Intraoperative Hydroxyethyl Starch 70/0.5 Is Not Related to Acute Kidney Injury in Surgical Patients

Intraoperative management and hemodynamic monitoring for ma- jor abdominal surgery : a narrative review

Background : Several trials suggest that postoperative outcomes may be improved by the use of hemodynamic monitoring, but a survey by the American Society of Anesthesiologists (ASA) and the European Society of Anaesthesiology (ESA) showed that cardiac output is monitored by only 34% of ASA and ESA respondents and central venous pressure is monitored by 73% of ASA respondents and 84% of ESA respondents. Moreover, 86.5% of ASA respondents and 98.1% of ESA respondents believe that their current hemodynamic management could be improved (1). The interaction of general anesthesia and surgical stress is the main problem and the leading cause for postoperative morbidity and mortality. The choice of a suitable hemodynamic monitoring system for patients at high anesthesiological risk is of crucial importance to reduce the incidence of major postoperative complications. The aim of the present review is to summarize the benefits of a defined path beginning before surgery, and discuss the available evidence supporting the efficacy and safety of an individualized hemodynamic approach for major abdominal surgery. Objective : To evaluate the clinical effectiveness of a perioperative hemodynamic therapy algorithm in high risk patients

Large volume infusions of hydroxyethyl starch during cardiothoracic surgery may be associated with postoperative kidney injury: propensity-matched analysis

Background

The safety of intraoperative administration of hydroxyethyl starch (HES) has been debated. We hypothesized that intraoperative use of HES is associated with postoperative acute kidney injury (AKI) following cardiopulmonary bypass (CPB).

Materials and methods

Patients who underwent cardiothoracic surgery using CPB between 2007 and 2014 were retrospectively reviewed. The incidence of AKI within 7 days after surgery, defined by the Kidney Disease Improving Global Outcome criteria, was compared for patients who did or did not receive 6% (70/0.5) or 6% (130/0.4) HES for anesthesia management before or after CPB. Multivariable logistic regression and propensity matching analysis were performed to examine whether use of HES is associated with postoperative AKI. Outcomes comparing patients receiving HES ≥ 1000 mL and < 1000 mL were also compared.

Results

Data from 1976 patients were reviewed. All patients received 70/0.5 HES as a part of the priming solution for CPB. The incidence of postoperative AKI was 28.2% in patients who received HES and 26.0% in patients who did not (p = 0.33). In multivariable analysis, there was no correlation between the use of HES and the incidence of AKI (odds ratio 0.87, 95% CI 0.30–2.58, p = 0.81). Propensity matching showed that the incidence of AKI was not significantly different between 481 patients administered with HES and 962 patients (26.6% vs. 26.9%, p = 0.95) who did not receive HES for anesthesia management. However, peak creatinine levels, needed for renal replacement therapy, and in-hospital mortality were higher, and 28-day hospital-free days were lower in patients receiving HES ≥ 1000 mL than those receiving HES < 1000 mL (p < 0.05).

Conclusions

Intraoperative use of HES was not associated with postoperative AKI following CPB. However, administration of large volumes of HES may be associated with kidney-related adverse clinical outcomes.

Starch Wars-New Episodes of the Saga. Changes in Regulations on Hydroxyethyl Starch in the European Union

After a safety review of hydroxyethyl starch (HES) solutions in 2013, restrictions on the use of HES were introduced in the European Union (EU) to reduce the risk of kidney injury and death in certain patient populations. Similar restrictions were introduced by the Food and Drug Administration in the United States and other countries. In October 2017, a second safety review of HES solutions was triggered by the European pharmacovigilance authorities based on a request by the Swedish Medical Products Agency to completely suspend HES. After several meetings and repeated evaluations, the recommendation to ban HES was ultimately not endorsed by the responsible committee; however, there was a vote for more restricted access to the drug and rigorous monitoring of policy adherence. This review delineates developments in the European pharmacovigilance risk assessment of HES solutions between 2013 and 2018. In addition, the divergent experts' opinions and the controversy surrounding this official assessment are described. As the new decisions might influence the availability of HES products for veterinary patients, potential alternatives to HES solutions, such as albumin solutions and gelatin, are briefly discussed.

Postoperative renal function in parturients with severe preeclampsia who underwent cesarean delivery: a retrospective observational study

Although postoperative renal dysfunction is relatively rare after cesarean delivery, preeclampsia is considered as the high-risk population. On the other hand, hydroxyethyl starch (HES) administration for preventing maternal hypotension induced by spinal anesthesia for cesarean delivery is a common practice. However, the effect of HES administration during cesarean delivery on postoperative kidney function in parturients with severe preeclampsia is not well investigated. We retrospectively reviewed both medical and anesthesia records of patients with severe preeclampsia who underwent cesarean delivery from January 2011 to December 2013. Preoperative blood examinations were compared with postoperative values. All parturients received 6% HES 70/0.5 for preventing anesthesia-induced hypotension or for volume resuscitation during cesarean delivery. A total of 87 severe preeclampsia parturients were underwent cesarean section during the period. The amounts of HES administration were 859 ± 206 mL. There was significant reduction in serum creatinine, from 0.70 ± 0.29 mg/dL preoperatively to 0.62 ± 0.17 mg/dL in 3-7 days after the cesarean. Only one patient had postoperatively elevated serum creatinine up to clinically significant level (from 0.64 mg/dL to 1.35 mg/kg).

Update on perioperative acute kidney injury

PURPOSE OF REVIEW

In this review, we discuss the latest updates on perioperative acute kidney injury (AKI) and the specific considerations that are relevant to different surgeries and patient populations.

RECENT FINDINGS

AKI diagnosis is constantly evolving. New biomarkers detect AKI early and shed a light on the possible cause of AKI. Hypotension, even for a short duration, is associated with perioperative AKI. The debate on the deleterious effects of chloride-rich solutions is still far from conclusion. Remote ischemic preconditioning is showing promising results in the possible prevention of perioperative AKI. No definite data show a beneficiary effect of statins, fenoldepam, or sodium bicarbonate in preventing AKI.

SUMMARY

Perioperative AKI is prevalent and associated with significant morbidity and mortality. Considering the lack of effective preventive or therapeutic interventions, this review focuses on perioperative AKI: measures for early diagnosis, defining risks and possible mechanisms, and summarizing current knowledge for intraoperative fluid and hemodynamic management to reduce risk of AKI.

Risk factors for and the prevention of acute kidney injury after abdominal surgery

Postoperative acute kidney injury in patients undergoing abdominal surgery is not rare and often results in bad outcomes for patients. The incidence of postoperative acute kidney injury is hard to evaluate reliably due to its non-unified definitions in different studies. Risk factors for acute kidney injury specific to abdominal surgery include preoperative renal insufficiency, intraabdominal hypertension, blood transfusion, bowel preparation, perioperative dehydration, contrast agent and nephrotoxic drug use. Among these, preoperative renal insufficiency is the strongest predictor of acute kidney injury. The peri-operative management of high-risk patients should include meticulous selection of fluid solutions. Balanced crystalloid solutions and albumin are generally thought to be relatively safe, while the safety of hydroxyethyl starch solutions has been controversial. The purpose of the present review is to discuss the current knowledge regarding postoperative acute kidney injury in abdominal surgical settings to help surgeons make better decisions concerning the peri-operative management.

Impact of hydroxyethyl starch 70/0.5 on acute kidney injury after gastroenterological surgery

Background

Previous studies reported a higher mortality risk and a greater need for renal replacement therapy in patients administered hydroxyethyl starch (HES) rather than other fluid resuscitation preparations. In this study, we investigated the association between 6% HES 70/0.5 use and postoperative acute kidney injury (AKI) in gastroenterological surgery patients.

Methods

We conducted retrospective full-cohort and propensity-score-based analyses of patients who underwent gastroenterological surgery between June 2011 and August 2013 in a Japanese university hospital. The study sample comprised 66 AKI and 2,152 non-AKI patients in the full-cohort analysis and 35 AKI and 1,269 non-AKI patients in the propensity-score-based analysis. Propensity scores were calculated using an ordered logistic regression model in which the dependent variable comprised three groups based on HES infusion volumes (0, 1–999, and ≥ 1,000 ml). The association between HES groups and postoperative AKI incidence was analyzed using multiple logistic regression models. Other candidate independent variables included patient characteristics and intraoperative measures.

Results

In the full-cohort analysis, 40 (60.6%) AKI patients were diagnosed as "risk", 15 (22.7%) as "injury," and 11 (16.7%) as "failure". In the propensity-score-based analysis, the corresponding values were 22 (62.9%), 8 (22.9%), and 5 (14.3%). There was no significant association between total infused HES and postoperative AKI incidence in either the full-cohort or the propensity-score-based analysis (P = 0.168 and P = 0.42, respectively).

Conclusions

AKI incidence was not associated with clinical 6% HES 70/0.5 administration in gastroenterological surgery patients treated at a single center.

Perioperative risk factors for acute kidney injury after liver resection surgery: an historical cohort study

PURPOSE

This study aimed to identify the incidence and risk factors for acute kidney injury (AKI) after liver resection surgery and to clarify the relationship between postoperative AKI and outcome.

METHODS

We conducted a historical cohort study of patients who underwent liver resection surgery with sevoflurane anesthesia from January 2004 to October 2011. Acute kidney injury was diagnosed based on the Acute Kidney Injury Network classification within 72 hr after the surgery. Patient data, surgical and anesthetic data, and laboratory data were extracted manually from the patients' electronic charts. Multivariable logistic regression analysis was used to identify perioperative risk factors for postoperative AKI.

RESULTS

Acute kidney injury was diagnosed in 78 of 642 patients (12.1%; 95% confidence interval [CI]: 9.7 to 14.9). Multivariable analysis showed an independent association between postoperative AKI and preoperative estimated glomerular filtration rate (adjusted odds ratio [aOR] 0.74; 95% CI: 0.64 to 0.85), preoperative hypertension (aOR 2.10; 95% CI: 1.11 to 3.97), and intraoperative red blood cell transfusion (aOR 1.04; 95% CI: 1.01 to 1.07). Development of AKI within 72 hr after liver resection surgery was associated with increased hospital mortality, prolonged length of stay, and increased rates of mechanical ventilation, reintubation, and renal replacement therapy.

CONCLUSION

Perioperative risk factors for AKI after liver resection surgery are similar to those established for other surgical procedures. Further studies are needed to establish causality and to determine whether interventions on modifiable risk factors can reduce the incidence of postoperative AKI and improve patient outcome. This study was registered at the University Hospital Medical Information Network (UMIN) Center (UMIN 000008089).

The incidence of coagulopathy in pregnant patients with intrahepatic cholestasis: should we delay or avoid neuraxial analgesia?

STUDY OBJECTIVE

To estimate the incidence of coagulopathy in patients with intrahepatic cholestasis inhepatic cholestasis of pregnancy (ICP).

DESIGN

Retrospective cohort investigation.

SETTING

University medical center.

MEASUREMENTS

The records of 319 parturients who met study inclusion criteria were reviewed for various laboratory values. The primary outcome was the incidence of abnormal hemostasis, defined as prothrombin time (PT) greater than 14.5 seconds (INR>1.2). The incidence of postpartum hemorrhage was evaluated as a secondary outcome.

MAIN RESULTS

The incidence (95% CI) of abnormal PT was 0% (0 to 1.8). Other coagulation tests [partial thromboplastin time (PTT) and platelet count] were also normal, even in study subjects with significant (>5 times) elevation of liver enzymes. The incidence of postpartum hemorrhage after vaginal delivery was 2.4% (4 of 208 pts) and 6.3% (7 of 111 pts) after Cesarean delivery.

CONCLUSIONS

Coagulation abnormalities are rare in pregnant patients with ICP, even when a strict criterion is utilized (INR<1.2). The use of neuraxial anesthesia and/or analgesia may not necessarily be delayed in parturients with isolated ICP.

Molecular size and origin do not influence the harmful side effects of hydroxyethyl starch on human proximal tubule cells (HK-2) in vitro

BACKGROUND

Recently, clinical trials revealed renal impairment induced by hydroxyethyl starch (HES) in septic patients. In prior studies, we managed to demonstrate that HES accumulated in renal proximal tubule cells (PTCs). The related pathomechanism has not yet been discovered. To validate our hypothesis that the HES molecule itself is harmful, regardless of its molecule size or origin, we conducted a comprehensive study to elucidate the influences of different HES preparations on PTC viability in vitro.

METHODS

Cell viability of human PTC was measured with a cytotoxicity assay, quantifying the reduction of tetrazolium salt to colored formazan. Experiments were performed by assessing the influence of different carrier solutions of HES (balanced, nonbalanced, culture medium), different average molecular weights (70, 130, 200 kDa), different origins (potato or corn derived), and various durations of incubation (2-21 hours). Furthermore, HES 130/0.4 was fractionated by ultrafiltration, and the impact on cell viability of average single-size fractions with <3, 3 to 10, 10 to 30, 30 to 50, 50 to 100, and >100 kDa was investigated. We also tested the possible synergistic effects of inflammation induced by tumor necrosis factor-α.

RESULTS

All tested HES solutions, regardless of origin or carrier matrix, decreased cell viability in an equivalent, dose-dependent manner. Coincubation with tumor necrosis factor-α did not reduce HES-induced reduction of cell viability. Minor differences were detected comparing 70, 130, and 200 kDa preparations. Analysis of fractionated HES revealed that each fraction decreased cell viability. Even small HES molecules (10-30 kDa) were significantly deleterious.

CONCLUSIONS

For the first time, we were able to show that only the total mass of HES molecules applied is responsible for the harmful impact on renal PTC in vitro. Neither molecular size nor their origin showed any relevance.

Liberal or restricted fluid administration: are we ready for a proposal of a restricted intraoperative approach?

BACKGROUND

Fluid management in the perioperative period has been extensively studied but, despite that, "the right amount" still remains uncertain. The purpose of this paper is to summarize the state of the art of intraoperative fluid approach today.

DISCUSSION

In the current medical literature there are only heterogeneous viewpoints that gives the idea of how confusing the situation is. The approach to the intraoperative fluid management is complex and it should be based on human physiology and the current evidence.

SUMMARY

An intraoperative restrictive fluid approach in major surgery may be beneficial while Goal-directed Therapy should be superior to the liberal fluid strategy. Finally, we propose a rational approach currently used at our institution.

Low molecular weight pentastarch is more effective than crystalloid solution in goal-directed fluid management in patients undergoing major gastrointestinal surgery

BACKGROUND

This prospective observational study compared the volume effect between hydroxyethyl starch (HES) and crystalloid solution and its context dependency in intraoperative goal-directed fluid management.

METHODS

With institutional review board (IRB) approval, 35 patients undergoing major gastrointestinal surgery were enrolled. Fluid challenge consisting of 250 ml of either bicarbonate Ringer solution (BRS) or low molecular weight pentastarch (HES 70/0.5) was given to maintain stroke volume index >35 ml/m2. The context of fluid challenge was classified as related to either epidural block (EB) or blood loss (BL) or as nonspecific. The primary end point was the interval between index fluid challenge and the next fluid challenge, and the secondary end point was the hemodynamic parameter at the end of fluid challenge. Differences in these parameters in each clinical context were compared between BRS and HES 70/0.5. A p value <0.05 was considered statistically significant.

RESULTS

Eighty-eight, 77, and 127 fluid challenges were classified as related to EB and BL and as nonspecific, respectively. In the nonspecific condition, the median (range) interval after fluid challenge with HES 70/0.5 and BRS was 45 (11-162) min and 18 (8-44) min, respectively, and the difference was statistically significant. Also, mean arterial pressure and stroke volume index significantly increased, whereas stroke volume variation significantly decreased after fluid challenge with HES 70/0.5 compared with BRS. Such differences were not observed in the other situations.

CONCLUSIONS

HES 70/0.5 exerted larger volume effects than did crystalloid under nonspecific conditions. However, similar volume effects were observed during volume loss and extensive sympathetic blockade.