury is poorly studied. We evaluated the incidence and trajectories of postoperative subclinical acute kidney injury (sPO-AKI), acute kidney injury (PO-AKI), acute kidney disease (PO-AKD), and their relationships with chronic kidney disease (CKD), major adverse kidney events (MAKE30), and all-cause mortality at 30 days after surgery.

Methods

In a pre-planned, nested cohort sub study of the Myocardial Injury in Noncardiac Surgery in Sweden (MINSS) study, we included 588 patients from two hospitals. We determined the incidence of PO-AKI, PO-AKD, and CKD according to the ADQI-POQI consensus criteria. sPO-AKI was defined as a 25-49% increase in serum creatinine concentration within 7 days of surgery.

Results

A total of 59 (10.2%) patients fulfilled the criteria for sPO-AKI, 41 (7.1%) patients for PO-AKI, 29 (6.2%) for PO-AKD, and 6 (1.2%) for CKD. Similar proportions of patients with sPO-AKI and PO-AKI developed PO-AKD. An association was identified between the combined group of sPO-AKI and PO-AKI and 30-day mortality (Cramer's V: 0.1, P=0.037). PO-AKD (Cramer's V: 0.4, P<0.001) was associated with MAKE30 and 30-day mortality. All patients with CKD had pre-existing PO-AKD.

Conclusions

Subclinical postoperative kidney injury not fulfilling the KDIGO criteria occurred in every 10th patient, and one in 14 suffered from PO-AKI after major abdominal surgery. A majority of PO-AKD cases was preceded by sPO-AKI and PO-AKI. Early kidney injuries were associated with longer-term adverse outcomes including MAKE30, 30-day mortality, and CKD.

Renal dysfunction in surgical patients

PURPOSE OF REVIEW

To provide an overview of the current diagnostic criteria for acute kidney injury (AKI) including their limitations and to discuss prevention and treatment approaches in the perioperative setting.

RECENT FINDINGS

AKI is common in the perioperative period and is associated with worse short- and long-term outcomes. Current definitions of AKI have several limitations and lead to delayed recognition of kidney dysfunction which is why novel diagnostic approaches by using renal biomarkers may be helpful. In general, prevention of the development and progression of AKI is vital as a causal treatment for AKI is currently not available. Optimization of kidney perfusion and avoidance of nephrotoxic drugs reduce the occurrence of AKI in surgical patients. Angiotensin II as a new vasopressor, the use of remote ischemic preconditioning, and amino acids may be approaches with a positive effect on the kidneys.

SUMMARY

Evidence suggests that the implementation of supportive measures in patients at high risk for AKI might reduce the occurrence of AKI. Novel biomarkers can help allocating resources by detecting patients at high risk for AKI.

Joint models inform the longitudinal assessment of patient-reported outcomes in clinical trials: a simulation study and secondary analysis of the restrictive Vs. liberal fluid therapy for major abdominal surgery (RELIEF) randomized controlled trial

OBJECTIVES

Evaluate the utility of a joint model when analysing a patient-reported endpoint as part of a randomized controlled trial (RCT) in which censoring occurs when patients die during follow-up.

STUDY DESIGN AND SETTING

The present study comprises two parts as follows: first we reanalyzed data from a previously published RCT comparing two fluid regimens in the first 24 hours of major abdomino-pelvic surgery ('Restrictive versus Liberal Fluid Therapy for Major Abdominal Surgery [RELIEF]' trial). In this trial, patient-reported disability was measured at multiple timepoints before and after surgery. Next, we conducted a simulation study to jointly emulate patient-reported disability and survival, similar to the RELIEF trial, under nine treatment-outcome scenarios. In both parts, we compared a joint model analysis to a linear mixed-effect model combined with one of the several traditional methods of handling longitudinal missingness as follows: available data analysis, complete case analysis, last observation carried forward, and worst-case assumption.

RESULTS

In part one, the joint model revealed no between-group differences in patient-reported disability at 1, 3, 6, and 12 months after surgery. The worst-case approach consistently resulted in the largest deviation from the joint model estimates, although in this particular setting none of the approaches materially changed the study's conclusions. In part two, the simulations revealed that across all treatment-outcome scenarios, the joint model expectedly produced unbiased estimates of patient-reported disability. Similarly, employing an approach based on all available data (ie, relying on the maximum likelihood estimator for handling missingness) yielded disability estimates close to the simulated values, albeit with slight bias across some scenarios. The last observation carried forward approach that mirrored the joint model's estimates except when the treatment had a nonnull effect on patient-reported disability. The worst-case analysis resulted in high bias, which was particularly evident when the treatment had a large effect on survival. The complete case analysis resulted in high bias across all scenarios.

CONCLUSION

In randomized trials that employ a patient-reported outcome as one of their endpoints, a joint model can address bias arising from informative missingness related to death. Methods for handling missingness based on all available data appear to be a reasonable alternative to joint models, with only slight bias across some simulated scenarios.

PLAIN LANGUAGE SUMMARY

'Patient-centered research' focuses on outcomes that are prioritized by patients. This approach often involves asking patients to complete questionnaires about their health experiences. However, if a patient does not finish a study, dealing with their missing answers can pose significant challenges. Joint models are a recent statistical method that may help address this issue. In this study, we used joint models in a real-world clinical trial, and in a series of simulated trials, to determine how well they handle missing questionnaire data from patients. We found that joint models offer significant benefits over most traditional methods used to analyze clinical trials.

Restrictive versus Decision Support Guided Fluid Therapy during Major Hepatic Resection Surgery: A Randomized Controlled Trial

BACKGROUND

Fluid therapy during major hepatic resection aims at minimizing fluids during the dissection phase to reduce central venous pressure, retrograde liver blood flow, and venous bleeding. This strategy, however, may lead to hyperlactatemia. The Acumen assisted fluid management system uses novel decision support software, the algorithm of which helps clinicians optimize fluid therapy. The study tested the hypothesis that using this decision support system could decrease arterial lactate at the end of major hepatic resection when compared to a more restrictive fluid strategy.

METHODS

This two-arm, prospective, randomized controlled, assessor- and patient-blinded superiority study included consecutive patients undergoing major liver surgery equipped with an arterial catheter linked to an uncalibrated stroke volume monitor. In the decision support group, fluid therapy was guided throughout the entire procedure using the assisted fluid management software. In the restrictive fluid group, clinicians were recommended to restrict fluid infusion to 1 to 2 ml · kg-1 · h-1 until the completion of hepatectomy. They then administered fluids based on advanced hemodynamic variables. Noradrenaline was titrated in all patients to maintain a mean arterial pressure greater than 65 mmHg. The primary outcome was arterial lactate level upon completion of surgery (i.e., skin closure).

RESULTS

A total of 90 patients were enrolled over a 7-month period. The primary outcome was lower in the decision support group than in the restrictive group (median [quartile 1 to quartile 3], 2.5 [1.9 to 3.7] mmol · l-1vs. 4.6 [3.1 to 5.4] mmol · l-1; median difference, -2.1; 95% CI, -2.7 to -1.2; P < 0.001). Among secondary exploratory outcomes, there was no difference in blood loss (median [quartile 1 to quartile 3], 450 [300 to 600] ml vs. 500 [300 to 800] ml; P = 0.727), although central venous pressure was higher in the decision support group (mean ± SD of 7.7 ± 2.0 mmHg vs. 6.6 ± 1.1 mmHg; P < 0.002).

CONCLUSIONS

Patients managed using a clinical decision support system to guide fluid administration during major hepatic resection had a lower arterial lactate concentration at the end of surgery when compared to a more restrictive fluid strategy. Future trials are necessary to make conclusive recommendations that will change clinical practice.

EDITOR’S PERSPECTIVE

Perioperative Liver and Kidney Diseases

Perioperative risks associated with acute hepatitis, cirrhosis, and chronic kidney disease are substantial and prevalence of underlying chronic kidney or liver disease is rising; surgeries in these populations have accordingly become more common. Optimal perioperative management in both cases is paramount; this article focuses on understanding disease pathophysiology, a targeted preoperative evaluation, accurate estimation of perioperative risk, and anticipation and management of common postoperative complications.

Ringer's lactate administered at 15 °C leads to a greater and more prolonged increase in blood pressure compared to 37 °C

18 Participants were randomized to receive 30 ml/kg bodyweight Ringer's Lactate at 37° or 15 °C over 30 min. In a second session, participants were crossed over. Over a 120 min period after starting the fluid bolus we measured mean arterial pressure (MAP), cardiac output, systemic vascular resistance, and catecholamine levels. After infusion with cold fluids, the absolute increase in MAP at 45 min was significantly higher at + 6.5 mmHg (95% CI 4.8-8.2) compared with warm fluids (+ 0.6 mmHg, 95% CI, - 1.6 to 2.8; p < 0.001). This increase in MAP was longer-lasting after cold fluids (81.7 min, 95% CI 62.5-100.9) than after warm fluids (19.2, 95% CI 3.4-35; p < 0.001). While cardiac output was similar, systemic vascular resistance increase was greater after cold fluids (159 dyn s/cm5, 95% CI 9.5-309) compared to warm fluids (- 66 dyn s/cm5, 95% CI - 191 to 57; p = 0.012). Moreover, noradrenaline increased by up to 246% during cold fluids, and decreased with warm fluids (p < 0.001). Fluid bolus given at 15 °C, compared to 37 °C, leads to a greater and more prolonged increase in MAP accompanied by release of intrinsic noradrenaline and vasoconstriction. These results suggest that fluid temperature rather than volume is predominantly responsible for any increase in MAP.Trial Registration: EudraCT-nummer 2022-002137-34 and clinicaltrials.gov NCT05610254 (first registration 09/11/2022).

Identifying septic shock subgroups to tailor fluid strategies through multi-omics integration

Fluid management remains a critical challenge in the treatment of septic shock, with individualized approaches lacking. This study aims to develop a statistical model based on transcriptomics to identify subgroups of septic shock patients with varied responses to fluid strategy. The study encompasses 494 septic shock patients. A benefit score is derived from the transcriptome space, with higher values indicating greater benefits from restrictive fluid strategy. Adherence to the recommended strategy is associated with a hazard ratio of 0.82 (95% confidence interval: 0.64-0.92). When applied to the baseline hospital mortality rate of 16%, adherence to the recommended fluid strategy could potentially lower this rate to 13%. A proteomic signature comprising six proteins is developed to predict the benefit score, yielding an area under the curve of 0.802 (95% confidence interval: 0.752-0.846) in classifying patients who may benefit from a restrictive strategy. In this work, we develop a proteomic signature with potential utility in guiding fluid strategy for septic shock patients.

Risk factors for postoperative acute kidney injury after radical cystectomy for bladder cancer in the era of ERAS protocols: A retrospective observational study

BACKGROUND

Radical cystectomy (RC) is a major surgery associated with a high morbidity rate. Perioperative fluid management according to enhanced recovery after surgery (ERAS) protocols aims to maintain patients in an optimal euvolemic state while exposing them to acute kidney injury (AKI) in the event of hypovolemia. Postoperative AKI is associated with severe morbidity and mortality. Our main objective was to determine the association between perioperative variables, including some component of ERAS protocols, and occurrence of postoperative AKI within the first 30 days following RC in patients presenting bladder cancer. Our secondary objective was to evaluate the association between a postoperative AKI and the occurrence or worsening of a chronic kidney disease (CKD) within the 2 years following RC.

METHODS

We conducted a retrospective observational study in a referral cancer center in France on 122 patients who underwent an elective RC for bladder cancer from 01/02/2015 to 30/09/2019. The primary endpoint was occurrence of AKI between surgery and day 30. The secondary endpoint was survival without occurrence or worsening of a postoperative CKD. AKI and CKD were defined by KDIGO (Kidney Disease: Improving Global Outcomes) classification. Logistic regression analyse was used to determine independent factors associated with postoperative AKI. Fine and Gray model was used to determine independent factors associated with postoperative CKD.

RESULTS

The incidence of postoperative AKI was 58,2% (n = 71). Multivariate analysis showed 5 factors independently associated with postoperative AKI: intraoperative restrictive vascular filling < 5ml/kg/h (OR = 4.39, 95%CI (1.05-18.39), p = 0.043), postoperative sepsis (OR = 4.61, 95%CI (1.05-20.28), p = 0.043), female sex (OR = 0.11, 95%CI (0.02-0.73), p = 0.022), score SOFA (Sequential Organ Failure Assessment) at day 1 (OR = 2.19, 95%CI (1.15-4.19), p = 0.018) and delta serum creatinine D1 (OR = 1.06, 95%CI (1.02-1.11), p = 0.006). During the entire follow-up, occurrence or worsening of CKD was diagnosed in 36 (29.5%). A postoperative, AKI was strongly associated with occurrence or worsening of a CKD within the 2 years following RC even after adjustment for confounding factors (sHR = 2.247, 95%CI [1.051-4.806, p = 0.037]).

CONCLUSION

A restrictive intraoperative vascular filling < 5ml/kg/h was strongly and independently associated with the occurrence of postoperative AKI after RC in cancer bladder patients. In this context, postoperative AKI was strongly associated with the occurrence or worsening of CKD within the 2 years following RC. A personalized perioperative fluid management strategy needs to be evaluated in these high-risk patients.

Crystalloid volume versus catecholamines for management of hemorrhagic shock during esophagectomy: assessment of microcirculatory tissue oxygenation of the gastric conduit in a porcine model using hyperspectral imaging - an experimental study

INTRODUCTION

Oncologic esophagectomy is a two-cavity procedure with considerable morbidity and mortality. Complex anatomy and the proximity to major vessels constitute a risk for massive intraoperative hemorrhage. Currently, there is no conclusive consensus on the ideal anesthesiologic countermeasure in case of such immense blood loss. The objective of this work was to identify the most promising anesthesiologic management in case of intraoperative hemorrhage with regards to tissue perfusion of the gastric conduit during esophagectomy using hyperspectral imaging.

MATERIAL AND METHODS

An established live porcine model ( n =32) for esophagectomy was used with gastric conduit formation and simulation of a linear stapled side-to-side esophagogastrostomy. After a standardized procedure of controlled blood loss of about 1 l per pig, the four experimental groups ( n =8 each) differed in anesthesiologic intervention, that is, (I) permissive hypotension, (II) catecholamine therapy using noradrenaline, (III) crystalloid volume supplementation, and (IV) combined crystalloid volume supplementation with noradrenaline therapy. Hyperspectral imaging tissue oxygenation (StO 2 ) of the gastric conduit was evaluated and correlated with systemic perfusion parameters. Measurements were conducted before (T0) and after (T1) laparotomy, after hemorrhage (T2), and 60 min (T3) and 120 min (T4) after anesthesiologic intervention.

RESULTS

StO 2 values of the gastric conduit showed significantly different results between the four experimental groups, with 63.3% (±7.6%) after permissive hypotension (I), 45.9% (±6.4%) after catecholamine therapy (II), 70.5% (±6.1%) after crystalloid volume supplementation (III), and 69.0% (±3.7%) after combined therapy (IV). StO 2 values correlated strongly with systemic lactate values (r=-0.67; CI -0.77 to -0.54), which is an established prognostic factor.

CONCLUSION

Crystalloid volume supplementation (III) yields the highest StO 2 values and lowest systemic lactate values and therefore appears to be the superior primary treatment strategy after hemorrhage during esophagectomy with regards to microcirculatory tissue oxygenation of the gastric conduit.

Comparison of 4% Albumin and Ringer's Acetate on Hemodynamics in On-pump Cardiac Surgery: An Exploratory Analysis of a Randomized Clinical Trial

OBJECTIVES

Compare hemodynamics between 4% albumin and Ringer's acetate.

DESIGN

Exploratory analysis of the double-blind randomized ALBumin In Cardiac Surgery trial.

SETTING

Single-center study in Helsinki University Hospital.

PARTICIPANTS

We included 1,386 on-pump cardiac surgical patients.

INTERVENTION

We used 4% albumin or Ringer's acetate administration for cardiopulmonary bypass priming, volume replacement intraoperatively and 24 hours postoperatively.

MEASUREMENTS AND MAIN RESULTS

Hypotension (time-weighted average mean arterial pressure of <65 mmHg) and hyperlactatemia (time-weighted average blood lactate of >2 mmol/L) incidences were compared between trial groups in the operating room (OR), and early (0-6 hours) and late (6-24 hours) postoperatively. Associations of hypotension and hyperlactatemia with the ALBumin In Cardiac Surgery primary outcome (≥1 major adverse event [MAE]) were studied. In these time intervals, hypotension occurred in 118, 48, and 17 patients, and hyperlactatemia in 313, 131, and 83 patients. Hypotension and hyperlactatemia associated with MAE occurrence. Hypotension did not differ between the groups (albumin vs Ringer's: OR, 8.8% vs 8.5%; early postoperatively, 2.7% vs 4.2%; late postoperatively, 1.2% vs 1.3%; all p > 0.05). In the albumin group, hyperlactatemia was less frequent late postoperatively (2.9% vs 9.1%; p < 0.001), but not earlier (OR, 22.4% vs 23.6%; early postoperatively, 7.9% vs 11.0%; both p > 0.025 after Bonferroni-Holm correction).

CONCLUSIONS

In on-pump cardiac surgery, hypotension and hyperlactatemia are associated with the occurrence of ≥1 MAE. Compared with Ringer's acetate, albumin did not decrease hypotension and decreased hyperlactatemia only late postoperatively. Albumin's modest hemodynamic effect is concordant with the finding of no difference in MAEs between albumin and Ringer's acetate in the ALBumin In Cardiac Surgery trial.

The effect of intraoperative goal-directed fluid therapy in patients under anesthesia for gastrointestinal surgery

BACKGROUND

Intraoperative fluid management is an important aspect of anesthesia management in gastrointestinal surgery. Intraoperative goal-directed fluid therapy (GDFT) is a method for optimizing a patient's physiological state by monitoring and regulating fluid input in real-time.

AIM

To evaluate the efficacy of intraoperative GDFT in patients under anesthesia for gastrointestinal surgery.

METHODS

This study utilized a retrospective comparative study design and included 60 patients who underwent gastrointestinal surgery at a hospital. The experimental group (GDFT group) and the control group, each comprising 30 patients, received intraoperative GDFT and traditional fluid management strategies, respectively. The effect of GDFT was evaluated by comparing postoperative recovery, complication rates, hospitalization time, and other indicators between the two patient groups.

RESULTS

Intraoperative blood loss in the experimental and control groups was 296.64 ± 46.71 mL and 470.05 ± 73.26 mL (P < 0.001), and urine volume was 415.13 ± 96.72 mL and 239.15 ± 94.69 mL (P < 0.001), respectively. The postoperative recovery time was 5.44 ± 1.1 days for the experimental group compared to 7.59 ± 1.45 days (P < 0.001) for the control group. Hospitalization time for the experimental group was 10.87 ± 2.36 days vs 13.65 ± 3 days for the control group (P < 0.001). The visual analogue scale scores of the experimental and control groups at 24 h and 48 h post-surgery were 3.38 ± 0.79 and 4.51 ± 0.86, and 2.05 ± 0.57 and 3.51 ± 0.97 (P < 0.001), respectively. The cardiac output of the experimental and control groups was 5.99 ± 1.04 L/min and 4.88 ± 1.17 L/min, respectively, while the pulse pressure variability for these two groups was 10.87 ± 2.36% and 17.5 ± 3.21%, respectively.

CONCLUSION

The application of GDFT in gastrointestinal surgery can significantly improve postoperative recovery, reduce the incidence of complications, and shorten hospital stays.

Evaluation of the effect of fluid management on intracranial pressure in patients undergoing laparoscopic gynaecological surgery based on the ratio of the optic nerve sheath diameter to the eyeball transverse diameter as measured by ultrasound: a randomised controlled trial

BACKGROUND

During gynecological laparoscopic surgery, pneumoperitoneum and the Trendelenburg position (TP) can lead to increased intracranial pressure (ICP). However, it remains unclear whether perioperative fluid therapy impacts ICP. The purpose of this research was to evaluate the impact of restrictive fluid (RF) therapy versus conventional fluid (CF) therapy on ICP in gynecological laparoscopic surgery patients by measuring the ratio of the optic nerve sheath diameter (ONSD) to the eyeball transverse diameter (ETD) using ultrasound.

METHODS

Sixty-four patients who were scheduled for laparoscopic gynecological surgery were randomly assigned to the CF group or the RF group. The main outcomes were differences in the ONSD/ETD ratios between the groups at predetermined time points. The secondary outcomes were intraoperative circulatory parameters (including mean arterial pressure, heart rate, and urine volume changes) and postoperative recovery indicators (including extubation time, length of post-anaesthesia care unit stay, postoperative complications, and length of hospital stay).

RESULTS

There were no statistically significant differences in the ONSD/ETD ratio and the ONSD over time between the two groups (all p > 0.05). From T2 to T4, the ONSD/ETD ratio and the ONSD in both groups were higher than T1 (all p < 0.001). From T1 to T2, the ONSD/ETD ratio in both groups increased by 14.3%. However, the extubation time in the RF group was shorter than in the CF group [median difference (95% CI) -11(-21 to -2) min, p = 0.027]. There were no differences in the other secondary outcomes.

CONCLUSION

In patients undergoing laparoscopic gynecological surgery, RF did not significantly lower the ONSD/ETD ratio but did shorten the tracheal extubation time, when compared to CF.

TRIAL REGISTRATION

ChiCTR2300079284. Registered on December 29, 2023.

Acute kidney injury in the acute care surgery patient: What you need to know

ABSTRACT

Acute kidney injury is associated with poor outcomes in the trauma and emergency general surgery population, and recent consensus definitions have allowed for significant advances in defining the burden of disease. The current definitions rely on overall functional measures (i.e., serum creatinine and urine output), which can be confounded by a variety of clinical factors. Biomarkers are increasingly being investigated as more direct diagnostic assays for the diagnosis of acute kidney injury and may allow earlier detection and more timely therapeutic intervention. Etiologies fall into two general categories: disorders of renal perfusion and exposure to nephrotoxic agents. Therapy is largely supportive, and prevention offers the best chance to decrease clinical impact.

Effect of rigorous fluid management using monitoring of ECW ratio by bioelectrical impedance analysis in critically ill postoperative patients: A prospective, single-blind, randomized controlled study

BACKGROUND & AIMS

Precise assessment of postoperative volume status is important to administrate optimal fluid management. Bioelectrical impedance analysis (BIA) which measures the body composition using electric character. Extracellular water (ECW) ratio by BIA represented as the ratio of ECW to total body water (TBW) and is known to reflect the hydration status. Based on this, we aimed to determine whether aggressive fluid control using ECW ratio could improve clinical outcomes through a single blind, randomized controlled trial.

METHODS

From November 2021 to December 2022, intensive care unit (ICU) patients admitted after surgery were randomly assigned to an intervention group or a control group whether postoperative fluid management was controlled via BIA. Among patients in the intervention group, dehydrated patients received a bolus infusion with crystalloid fluid whereas diuretics were administrated to overhydrated patients until the value of ECW ratio fell within its normal setting range (0.390-0.406). Contrarily, BIA was performed once a day for the control group. Patients in the control group received traditional fluid treatment regardless of BIA results. Primary outcome was in-hospital mortality in two groups. The secondary outcomes were postoperative morbidities, 28-day mortality.

RESULTS

77 patients of the intervention group and 90 patients of the control group were finally analyzed. The in-hospital mortality (0 in intervention, 4.4% in control, p = 0.125) and 28-day mortality (1.3% in intervention, 14.4% in control, p = 0.002) showed lower incidence in the intervention group than in the control group. In multivariate analysis, the overhydrated status whose ECW ratio exceeding 0.406 [odds ratio (OR): 2.731, 95% confidence interval (CI): 1.001-7.663, p = 0.049] and high capillary leak index (CLI) value at ICU admission (OR: 1.024, 95% CI: 1.008-1.039, p = 0.002) were risk factors of postoperative morbidities. Regarding the 28-day mortality, high CLI value (OR: 1.025, 95% CI: 1.002-1.050, p = 0.037) and traditional strategy without BIA monitoring (OR: 9.903, 95% CI: 1.095-89.566, p = 0.041) were the significant predisposing factors.

CONCLUSION

Our results revealed the rigorous fluid treatment with volume control based on ECW ratio by BIA failed to achieve significant improvement in in-hospital mortality, but it could reduce 28-day mortality of ICU patients. Monitoring of ECW ratio may help establish optimal fluid treatment strategies for postoperative ICU patients who are susceptible to fluid imbalances with fluid overload.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT06097923, retrospectively registered on October 16, 2023, https://clinicaltrials.gov/study/NCT06097923?term=NCT06097923&rank=1.

Comparison between the effects of epidural and intravenous patient-controlled analgesia on postoperative disability-free survival in patients undergoing thoracic and abdominal surgery: A post hoc analysis

BACKGROUND

Thoracic epidural analgesia (TEA) and intravenous patient-controlled analgesia (IV-PCA) are widely used to mitigate immediate postoperative pain; however, their effects on long-term disability-free survival are poorly documented. This study aimed to compare the effects of postoperative TEA and IV-PCA on disability-free survival in patients who underwent thoracic or abdominal surgery.

METHODS

This post hoc analysis of a prospective observational study included 845 inpatients aged ≥55 years that underwent elective thoracic and abdominal surgery between 1 April 2016 and 28 December 2018 in a tertiary care hospital. Inverse probability of treatment weighted (IPTW) using stabilized inverse propensity scores was adopted to minimize bias. The primary outcome in this study was disability-free survival, defined as survival with a 12-item World Health Organization Disability Assessment Schedule 2.0 score of <16%, assessed at 3 months and 1 year after surgery.

RESULTS

The final analysis included 601 patients who received TEA and 244 who received IV-PCA. After IPTW, the weighted incidence of disability-free survival at 3 months and 1 year was 60.5% and 61.4% in the TEA group and 78.3% and 66.2% in the IV-PCA group, respectively. The adjusted OR for disability-free survival at 3 months and 1 year was 0.84 (95% confidence interval [CI]: 0.50-1.39) and 1.21 (95% CI: 0.72-2.05), respectively, for the TEA group.

CONCLUSION

No significant differences were observed in the disability-free survival at 3 months and 1 year after elective thoracic and abdominal surgery in patients aged ≥55 years who received TEA or IV-PCA.

SIGNIFICANCE STATEMENT

This study is the first in our setting to document the long-term effects of patient-controlled analgesia. In a post hoc analysis of our prospective cohort study, we show that although differences in chronic postsurgical pain exist at 3 months post-surgery, disability-free survival rates at 1 year do not differ irrespective of the choice of patient-controlled analgesia. The findings of this study highlight the need for shared decision-making between clinicians and patients.

Role of Peripheral Parenteral Nutrition Composition on Clinical Outcomes in Patients Undergoing Gastrectomy or Colectomy: A Phase III Indian Clinical Trial

Aims and background

Various types of parenteral nutritional products exist, each with specific formulations designed to meet the diverse nutritional needs of patient's post-abdominal surgery. Here, two different parenteral nutrition (PN) solutions BFLUID and NUTRIFLEX PERI are compared in terms of therapeutic efficacy and safety profile.

Materials and methods

A prospective, multi-center, randomized, parallel-group, non-inferiority Phase III clinical trial compared two PN solutions namely BFLUID (N = 78) and NUTRIFLEX PERI (N = 72) in 150 patients undergoing gastrectomy or colectomy. Primary endpoints included length of hospital stay while secondary endpoints included assessment and comparison of length of ICU/HDU stay, assessment of incidents of infections and mortality, change in blood levels of vitamin B1, change in nutritional parameters, thrombophlebitis, pain at the injection site, and recording of adverse events (AEs).

Results

There was no significant difference in terms of length of hospital stay, length of ICU/HDU stay as well as changes in nutritional parameters from baseline and change in blood levels of vitamin B1 from baseline. Both study groups exhibited comparability in terms of AEs, pain at the injection site, and the incidence of phlebitis. There was no significant difference in the number and severity of adverse events reported in both groups. Additionally, no signs of infection were observed in patients from either group.

Conclusion

The trial successfully demonstrated the non-inferiority of BFLUID to NUTRIFLEX PERI. Moreover, the results indicated that PN enriched with high levels of branched-chain amino acids (BCAAs), essential amino acids (EAAs), and thiamine is both safe and efficacious for adult patients undergoing gastrectomy or colectomy.

How to cite this article

Goyal A, Pathak A, BS Madhu, Soni H, Bhatt K, Raju KVVN, et al. Role of Peripheral Parenteral Nutrition Composition on Clinical Outcomes in Patients Undergoing Gastrectomy or Colectomy: A Phase III Indian Clinical Trial. Indian J Crit Care Med 2024;28(9):871-878.

Predictive modelling for postoperative acute kidney injury: big data enhancing quality or the Emperor's new clothes?

The increased availability of large clinical datasets together with increasingly sophisticated computing power has facilitated development of numerous risk prediction models for various adverse perioperative outcomes, including acute kidney injury (AKI). The rationale for developing such models is straightforward. However, despite numerous purported benefits, the uptake of preoperative prediction models into clinical practice has been limited. Barriers to implementation of predictive models, including limitations in their discrimination and accuracy, as well as their ability to meaningfully impact clinical practice and patient outcomes, are increasingly recognised. Some of the purported benefits of predictive modelling, particularly when applied to postoperative AKI, might not fare well under detailed scrutiny. Future research should address existing limitations and seek to demonstrate both benefit to patients and value to healthcare systems from implementation of these models in clinical practice.

High intraoperative fluid load associated with prolonged length of hospital stay and complications after non-cardiac surgery in neonates

Inappropriate perioperative fluid load can lead to postoperative complications and death. This retrospective study was designed to investigate the association between intraoperative fluid load and outcomes in neonates undergoing non-cardiac surgery. From April 2020 to September 2022, 940 neonates who underwent non-cardiac surgery were retrospectively enrolled and their perioperative data were harvested for further analysis. According to recorded intraoperative fluid volumes defined as ml.kg-1 h-1, patients were mandatorily divided into quintile with fluid load as restrictive (quintile 1, Q1), moderately restrictive (Q2), moderate (Q3), moderately liberal (Q4), and liberal (Q5). The primary outcomes were defined as prolonged length of hospital stay (LOS) (postoperative LOS ≥ 14 days), complications beyond prolonged LOS, and 30-day mortality. Secondary outcomes included postoperative complications within 14 days of hospital stay. The intraoperative fluid load was in Q1 of 6.5 (5.3-7.3) (median and IQR); Q2: 9.2 (8.7-9.9); Q3: 12.2 (11.4-13.2); Q4: 16.5 (15.4-18.0); and Q5: 26.5 (22.3-32.2) ml.kg-1 h-1. The odd of prolonged LOS was positively correlated with an increase fluid volume (Q5 quintile: OR 2.602 [95% CI 1.444-4.690], P = 0.001), as well as complications beyond prolonged LOS (Q5: OR 3.322 [95% CI 1.656-6.275], P = 0.001). The overall 30-day mortality rate was increased with high intraoperative fluid load but did not reach to a statistical significance after adjusted with confounders. Furthermore, the highest quintile of fluid load (26.5 ml.kg-1 h-1, IQR [22.3-32.2]) (Q5 quintile) was significantly associated with longer postoperative mechanical ventilation time compared with Q1 (Q5: OR 2.212 [95% CI 1.101-4.445], P = 0.026).    Conclusion: Restrictive intraoperative fluid load had overall better outcomes, whilst high fluid load was significantly associated with prolonged LOS and complications after non-cardiac surgery in neonates.    Trial registration:  Chictr.org.cn Identifier: ChiCTR2200066823 (December 19, 2022). What is Known: • Inappropriate perioperative fluid load can lead to postoperative complications and even death. What is New: • High perioperative fluid load was significantly associated with an increased length of stay after non-cardiac surgery in neonates, whilst low fluid load was consistently related to better postoperative outcomes.