Lactate is correlated with the indocyanine green elimination rate in liver resection for cirrhotic patients

Comparing the accuracy of prediction models to detect clinically relevant post-hepatectomy liver failure early after major hepatectomy

BACKGROUND

Arterial lactate measurements were recently suggested as an early predictor of clinically relevant post-hepatectomy liver failure (PHLF). This needed to be evaluated in the subgroup of major hepatectomies only.

METHOD

This observational cohort study included consecutive elective major hepatectomies at Karolinska University Hospital from 2010 to 2018. Clinical risk factors for PHLF, perioperative arterial lactate measurements and routine lab values were included in uni- and multivariable regression analysis. Receiver operating characteristics and risk cut-offs were calculated.

RESULTS

In total, 649 patients constituted the study cohort, of which 92 developed PHLF grade B/C according to the International Study Group of Liver Surgery (ISGLS). Lactate reached significantly higher intra- and postoperative levels in PHLF grades B and C compared to grade A or no liver failure (all P < 0.002). Lactate on postoperative day (POD) 1 was superior to earlier measurement time points in predicting PHLF B/C (AUC 0.75), but was outperformed by both clinical risk factors (AUC 0.81, P = 0.031) and bilirubin POD1 (AUC 0.83, P = 0.013). A multivariable logistic regression model including clinical risk factors and bilirubin POD1 had the highest AUC of 0.87 (P = 0.006), with 56.6% sensitivity and 94.7% specificity for PHLF grade B/C (cut-off ≥0.32). The model identified 46.7% of patients with 90-day mortality and had an equally good discriminatory potential for mortality as the established ISGLS criteria for PHLF grade B/C but could be applied already on POD1.

CONCLUSION

The potential of lactate to predict PHLF following major hepatectomy was inferior to a prediction model consisting of clinical risk factors and bilirubin on first post-operative day.

Interaction between anesthetic conditioning and ischemic preconditioning on metabolic function after hepatic ischemia-reperfusion in rabbits

BACKGROUND

Both anesthetic-induced and ischemic preconditioning are protective against hepatic ischemia-reperfusion injury. However, the effects of these preventive methods on the metabolic function remain to be elucidated. We investigated the anesthetic conditioning and ischemic preconditioning on the metabolic function of the rabbit model of hepatic ischemia-reperfusion.

METHODS

After approval by the institutional animal care and use committee, 36 Japanese White rabbits underwent partial hepatic ischemia for 90 min either under sevoflurane or propofol anesthesia. All the rabbits underwent 90 min of hepatic ischemia, and half of the rabbits in each group underwent additional 10-min ischemia and 10-min reperfusion before index ischemia. Hepatic microvascular blood flow was intermittently measured during reperfusion period, and galactose clearance, serum aminotransferase activities, and lactate concentrations were determined 180 min after reperfusion.

RESULTS

Neither anesthetic conditioning with sevoflurane nor ischemic preconditioning altered hepatic microvascular blood flow during reperfusion and serum transaminase activities after reperfusion. However, galactose clearance of reperfused liver was significantly higher under sevoflurane anesthesia than propofol (0.016 ± 0.005/min vs. 0.011 ± 0.004/min). Statistically significant interaction between anesthetic choice and application of ischemic preconditioning suggests that the ischemic preconditioning is selectively protective under propofol anesthesia. Increase of blood lactate concentration was significantly suppressed under sevoflurane anesthesia compared to propofol (1.5 ± 0.8 vs. 3.9 ± 1.4 mmol/l) without any statistically significant interaction with the application of ischemic preconditioning.

CONCLUSION

Sevoflurane attenuated the decrease of galactose clearance and increase of the blood lactate after reperfusion compared to propofol. Application of ischemic preconditioning was significantly protective under propofol anesthesia.

Assessment of liver perfusion and function by indocyanine green in the perioperative setting and in critically ill patients

Indocyanine green (ICG) is a water-soluble dye that is bound to plasma proteins when administered intravenously and nearly completely eliminated from the blood by the liver. ICG elimination depends on hepatic blood flow, hepatocellular function and biliary excretion. ICG elimination is considered as a useful dynamic test describing liver function and perfusion in the perioperative setting, i.e., in liver surgery and transplantation, as well as in critically ill patients. ICG plasma disappearance rate (ICG-PDR) which can be measured today by transcutaneous systems at the bedside is a valuable method for dynamic assessment of liver function and perfusion, and is regarded as a valuable prognostic tool in predicting survival of critically ill patients, presenting with sepsis, ARDS or acute liver failure.

Does acid-base equilibrium correlate with remnant liver volume during stepwise liver resection?

Small for size and flow syndrome (SFSF) is one of the most challenging complications following extended hepatectomy (EH). After EH, hepatic artery flow decreases and portal vein flow increases per 100 g of remnant liver volume (RLV). This causes hypoxia followed by metabolic acidosis. A correlation between acidosis and posthepatectomy liver failure has been postulated but not studied systematically in a large animal model or clinical setting. In our study, we performed stepwise liver resections on nine pigs to defined SFSF limits as follows: step 1: segment II/III resection, step 2: segment IV resection, step 3: segment V/VIII resection (RLV: 75, 50, and 25%, respectively). Blood gas values were measured before and after each step using four catheters inserted into the carotid artery, internal jugular vein, hepatic artery, and portal vein. The pH, [Formula: see text], and base excess (BE) decreased, but [Formula: see text] values increased after 75% resection in the portal and jugular veins. EH correlated with reduced BE in the hepatic artery. Pco₂ values increased after 75% resection in the jugular vein. In contrast, arterial Po₂ increased after every resection, whereas the venous Po₂ decreased slightly. There were differences in venous [Formula: see text], BE in the hepatic artery, and Pco₂ in the jugular vein after 75% liver resection. Because 75% resection is the limit for SFSF, these noninvasive blood evaluations may be used to predict SFSF. Further studies with long-term follow-up are required to validate this correlation.NEW & NOTEWORTHY This is the first study to evaluate acid-base parameters in major central and hepatic vessels during stepwise liver resection. The pH, [Formula: see text], and base excess (BE) decreased, but [Formula: see text] values increased after 75% resection in the portal and jugular veins. Extended hepatectomy correlated with reduced BE in the hepatic artery. Because 75% resection is the limit for small for size and flow syndrome (SFSF), postresection blood gas evaluations may be used to predict SFSF.

Green light for liver function monitoring using indocyanine green? An overview of current clinical applications

The dye indocyanine green is familiar to anaesthetists, and has been studied for more than half a century for cardiovascular and hepatic function monitoring. It is still, however, not yet in routine clinical use in anaesthesia and critical care, at least in Europe. This review is intended to provide a critical analysis of the available evidence concerning the indications for clinical measurement of indocyanine green elimination as a diagnostic and prognostic tool in two areas: its role in peri-operative liver function monitoring during major hepatic resection and liver transplantation; and its role in critically ill patients on the intensive care unit, where it is used for prediction of mortality, and for assessment of the severity of acute liver failure or that of intra-abdominal hypertension. Although numerous studies have demonstrated that indocyanine green elimination measurements in these patient populations can provide diagnostic or prognostic information to the clinician, 'hard' evidence - i.e. high-quality prospective randomised controlled trials - is lacking, and therefore it is not yet time to give a green light for use of indocyanine green in routine clinical practice.

Systematic review of pathophysiological changes following hepatic resection

OBJECTIVES

Major hepatic resection is now performed frequently and with relative safety, but is accompanied by significant pathophysiological changes. The aim of this review is to describe these changes along with interventions that may help reduce the risk for adverse outcomes after major hepatic resection.

METHODS

The MEDLINE, EMBASE and CENTRAL databases were searched for relevant literature published from January 2000 to December 2011. Broad subject headings were 'hepatectomy/', 'liver function/', 'liver failure/' and 'physiology/'.

RESULTS

Predictable changes in blood biochemistry and coagulation occur following major hepatic resection and alterations from the expected path indicate a complicated course. Susceptibility to sepsis, functional renal impairment, and altered energy metabolism are important sequelae of post-resection liver failure.

CONCLUSIONS

The pathophysiology of post-resection liver failure is difficult to reverse and thus strategies aimed at prevention are key to reducing morbidity and mortality after liver surgery.

Surrogate endpoints in liver surgery related trials: a systematic review of the literature

BACKGROUND

Although the safety of liver surgery has improved enormously, hepatic surgery continues to face challenging complications. Therefore, improvements supported by evidence-based guidelines are still required. The conduct of randomized controlled trials in liver surgery using dichotomous outcomes requires a large sample size. The use of surrogate endpoints (SEPs) reduces sample size but SEPs should be validated before use.

AIM

The aim of this review was to summarize the SEPs used in hepatic surgery related trials, their definitions and recapitulating the evidence validating their use.

METHOD

A systematic computerized literature search in the biomedical database PubMed using the MeSH terms 'hepatectomy' or 'liver resection' or 'liver transection' was conducted. Search was limited to papers written in the English language and published between 1 January 2000 and 1 January 2010.

RESULTS

A total of 593 articles met the search terms and 49 articles were included in the final selection. Standard biochemical liver functions tests were the most frequently used SEP (32 of 49 the studies). The used definitions of SEPs varied greatly among the studies. Most studies referred to earlier published material to justify their choice of SEP. However, no validating studies were found.

CONCLUSION

Many SEPs are used in liver surgery trials however there is little evidence validating them.

Hyperlactemia can predict the prognosis of liver resection

Although hyperlactemia is known to accompany hepatic failure and metabolic acidosis, few reports examined the relationships between lactate concentrations and outcome after liver resection. We examined the ability of arterial plasma lactate concentration to predict the patient outcome after hepatectomy. The relationships of arterial lactate and base excess (BE) measured on admission to the intensive care unit (ICU) after hepatectomy to postoperative outcome were investigated in 151 consecutive patients. Lactate level was significantly higher in nonsurvivors than in survivors (P < 0.001), and in patients with postoperative complications than in those without complications (P < 0.001). Base excess was significantly reduced in nonsurvivors (P < 0.001) and in patients with postoperative complications (P = 0.004). The area under the receiver-operator curve of lactate to mortality was 0.86, whereas that of BE to the mortality was 0.82. Moderate correlation was observed between the lactate level at ICU admission and the highest total bilirubin concentration measured within 14 days after the surgery (r = 0.61), whereas the correlation between BE and bilirubin levels was lower (r = 0.35). Using multivariate analysis, the lactate level independently predicted mortality (P = 0.008) and morbidity (P = 0.013). Lactate (P < 0.001) and BE (P = 0.0068) levels both independently predicted the highest bilirubin concentration. The arterial plasma lactate concentration measured on admission to ICU seemed an excellent predictor of patient outcome after liver resection.

A critical evaluation of hepatic resection in cirrhosis: optimizing patient selection and outcomes

Hepatic resection has long been the mainstay of treatment of primary liver cancers, particularly hepatocellular carcinoma (HCC). Because of the high incidence of cirrhosis in patients with HCC, the use of resection was initially limited by the ability of the cirrhotic liver to sustain the surgical insult and the mass reduction. Today, hepatectomy in cirrhosis is undergoing a remarkable evolution. Although surgical and anesthetic improvements have increased the safety of this option, the rapid development of alternative therapies has decreased the need for it. Local excision for small HCC is likely to be replaced by image-guided, percutaneous ablative techniques. Furthermore, total replacement of a cirrhotic liver may be a more effective long-term cure than resection. Unquestionably, resection remains the optimal approach for patients with large tumors and healthy underlying liver function. The role of rapidly evolving new approaches will remain the subject of intensive inquiry in the years to come. In this report, we have attempted to clarify current practice with respect to the evaluation, selection, and technique of resection in cirrhosis, and identify areas of active inquiry.

Bacterial translocation, endotoxaemia and apoptosis following Pringle manoeuvre in rats

BACKGROUND

Intraoperative occlusion of the hepatoduodenal ligament (Pringle manoeuvre (Pm)) is often employed for the reduction of blood loss during liver surgery. No data exist to date on the effects of Pm on mucosal barrier dysfunction, systemic bacterial translocation (BT), endotoxaemia and apoptosis.

MATERIALS AND METHODS

Sixty-five male Wistar rats in three groups: I (n=25) controls, II (n=20) sham operation, III (n=20) occlusion of the hepatoduodenal ligament (Pm). Tissue samples from mesenteric lymph nodes (MLNs), liver, lungs and spleen were analysed after 30 min and at 24 h. Endotoxin was measured in portal and aortic blood and routine haematological and biochemical parameters were measured before and after Pm.

RESULTS

No differences were found in the blood parameters before and after Pm, but a significant increase in contaminated MLNs and liver was noted. All cultured bacteria were enteric in origin. Portal and aortic endotoxin were significantly increased. Overall the ileal architecture remained intact in all specimens studied and no significant pathology was observed. The ABC increased after Pm significantly (P<0.01).

CONCLUSION

Normothermic Pm of 30 min duration results in immediate and delayed gut barrier failure by significantly increasing BT and endotoxaemia which might be attributed to portal stasis leading to intestinal congestion as well as temporary liver ischaemia. Apoptosis increased significantly 30 min after performing the Pm.

Surgery in the patient with liver disease

Management of the surgical patient with liver disease begins with a careful preoperative assessment (Fig. 1). Any clues to liver disease on history and physical examination should be investigated to ascertain the cause of the clinical finding. More data on surgical patients with unexpected liver disease are now available. Patients undergoing emergent surgery are at significant risk of developing liver dysfunction. Child's class still correlates strongly to postoperative complications. Cornerstones of perioperative management in these patients are medical treatment of complications of chronic liver disease, such as ascites; coagulopathy; prevention of encephalopathy; and rapid treatment of dangerous postoperative complications, such as acute acalculous cholecystitis. Evolving knowledge of the effects of anesthesia, improving surgical techniques, and use of better diagnostic tests will help in the reduction of perioperative complications in these patients.