The relationship between inhalational anesthetic requirements and the severity of liver disease in liver transplant recipients according to three phases of liver transplantation. Transplant Proc. 2010;42:854-857. [PMID: 20430189 DOI: 10.1016/j.transproceed.2010.02.057]

Optimal anesthetic conduct regarding immediate and short-term outcomes after liver transplantation - Systematic review of the literature and expert panel recommendations

BACKGROUND

In the era of enhanced recovery after surgery, there is significant discussion regarding the impact of intraoperative anesthetic management on short-term outcomes following liver transplantation (LT), with no clear consensus in the literature.

OBJECTIVES

To identify whether or not intraoperative anesthetic management affects short-term outcomes after liver transplantation.

DATA SOURCES

Ovid MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Central.

METHODS

A systematic review following PRISMA guidelines was undertaken. The systematic review was registered on PROSPERO (CRD42021239758). An international expert panel made recommendations for clinical practice using the GRADE approach.

RESULTS

After screening, 14 studies were eligible for inclusion in this systematic review. Six were prospective randomized clinical trials, three were prospective nonrandomized clinical trials, and five were retrospective studies. These manuscripts were reviewed to look at five questions regarding anesthetic care and its impact on short term outcomes following liver transplant. After review of the literature, the quality of evidence according to the following outcomes was as follows: intraoperative and postoperative morbidity and mortality (low), early allograft dysfunction (low), and hospital and ICU length of stay (moderate).

CONCLUSIONS

For optimal short term outcomes after liver transplantation, the panel recommends the use of volatile anesthetics in preference to total intravenous anesthesia (TIVA) (Level of Evidence: Very low; Strength of Recommendation: Weak) and minimum alveolar concentration (MAC) versus bispectral index (BIS) for depth of anesthesia monitoring (Level of Evidence: Very low; Strength of Recommendation: Weak). Regarding ventilation and oxygenation, the panel recommends a restrictive oxygenation strategy targeting a PaO₂ of 70-120 mmHg (10-14 kPa), a tidal volume of 6-8 ml/kg ideal body weight (IBW), administration of positive end expiratory pressure (PEEP) tailored to patient intraoperative physiology, and recruitment maneuvers. (Level of evidence: Very low; Strength of Recommendation: Strong). Finally, the panel recommends the routine use of antiemetic prophylaxis. (Level of evidence: low; Strength of Recommendation: Strong).

The Requirement of Isoflurane and Remifentanil During Liver Transplantation Using Bispectral Index and Surgical Pleth Index: An Observational Study

BACKGROUND

During liver transplantation (LT), patients and surgical factors potentially influence the pharmacokinetics of the anesthetic agents. The aim of this study was to investigate the requirement of isoflurane and remifentanil according to severity of liver disease during LT under balanced anesthesia.

METHODS

We enrolled 44 patients undergoing LT. Anesthetic depth was maintained within the bispectral index score of 40 to 60 and Surgical Pleth Index of 20 to 60. Patients were divided into 2 groups according to their median Model for End-Stage Liver Disease (MELD) score: low MELD group and high MELD group. We compared end-tidal inhaled anesthetics and remifentanil consumption.

RESULTS

Patients were divided into 2 groups according to median value of MELD score: MELD score <16 (low MELD group; n = 20) or MELD ≥16 (high MELD group; n = 20). There was no significant difference between the 2 groups in end-tidal concentration of isoflurane during 3 phases. However, the remifentanil requirement was lower in the high MELD group during the dissection and anhepatic phases (mean (SD), 0.105 (0.067) vs 0.064 (0.055) µg/kg/min; P = .037, and 0.167 (0.096) vs 0.108 (0.079) µg/kg/min; P = .039, respectively; low MELD group vs high MELD group) with no significant difference during the neohepatic phase.

CONCLUSIONS

The severity of liver dysfunction based on MELD score affected the intraoperative remifentanil requirement during LT. Patients with cirrhosis are required to use analgesics appropriate to their individual patient characteristics in clinical practice.

Effects of different remifentanil target concentrations on MACBAR of sevoflurane in patients with liver dysfunction under carbon dioxide pneumoperitoneum stimulus: A randomized controlled trial

WHAT IS KNOWN AND OBJECTIVE

Remifentanil can effectively decrease the sevoflurane concentration to block sympathetic adrenergic response to CO₂ pneumoperitoneum stimulus,and liver dysfunction will significantly reduce the MAC_BAR (minimum alveolar concentration for blocking adrenergic response) of sevoflurane. However, the effects of different remifentanil concentrations on the MAC_BAR of sevoflurane in patients with liver dysfunction are unclear. The aim of this study was to observe the effects of different remifentanil concentrations by intravenous target-controlled infusion on the MAC_BAR of sevoflurane in patients with grade B liver dysfunction under carbon dioxide pneumoperitoneum stimulus.

METHODS

Seventy-five patients with grade B liver dysfunction undergoing elective laparoscopic surgery were selected, and randomly divided into three groups with remifentanil plasma target concentrations of 0 (group R₀ ), 1 (group R₁ ) and 2 (group R₂ ) ng/ml. Anaesthesia was induced by intravenous injection of propofol 2-3 mg/kg, remifentanil 2 μg/kg and cisatracurium 0.15 mg/kg. All groups were inhaled different concentrations of sevoflurane. The determination of sevoflurane MAC_BAR in each group was used a method of sequential-allocation technique, and venous blood samples were taken before and after the creation of carbon dioxide pneumoperitoneum to determine plasma adrenaline and noradrenaline concentrations.

RESULTS AND DISCUSSIONS

The MAC_BAR of sevoflurane in groups R₀ , R₁ and R₂ was 4.83%, 3.00% and 2.10%, respectively. The MAC_BAR of sevoflurane was significantly difference among the three groups. When a similar effect of MAC_BAR had achieved in each group, no significant differences were found in the changes of plasma adrenaline and noradrenaline concentrations before and after the creation of pneumoperitoneum. What is new and conclusion Target-controlled infusion of different concentrations of remifentanil can reduce sevoflurane MAC_BAR during pneumoperitoneum stimulation in patients with liver dysfunction in some degree. However, the changes of plasma adrenaline and noradrenaline concentrations are consistent in the three groups when patient's stress response was inhibited at the same degree.

Anesthesia for the Patient with Severe Liver Failure

The incidence of liver failure continues to increase, and it is associated with increased perioperative morbidity and mortality. Liver failure is associated with multiorgan dysfunction, including central nervous, cardiac, respiratory, gastrointestinal, renal, and hematological systems. Preoperative identification, optimization, and tailored anesthetic management are essential for optimum outcomes in patients with liver disease undergoing surgery. The coagulopathy of liver failure is a balanced coagulopathy better assessed by thromboelastography than conventional testing, and it is not directly associated with bleeding risk.

Anesthesia for the Patient with Severe Liver Failure

The incidence of liver failure continues to increase, and it is associated with increased perioperative morbidity and mortality. Liver failure is associated with multiorgan dysfunction, including central nervous, cardiac, respiratory, gastrointestinal, renal, and hematological systems. Preoperative identification, optimization, and tailored anesthetic management are essential for optimum outcomes in patients with liver disease undergoing surgery. The coagulopathy of liver failure is a balanced coagulopathy better assessed by thromboelastography than conventional testing, and it is not directly associated with bleeding risk.

Comparison of bispectral index targeted end-tidal concentration of desflurane during three phases of orthotopic liver transplantation

BACKGROUND AND AIMS

Reduced inhalational anaesthetic requirement in end-stage liver disease during living donor orthotopic liver transplantation (LD-OLT) is due to increased endogenous opioids. This study evaluated the changes in bi-spectral index (BIS) monitored end-tidal desflurane (ETDes) requirements during 'dissection', 'anhepatic', and 'neohepatic' phases of LD-OLT.

METHODS

This prospective, cohort study included 40 adults undergoing LD-OLT under general anaesthesia (GA). All patients received BIS-guided desflurane GA. ETDes requirements in three phases of LD-OLT (primary objective); relationship between inhalational anaesthetic requirements and severity of liver disease; and effect of changes in mean arterial pressure (MAP) and body temperature on ETDes concentration for all three phases were also evaluated.

RESULTS

ETDes during the 'dissection' phase (2.92 ± 0.65%) was > 'anhepatic' (2.68 ± 0.85%, P = 0.049) and 'neohepatic' phases (2.58 ± 0.71%, P = 0.005). Patients with model of end-stage liver disease (MELD) score < 20 returned significantly greater ETDes than those with MELD score ≥20 during the 'dissection' (MELD <20: 3.11 ± 0.49%; MELD ≥20: 2.58 ± 0.77%, P = 0.01) and 'anhepatic'(MELD <20: 2.96 ± 0.76%; MELD ≥20: 2.17 ± 0.79%, P = 0.003) phases. A positive correlation was observed between ETDes(r = 0.584, P = 0.001) and temperature in the 'dissection' phase only.

CONCLUSION

In patients undergoing LD-OLT, BIS monitoring guidance of depth of desflurane GA suggests lower desflurane requirements during 'anhepatic' and the 'neohepatic' phase of surgery. Also, the desflurane requirement is greater in patients with lesser severity of liver disease.

Pilot study of closed-loop anaesthesia for liver transplantation

BACKGROUND

Automated titration of propofol and remifentanil guided by the bispectral index (BIS) has been used for numerous surgical procedures. Orthotopic liver transplantation (OLT) uniquely combines major changes in circulating volume, an anhepatic phase, and ischaemia-reperfusion syndrome. We assessed the behaviour of this automated controller during OLT.

METHODS

Adult patients undergoing OLT were included in this pilot study. Consumption of propofol and remifentanil was calculated for each surgery period (dissection, anhepatic, and liver reperfusion phases). Arterial blood samples were collected at several time points to allow comparison of actual with calculated propofol and remifentanil concentrations. Data are presented as median [25th and 75th percentiles] or percentage (95% confidence interval).

RESULTS

Thirteen patients were studied. System performance, defined as the percentage of time with BIS in the range 40-60, was 88% (86-94) of the total duration of anaesthesia. Propofol requirement was decreased during the anhepatic phase compared with the dissection phase (2.9 [1.9-5.0] mg kg(-1) h(-1) and 4.6 [3.5-8.1] mg kg(-1) h(-1); P<0.03) while remifentanil consumption was unchanged (0.11 [0.09-0.19] µg kg- (1) min(-1)). Bland-Altman analysis showed a weak concordance for propofol (bias of 0.7 µg ml(-1) and limits of agreement of -2.2 to +3.7 µg ml(-1)) and remifentanil (bias of 1.3 ng ml(-1) and limits of agreement -4.3 to +6.8 ng ml(-1)). No adverse events were reported during anaesthesia.

CONCLUSIONS

This pilot study indicates that automated titration of propofol and remifentanil guided by the BIS is feasible during OLT.

The anhepatic phase extended by temporary portocaval shunt does not affect anesthetic sensitivity and postoperative cognitive function: A case-control study

Temporary portocaval shunt (TPCS) prolongs the duration of the anhepatic phase, during which anesthetic sensitivity is highest among the 3 phases of living donor liver transplantation (LDLT). Cognitive dysfunction has been associated with increased anesthetic sensitivity and poor hepatic function. Therefore, we assessed anesthetic sensitivity to desflurane and perioperative cognitive function in patients undergoing LDLT, in whom the duration of the anhepatic phase was extended by TPCS to test the hypothesis that the prolonged anhepatic phase increases anesthetic sensitivity and causes postoperative cognitive decline.This case-control study was conducted in 67 consecutive patients undergoing LDLT from February 2014 to January 2016. Anesthesia was maintained at a 0.6 end-tidal age-adjusted minimum alveolar concentration of desflurane. The bispectral index (BIS) was maintained at less than 60 and averaged at 1-minute intervals. The mini-mental state examination (MMSE-KC) was performed 1 day before and 7 days after the LDLT. All parameters were compared between the patients undergoing TPCS (TPCS group) and the remaining patients (non-TPCS group).TPCS was performed in 16 patients (24%). TPCS prolonged the duration of the anhepatic phase (125.9 ± 29.4 vs 54.9 ± 20.5 minutes [mean ± standard deviation], P < 0.0001). The averaged BIS values during the 3 phases were comparable between the 2 groups. No significant interval changes in the averaged BIS values were observed during the 3 consecutive phases. Similarly, there were no significant differences in MMSE-KC score assessed 1 day before and 7 days after LDLT between the 2 groups. The preoperative MMSE-KC scores were unchanged postoperatively in the 2 groups.The extension of the anhepatic phase did not affect anesthetic sensitivity and postoperative cognitive function.

Effect of the severity of liver dysfunction on the minimum alveolar concentration of sevoflurane responding to an electronic stimulation in cirrhotic patients

BACKGROUND

It has been observed that patients with liver dysfunction need lower dose anesthetic compared patients with normal liver function. The minimum amount of volatile anesthetic to achieve an optimal depth of anesthesia for these patients is still unclear. In this study, Minimum alveolar concentration (MAC) of the sevoflurane was determined using an electric stimulation and the effect of severity of liver dysfunction on the MAC was observed in cirrhotic patients.

METHODS

Thirty patients undergoing upper abdominal surgery were divided into the following groups: group N (normal liver function), group A (Child-Pugh grade A) and group B (Child-Pugh grade B-C). Neuropsychological tests were performed before surgery. We measured MAC_electric (minimum alveolar concentration that prevents movement in response to an electric stimulation in 50 % of patients) of sevoflurane in cirrhotic patients with liver dysfunction using an electrical stimulation of 80 mA at 50 Hz, and analyzed factors that associated change of MAC.

RESULTS

According to the neuropsychological tests, there were 7 and 4 patients with minimal hepatic encephalopathy in Groups B and A, respectively. MAC_electric in cirrhotic patients with liver dysfunction decreased significantly compared to that in healthy liver patients (1.51 ± 0.16 vol. %, 1.33 ± 0.14 vol. % and 1.17 ± 0.13 vol. % in Group N, A and B, respectively), while MAC_electric was comparable between the cirrhotic patients with different Child-Pugh grade. The Alanine Aminotransferase (ALT) and baseline values of bispectral index (BIS) were risk factors associated with the lowering of MAC_electric (p < 0.05).

CONCLUSION

MAC_electric of sevoflurane in cirrhotic patients was significantly lower than that of patients with a healthy liver. The severity of liver dysfunction had no effect on the MAC_electric of sevoflurane in cirrhotic patients.

TRIAL REGISTRATION

This study has been registered in the Chinese Clinical Trial Register in August 3, 2011 (No. ChiCTR-TRC-11001507 ).

Analgesia after liver transplantation

This article addresses postoperative analgesia in patients with end-stage liver disease who have undergone liver transplantation (LT). Postoperative analgesia determines how patients perceive LT. Although important, this topic is underrepresented in the current literature. With an increased frequency of fast tracking in LT, efficient intra- and postoperative analgesia are undergoing changes. We herein review the current literature, compare the benefits and disadvantages of the therapeutic options, and make recommendations based on the current literature and clinical experience.

Split liver transplantation: What’s unique?

The intraoperative management of split liver transplantation (SLT) has some unique features as compared to routine whole liver transplantations. Only the liver has this special ability to regenerate that confers benefits in survival and quality of life for two instead of one by splitting livers. Primary graft dysfunction may result from small for size syndrome. Graft weight to recipient body weight ratio is significant for both trisegmental and hemiliver grafts. Intraoperative surgical techniques aim to reduce portal hyperperfusion and decrease venous portal pressure. Ischemic preconditioning can be instituted to protect against ischemic reperfusion injury which impacts graft regeneration. Advancement of the technique of SLT is essential as use of split cadaveric grafts expands the donor pool and potentially has an excellent future.

Entropy-guided end-tidal desflurane concentration during living donor liver transplantation

Background:

The three phases of living donor liver transplantation (LDLT) represent different liver conditions. The aim is to study the required end-tidal desflurane concentration (ET-Des) guided with entropy monitoring for the depth of anesthesia.

Methods:

After the Ethics and Research Committee approval, 40 patients were included in this prospective study. Anesthesia was maintained with Desflurane-O2-air. State entropy (SE) and Response entropy (RE) were kept between 40 and 60.

Results:

Age and Model for End-stage Liver Disease (MELD) score were 45±10 years and 15.43±3.92, respectively. ET-Des were significantly lower in the anhepatic phase (2.8±0.4%) than in the pre-anhepatic and neohepatic phases (3.3±0.3%, 3.47±0.3%, respectively, P<0.001). The SE and RE for pre-anhepatic, anhepatic, and neohepatic phases were (45.6±3.7, 47.4±3.2), (44.7±2.1, 46.4±2.04), and (46.1±3.3, 47.9±3.3), respectively, with no significant changes between the phases, P > 0.05. Total operative time was 651±88 minutes, and for each phase it was 276±11, 195±55, and 191±24 minutes, respectively. Significant changes were found in hemoglobin g/dl and hematocrit % between the three phases (10.28±1.5, 30.48±4.3), (9.45±1.34, 28.36±4.1), and (8.88±1.1, 26.63±3.5), P<0.05. The heart rate and mean blood pressures were stable despite the cardiac index demonstrated a significant reduction during the anhepatic phase (2.99±0.22) when compared to the pre-anhepatic and neohepatic phases (3.60±0.29) and (4.72±0.32), respectively, (P<0.05). There was a significant correlation between CI and ET-Des% (r=0.604, P<0.05).

Conclusion:

Inhalational anesthetic requirements differed from one phase to another during LDLT, with requirements being the least during the anhepatic phase. Monitoring of the anesthesia depth was required, to avoid excess administration, which could compromise the hemodynamics before the critical time of reperfusion.

Clinical practice of early extubation after liver transplantation

BACKGROUND

Anesthetic practices such as early tracheal extubation facilitate postoperative recovery. Early extubation after liver transplantation has been adopted by some centers in the recent two decades. No universal clinical guidelines are used and questions remain. This review aimed to address the current status of early extubation after liver transplantation.

DATA SOURCES

A literature search of MEDLINE and ISI Web of Knowledge databases was performed using terms such as liver transplantation, early extubation, immediate tracheal extubation, fast tracking or fast track anesthesia and postoperative tracheal extubation. Additional papers were identified by a manual search of the references in the key articles.

RESULTS

Review of the available literature provided an insight into the definition, evolution, advantages and risks of early extubation, and anesthetic techniques that prompt early extubation in liver transplant patients. Early extubation has proved to be feasible and safe in these patients, but the outcomes are still uncertain.

CONCLUSIONS

Early extubation after liver transplantation is feasible, safe and cost-effective in the majority of patients and has been increasingly accepted as an option for conventional postoperative ventilation. Comprehensive and individualized evaluation of the patient's condition before extubation by an experienced anesthesiologist is the cornerstone of success. Understanding of its effect on the outcome remains incomplete. In the future, additional trials are required to establish universal early extubation guidelines and to determine its benefits for patients and practitioners.

Liver transplantation: Advances and perioperative care

Liver transplantation is one of the treatments for many-life threatening liver diseases. Numerous advances in liver transplant surgery, anaesthesia and perioperative care have allowed for an increasing number of these procedures. The purpose of this review is to consider some of the important advances in perioperative care of liver transplant patients such as pre-operative evaluation, intraoperative monitoring and management and early extubation. A PubMed and EMBASE search of terms “Anaesthesia” and “Liver Transplantation” were performed with filters of articles in “English”, “Adult” and relevant recent publications of randomised control trial, editorial, systemic review and non-systemic review were selected and synthesized according to the author's personal and professional perspective in the field of liver transplantation and anaesthesia. The article outlines strategies in organ preservation, training and transplant database for further research.

Anesthetic considerations for the patient with liver disease

PURPOSE OF REVIEW

An increasing number of patients requiring surgery are presenting with chronic or end stage liver disease. The management of these patients demands anesthesiologists with in-depth knowledge of the consequences of hepatic dysfunction, the effects on other organs, the risk of surgery, and the impact of anesthesia.

RECENT FINDINGS

Chronic or end stage liver disease is associated with an increased risk of perioperative morbidity and mortality. It is essential to preoperatively assess possible hepatic encephalopathy, pleural effusions, hepatopulmonary syndrome, hepatopulmonary hypertension, hepatorenal syndrome, cirrhotic cardiomyopathy, and coagulation disorders. The application of two scoring systems, that is, Child-Turcotte-Pugh and model for end stage liver disease, helps to estimate the risk of surgery. The use of propofol is superior to benzodiazepines as intravenous narcotics. Although enflurane and halothane are discouraged for maintenance of anesthesia, all modern volatile anesthetics appear comparable with respect to outcome. Fentanyl, sufentanil, and remifentanil as opioids and cis-atracurium for relaxation may be the best choices in liver insufficency. Regional anesthesia is valuable for postoperative pain management.

SUMMARY

Current studies have employed different anesthetic approaches in the preoperative and intraoperative management in order to improve outcomes of patients with liver disease.

The relationship between postoperative intravenous patient-controlled fentanyl analgesic requirements and severity of liver disease

PURPOSE

Decreased inhalational anesthetic requirements during orthotopic liver transplantation (OLT) have been reported according to the severity of the pre-existent disease as well as decreased opioid requirements thereafter. The aim of the present study was to determine the relationship between postoperative opioid requirements and severity of liver disease among OLT patients.

METHODS

We retrospectively reviewed 44 recipients who used intravenous fentanyl-based patient-controlled analgesia (PCA) after OLT from November 2009 to May 2010. The severity of liver disease was assessed using the model for end-stage liver disease (MELD) score. Recipients were divided into a low-MELD group (<20; n=30) and a high-MELD group (≥20; n=14). The amounts of PCA infusion and rescue opioid up to 3 postoperative days (POD) were compared between the 2 groups. The intensity of pain at rest and when coughing was assessed using visual analog scale (VAS) scores.

RESULTS

The cumulative opioid requirements via PCA on POD 1, 2, and 3 were significantly lower in the high-MELD than the low-MELD group. The amounts of rescue opioid were similar between the 2 groups. However, the intensity of pain at both rest and when coughing on POD 1, 2, and 3 were significantly less severe in the high-MELD than the low-MELD group.

CONCLUSIONS

OLT patients with high MELD scores required less postoperative opioids and experienced less pain than those with low scores. Therefore, postoperative pain control after OLT should be carefully titrated according to the severity of the liver disease.