Nephrotoxicity of Sevoflurane Versus Desflurane Anesthesia in Volunteers

The effect of different anesthetics on the incidence of AKI and AKD after neurosurgical procedures

Acute kidney injury (AKI) incidence after neurosurgical operations has been reported as 10-14%. The literature regarding the incidence of nosocomial acute kidney disease (AKD) following neurosurgery is scarce. This retrospective, single-center, observational study aimed to assess the impact of different anaesthetics on development of postoperative AKI and persistent AKD in neurosurgical patients. We have categorized patients depending by the type of total intravenous anaestesia with propofol or sevoflurane. Most patients (74%) were on total intravenous anesthesia with propofol, while the rest (26%) were on sevoflurane. Patients were divided into subgroups with and without AKD depending on glomerular filtration rate 60 ml/min regarding kidney function at the end of intensive care unit stay. AKI was diagnosed in 341 (5.39%) patients. Significantly higher number of patients developed AKD in the sevoflurane group (16.9% vs. 6.3%). There was a significantly higher number of patients with both high and low AKI stages on sevoflurane and with hypotension during operation. Anaesthesia with sevoflurane had increased OR of 5.09 and ROC value of 0.681 for development of AKI. Anesthesia with sevoflurane had an increased OR of 4.98 and ROC value of 0.781 for development of AKD. Mortality was independently associated with anesthesia with sevoflurane, AKI development, hypotension during operation and AKD. Anesthesia with sevoflurane, hypotension during operation, and the development of AKD at the end of ICU stay were associated with higher mortality in the whole group (HR 6.996, HR 1.924 and HR 4.969, respectively). Patients treated with balanced anesthesia with sevoflurane had more frequent AKI and AKD with shorter survival. Renal toxicity of sevoflurane is pronounced in hypotension during operation and with a history of diabetes and coronary disease.

Effects of Desflurane versus sevoflurane on graft outcome of patients with cirrhosis receiving steatotic liver graft in deceased donor liver transplantation

STUDY OBJECTIVE

This study aimed to analyze the effects of two volatile anesthetic agents, desflurane and sevoflurane, on graft outcomes in patients undergoing deceased donor liver transplantation (DDLT) for cirrhosis, with a specific focus on fatty grafts.

DESIGN

A retrospective observational study.

SETTING

A tertiary hospital (Severance Hospital, Korea).

PATIENTS

This study included 151 patients with liver cirrhosis who underwent DDLT for cirrhosis between January 2006 and December 2022.

INTERVENTIONS

Patients were grouped according to maintenance anesthesia received (desflurane or sevoflurane), the model for end-stage liver disease (MELD) score, and macrovesicular steatosis (MVS) of the liver graft.

MEASUREMENTS

Survival curves were constructed from the date of surgery to graft failure or death. After propensity score matching (PSM), Cox regression analysis was used to compare hazards ratios (HR) for 5-year graft and overall survival. Subgroup analyses were performed for the MELD score and MVS of the liver graft. Incidences of 1-month acute rejection and early allograft dysfunction (EAD) were also compared between the two groups.

MAIN RESULTS

Among 151 eligible patients, 49 patients remained in each group after PSM, with 14 (28.6 %) graft failures and deaths occurring in each group. In matched analysis, sevoflurane showed poorer 5-year graft and overall survival compared to desflurane in recipients of graft with ≥10 % MVS, and this trend was significant in patients with MELD score of ≥35. In Cox regression model, compared to desflurane sevoflurane showed a propensity score-matched HR of 5.8 (95 % CI, 1.13-30.50 for both 5-year graft and overall survival. Additionally, sevoflurane showed an increased risk of 1-month acute rejection; however, no difference was observed for EAD.

CONCLUSIONS

Sevoflurane as a maintenance agent during DDLT in recipients with high MELD scores and fatty grafts may be associated with poorer outcomes compared to desflurane.

Effect of anesthetics on postoperative nausea and vomiting after peripheral vascular surgery in end-stage renal disease patients: A retrospective observational study

Background

Propofol-based total intravenous anesthesia (TIVA) is considered a prophylactic approach to decrease postoperative nausea and vomiting (PONV). Despite general anesthesia commonly being performed in end-stage renal disease (ESRD) patients, PONV in ESRD patients has not been well-described. We investigated PONV in peripheral vascular surgery under general anesthesia in ESRD patients.

Methods

To compare PONV between propofol-based TIVA and anesthesia with volatile anesthetics, we collected retrospective data from patients who underwent peripheral vascular surgery under general anesthesia from July 2018 to April 2020. We performed univariable and multivariable analyses, including factors that could be associated with PONV and those previously shown to affect PONV.

Result

A total of 1,699 peripheral vascular surgeries under general anesthesia in ESRD patients were eligible for analysis. Based on the multivariable analysis, TIVA (odds ratio [OR], 0.45; 95% confidence interval [CI], 0.35-0.60; P < 0.001) significantly decreased PONV. Female sex (OR, 1.85; 95% CI, 1.44-2.38; P < 0.001) and anesthetic duration (OR, 1.01; 95% CI, 1.00-1.01; P < 0.001) were associated with increased PONV.

Conclusion

Propofol-based TIVA is the most influential factor decreasing PONV after peripheral vascular surgery in ESRD patients. Anesthesiologists can apply propofol-based TIVA as an alternative to anesthesia with volatile anesthetics.

Renal injury from sevoflurane in noncardiac surgery: a retrospective cohort study

BACKGROUND

Sevoflurane is metabolised into Compound A and fluoride that carry a hypothetical risk of nephrotoxicity. However, a clinically significant association between sevoflurane use and acute kidney injury (AKI) in humans has not been established.

METHODS

We retrospectively reviewed 15 552 patients who underwent noncardiac surgery under general anaesthesia using a volatile agent lasting >3 h between July 2016 and May 2019 at a single centre. Patients were divided into a sevoflurane group or no sevoflurane group (desflurane or isoflurane). The primary outcome was incidence of postoperative AKI, which was defined based on the Kidney Disease: Improving Global Outcomes criteria using creatinine concentration within 48 h postoperatively. Propensity score analysis using inverse probability of treatment weighting and propensity score matching was designed to compare outcomes between groups.

RESULTS

Amongst 13 701 included patients, 11 070 (80.8%) received sevoflurane during anaesthesia. The incidence of AKI was 2.3% (257/11 070) and 2.5% (66/2631) in the sevoflurane and no sevoflurane groups, respectvely (P=0.57). After inverse probability of treatment weighting adjustment, sevoflurane anaesthesia was not significantly associated with postoperative AKI (odds ratio [OR] 1.32; 95% confidence interval [CI]: 0.99-1.76; P=0.059). In the matched cohort, the incidence of AKI was 3.1% (81/2626) and 2.4% (62/2626) in the sevoflurane and no sevoflurane groups, respectively, and sevoflurane anaesthesia was not associated with postoperative AKI (OR 1.32; 95% CI: 0.94-1.86; P=0.11).

CONCLUSIONS

Sevoflurane anaesthesia for >3 h was not associated with postoperative renal injury compared with anaesthesia using other volatile agents.

Minimal fresh gas flow sevoflurane anesthesia and postoperative acute kidney injury in on-pump cardiac surgery: a randomized comparative trial

BACKGROUND

Compound A is generated by sevoflurane when it reacts with carbon dioxide absorbers with strong bases at minimal fresh gas flow (FGF) and is nephrotoxic in animals. No conclusive data has shown increased risk in humans. The aim of this study was to investigate if minimal FGF promotes an increase in the incidence of acute kidney injury (AKI) when compared to high FGF in patients undergoing on-pump cardiac surgery under sevoflurane anesthesia.

METHODS

Two hundred and four adult patients scheduled for on-pump cardiac surgery under sevoflurane anesthesia were randomly allocated to two groups differentiated by FGF: minimal FGF (0.5 L.min^-1) or high FGF (2.0 L.min^-1). Baseline creatinine measured before surgery was compared daily to values assayed on the first five postoperative days, and 24-hour urinary output was monitored, according to the KDIGO (Kidney Disease Improving Global Outcomes) guideline to define postoperative cardiac surgery-associated acute kidney injury (CSA-AKI). Creatinine measurements were also obtained 20 and 120 days after hospital discharge.

RESULTS

Postoperative AKI occurred in 55 patients, 26 patients (29.5%) in the minimal FGF group and 29 patients (31.5%) in the high FGF group (p = 0.774). Twenty days after discharge, 11 patients (6.1%) still had CSA-AKI and 120 days after discharge only 2 patients (1.6%) still had CSA-AKI.

CONCLUSIONS

When compared to high FGF, minimal FGF sevoflurane anesthesia during on-pump cardiac surgery is not associated with increased risk of postoperative AKI in this population at high risk for renal injury.

Predicting cost of inhalational anesthesia at low fresh gas flows: impact of a new generation carbon dioxide absorbent

It is well known that low fresh gas flows result in lower cost of inhalational agents. A new generation of carbon dioxide absorbents allows low flow anesthesia with all anesthetics but these new compounds are more expensive. This study examines the cost of inhalational anesthesia at different fresh gas flows combined with the cost of absorbent. The cost of sevoflurane and desflurane is lower at low fresh gas flows. Paradoxically the cost of isoflurane is cheaper at 2 L/min than at lower fresh gas flows due to increased cost of carbon dioxide absorbent. Therefore low fresh gas flows should be used when feasible with sevoflurane and desflurane, but higher fresh gas flows up to 2 L/min may be more economical with isoflurane during maintenance phase of anesthesia.

Transient postoperative glycosuria after isoflurane exposure in two dogs

The present report describes two surgical cases involving the development of sudden glycosuria after isoflurane anaesthesia, despite the dogs having normal blood glucose levels and renal glucose reabsorption. The glycosuria manifested 1 day after surgery and resolved spontaneously within 2 days in both cases. Considering that the surgeries (subcutaneous mandibular mass removal and fracture repair) were unrelated to the kidneys, and there were no remarkable events during anaesthesia, the glycosuria may have been associated with the isoflurane anaesthesia. There have been several previous reports of glycosuria in human patients following transient proximal tubule dysfunction due to volatile anaesthetics. This case report suggests the possibility of transient renal dysfunction following isoflurane anaesthesia in these two clinically healthy dogs. However, considering the observational nature of this report, it can not be excluded that any other procedure performed in these animals was responsible of the observed glycosuria.

Comparative effect of desflurane and sevoflurane on liver function tests of patients with impaired hepatic function undergoing cholecystectomy: A randomized clinical study

Background and Aim:

Desflurane and sevoflurane are the most common volatile anesthetics used during laparoscopic and hepatic surgery. The objective of the study was to evaluate the effect of desflurane and sevoflurane in patients with elevated preoperative liver functions undergoing laparoscopic cholecystectomy.

Methods:

The study was a randomized study and included 162 patients classified randomly into two groups: Desflurane group: The patients received desflurane (end-tidal concentration 4%–6%) as an inhalational agent during the whole procedure. Sevoflurane group: The patients received sevoflurane (end-tidal concentration 2%–4%) as an inhalational agent during the whole procedure. The investigations included serum level of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyltransferase (GGT), and total bilirubin. The values were serially collected at the following timepoints; T0:at the preoperative period, T1:directly after surgery, T2:1^st postoperative day, T3:2^nd postoperative day, T4:3^rd postoperative day, T5:5^th postoperative day, T6:7^th postoperative day, and T7:10^th postoperative day. The statistics were described in terms of mean ± standard deviation, frequencies, and percentages.

Results:

The preoperative liver enzymes and total bilirubin were higher than the normal range in patients of the two groups. Postoperatively, there was a decrease in the AST and ALT with desflurane more than sevoflurane from T1 to T6(P < 0.05). The ALP, GGT, and bilirubin decreased in patients of the two groups, but the comparison was insignificant (P > 0.05).

Conclusion:

The desflurane is a safe inhalational volatile for maintenance of anesthesia in patients with impaired liver function undergoing laparoscopic cholecystectomy. It was associated with a decrease in the liver enzymes more than the sevoflurane.

Renal effects of general anesthesia from old to recent studies

Various types of anesthesia are being utilized to maintain physiologically secured surgical conditions. Nearly all categories of general anesthesia are characterized by various perioperative and postoperative complications. These shortcomings are important aspects that need to be considered by the anesthesiologist and surgeon before administration of these compounds. The renal effects of anesthesia play an important role in understanding possible systemic changes due to the fact that the kidney has a direct or indirect impact on nearly all the systems of the body. Various studies have been conducted to find out changes in renal parameters and its systemic effects upon administration of the anesthesia and its postoperative repercussions. Besides that, the impaired renal function might have an impact on the excretion of anesthetic metabolites, which can lead to long-term dysfunction. Patients with a previous history of disease ought to be brought under consideration because these chemicals can ameliorate pre-existent symptoms. This review is intended to discuss the early and latest studies based on the effects of general anesthesia on the renal system.

A Comparison of the Effects of Prolonged (>10 Hour) Low-flow Sevoflurane, High-flow Sevoflurane, and Low-flow Isoflurane Anaesthesia on Hepatorenal Function in Orthopaedic Patients

This study compared the effects of low-flow sevoflurane, high-flow sevoflurane and low-flow isoflurane on hepatorenal function during and after more than 10 hours of anaesthesia. Twenty-five patients scheduled for elective orthopaedic surgery were categorized into three groups; low-flow sevoflurane (fresh gas flow at 1 litre/min, n=9), high-flow sevoflurane (5 l/min, n=7), or low-flow isoflurane (1 l/min, n=9). Inspiratory compound A concentrations were measured. The groups had similar duration of anaesthesia and exposure to anaesthetic agents. The area under the curve of concentration (mean, SD) of compound A in the low-flow sevoflurane group (359.8, 106.1 ppm.h) was greater than that in the high-flow sevoflurane group (61.1, 29.3 ppm.h; P<0.01). All groups showed normal plasma creatinine and creatinine clearance, and transient postoperative increases in plasma alanine aminotrans-ferase and alpha glutathione-S-transferase, as well as urinary glucose and alpha glutathione-S-transferase, with no significant differences between groups. There were no significant relationships between the area under the curve of concentration of compound A and the biomarkers. These findings suggest that prolonged anaesthesia with low-flow sevoflurane has similar effects on hepatorenal function to prolonged anaesthesia with high-flow sevoflurane and low-flow isoflurane.

Comparison of Two Different Inhalation Anesthetics on Grafted Kidney Function in Patients Undergoing Renal Transplantation Surgery: Desflurane or Sevoflurane?

BACKGROUND

Anesthetic management of patients during renal transplantation is vitally important for ensuring proper functioning of kidneys that have undergone ischemia-reperfusion damage. The goal of this prospective study was to compare the effects of 2 different inhalation agents (sevoflurane and desflurane) on grafted kidney function in renal transplantation surgery.

METHODS

Sixty-five patients who were scheduled for living donor renal transplantation were enrolled in the study. General anesthesia was performed on all patients. Thirty-five pairs of recipients and donors were anesthetized with sevoflurane (group S) and 30 pairs of recipients and donors were anesthetized with desflurane (group D). Each patient's demographic characteristics, immunologic and clinical data, and hemodynamic parameters were recorded. The estimated glomerular filtration rate was calculated in the preoperative period and on postoperative days 1 and 7. The blood samples were collected before the operation and on postoperative days 1 and 7 for measurement of serum creatinine, neutrophil gelatinase-associated lipocalin, and interleukin 18.

RESULTS

There were no significant differences in demographic characteristics or immunologic data between group D and group S. Intraoperative heart rate and mean arterial blood pressure were the same between groups. Creatinine, estimated glomerular filtration rate, neutrophil gelatinase-associated lipocalin, and interleukin 18 values did not differ between groups (P > .05) in the preoperative period and postoperative days 1 and 7.

CONCLUSIONS

Sevoflurane and desflurane had no adverse effects on grafted kidney functions according to short-term graft outcomes in patients undergoing living donor renal transplantation.

Impact of CYP2E1, GSTA1 and GSTP1 gene variants on serum alpha glutathione S-transferase level in patients undergoing anaesthesia

BACKGROUND

The serum glutathione S-transferase alpha (α-GST) concentration has been used as a marker of hepatic condition. After sevoflurane anaesthesia a mild impairment of hepatocellular integrity was observed. Genetic polymorphisms in CYP2E1, GSTA1 and GSTP1 genes, affecting enzymes activity, may possibly influence the hepatotoxic effect of sevoflurane. The aim of this study was to assess the influence of genetic polymorphism of CYP2E1, GSTA1 and GSTP1 genes on serum α-GST level in 86 unrelated patients representing ASA physical status I-II, undergoing laryngological surgery under general anaesthesia with sevoflurane.

METHODS

The serum samples from three perioperative time points were analyzed using ELISA. Genetic variants were detected by pyrosequencing and sequencing. Finally, the statistical associations between serum α-GST concentration and analyzed alleles of CYP2E1, GSTP1 and GSTA1 genes were estimated.

RESULTS

The allele GSTA1*B (-567G, -69T, -52A) frequency was 0.43, whereas the alleles c.313G and c.341T of GSTP1 were identified with frequencies of 0.28 and 0.1 respectively. The -1053T allele of the CYP2E1 gene was observed with 0.01 frequency. We found serum α-GST concentrations in homozygous changes c.313A>G and c.341C>T of the GSTP1 gene significantly higher at the end of anaesthesia as compared with the levels at pre-anaesthetic and 24 h post-anaesthetic time points. Moreover, GSTA1 wild type genotype was associated with increased α-GST concentration at 24 h after the end of anaesthesia.

CONCLUSIONS

GSTP1 gene polymorphism has an impact on the perioperative serum α-GST concentration in patients undergoing sevoflurane anaesthesia. A similar association, although not statistically significant exists between GSTA1 gene variants and perioperative serum α-GST level.

Case report: proximal tubule impairment following volatile anesthetic exposure

The safety of contemporary volatile anesthetic agents with respect to kidney function is well established, and growing evidence suggests that volatile anesthetics even protect against ischemic nephropathy. However, studies examining effects of volatile anesthetics on kidney function frequently demonstrate transient proteinuria and glycosuria following exposure to these agents, although the cause of these findings has not been thoroughly examined. We describe the case of a patient who underwent a neurosurgical procedure, then experienced glycosuria without hyperglycemia that resolved within days. Following a second neurosurgical procedure, the patient again developed glycosuria, now associated with ketonuria. Further examination demonstrated nonalbuminuric proteinuria in conjunction with urinary wasting of phosphate and potassium, indicative of proximal tubule impairment. We suggest that transient proximal tubule impairment may play a role in the proteinuria and glycosuria described following volatile anesthetic exposure and discuss the relationship between these observations and the ability of these agents to protect against ischemic nephropathy.

Propofol increases morbidity and mortality in a rat model of sepsis

INTRODUCTION

Severe sepsis is associated with approximately 50% mortality and accounts for tremendous healthcare costs. Most patients require ventilatory support and propofol is commonly used to sedate mechanically ventilated patients. Volatile anesthetics have been shown to attenuate inflammation in a variety of different settings. We therefore hypothesized that volatile anesthetic agents may offer beneficial immunomodulatory effects during the course of long-term intra-abdominal sepsis in rats under continuous sedation and ventilation for up to 24 hours.

METHODS

Sham operation or cecal ligation and puncture (CLP) was performed in adult male Wistar rats followed by mechanical ventilation. Animals were sedated for 24 hours with propofol (7 to 20 mg/kg/h), sevoflurane, desflurane or isoflurane (0.7 minimal alveolar concentration each).

RESULTS

Septic animals sedated with propofol showed a mean survival time of 12 hours, whereas >56% of all animals in the volatile groups survived 24 hours (P <0.001). After 18 hours, base excess in propofol + CLP animals (-20.6 ± 2.0) was lower than in the volatile groups (isoflurane + CLP: -11.7 ± 4.2, sevoflurane + CLP: -11.8 ± 3.5, desflurane + CLP -14.2 ± 3.7; all P <0.03). Plasma endotoxin levels reached 2-fold higher levels in propofol + CLP compared to isoflurane + CLP animals at 12 hours (P <0.001). Also blood levels of inflammatory mediators (tumor necrosis factor-α, interleukin-1β, interleukin-10, CXCL-2, interferon-γ and high mobility group protein-1) were accentuated in propofol + CLP rats compared to the isoflurane + CLP group at the same time point (P <0.04).

CONCLUSIONS

This is the first study to assess prolonged effects of sepsis and long-term application of volatile sedatives compared to propofol on survival, cardiovascular, inflammatory and end organ parameters. Results indicate that volatile anesthetics dramatically improved survival and attenuate systemic inflammation as compared to propofol. The main mechanism responsible for adverse propofol effects could be an enhanced plasma endotoxin concentration, leading to profound hypotension, which was unresponsive to fluid resuscitation.

An Open-label Comparison of a New Generic Sevoflurane Formulation With Original Sevoflurane in Patients Scheduled for Elective Surgery Under General Anesthesia

PURPOSE

To compare the stability, effectiveness, and safety profiles of a new generic sevoflurane with those of the original sevoflurane formulation in patients undergoing elective surgery.

METHODS

An accelerated 3-month storage test was performed to evaluate the compositional changes in generic sevoflurane stored in glass bottles. In addition, 182 patients were randomly allocated to receive generic (n = 89 [54 men and 35 women]; mean [SD] age, 49.9 [11.6] years) or original (n = 93 [61 men and 32 women]; mean [SD] age, 49.6 [11.1] years) sevoflurane at a gas flow of 3 L/min for approximately 3 hours. The mean minimum alveolar concentration (MAC) during sevoflurane anesthesia was evaluated, and gas samples for measuring compound A were collected from the inspiratory limb of the circuit at preset intervals. Blood samples for measuring serum inorganic fluoride were obtained at preset intervals (pharmacokinetic group: generic/original sevoflurane = 45/46). Renal biomarkers, such as N-acetyl-β-glucosaminidase, α- and π-glutathione-S-transferase, albumin, urine protein and osmolality, serum creatinine and osmolality, creatinine clearance, and blood urea nitrogen, were measured at preset intervals (renal biomarker group: generic/original sevoflurane = 44/47). Adverse reactions were monitored for 72 hours after discontinuation of sevoflurane use.

FINDINGS

Generic sevoflurane contained in glass bottles was stable for 3 months. The mean MAC was similar for generic and original sevoflurane (median [range], 0.93 [0.67-1.29] vs 0.94 [0.63-1.5] vol%). Adverse event rates were similar (90.3% vs 84.3%), as were the AUClast of inorganic fluoride (333.7 [112.7-1264.7] vs 311.9 [81.5-1266.5] hours·μmol/L) and compound A (51.8 [6.3-204.5] vs 55.3 [10.8-270.6] hours·ppm). Biomarkers associated with renal injury were not significantly different between the 2 formulations.

IMPLICATIONS

No significant difference was found in the mean MAC between generic and original sevoflurane. ClinicalTrials.gov identifier: NCT01096212.

The role of inhalational anesthetic drugs in patients with hepatic dysfunction: a review article

Context:

Anesthetic drugs including halogenated anesthetics have been common for many years. Consequent hepatic injury has been reported in the literature. The mechanism of injury is immunoallergic. The first generation drug was halothane; it had the most toxicity when compared to other drugs. The issue becomes more important when the patient has an underlying hepatic dysfunction.

Evidence Acquisition:

In this paper, reputable internet databases from 1957–2014 were analyzed and 43 original articles, 3 case reports, and 3 books were studied. A search was performed based on the following keywords: inhalational anesthesia, hepatic dysfunction, halogenated anesthetics, general anesthesia in patients with hepatic diseases, and side effects of halogenated anesthetics from reliable databases. Reputable websites like PubMed and Cochrane were used for the searches.

Results:

In patients with hepatic dysfunction in addition to hepatic system and dramatic hemostatic dysfunction, dysfunction of cardiovascular, renal, respiratory, gastrointestinal, and central nervous systems may occur. On the other hand, exposure to inhalational halogenated anesthetics may have a negative impact (similar to hepatitis) on all aforementioned systems in addition to direct effects on liver function as well as the effects are more pronounced in halothane.

Conclusions:

Despite the adverse effects of inhalational halogenated anesthetics (especially halothane) on hepatic patients when necessary. The effects on all systems must be considered and the necessary preparations must be provided. These drugs are still used, if necessary, due to the presence of positive effects and advantages mentioned in other studies as well as the adverse effects of other drugs.

Glutathione S-transferase as a toxicity indicator in general anesthesia: genetics and biochemical function

General anesthesia may lead in patients to unexpected and adverse reactions including toxicity. Glutathione S-transferases (GSTs) are enzymes responsible for the detoxification process of anesthetic agents. Plasma and urine GST measurements are used in multiple studies as a hepatocellular integrity or renal injury indicator. The importance of GST enzyme measurements in monitoring the hepatotoxic and nephrotoxic effect in anesthetized patients is presented. The biochemical function and specific properties of GST render it a prognostic biomarker. This review demonstrates that GST can be valuable and promising toxicity indicator in patients undergoing general anesthesia.

Hepatotoxicity of halogenated inhalational anesthetics

Context:

Halogenated inhalational anesthetics are currently the most common drugs used for the induction and maintenance of general anesthesia. Postoperative hepatic injury has been reported after exposure to these agents. Based on much evidence, mechanism of liver toxicity is more likely to be immunoallergic. The objective of this review study was to assess available studies on hepatotoxicity of these anesthetics.

Evidence Acquisition:

We searched PubMed, Google Scholar, Scopus, Index Copernicus, EBSCO and the Cochrane Database using the following keywords: “inhalational Anesthetics” and “liver injury”; “inhalational anesthetics” and “hepatotoxicity”; “volatile anesthetics” and “liver injury”; “volatile anesthetics” and hepatotoxicity for the period of 1966 to 2013. Fifty two studies were included in this work.

Results:

All halogenated inhalational anesthetics are associated with liver injury. Halothane, enflurane, isoflurane and desflurane are metabolized through the metabolic pathway involving cytochrome P-450 2E1 (CYP2E1) and produce trifluoroacetylated components; some of which may be immunogenic. The severity of hepatotoxicity is associated with the degree by which they undergo hepatic metabolism by this cytochrome. However, liver toxicity is highly unlikely from sevoflurane as is not metabolized to trifluoroacetyl compounds.

Conclusions:

Hepatotoxicity of halogenated inhalational anesthetics has been well documented in available literature. Halothane-induced liver injury was extensively acknowledged; however, the next generation halogenated anesthetics have different molecular structures and associated with less hepatotoxicity. Although anesthesia-induced hepatitis is not a common occurrence, we must consider the association between this disorder and the use of halogenated anesthetics.

Effect of sevoflurane anesthesia on the severity of renal histopathologic changes in rabbits pretreated with gentamicin: A controlled, investigator-blinded, experimental study

BACKGROUND

Inorganic fluoride and compound A are potential nephrotoxic products of sevoflurane, a halogenated inhalational general-anesthetic drug.

OBJECTIVE

The aim of this study was to microscopically examine the effect of sevoflurane on the severity of renal histopathologic changes in rabbits pretreated with gentamicin.

METHODS

In this controlled, investigator-blinded, experimental study at the Firat University School of Medicine, Elazig, Turkey, male New Zealand white rabbits (age range, 6-8 months; weight range, 2600-3400 g) were randomly divided into 4 groups of equal size. The gentamicin group received IM gentamicin 10 mg/kg · d(-1) for 10 days. Rabbits in the sevoflurane group received pH-balanced saline solution at a volume of 10 mg/kg · d(-1) for 10 days, equivalent to the volume of gentamicin administered to the gentamicin group. On day 11, anesthesia was induced with 8% sevoflurane in 50% oxygen and air using a suitable facemask. When a sufficient depth of anesthesia (loss of eyelash reflex and tolerance to tail-clamp stimuli) was reached (without a muscle relaxant), the rabbits were intubated (3-mm ID) and allowed to breathe spontaneously. End-tidal or end expiratory concentration of sevoflurane was then decreased to 4% and the rabbits were anesthetized at a flow rate of 4 L/min for 4 hours. The rabbits in the gentamicin + sevoflurane group were treated with IM gentamicin at a dosage of 10 mg/kg · d(-1) for 10 days. On day 11, they were exposed to sevoflurane, as described for the sevoflurane group. The control group received IM pH-balanced saline solution for the duration of the study. Twenty-four hours after treatment completion, all rabbits were euthanized and kidney tissue samples were obtained. Histopathologic examinations were then carried out using light microscopy. Changes in renal histopathology were based on the percentage of acute tubular necrosis (ATN) and judged on a scale from none to severe.

RESULTS

Forty male New Zealand white rabbits (mean [SD] age, 7 [0.49] months; mean [SD] weight, 2900 [150] g) were divided into 4 groups of 10 rabbits each. Proximal renal tubule cell injury in the form of ATN (the mean score) was significantly greater in the 3 treatment groups than in the control group (all, P < 0.001), especially at the corticomedullary junction. In the 3 treatment groups, the most severe renal damage observed was rated as mild (10%-25%). More rabbits in the gentamicin + sevoflurane group had mild renal damage (7) than in the gentamicin group (4) or the sevoflurane group (4), but the between-group differences were not statistically significant.

CONCLUSION

In this experimental study of the effects of sevoflurane on the severity of renal histopathologic changes, a higher percentage of rabbits were observed to have greater renal damage in the gentamicin + sevoflurane group than the other groups. However, between-group differences did not reach statistical significance.

Anesthetic gases and occupationally exposed workers

The aim of this study is to estimate whether the occupational exposure to low dose anesthetic gases could cause alterations of blood parameters in health care workers. 119 exposed subjects and 184 not exposed controls were included in the study. Each worker underwent the complete blood count test (CBC), proteinaemia, leukocyte count, serum lipids, liver and kidney blood markers. The liver blood markers show statistically significant differences in health care workers compared with controls (p<0.05), a statistically significant decrease in neutrophils and an increase of lymphocytes in health care workers compared with controls (p<0.05). The prevalence of values outside the range for GPT, GGT, total bilirubin, lymphocytes and neutrophils was statistically significant in health care workers compared with controls (p<0.05). The results suggest that occupational exposure to low dose anesthetic gases could influence some haematochemical hepatic and hematopoietic parameters in exposed health care workers.

Nicardipine infusion for hypotensive anesthesia during orthognathic surgery has protective effect on renal function

PURPOSE

Hypotensive anesthesia may adversely affect renal function. The purpose of this study was to evaluate the renoprotective effect of nicardipine in patients undergoing orthognathic surgery under hypotensive anesthesia.

MATERIALS AND METHODS

In this double-blinded randomized controlled study, healthy patients undergoing orthognathic surgery were enrolled to evaluate renal function during and after hypotensive anesthesia. The predictor variable was the agent, nicardipine vs remifentanil, used to maintain mean arterial pressure at 50 to 65 mm Hg. Primary outcome variables were renal function markers and secondary outcome variables were hemodynamic data, which were measured before hypotension, 2 hours after hypotension, 1 hour postoperatively (t3), and 24 hours postoperatively. Linear mixed model was used to analyze repeatedly measured data.

RESULTS

Forty-six patients were randomly allocated to receive remifentanil (R group; n = 23) or nicardipine (N group; n = 23). The renal tubular function marker, urinary N-acetyl-1-β-D-glucosaminidase (NAG), was lower at t3 in the N group than in the R group (P = .014). In the N group, fractional excretion of sodium was significantly higher at t3 compared with baseline (P < .0001). The 2 groups did not show any differences in estimated creatinine clearance and serum cystatin C.

CONCLUSION

Subclinical and reversible renal dysfunction appears during hypotensive anesthesia in patients undergoing orthognathic surgery. Continuous infusion of nicardipine attenuated the increase in NAG, which is a marker of renal tubular injury, during hypotensive anesthesia with desflurane and remifentanil.

Sevoflurane has no adverse effects on renal function in cirrhotic patients: a comparison with propofol

BACKGROUND

Cirrhotic patients are prone to developing renal dysfunction after anaesthesia and surgery. However, no consensus has been reached whether sevoflurane could have adverse effects on renal function in cirrhotic patients. We hypothesised that the use of sevoflurane for general anaesthesia would lead to post-operative renal dysfunction in cirrhotic patients undergoing liver resection.

METHODS

A total of 200 patients undergoing liver resection were randomly assigned to a propofol or sevoflurane group. The influence of sevoflurane or propofol on renal function was evaluated by the maximal change, the difference between the pre-operative baseline and the highest values of serum creatinine and blood urea nitrogen measured at day 1, 3 and 6 post-operatively.

RESULTS

The maximal change in serum creatinine after liver resection was -4.52 (5.78) μmol/l and -3.37 (7.34) μmol/l with P = 0.398, and that in blood urea nitrogen was 0.41 (1.49) mmol/l and 0.93 (1.54) mmol/l with P = 0.098 between the sevoflurane group (n = 52) and the propofol group (n = 50), respectively.

CONCLUSIONS

Sevoflurane does not seem to impair post-operative renal function in cirrhotic patients undergoing liver resection.

Comparison of hepatic and renal function between inhalation anesthesia with sevoflurane and remifentanil and total intravenous anesthesia with propofol and remifentanil for thyroidectomy

BACKGROUND

Inhalation anesthetics are an important factor for postoperative hepatic and renal dysfunction. In this regard, TIVA can reduce the risk of hepatic and renal dysfunction inherited to inhalation anesthetics. The present study was conducted to determine whether hepatic and renal functions differ after anesthesia with sevoflurane and propofol.

METHODS

Two hundred patients, ASA physical status class I, II, scheduled for an elective thyroidectomy were randomly divided into two groups. Anesthesia was maintained with sevoflurane 1-2% and remifentanil in the sevoflurane group (Group S) and propofol 2-5 ug/ml and remifentanil 2-5 ng/ml at the effect site, using a target controlled infusion (TCI) pump in the TIVA group (Group T) to maintain BIS of 40-60. To evaluate the hepatic and renal function, aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN) and creatinine were tested at preoperation (baseline), postoperative 1 day and 3 days.

RESULTS

AST was increased at postoperative 1 day and 3 days, compared with that of the preoperation in Group S, and postoperative 1 day in Group T, but the values were within its normal limit. ALT was not changed after anesthesia in both groups. BUN was increased at postoperative 1 day, compared with that of the preoperation in Group S, but the value was within its normal limit. Creatinine was not changed after anesthesia in both groups.

CONCLUSIONS

The changes of hepatic and renal function after inhalation anesthesia with sevoflurane and TIVA with propofol and remifentanil for thyroidectomy were clinically insignificant, and there was no difference between the two methods.

Urinary lipid and protein oxidation products upon halothane, isoflurane, or sevoflurane anesthesia in humans: potential biomarkers for a subclinical nephrotoxicity

OBJECTIVE

To investigate whether lipid and protein oxidation products are elevated and correlated with routine clinical markers of hepatic and renal function in patients anesthetized with halothane, isoflurane, or sevoflurane.

METHODS

Urine and blood samples were collected from patient groups. Excretion of aldehydes, acetone, and o,o'-dityrosine was measured before and after anesthesia. Blood samples were analysed for clinical markers.

RESULTS

Urinary concentrations of aldehydes, acetone, o,o'-dityrosine and glucose were significantly increased after anesthesia in halothane and sevoflurane groups earlier than clinical markers. Significant correlations were found in sevoflurane group.

CONCLUSION

Lipid and protein oxidation contributes to subclinical sevoflurane nephrotoxicity. Oxidation products may serve as early biomarkers.

Effect of sevoflurane on grafted kidney function in renal transplantation

BACKGROUND

The objective of this retrospective study was to determine if there are any differences in grafted kidney function in recipients of kidney transplantation (KT) when donors and recipients were anesthetized with sevoflurane compared to desflurane.

METHODS

Seventy-three pairs of donors-recipients were anesthetized with sevoflurane (Sevo group) and 71 pairs were anesthetized with desflurane (Des group). We retrospectively investigated the blood urea nitrogen (BUN) levels, creatinine (Cr) levels, and estimated glomerular filtration rates (eGFR) of the recipients in both groups for 1 year postoperatively. We tested non-inferiority for serum creatinine at discharge and 1 year after KT. Short-term (1 year) outcomes of KT were assessed by the incidence of delayed graft function (DGF), acute rejection episodes (ARE), and graft failure.

RESULTS

There were no differences in BUN, Cr, eGFR, or outcomes of KT at 1 year postoperatively. Specifically, the 95% confidence interval for the difference in creatinine levels between the Sevo and Des groups was less than the margin of equivalence at the time of discharge and 1 year after surgery. The occurrences of DGF, ARE, and graft failure were comparable between the groups.

CONCLUSIONS

Compared to desflurane, sevoflurane had no adverse effects on grafted renal function or on the short-term outcome of renal transplantation.

[Retrospective comparative study between sevoflurane and propofol in maintaining anaesthesia during liver transplant: Effects on kidney and liver function]

OBJECTIVE

To compare the post-operative effects of sevoflurane versus propofol on liver and kidney function while maintaining anaesthesia in the orthotopic liver transplant (OLT), as well as to analyse the short-term survival as regards these functions.

PATIENTS AND METHODS

A retrospective analysis was conducted on patients subjected to an OLT between January 2002 and December 2009. Patients on pre-transplant haemodialysis, re-transplants, and hepatorenal transplants were excluded. The incidence of acute renal failure, initial dysfunction of the graft, reperfusion syndrome, rejection, and the transaminase peak depending value depending on the hypnotic used, were recorded.

RESULTS

About one-third (31.2%) of the patients developed acute renal failure and 11.9% an initial dysfunction, with no differences between the groups. There was a tendency for a lower incidence of initial dysfunction of the graft in the sevoflurane group (8.6% compared to 12.8%), a lower transaminase peak (greater than 2000 U/L, 12.1% versus 15.9%), and a lower incidence of reperfusion syndrome (10.3% compared to 21.6%).

CONCLUSIONS

Despite the fact that the renal metabolism sevoflurane is elevated, we did not find any higher incidence of acute renal failure. Sevoflurane in the liver transplant anaesthesia is as least equally as safe propofol as regards renal function and liver function. New prospective studies are needed to clarify the possible effects of the hypnotic in liver transplant.

Urinary α-GST and π-GST for prediction of dialysis requirement or in-hospital death in established acute kidney injury

CONTEXT

Urinary α-glutathione S-transferase (α-GST) and π-glutathione S-transferase (π-GST) are promising proximal and distal tubular leakage markers for early detection of acute kidney injury (AKI).

OBJECTIVE

To examine the performance of these markers for predicting the composite of dialysis requirement or in-hospital death in patients with an established diagnosis of AKI.

MATERIALS AND METHODS

Prospective cohort study of 245 adults with AKI. A single urinary α-GST and π-GST measurement was obtained at time of nephrology consultation.

RESULTS

Overall, urinary π-GST performed better than α-GST for prediction of dialysis requirement (AUC 0.59 vs. 0.56), and the composite outcome (AUC 0.58 vs. 0.56). In subgroup analyses, π-GST displayed better discrimination for prediction of dialysis requirement in patients with baseline eGFR <60 mL/min/1.73 m(2) (AUC 0.61) and oliguria (AUC 0.72). Similarly, α-GST performed better in patients with stage-1 (AUC 0.66) and stage-2 AKI (AUC 0.80).

CONCLUSIONS

In patients with an established diagnosis of AKI, a single urinary π-GST measurement performed better than α-GST at predicting dialysis requirement or death, but neither marker had good prognostic discrimination.

Biochemical Effects of Low-Flow Anesthesia with Inhalation agents in Patients undergoing Laparoscopic Surgery

This study was designed to investigate the effects of low-flow anesthesia with sevoflurane and desflurane on renal and hepatic functions in patients undergoing laparoscopic abdominal surgery. Twenty patients with ASA I or II (American Society of Anesthesiologists classification) physical scores were included in the study. There were no significant differences between sevoflurane and desflurane groups with respect to age, weight, body mass index, duration of the operation and the anesthesia. In both groups, renal function parameters such as urea, BUN, creatinine and calculated creatinine clearance did not show significant differences at 24 and 48 hours. Homocysteine levels, which showed renal metabolic function, did not change significantly at 24 and 48 hours when compared to baseline levels in both groups. Transaminases were not significantly different between the two groups from baseline to 24 and 48 hours. These differences between the preoperative and postoperative values of biochemical parameters were similar for both anesthetic groups (p>0.05). Low-flow anesthesia did not cause impairment in terms of renal and hepatic functions.

Evaluation of Novel Biomarkers of Nephrotoxicity in Two Strains of Rat Treated with Cisplatin

Cisplatin is an anticancer agent that induces renal proximal tubule lesions in many species. Studies were conducted in Sprague-Dawley and Han-Wistar rats to evaluate the utility of novel preclinical biomarkers of nephrotoxicity for renal lesions caused by this compound. Groups of 10 males of each strain were given a single intraperitoneal injection of 0.3, 1, or 3 mg/kg cisplatin and were sacrificed on days 2, 3, and 5. The novel biomarkers α-glutathione-S-transferase (α-GST) (for proximal tubular injury), μ-glutathione-S-transferase (μ-GST) (for distal tubular injury), clusterin (for general kidney injury), and renal papillary antigen-1 (RPA-1) (for collecting duct injury) were measured in urine by enzyme immunoassay. Histologically, degeneration and necrosis of the S3 segment of the renal proximal tubule were observed on day 2 (Han-Wistar) and days 3 and 5 (both strains) at 1 and 3 mg/kg. Results showed that in both strains of rats, urinary α-GST and clusterin can be detected in urine soon after injury, are more sensitive than BUN and serum creatinine, and therefore are usable as noninvasive biomarkers of proximal tubule injury. Changes in both μ-GST or RPA-1 were considered to represent secondary minor effects of proximal tubular injury on distal segments of the nephron.

The relationship between inhalational anesthetic requirements and the severity of liver disease in liver transplant recipients according to three phases of liver transplantation

PURPOSE

Orthotopic liver transplantation (OLT) patients are known to show decreased intraoperative anesthetic requirements compared with patients undergoing other liver surgeries. The aim of this study was to determine the relationship between inhalational anesthetic requirements and the severity of liver disease among OLT patients.

METHODS

Fifty patients undergoing first living donor OLT were divided into 2 groups: model for end-stage liver disease (MELD) score<20 (low-MELD group; n=25) versus, MELD score>or=20 (high-MELD group; n=25). Anesthesia was maintained with desflurane and inspired concentration was titrated to maintain the bispectral index between 40 and 50. Neither intraoperative opioid nor epidural or intrathecal analgesia was used. End-tidal desflurane concentration (ETdes) was measured every 5 minutes and averaged in 30-minute intervals. These values were divided into 3 phases: preanhepatic (P 0.5 hour, P 1 hour, and P 1.5 hours), anhepatic (A 0.5 hour, A 1 hour, A 1.5 hours, and A 2 hours), and postreperfusion (R 0.5 hour, R 1 hour, R 1.5 hours, R 2 hours, R 2.5 hours, and R 3 hours). Results were compared between the 2 groups.

RESULTS

The demographic and intraoperative data were similar between the 2 groups. ETdes to maintain comparable anesthetic depth was significantly lower during the preanhepatic and anhepatic phases in the high-MELD than the low-MELD group, but there was no significant difference during the postreperfusion period.

CONCLUSIONS

OLT patients with high MELD scores showed less inhalational anesthetic requirements during the preanhepatic and the anhepatic periods than those with low MELD scores.

The effects of desflurane and sevoflurane on hepatic and renal functions after right hepatectomy in living donors*

We compared postoperative hepatic and renal functions between the two inhalational anesthetics, desflurane and sevoflurane in living donors undergoing right hepatectomy. Seventy-four adult donors were randomly allocated into Des group (n = 37) and sevo group (n = 37). Before the induction of anesthesia, morphine sulfate 400 microg was injected intrathecally. Anesthesia was maintained with one minimum alveolar concentration (MAC) of deflurane or sevoflurane plus continuous intravenous remifentanil. Liver and renal function tests were performed and analysed at preoperative period, immediately after operation, and on 1st, 2nd, 3rd, 5th, 7th, and 30th postoperative days (PODs). Aspartate aminotransferase (AST) showed significant elevations from the day of surgery to POD 3 and alanine aminotransferase (ALT) was significantly elevated on POD 1 and POD 3 in the sevo group. Albumin level was significantly lower on POD 2 in the sevo group. Creatinine was significantly higher on POD 3 and POD 30 and estimated glomerular filtration ratio was significantly lower on POD 3 and POD 30 in the sevo group. No patient developed hepatic or renal failures. The results of our study showed better postoperative hepatic and renal function test with desflurane than sevoflurane at equivalent dose of 1 MAC in living donors undergoing right hepatectomy, but further study is required to evaluate clinical importance.

Fatal subacute liver failure after repeated administration of sevoflurane anaesthesia

Sevoflurane is a widely used halogenated inhalation anaesthetic. In comparison with other similar anaesthetics, it is not metabolized to potentially hepatotoxic trifluoroacetylated proteins. In this case report, we present a 66-year-old woman with breast carcinoma, who underwent sevoflurane general anaesthesia twice in 25 days. Soon after the second elective surgical procedure, jaundice and marked elevations in serum transaminases developed. The patient died 66 days thereafter. Autopsy results denied evidence of major cardiovascular abnormality, and histological examination confirmed massive liver cell necrosis with no feature of chronic liver injury. Sevoflurane anaesthesia was imputed as the cause after exclusion of other possible aetiological agents. Besides, coexistent malignant tumours found in the patient could have modulated the immunological response to the applied anaesthetic followed by fatal consequences.

The age- and gender-dependent effects of desflurane and sevoflurane on rat liver

OBJECTIVE

This study aimed to investigate the age- and gender-dependent effects of desflurane and sevoflurane on the liver.

MATERIAL AND METHOD

Upon the approval of ethics committee, 84 rats were divided into four groups as 21 young male, 21 young female, 21 old male, and 21 old female rats. Then, each group was further divided into three groups as desflurane, sevoflurane, and control groups. Maintaining the minimum alveolar concentration of 1, desflurane at 6vol% and sevoflurane at 2vol% in 6Lmin(-1) 100% O2 were administered for 2h in a transparent plastic container of 40cmx40cmx70cm. Each liver preparation was evaluated for hydropic degeneration, nuclear polymorphism, portal neutrophile infiltration, portal lymphocyte infiltration, and focal necrosis, and each preparation was assigned injury points of 0-3; thus, the number of histopathologically injured cases, total injury scores of each preparation, and the mean injury scores of each group were determined.

RESULTS

Desflurane and sevoflurane did not significantly increase hepatic injury in the young male rats, while both agents caused significantly more hepatic injury in the young female rats. In the old rats, both desflurane and sevoflurane inflicted more hepatic injury on both genders. In addition, desflurane caused more hepatic injury in the old female rats than in the young female or the old male rats.

CONCLUSION

Hepatic injury associated with desflurane and sevoflurane was mild to moderate, suggesting that both agents can be safely used in routine anaesthesia procedures.

Saving sevoflurane and hastening emergence from anaesthesia using an anaesthetic-conserving device

BACKGROUND AND OBJECTIVE

This study compared an anaesthetic-conserving device (AnaConDa) and a conventional vaporizer in terms of sevoflurane consumption and emergence from anaesthesia using a total gas flow of 4 l min(-1), with a rebreathing circuit.

PATIENTS AND METHODS

Twenty-four patients for gastrectomy, aged 30-70 years, were divided into AnaConDa and control groups. Anaesthesia was induced with midazolam, propofol, fentanyl and vecuronium. The total gas flow was fixed at 4 l min(-1) (nitrous oxide 2 l min(-1) and oxygen 2 l min(-1)). Sevoflurane administration was started at 0.5% (vaporizer setting) in the control group and 25 ml h(-1) in the AnaConDa group, then the end-tidal sevoflurane concentration was kept between 0.3 and 0.5% in both groups. Analgesia was obtained with intermittent epidural administration of mepivacaine. The time to first detection of end-tidal sevoflurane, sevoflurane consumption and emergence time were compared between the two groups.

RESULTS

The AnaConDa group showed a significantly longer time to first detection of end-tidal sevoflurane (211 +/- 75 vs. 40 +/- 18 s), smaller sevoflurane consumption (12 +/- 3 vs. 42 +/- 9 ml), and shorter emergence time (12 +/- 2 vs. 16 +/- 1 min) than the control group.

CONCLUSION

The AnaConDa could decrease sevoflurane consumption and hasten emergence from anaesthesia, but increasing sevoflurane concentration with AnaConDa at the start of anaesthesia might take longer than that with a conventional vaporizer.

Biomarkers of nephrotoxic acute kidney injury

Acute kidney injury (AKI) is a common condition with significant associated morbidity and mortality. Epidemiologic data suggest that a significant proportion of AKI cases is at least partially attributable to nephrotoxin exposure. This is not surprising given intrinsic renal susceptibility to toxicant-induced injury, a consequence of the unique physiologic and biochemical properties of the normally functioning kidney. A number of pathophysiologic mechanisms have been identified that mediate toxic effects on the kidney, resulting in a variety of clinical syndromes ranging from subtle changes in tubular function to fulminant renal failure. Unfortunately, standard metrics used to diagnose and monitor kidney injury, such as blood urea nitrogen and serum creatinine, are insensitive and nonspecific, resulting in delayed diagnosis and intervention. Considerable effort has been made to identify biomarkers that will allow the earlier diagnosis of AKI. Further characterization of these candidate biomarkers will clarify their utility in the setting of acute nephrotoxicity, define new diagnostic and prognostic paradigms for kidney injury, facilitate clinical trials, and lead to novel effective therapies.

Contrast-induced nephropathy

Interventional radiological procedures involving anaesthesia are generally increasing. Contrast-induced nephropathy (CIN), usually defined as an increase in serum creatinine of 44 micromol litre(-1) (0.5 mg dl(-1)) or a 25% increase from the baseline value 48 h after intravascular injection of contrast media, is a common and potentially serious complication of the use of iodinated contrast media in patients at risk of acute renal injury. It is an important cause of hospital-acquired renal failure, may be a difficult differential diagnosis and the incidence does not appear to have changed over the last few decades. In the general population, the incidence of CIN is estimated to be 1-2%. However, the risk for developing CIN may be as high as 50% in some patient subgroups, such as those with diabetes mellitus and pre-existing renal impairment. The impact of CIN on clinical outcomes has been evaluated most extensively in patients undergoing percutaneous coronary intervention where it is associated with increased mortality both in hospital and at 1 yr. As treatment is limited to supportive measures while awaiting the resolution of the renal impairment, emphasis needs to be directed at prevention.

A fatal case of fulminant hepatic necrosis following sevoflurane anesthesia

Volatile anesthetics can elevate cytosolic free Ca(2 +) by releasing calcium from internal calcium stores and uptaking calcium from extracellular medium. Sevoflurane is an inhaled anesthetic used worldwide. A clear understanding of the exact mechanism of hepatic injury induced by sevoflurane remains elusive. A 69-year-old man with preexisting mild renal dysfunction, having undergone sevoflurane general anesthesia twice in 2 days, developed moderate jaundice. Liver enzymes strongly increased and remained elevated until death, which occurred on the 6th day after the first surgical intervention. The microscopic liver examination revealed an extensive and confluent hepatic necrosis, characterised by a large amount of calcium deposition in hepatic cell cytoplasm. These data were confirmed by confocal laser scanning microscopy and a 3-D visualization of calcium depositions was evident in hepatocytes cytoplasm. Our findings are suggestive with the previous experimental reports that consider elevation of cytoplasmic calcium may be the basis of sevoflurane - induced hepatotoxicity.

Renal safety and extrahepatic defluorination of sevoflurane in hepatic transplantations

BACKGROUND

The main metabolic pathway for defluorination of sevoflurane in the liver produces inorganic fluoride (Fl). The metabolism and effect of sevoflurane on the kidney is not clear during anhepatic phase in liver transplantation. The goal of the present study was to investigate the metabolism and renal effect of sevoflurane by measuring plasma and urine inorganic fluoride, urinary N-acetyl-glucosaminidase (NAG), and plasma creatinine levels in patients undergoing liver transplantations.

METHODS

After institutional approval and informed consent, we studied nine cases of orthotopic liver transplantation after anesthesia was induced with 5 mg . kg(-1) thiopental, 1 mug . kg(-1) fentanyl intravenously, the trachea was intubated after vecuronium bromide 0.1 mg . kg(-1). Anesthesia was maintained with sevoflurane (2%), O(2), and N(2)O at a total gas flow of 6 L . min(-1) using a semiclosed circle system with a sodalime canister. Blood and urine samples were obtained to measure plasma and urine fluoride concentrations and urinary NAG excretions before induction (P0), hourly during resection (P1, P2, P3), every 15 minutes during anhepatic phase (A1, A2, A3), hourly after reperfusion (neohepatic phase) (N1, N2, N3), and postoperative first hour (Po1). Preoperative (T0) and postoperative day 1 (T1), 3 (T3), 7 (T7) plasma blood urea nitrogen (BUN) and creatinine (Cr) levels were also recorded.

RESULTS

Mean duration of surgery was 9:06 +/- 0:09 hours. Mean inorganic fluoride concentrations in plasma were in the range of 0.71 +/- 0.30 to 28.73 +/- 3.31 mumole . L(-1). In P3, N1, N2, N3, increases in plasma inorganic fluoride concentrations were significant (P < .05) and reached a peak value at Po1. The mean urine inorganic fluoride concentrations were 12.49 +/- 2.04 to 256.7 +/- 49.62 mumole . L(-1). In A2, A3, N1, N2, and N3, mean urine inorganic fluoride concentrations were significantly increased (P < .05) and the peak value was observed at Po1. Mean NAG concentrations in urine varied (5.6 +/- 1.6 IU . L(-1) to 12.5 +/- 1.14 IU . L(-1)) and peak level was observed at 30 minutes of the anhepatic phase (A2), which did not exceed the normal values for urine NAG levels (1.5 to 6.1 U . L(-1)). No impairment was observed in serum BUN and creatinine levels at any time. While there was only a slight increase in NAG during anhepatic phase, there was no change in plasma F1.

CONCLUSIONS

Sevoflurane seemed to have minimal effect on kidney functions of BUN and Cr levels during liver transplantation. Although urine F1 and NAG levels increased during the anhepatic phase plasma F1, BUN, and Cr levels did not, suggesting that renal F1 production may occur in the absence of hepatic function. The renal effect of sevoflurane in chronic liver disease is controversial and must be investigated in further studies.

Hemodynamic, hepatorenal, and postoperative effects of desflurane-fentanyl and midazolam-fentanyl anesthesia in coronary artery bypass surgery

OBJECTIVE

The purpose of this study was to compare the hemodynamic, hepatorenal, and postoperative effects of desflurane-fentanyl and midazolam-fentanyl anesthesia during coronary artery bypass surgery.

DESIGN

Prospective study.

SETTING

University hospital.

PARTICIPANTS

Sixty patients undergoing elective coronary artery bypass grafting surgery with ejection fraction more than 45%.

INTERVENTIONS

Anesthesia was induced with etomidate, 0.2 mg/kg, and fentanyl, 5 microg/kg, in group D (n = 30) and with midazolam, 0.1 to 0.3 mg/kg, and fentanyl, 5 microg/kg, in group M (n = 30). Anesthesia was maintained with desflurane, 2% to 6%, and fentanyl, 15 to 25 microg/kg, in group D and midazolam infusion, 0.1 to 0.5 mg/kg/h, and fentanyl, 15 to 25 microg/kg, in group M.

MEASUREMENTS AND MAIN RESULTS

Hemodynamic monitoring included a 5-lead electrocardiogram, a radial artery catheter, and a pulmonary artery catheter. Data were obtained before induction of anesthesia (t0), after induction of anesthesia (t1), after intubation (t2), after surgical incision (t3), after sternotomy (t4), before cardiopulmonary bypass (t5), after protamine infusion (t6), and at the end of the surgery (t7). Blood samples were obtained to measure total bilirubin, aspartate aminotransferase, gamma glutamyl transferase, lactate dehydrogenase, alkaline phosphatase, creatinine, and blood urea nitrogen just before induction of anesthesia and at the first, fourth, and 14th days postoperatively.

CONCLUSIONS

Intraoperative hemodynamic responses were similar in both groups, and transient hepatic and renal dysfunctions were observed in the postoperative period in both groups. The extubation and intensive care unit discharge times were found to be shorter in the desflurane-fentanyl group.

Formation and toxicity of anesthetic degradation products

Toxic degradation products are formed from a range of old and modern anesthetic agents. The common element in the formation of degradation products is the reaction of the anesthetic agent with the bases in the carbon dioxide absorbents in the anesthesia circuit. This reaction results in the conversion of trichloroethylene to dichloroacetylene, halothane to 2-bromo-2-chloro-1,1-difluoroethylene, sevoflurane to 2-(fluoromethoxy)-1,1,3,3,3-pentafluoro-1-propene (Compound A), and desflurane, isoflurane, and enflurane to carbon monoxide. Dichloroacetylene, 2-bromo-2-chloro-1,1-difluoroethylene, and Compound A form glutathione S-conjugates that undergo hydrolysis to cysteine S-conjugates and bioactivation of the cysteine S-conjugates by renal cysteine conjugate beta-lyase to give nephrotoxic metabolites. The elucidation of the mechanisms of formation and bioactivation of degradation products has allowed for the safe use of anesthetics that may undergo degradation in the anesthesia circuit.

Closed system anaesthesia in dogs using liquid sevoflurane injection; evaluation of the square-root-of-time model and the influence of CO 2 absorbent

OBJECTIVE

To determine whether predictable alveolar concentrations of sevoflurane are reliably produced in dogs when liquid sevoflurane is injected into closed circuit breathing systems, as calculated by Lowe's square-root-of-time anaesthetic uptake model, and to confirm the validity of the model using soda lime and calcium hydroxide lime.

STUDY DESIGN

Prospective clinical study.

ANIMALS

Eleven healthy dogs with a mean body mass of 34 +/- 9 kg scheduled for pelvic limb orthopaedic surgery.

MATERIALS AND METHODS

Following pre-anaesthetic medication, anaesthesia was induced with propofol and maintained with sevoflurane in a closed circle system. Epidural anaesthesia was performed with morphine and bupivacaine. Liquid sevoflurane was injected into the circuit by syringe, using dosages and time intervals derived from Lowe's square-root-of-time anaesthetic uptake model. The target alveolar concentration chosen was 1.1 x MAC (2.6% end-tidal sevoflurane). Either soda lime (group S; n = 6) or calcium hydroxide lime (Amsorb; group A; n = 5) were used for CO(2) absorption. Sevoflurane concentration and the respiratory gas composition were measured with an infrared gas analyser.

RESULTS

End-tidal sevoflurane concentrations were close to the predicted value of 2.6% at 9 minutes (2.53 +/- 0.1% group S; 2.60 +/- 0.26% group A) and 16 minutes (2.55 +/- 0.30 group S; 2.52 +/- 0.28% group A) but declined thereafter to reach 50% (group S) and 64% (group A) of the predicted value at 121 minutes. There was a constant trend towards higher end-tidal sevoflurane concentrations in group A but the difference was not statistically significant.

CONCLUSIONS

The square-root-of-time model leads to significantly lower alveolar concentrations than expected, suggesting that the rate of sevoflurane uptake in dogs declines less rapidly than predicted. The use of Amsorb tends to reduce the deviation from predicted concentrations.

CLINICAL RELEVANCE

The model used in this study provided only an approximate guide to the volume of liquid sevoflurane required. Consequently, the definitive dose schedule must be based on measured anaesthetic concentrations and clinical monitoring.