Indocyanine green plasma disappearance rate: a new tool for the classification of paediatric patients with acute liver failure

[Analysis of indocyanine green plasma disappearance rate in clinical practice]

OBJECTIVE

To justify the optimal method for determining indocyanine green plasma disappearance rate (PDRICG).

MATERIAL AND METHODS

We analyzed PDRICG in intensive care units. Indocyanine green was administered intravenously at a dose of 0.25 mg/kg. PDRICG was analyzed simultaneously by using of three methods: 1) PDD (PiCCO2 LiMON device), 2) SBS with analysis of plasma samples on precise spectrophotometer, 3) SBS with analysis of plasma samples on simple experimental photometer.

RESULTS

PDD method was used for 346 PDRICG tests in 256 patients. Of these, 14.3% of measurements were erroneous. Paired tests using PDD and SBS methods were performed in 299 cases. SBS method resulted erroneous data in 0.6% of cases. Certain correlation (r=0.79, p<0.001) was found between the reference method (SBS with spectrophotometry) and the PDD method. Bland-Altman plot for these two methods showed that proportional bias of mean difference was caused by extremely high PDRICG of the PDD method (for example, more than 30%/min). Comparison of two SBS variants (spectrophotometer and experimental photometer) revealed good correlation (r=0.91, p<0.001).

CONCLUSION

SBS method for measuring PDRICG ensures accurate results under mechanical interferences in patients with impaired capillary blood flow. This eliminates the need for redo measurement. Duplication of the PDD and SBS methods is recommended when repeating the test is not possible (organ donors).

Hepatoprotective potential of a novel quinazoline derivative in thioacetamide-induced liver toxicity

Purpose: The compound quinazoline Q-Br, 3-(5-bromo-2-hydroxybenzylideneamino)-2-(5-bromo-2 hydroxyphenyl) 2,3-dihydroquinazoline-4(1H)-one (Q-Br) was evaluated for its antioxidant capacity and potential hepatoprotectivity against sub-chronic liver toxicity induced by thioacetamide in rats.

Materials and Methods: Rats were assigned into five groups; healthy (normal) and cirrhosis control groups were given 5% Tween 20 orally, the reference control group was given a Silymarin dose of 50 mg/kg, and low-dose Q-Br and high-dose Q-Br groups were given a daily dose of 25 mg/kg and 50 mg/g Q-Br, respectively. Liver status was detected via fluorescence imaging with intravenous injection of indocyanine green (ICG) and a plasma ICG clearance test. Liver malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were also tested. The degree of fibrosis was determined histologically by hematoxylin and eosin and Masson’s Trichrome staining. The immunohistochemistry of liver tissue inhibitor of metalloproteinase (TIMP-1), matrix metalloproteinase (MMP-2), and alpha-smooth muscle actin (α-SMA) was performed.

Results: Q-Br recorded mild antioxidant capacity, dose-dependent improvement in the liver status, and inhibition of oxidative stress compared to cirrhosis control. Histopathology notified a remarkable reduction in the degree of fibrosis. Immunohistochemistry revealed an obvious low expression of MMP-2 and α-SMA along with a higher expression of TIMP-1 in Q-Br- and Silymarin-treated livers.

Conclusion: Q-Br treatment altered the course of toxicity induced by thioacetamide suggesting significant hepatoprotective potential of Q-Br treatment.

Epstein-Barr virus-associated risk factors for post-transplant lymphoproliferative disease in pediatric liver transplant recipients

BACKGROUND

Post-transplant lymphoproliferative disorder (PTLD) are the most common de novo malignancies after liver transplantation (LT) in children. The aim of our study was to assess the role of pre-LT EBV status and post-LT EBV viral load as risk factors for developing PTLD in a cohort of pediatric LT recipients.

METHODS

Data of all children who underwent LT between January 2002 and December 2019 were collected. Two cohorts were built EBV pre-LT primary infected cohort and EBV post-LT primary infected cohort. Moreover, using the maximal EBV viral load, a ROC curve was constructed to find a cutoff point for the diagnosis of PTLD.

RESULTS

Among the 251 patients included in the study, fifteen PTLD episodes in 14 LT recipients were detected (2 plasmacytic hyperplasia, 10 polymorphic PTLD, 2 monomorphic PTLD, and 1 Classical-Hodgkin's lymphoma). Patients of the EBV post-LT primary infected cohort were 17.1 times more likely to develop a PTLD than patients of the EBV pre-LT primary infected cohort (2.2-133.5). The EBV viral load value to predict PTLD was set at 211 000 UI/mL (93.3% sensitivity and 77.1% specificity; AUC 93.8%; IC 0.89-0.98). In EBV post-LT primary infected cohort, patients with a viral load above 211 000 were 30 times more likely to develop PTLD than patients with a viral load below this value (OR 29.8; 3.7-241.1; p < 0.001).

CONCLUSIONS

The combination of pretransplant EBV serological status with EBV post-transplant viral load could be a powerful tool to stratify the risk of PTLD in pediatric LT patients.

Determination of hepatic clearance by derivations of the indocyanine green retention test in cirrhosis

BACKGROUND AND AIM

The study was undertaken in order to compare single injection indocyanine green (ICG)-clearances with the steady-state ICG-clearance (ICG_Cl ) in patients with cirrhosis in order to assess the most accurate estimate for ICG-clearance and to relate the ICG-clearances to established indicators of liver dysfunction.

METHODS

Thirty-eight patients (male 29) with cirrhosis (Child-Turcotte class A 8, class B 21, and class C 9) were studied during a hemodynamic investigation. A single injection of ICG was followed by blood samples for 5, 10, 15, and 20 min. The dose/plasma area clearance (Cl_A ) and plasma volume · initial slope clearance (Cl_PV ) were determined and compared with the steady-state infusion/plasma concentration ratio clearance (ICG_Cl ).

RESULTS

The Cl_A (310; 214; 502 mL/min) and Cl_PV (294; 164; 481 mL/min) correlated closely with ICG_Cl (243; 120; 383 mL/min [median; interquartile range], R = 0.95-0.98, P < 0.000), but were significantly higher than ICG_Cl (P < 0.001). All three clearance measures correlated significantly with biochemical and hemodynamic variables of liver dysfunction (P < 0.05-0.000). All three ICG-clearances showed significantly lower values in patients with ascites compared to those without, and lower ICG-clearance values were present in patients with esophageal varices compared to those without (P < 0.05-0.002).

CONCLUSION

Single injection markers (Cl_A and Cl_PV ) of the steady-state ICG-clearance as derived from the ICG-retention curve and the plasma volume correlate with ICG_Cl and established variables of portal hypertension and liver cell bile excretory dysfunction. Therefore, these markers can safely replace the more costly ICG_Cl .

Liver, Renal, and Cardiovascular Failure After Unintentional Overdose of Tizanidine in a 2-Year-Old Child

Tizanidine is a central alpha-2 adrenergic receptor agonist indicated for the treatment of spasticity in adults; however, its use in the pediatric population is considered off-label. In adults, the dose is gradually titrated until the desired reduction in muscle tone is achieved. Hypotension is a frequent adverse effect, but impaired liver function is not characteristic of alpha-2 adrenergic agonist overdose. We report a 2-year-old male affected with spastic quadriplegia (treated with clonazepam and tizanidine) and dysphagia (he was fed by nasogastric tube). Two days before admission caregivers ran out of clonazepam so they increased the tizanidine dose from 0.15 mg/kg/day to 1.6 mg/kg/day. Simultaneously his nasogastric tube fell out; therefore, he was unable to maintain proper oral nutrition and hydration. He presented to the emergency department hemodynamically unstable, with impaired consciousness and signs of severe dehydration. Blood tests revealed hepatic dysfunction without cholestasis and renal dysfunction. He was transferred to the pediatric intensive care unit. Treatment was mainly supportive, apart from tizanidine discontinuation. Metabolic and infectious diseases were ruled out so he was finally diagnosed as having liver, renal, and cardiovascular failure after tizanidine overdose, worsened by dehydration. His clinical status improved, and after 3 weeks he was discharged from the hospital, receiving clonidine instead of tizanidine to treat spasticity. Tizanidine overdose can result in serious complications that can be worsened because of patient comorbidities.

The Advantages of Indocyanine Green Fluorescence Imaging in Detecting and Treating Pediatric Hepatoblastoma: A Preliminary Experience

Background: Currently, indocyanine green (ICG) fluorescence imaging enables radical surgical resection in hepatoblastoma (HB) and has beneficial uses; however, its usage in pediatric patients is still limited. Methods: From 2015 to 2019, 17 hepatoblastoma patients underwent 22 fluorescence-guided surgery using ICG. ICG (0.3 mg/kg) was intravenously injected 24-48 h before the operation. With ICG/NIR camera, intraoperative identification of biological structures and demarcation of mass were conducted. Results: ICG fluorescence-guided surgery was performed for hepatoblastoma in 22 cases: 16, 1, and 2 cases underwent anatomic resection, partial hepatectomy, and liver transplantation, respectively. Six patients accompanied lung metastasis at the time of surgery, and two patients underwent lung surgery using ICG. The median interval from ICG injection to surgery was 38.3 h (range, 20.5-50.3 h). The median tumor size was 36.5 mm (range, 2-132 mm). According to the pathologic finding, the median safety margin was secured for 6 mm (range, 0-11 mm) and there was no residual finding at the liver at the follow-up computed tomography (CT). Conclusions: ICG fluorescence imaging in children with HB was feasible and safe for tumor demarcation and enhancing the accuracy of radical tumor resection.

Fluorescence Imaging Using Indocyanine Green Dye in the Pediatric Population

OBJECTIVES

Fluorescence imaging using indocyanine green (ICG) allows for the intraoperative mapping of the vascular supply of various tissue beds. Although generally safe and effective, rare adverse effects have been reported including anaphylactoid reactions. The current study retrospectively reviewed our experience the intraoperative administration of ICG to pediatric patients.

METHODS

The anesthetic records of patients who received ICG over a 2-year time period were retrospectively reviewed and demographic, surgical, and medication data retrieved. Objective intraoperative data before and after the administration of ICG were also recorded. These included heart rate, systolic and diastolic blood pressures, oxygen saturation, and peak inflating pressure.

RESULTS

The study cohort included 100 patients with a median age of 12 years (9.5 ± 7.4 years) and the median weight being 44.5 kg (45.9 ± 36.9 kg). ICG was administered intravenously to all patients. In all cases, 2.5 mg/mL ICG solution was used, with a median dose of 1.1 mL (1.79 ± 1.8 mL). Eight patients received more than 1 dose of ICG, with no adverse respiratory or hemodynamic effects related to its use.

CONCLUSIONS

ICG fluorescence is an important imaging modality that can be safely used as an intraoperative adjunct to various surgical procedures in the pediatric population.

Indocyanine green retention test in cirrhosis and portal hypertension: Accuracy and relation to severity of disease

BACKGROUND AND AIMS

Patients with cirrhosis and portal hypertension often develop complications relating to hepatic excretory dysfunction. The standard measurement of the hepatic excretion is the constant infusion indocyanine green clearance (ICG_CI ) technique. The ICG 15-min retention test (ICG-r15) is faster, more patient friendly, and cheaper. The aims were to compare the ICG-r15 test with the standard method, to assess relations to patient characteristics and survival, and to assess the ICG-r15 level in healthy control subjects.

METHODS

This study included 68 patients with cirrhosis and portal hypertension (Child class A/B/C:17/37/14). All patients underwent a full liver vein catheterization and hemodynamic evaluation with determination of ICG-r15 and ICG_CI as the reference in a subset of 38 patients. Sixteen healthy control subjects were included for compiling a reference interval.

RESULTS

The ICG-r15 was increased in the cirrhotic patients with increasing values in parallel with liver dysfunction (15/41/58%) in Child class A/B/C compared with 7% in the controls (P < 0.001). ICG-r15 correlated highly significantly with the ICG_CI (r = -0.96, P < 0.0001) and in a multivariate regression analysis with hepatic venous pressure gradient, markers of liver dysfunction and hyperdynamic circulation (P < 0.05-0.005). In the control group, normal reference values ranged from 0% to 13%. In addition, ICG-r15 was significantly related to mortality in the patient group (P = 0.02).

CONCLUSIONS

Indocyanine green-r15 reflects portal hypertension, the degree of hepatic failure, and survival and may replace the standard ICG_CI . A more elaborated reference interval needs to be compiled, and the prognostic value of ICG-r15 should be validated.

Minimally invasive assessment of hepatic function in children with indocyanine green elimination: a validation study

Objectives: Pediatric liver disease (PLD) covers a variety of etiologies and severities, from mild temporary illness to diseases with fatal outcomes. There is a demand for minimally invasive and reliable measures for assessment of the severity of PLD. Indocyanine green (ICG) elimination kinetics to estimate hepatic function has been used in adults for decades, however, due to invasiveness, the use in PLD is still limited. The aim of the present study was to evaluate minimally invasive estimation of ICG elimination by pulse spectrophotometry (ICGLi), in comparison with traditional spectrophotometry using serial blood samples (ICGbs). Methods: One hundred children aged 0-18 years were included in the study. ICG elimination kinetics was measured with ICGLi and ICGbs, and results compared by failure rates, mean difference, limits of agreement, Bland Altman plots and linear regression analysis. Plasma disappearance rates (PDRLi and PDRbs) were used for comparison. Results: One hundred and twelve simultaneous measurements in 87 patients were performed successfully. Mean difference for PDR (%/min) was 3.58 (95% CI 2.69; 4.47). Limits of agreement were -5.06; 12.22. A linear correlation between the two methods with a regression coefficient of 0.83 (SE 0.02 95% CI 0.80; 0.87) was found. For conversion we computed the following equation; PDRbs = 0.83 × PDRLi. Conclusions: The present study shows that ICG PDR can be obtained by a minimally invasive method and thus replace measures by serial blood samples in children with liver disease of different etiologies and severities. However, a systematic relative difference between the two methods exists. Our proposed correction factor needs to be validated in larger cohorts.

The Role of Liver Transplantation in Propionic Acidemia

Despite optimal medical treatment and strict low-protein diet, the prognosis of propionic acidemia (PA) patients is generally poor. We aim to report our experience with liver transplantation (LT) in the management of PA patients. Six patients with PA received a LT at a mean age of 5.2 years (1.3-7.5 years). The indications for LT were frequent metabolic decompensations in the first 4 patients and preventative in the last 2 patients. Two patients presented hepatic artery thromboses that were solved through an interventional radiologist approach. These patients showed a very high procoagulant state that was observed by thromboelastography. Arterial vasospasm without thrombus was observed in 2 patients during the LT surgery. In order to avoid hepatic artery thrombosis, an arterial conduit from the recipient aorta to the hepatic artery of the donor was used in the fifth patient. After LT, patients presented improvement in propionyl byproducts without complete normalization, but no decompensations have been observed. In conclusion, LT could be a good therapeutic option to improve the metabolic control and the quality of life of PA patients. Improved surgical strategies along with new techniques of interventional radiology allow us to perform the LT minimizing the complications derived from the higher risk of hepatic artery thrombosis.

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.

EASL Clinical Practical Guidelines on the management of acute (fulminant) liver failure

The term acute liver failure (ALF) is frequently applied as a generic expression to describe patients presenting with or developing an acute episode of liver dysfunction. In the context of hepatological practice, however, ALF refers to a highly specific and rare syndrome, characterised by an acute abnormality of liver blood tests in an individual without underlying chronic liver disease. The disease process is associated with development of a coagulopathy of liver aetiology, and clinically apparent altered level of consciousness due to hepatic encephalopathy. Several important measures are immediately necessary when the patient presents for medical attention. These, as well as additional clinical procedures will be the subject of these clinical practice guidelines.

Prognostic Impact of Indocyanine Green Plasma Disappearance Rate in Hepatocellular Carcinoma Patients after Radiofrequency Ablation: A Prognostic Nomogram Study

Objective Radiofrequency ablation has been used widely for the local ablation of hepatocellular carcinoma, particularly in its early stages. The study aim was to identify significant prognostic factors and develop a predictive nomogram for patients with hepatocellular carcinoma who have undergone radiofrequency ablation. We also developed the formula to predict the probability of 3- and 5-year overall survival based on clinical variables. Methods We retrospectively studied 96 consecutive patients with hepatocellular carcinoma who had undergone radiofrequency ablation as a first-line treatment. Independent and significant factors affecting the overall survival were selected using a Cox proportional hazards model, and a prognostic nomogram was developed based on these factors. The predictive accuracy of the nomogram was determined by Harrell's concordance index and compared with the Cancer of the Liver Italian Program score and Japan Integrated Staging score. Results A multivariate analysis revealed that age, indocyanine green plasma disappearance rate, and log (des-gamma-carboxy prothrombin) level were independent and significant factors influencing the overall survival. The nomogram was based on these three factors. The mean concordance index of the nomogram was 0.74±0.08, which was significantly better than that of conventional staging systems using the Cancer of the Liver Italian Program score (0.54±0.03) and Japan Integrated Staging score (0.59±0.07). Conclusion This study suggested that the indocyanine green plasma disappearance rate and age at radiofrequency ablation (RFA) and des-gamma-carboxy-prothrombin (DCP) are good predictors of the prognosis in hepatocellular carcinoma patients after radiofrequency ablation. We successfully developed a nomogram using obtainable variables before treatment.

Perioperative Non-Invasive Indocyanine Green-Clearance Testing to Predict Postoperative Outcome after Liver Resection

Background

Postoperative liver dysfunction may lead to morbidity and mortality after liver resection. Preoperative liver function assessment is critical to identify preexisting liver dysfunction in patients prior to resection. The aim of this study was to evaluate the predictive potential of perioperative indocyanine green (ICG)-clearance testing to prevent postoperative liver dysfunction and morbidity using standardized outcome parameters in a routine Western-clinical-setting.

Study Design

137 patients undergoing partial hepatectomy between 2011 and 2013, at the general hospital of Vienna, were included. ICG-clearance was recorded one day prior to surgery as well as on the first and fifth postoperative day. Postoperative liver dysfunction was defined according to the International Study Group of Liver Surgery and evaluation of morbidity was based on the Dindo-Clavien classification. Statistical analyses were based on non-parametric tests.

Results

Preoperative reduced ICG—plasma disappearance rate (PDR) as well as increased ICG—retention rate at 15 min (R15) were able to significantly predict postoperative liver dysfunction (Area under the curve = PDR: 0.716, P = 0.018; R15: 0.719, P = 0.016). Furthermore, PDR <17%/min. or R15 >8%, were able to accurately predict postoperative complications prior to surgery. In addition to this, ICG-clearance on postoperative day 1 comparably predicted postoperative liver dysfunction (Area under the curve = PDR: 0.895; R15: 0.893; both P <0.001), specifically, PDR <10%/min or R15 >20% on postoperative day 1 predicted poor postoperative outcome.

Conclusion

PDR and R15 may represent useful parameters to distinguish preoperative high and low risk patients in a Western collective as well as on postoperative day 1, to identify patients who require closer monitoring for potential complications.

Current use and perspective of indocyanine green clearance in liver diseases

Indocyanine green (ICG) is a water-soluble anionic compound that binds to plasma proteins after intravenous administration. It is selectively taken up at the first pass by hepatocytes and excreted unchanged into the bile. With the development of ICG elimination measurement by spectrophotometry, the ICG retention test has become a safe, rapid, reproducible, inexpensive and noninvasive tool for the assessment of liver function. Clinical evidence suggests that the ICG retention test can enable the establishment of tailored management strategies by providing prognostic information. In particular, this method has been evaluated as a prognostic marker in patients with advanced cirrhosis or awaiting liver transplantation. In addition, it is used as a marker of portal hypertension in cirrhotic patients, as a prognostic factor in intensive care units and for the assessment of liver function in patients undergoing liver surgery. Since recent technology enables ICG-PDR to be measured noninvasively at the bedside, this parameter is an attractive addition to liver function and regional haemodynamic monitoring. However, the current state-of-the-art as concerns this technology remains at a low level of evidence and thorough assessment is required.

Indocyanine green plasma disappearance rate as dynamic liver function test in critically ill patients

BACKGROUND

Indocyanine green (ICG) is a water-soluble fluorescent dye that is bound to plasma protein when administered intravenously. Removal of ICG from the blood depends on hepatic blood flow, function of the parenchymal cells and biliary excretion. ICG elimination is described as a useful dynamic liver function test.

METHODS

In this review, we looked at the most recent literature to clarify why ICG is useful in critically ill patients, the validity of the ICG plasma disappearance rate (ICG-PDR) measured transcutaneously and whether ICG-PDR has any prognostic value.

CONCLUSION

In conclusion, measuring ICG-PDR is a valuable method for dynamic assessment of liver function, and is found to be a valuable prognostic tool in predicting survival for septic patients, patients presenting with acute liver failure and critically ill patients.

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.