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

Detection and quantification of perioperative heparin-like effects by rotational thromboelastometry in living-donor liver transplant recipients: A prospective observational study

Background and Aims

Heparin-like effects (HLEs) can affect hemostasis during liver transplantation. The aim of this study was to assess the perioperative incidence and severity of HLE with rotational thromboelastometry (ROTEM) and activated partial thromboplastin time (aPTT).

Material and Methods

ROTEM and aPTT were measured intraoperatively and on postoperative days (POD) 1, 3, and 7. HLE was identified if ROTEM INTEM/HEPTEM CT-ratio was >1.25 and severe forms of HLE when ratio was ≥2. Based on aPTT, HLE was defined when aPTT ratio was >1.25 (patient aPTT/control aPTT).

Results

Thirty-eight recipients were included. Variable degrees of HLE were detected by aPTT-ratio and INTEM/HEPTEM CT ratio. No significant correlation existed between both ratios. Based on INTEM/HEPTEM CT ratio, HLE was detected in 7/38 during anhepatic phase, 19/38 post-reperfusion, 10/38 on POD1, 4/38 on POD3, and 0/38 on POD7. Four cases of severe HLE were identified by INTEM/HEPTEM CT ratio only in the anhepatic phase. Postoperative infusion of unfractionated heparin led to mild-moderate HLE on POD1 and 3 as evident by both tests. Red blood cell and plasma transfusion were higher with severe HLE (1350 ± 191 ml and 3558 ± 1407 ml). Composite adverse outcome of any complication or death within 3 months for patients without HLE, mild-moderate HLE, and severe HLE as detected by ROTEM was 27.8%, 42.9%, and 66.7%, respectively.

Conclusion

INTEM/HEPTEM CT ratio was able to detect and quantify HLE as aPTT ratio. The ability of the INTEM/HEPTEM CT ratio to identify severe HLE earlier in the anhepatic phase needs to be studied in a larger population. HLE is self-limiting, but when identified in a severe form, it is associated with worse outcome.

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.

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.

Organ protection in allograft recipients: anesthetic strategies to reduce postoperative morbidity and mortality

PURPOSE OF REVIEW

Organ protection remains a primary objective in the anesthetic management of patients undergoing transplantation. An ongoing effort has been made to develop strategies to improve graft outcome and reduce postoperative morbidity and mortality, but trials have reported conflicting results. The aim of this review was to provide a comprehensive summary of the anesthetic management in transplant recipients and to identify current strategies for organ protection.

RECENT FINDINGS

Decreasing blood products requirements, intraoperative blood glucose control and adequate postoperative pain therapy may improve patient outcome. Vasopressors have been reported to reduce perioperative bleeding but might be associated with postoperative acute renal failure in liver transplantation. Early extubation may increase survival rates in recipients. These perioperative challenges, along with other protective strategies, have been addressed in 20 recently published studies: 10 randomized controlled trials, nine retrospective studies and one prospective study.

SUMMARY

This review identified several promising strategies ensuring organ protection and improving patient outcome after solid organ transplantation. However, as outcomes were difficult to compare, further evidence will be needed before drawing firm conclusions.