Case scenario: Hemodynamic management of postoperative acute kidney injury

Effect of low-dose norepinephrine combined with goal-directed fluid therapy on postoperative pulmonary complications in lung surgery: A prospective randomized controlled trial

STUDY OBJECTIVE

Postoperative pulmonary complications (PPCs), the predominant complications following lung surgery, are closely associated with intraoperative fluid therapy. This study investigates whether continuous low-dose norepinephrine infusion combined with goal-directed fluid therapy (GDFT) reduced the risk of PPCs after lung surgery relative to either GDFT alone or standard fluid treatment.

DESIGN

A prospective, randomized controlled trial.

SETTING

The First Affiliated Hospital of Anhui Medical University, Anhui, China.

PATIENTS

The study included 184 patients undergoing elective thoracoscopic lung resection surgery.

INTERVENTIONS

Patients were randomized into three groups based on different fluid treatment regimens: Group C received standard fluid treatment, Group G received GDFT, and Group N received continuous low-dose norepinephrine infusion combined with GDFT.

MEASUREMENTS

The primary outcome was the incidence of PPCs, including respiratory infection, atelectasis, pneumothorax, pleural empyema, respiratory failure, pulmonary embolism and bronchopleural fistula, during the postoperative hospital stay. Secondary outcomes were hemodynamic variables and arterial blood gases. Additional recorded parameters included other postoperative complications such as bleeding, postoperative re-intubation, re-hospitalization within 30 days, and the length of hospital stay.

MAIN RESULTS

Group N showed a significantly lower PPCs incidence during hospitalization compared to Group C (11.5 % vs 27.9 %; odds ratio, 2.98; 95 % confidence interval, 1.17-8.31; P = 0.023). No significant difference in PPCs was found between Group N and Group G (11.5 % vs 14.5 %; odds ratio, 1.31; 95 % confidence interval, 0.46-3.91; P = 0.616). Additionally, there were no significant differences among the three groups in the components of PPCs. Group N showed higher mean arterial pressure and stroke volume index intraoperatively compared to Group C.

CONCLUSIONS

Continuous low-dose norepinephrine infusion combined with GDFT reduced PPCs incidence in elective lung surgery patients compared with standard fluid management, but showed no difference compared to GDFT alone.

CLINICAL TRIAL REGISTRATION

ChiCTR2200064081.

Meaning and Management of Perioperative Oliguria

Perioperative oliguria is an alarm signal. The initial assessment includes closer patient monitoring, evaluation of volemic status, risk-benefit of fluid challenge or furosemide stress test, and investigation of possible perioperative complications.

Gender-related differences in the performance of sequential organ failure assessment (SOFA) to predict septic shock after percutaneous nephrolithotomy

The study aims to identify whether gender differences exist in the sequential organ failure assessment (SOFA) score to the extent of affecting its predictive accuracy for septic shock after percutaneous nephrolithotomy (PCNL). A retrospective study of 612 patients undergoing PCNL was performed. The SOFA scores of male and female groups were compared to identify any gender differences. The ROC curve was used to find differences between the original and adjusted SOFA scores. Postoperative septic shock developed in 21 (3.43%) cases. A marginally significant discrepancy in median SOFA scores between genders was discovered in a subgroup of patients < 40 years old (p = 0.048). A gender difference existed in the SOFA score after PCNL, with greater proportion of high scores in female patients (p = 0.011). Male patients had a higher proportion of ≥ 2 sub-score in hepatic and renal systems than female patients, caused by their higher preoperative bilirubin and creatinine (p < 0.05). An adjusted SOFA score was created to replace the original postoperative SOFA score with the perioperative changed values of bilirubin and creatinine. Performance of the adjusted SOFA score for predicting septic shock was comparable with the original SOFA score (AUC 0.987 vs. 0.985, p = 0.932). Under the premise of ensuring 100% sensitivity, the adjusted SOFA score reduced the 43.7% (31/71) false-positive rate for predicting septic shock compared with the original SOFA score. In conclusion, the gender should not be neglected when applying SOFA score for patients after PCNL. The adjusted SOFA score eliminates negative effects caused by gender differences in predicting septic shock.

Effects of perioperative goal-directed fluid therapy combined with the application of alpha-1 adrenergic agonists on postoperative outcomes: a systematic review and meta-analysis

Background

Past studies have demonstrated that goal-directed fluid therapy (GDFT) may be more marginal than previously believed. However, beneficial effects of alpha-1 adrenergic agonists combined with appropriate fluid administration is getting more and more attention. This study aimed to systematically review the effects of goal-directed fluid therapy (GDFT) combined with the application of alpha-1 adrenergic agonists on postoperative outcomes following noncardiac surgery.

Methods

This meta-analysis included randomized controlled trials (RCTs) on GDFT combined with the application of alpha-1 adrenergic agonists in patients undergoing noncardiac surgery. The primary outcomes included the postoperative mortality rate and length of hospital stay (LOS). The secondary outcome indexes were the incidence of postoperative complications and recovery of postoperative gastrointestinal (GI) function. The traditional pairwise meta-analysis was conducted to compare the effect of fluid therapy. The quality of included RCTs was evaluated according to the Cochrane Collaboration’s risk-of-bias tool. Also, the publication bias was detected using funnel plots, Egger’s regression test, and Begg’s adjusted rank correlation test. The meta-analysis was conducted using the RevMan 5.3 and Stata 14.0 software.

Results

Thirty-two eligible RCTs were included in this meta-analysis. Perioperative GDFT combined with the application of alpha-1 adrenergic agonists was associated with a significant reduction in LOS (P = 0.002; I² = 69%), and overall complication rates (P = 0.04; I² = 41%). It facilitated gastrointestinal function recovery, as demonstrated by shortening the time to first flatus by 6.30 h (P < 0.00001; I² = 91%) and the time to toleration of solid food by 1.69 days (P < 0.00001; I² = 0%). Additionally, there was no significant reduction in short-term mortality in the GDFT combined with alpha-1 adrenergic agonists group (P = 0.05; I² = 0%).

Conclusion

This systematic review of available evidence suggested that the use of perioperative GDFT combined with alpha-1 adrenergic agonists might facilitate recovery in patients undergoing noncardiac surgery.

Electronic supplementary material

The online version of this article (10.1186/s12871-018-0564-y) contains supplementary material, which is available to authorized users.

Urinary neutrophil gelatinase-associated lipocalin (NGAL) distinguishes sustained from transient acute kidney injury after general surgery

Introduction

This prospective study tests the hypothesis that after general surgery urinary neutrophil gelatinase–associated lipocalin (NGAL) can distinguish between sustained acute kidney injury (AKI), typical of nephron damage, and transient AKI, commonly seen with hemodynamic variation and prerenal azotemia.

Methods

Urine was collected in 510 patients within 2 to 3 hours after general surgery, and urinary NGAL was determined using enzyme-linked immunosorbent assay. Patients who met AKIN stage 1 criteria of AKI were subclassified into those with sustained AKI (serum creatinine elevation for at least 3 days) and those with transient AKI (serum creatinine elevation for less than 3 days).

Results

Seventeen of 510 patients (3.3%) met the stage 1 AKIN criteria within 48 hours of surgery. Elevations in serum creatinine were sustained in 9 and transient in 8 patients. Urinary NGAL was significantly elevated only in patients with sustained AKI (204.8 ± 411.9 ng/dl); patients with transient AKI had urinary NGAL that was indistinguishable from that of patients who did not meet AKIN criteria at all (30.8 ± 36.5 ng/dl vs. 31.9 ± 113 ng/dl). The area under the curve of the receiver operating characteristic curve of urinary NGAL to predict sustained AKI was 0.85 (95% confidence interval: 0.773–0.929, P < 0.001).

Discussion

Urinary NGAL levels measured 2 to 3 hours after surgery were able to distinguish the kinetics of creatinine (sustained AKI vs. transient AKI) over the subsequent week. Transient AKI is an easily reversible state that is likely not associated with substantial tubular injury and therefore NGAL release. Using AKIN criteria, both transient and sustained AKI are classified as AKI even though our data demonstrate that they are possibly different entities.

Failure of renal biomarkers to predict worsening renal function in high-risk patients presenting with oliguria

PURPOSE

Oliguria is a common symptom in critically ill patients and puts patients in a high risk category for further worsening renal function (WRF). We performed this study to explore the predictive value of biomarkers to predict WRF in oliguric intensive care unit (ICU) patients.

PATIENTS AND METHODS

Single-center prospective observational study. ICU patients were included when they presented a first episode of oliguria. Plasma and urine biomarkers were measured: plasma and urine neutrophil gelatinase-associated lipocalin (pNGAL and uNGAL), urine α1-microglobulin, urine γ-glutamyl transferase, urine indices of tubular function, cystatin C, C terminal fragment of pro-arginine vasopressin (CT-ProAVP), and proadrenomedullin (MR-ProADM).

RESULTS

One hundred eleven patients formed the cohort, of whom 41 [corrected] had worsening renal function. Simplified Acute Physiology Score (SAPS) II was 41 (31-51). WRF was associated with increased mortality (hazard ratio 8.65 [95 % confidence interval (CI) 3.0-24.9], p = 0.0002). pNGAL, MR-ProADM, and cystatin C had the best odds ratio and area under the receiver-operating characteristic curve (AUC-ROC: 0.83 [0.75-0.9], 0.82 [0.71-0.91], and 0.83 [0.74-0.90]), but not different from serum creatinine (Screat, 0.80 [0.70-0.88]). A clinical model that included age, sepsis, SAPS II, and Screat had AUC-ROC of 0.79 [0.69-0.87]; inclusion of pNGAL increased the AUC-ROC to 0.86 (p = 0.03). The category-free net reclassification index improved with pNGAL (total net reclassification index for events to higher risk 61 % and nonevents to lower 82 %).

CONCLUSIONS

All episodes of oliguria do not carry the same risk. No biomarker further improved prediction of WRF compared with Screat in this selected cohort of patients at increased risk defined by oliguria.

Evidence of uncoupling between renal dysfunction and injury in cardiorenal syndrome: insights from the BIONICS study

OBJECTIVE

The objective of the study was to assess urinary biomarkers of renal injury for their individual or collective ability to predict Worsening renal function (WRF) in patients with acutely decompensated heart failure (ADHF).

METHODS

In a prospective, blinded international study, 87 emergency department (ED) patients with ADHF were evaluated with biomarkers of cardiac stretch (B type natriuretic peptide [BNP] and its amino terminal equivalent [NT-proBNP], ST2), biomarkers of renal function (creatinine, estimated glomerular filtration rate [eGFR]) and biomarkers of renal injury (plasma neutrophil gelatinase associated lipocalin [pNGAL], urine kidney injury molecule-1 [KIM-1], urine N-acetyl-beta-D-glucosaminidase [NAG], urine Cystatin C, urine fibrinogen). The primary endpoint was WRF.

RESULTS

26% developed WRF; baseline characteristics of subjects who developed WRF were generally comparable to those who did not. Biomarkers of renal function and urine biomarkers of renal injury were not correlated, while urine biomarkers of renal injury correlated between each other. Biomarker concentrations were similar between patients with and without WRF except for baseline BNP. Although plasma NGAL was associated with the combined endpoint, none of the biomarker showed predictive accuracy for WRF.

CONCLUSIONS

In ED patients with ADHF, urine biomarkers of renal injury did not predict WRF. Our data suggest that a weak association exists between renal dysfunction and renal injury in this setting (Clinicaltrials.gov NCT#0150153).

Novelties in biomarkers for the management of circulatory failure

PURPOSE OF REVIEW

The purpose of the present work was to review the literature on the role of biomarkers for the diagnosis, the risk stratification, and the management of circulatory failure.

RECENT FINDINGS

Recent research has highlighted how biomarkers could guide physicians in making proper diagnosis of the cause of the circulatory failure, assessing the consequence in terms of organ injury and function, refining prognosis prediction and stratification of patients, and guiding treatments, in patients with cardiovascular failure.

SUMMARY

Because of the tight association between circulatory and renal failure, we put a special emphasis on cardiovascular [B-type natriuretic peptide (BNP), Nt-proBNP, troponin, QSOX-1, sST-2, mid-regional pro-atrial natriuretic peptide] and renal biomarkers (neutrophil gelatinase-associated lipocalin, cystatin C, liver-type fatty acid-binding protein, kidney injury molecule-1, insulin-like growth factor-binding protein-7, tissue inhibitor of metalloproteinase-2). We also discuss nonspecific biomarkers (pro-ADM, glycemia, MicroRNA, chromogramin A) in this setting. We discuss the potential interest and limits, from diagnosis to prognosis reclassification, of cutting-edge new biomarkers, but also widely available and inexpensive biomarkers, in the particular setting of circulatory failure.

Critical role of interleukin-11 in isoflurane-mediated protection against ischemic acute kidney injury in mice

BACKGROUND

Isoflurane releases renal tubular transforming growth factor-β1 (TGF-β1) and protects against ischemic acute kidney injury. Recent studies suggest that TGF-β1 can induce a cytoprotective cytokine interleukin (IL)-11. In this study, the authors tested the hypothesis that isoflurane protects against ischemic acute kidney injury by direct induction of renal tubular IL-11 synthesis.

METHODS

Human kidney proximal tubule cells were treated with 1.25-2.5% isoflurane or carrier gas (room air + 5% carbon dioxide) for 0-16 h. The authors also anesthetized C57BL/6 mice with 1.2% isoflurane or with equianesthetic dose of pentobarbital for 4 h. In addition, the authors subjected IL-11 receptor (IL-11R) wild-type, IL-11R-deficient, or IL-11 neutralized mice to 30-min renal ischemia followed by reperfusion under 4 h of anesthesia with pentobarbital or isoflurane (1.2%).

RESULTS

Isoflurane increased IL-11 synthesis in human (approximately 300-500% increase, N = 6) and mouse (23 ± 4 [mean ± SD] fold over carrier gas group, N = 4) proximal tubule cells that were attenuated by a TGF-β1-neutralizing antibody. Mice anesthetized with isoflurane showed significantly increased kidney IL-11 messenger RNA (13.8 ± 2 fold over carrier gas group, N = 4) and protein (31 ± 9 vs. 18 ± 2 pg/mg protein or approximately 80% increase, N = 4) expression compared with pentobarbital-anesthetized mice, and this increase was also attenuated by a TGF-β1-neutralizing antibody. Furthermore, isoflurane-mediated renal protection in IL-11R wild-type mice was absent in IL-11R-deficient mice or in IL-11R wild-type mice treated with IL-11-neutralizing antibody (N = 4-6).

CONCLUSION

In this study, the authors suggest that isoflurane induces renal tubular IL-11 via TGF-β1 signaling to protect against ischemic acute kidney injury.