Association of Platelet Count and Platelet Transfusion With Serotonin Level During Living Donor Liver Transplantation: Possible Connection to Graft Regeneration

BACKGROUND

We recently showed that platelet counts and the amount of platelet transfusion during liver transplantation are positively associated with early graft regeneration. It was hypothesized that platelet-derived serotonin mediates liver regeneration.

OBJECTIVES

This study aimed to evaluate the association between intraoperative platelet count, platelet transfusion, and serum serotonin level.

METHODS

Thirty-two recipients undergoing living-donor liver transplantation were enrolled into this prospective observational study. Serum platelet counts and serotonin levels were measured at the following times: anesthetic induction, start of the anhepatic phase, before graft reperfusion, 5 minutes/1 hour/3 hours/5 hours after graft reperfusion, and before/after platelet transfusion. Serotonin was measured by using a liquid chromatography tandem mass spectrometry.

RESULTS

Serotonin level at the anesthetic induction was 24.5 μg/mL (interquartile range, 14.6 to 38.1 μg/mL). During surgery, serial changes in platelet counts and serotonin levels showed a similar trend: they decreased during the anhepatic phase, increased during the first hour after graft reperfusion, and thereafter gradually decreased. Serotonin level was positively correlated with platelet counts (correlation coefficient = 0.620, P < .001). Allogeneic platelet transfusion significantly increased platelet count from 22 (19-31) × 10⁹/L to 53 (50-81) × 10⁹/L (P = .008) and it also increased serum serotonin from 11.04 (6.41-15.34) μg/mL to 34.26 (25.86-41.94) μg/mL (P = .008).

CONCLUSIONS

Our findings indicate that allogeneic platelets could act as effector cells deriving serotonins. Also, our findings support the hypothesis that the association between platelets and post-transplantation graft regeneration is mediated by serotonin. Further studies are warranted regarding the respective role of serotonin and other platelet-derived molecules mediating liver regeneration.

Ischemic Preconditioning Produces Comparable Protection Against Hepatic Ischemia/Reperfusion Injury Under Isoflurane and Sevoflurane Anesthesia in Rats

BACKGROUND

Various volatile anesthetics and ischemic preconditioning (IP) have been demonstrated to exert protective effect against ischemia/reperfusion (I/R) injury in liver. We aimed to determine whether application of IP under isoflurane and sevoflurane anesthesia would confer protection against hepatic I/R injury in rats.

METHODS

Thirty-eight rats weighing 270 to 300 grams were randomly divided into 2 groups: isoflurane (1.5%) and sevoflurane (2.5%) anesthesia groups. Each group was subdivided into sham (n = 3), non-IP (n = 8; 45 minutes of hepatic ischemia), and IP (n = 8, IP consisting of 10-minute ischemia plus 15-minute reperfusion before prolonged ischemia) groups. The degree of hepatic injury and expressions of B-cell lymphoma 2 (Bcl-2) and caspase 3 were compared at 2 hours after reperfusion.

RESULTS

Hepatic ischemia induced significant degree of I/R injuries in both isoflurane and sevoflurane non-IP groups. In both anesthetic groups, introduction of IP dramatically attenuated I/R injuries as marked by significantly lower aspartate aminotransferase and aminotransferase levels and better histologic grades compared with corresponding non-IP groups. There were 2.3- and 1.7-fold increases in Bcl-2 mRNA levels in isoflurane and sevoflurane IP groups, respectively, compared with corresponding non-IP groups (both P < .05). Caspase 3 level was significantly high in the isoflurane non-IP group compared with the sham group; however, there were no differences among the sevoflurane groups.

CONCLUSIONS

The degree of hepatic I/R injury was significantly high in both isoflurane and sevoflurane groups in rats. However, application of IP significantly protected against I/R injury in both volatile anesthetic groups to similar degrees, and upregulation of Bcl-2 might be an important mechanism.

Evaluation of "flat-line" thromboelastography after reperfusion during liver transplantation

BACKGROUND

"Flat-line" (no clot formation) thromboelastography (TEG) is frequently observed after graft reperfusion during liver transplantation (LT). We aimed to evaluate the incidence and causes of flat-line TEG after graft reperfusion during LT.

METHODS

With institutional review board approval, data of 208 consecutive recipients who underwent LT from May 2010 to May 2012 were retrospectively reviewed. We performed 3 different types of TEG measurements at 5 minutes after graft reperfusion: native TEG (nTEG), tranexamic acid-added TEG (tTEG), and protamine-added TEG (pTEG). The flat-line TEG was defined as having no trace at all at 60 minutes of TEG. We examined the incidence and causes of flat-line nTEG. We also compared recipients with flat-line nTEG (F group) and clot-forming nTEG (C group).

RESULTS

One hundred eighty-two recipients were included in the final analysis. The incidence of flat-line nTEG was 27% (49/182 cases). Among 49 recipients in the F group, 28 recipients showed clot formation in both tTEG and pTEG, 19 recipients in only tTEG, and 1 recipient in only pTEG; 1 recipient showed no clot formation in any TEGs. Graft from the deceased donor was more frequently observed in the F group than in the C group (P = .039). The F group showed decreased platelet count (P = .001), increased prothrombin time (P = .002), and decreased fibrinogen (P = .009) compared with the C group.

CONCLUSIONS

No clot formation was relatively common after reperfusion during LT, and the main causes were hyperfibrinolysis and heparin effect. Liver graft from deceased donors was associated more frequently with no clot formation after reperfusion during LT.

Risk factors for inadvertent hypothermia during adult living-donor liver transplantation

BACKGROUND

Hypothermia (core temperature <35°C) causes multiple physiologic disturbances, including coagulopathy and cardiac dysfunction. Patients undergoing liver transplantation are at risk of inadvertent hypothermia and might be more vulnerable to its adverse effects. We sought to identify the factors contributing to hypothermia during living-donor liver transplantation (LDLT), which have not yet been studied in depth.

METHODS

Medical records of 134 recipients who underwent adult-to-adult LDLT were reviewed. Core temperature at the following time points were taken: anesthetic induction, skin incision, start and end of the anhepatic phase, and hourly after hepatic reperfusion.

RESULTS

Of 134 recipients, 29 (21.6%) developed hypothermia during surgery. Four independent risk factors for hypothermia were identified: small body weight-to-body surface area ratio, acute hepatic failure, high Model for End-Stage Liver Disease (MELD) score, and low graft-to-recipient weight ratio. The amount of core temperature drop was positively correlated with the number of involved risk factors. Each risk factor had a respective contribution according to the operative phases: body weight-to-body surface area ratio and the MELD score for the preanhepatic phase, acute deterioration of hepatic failure for the anhepatic phase, and graft-to-recipient weight ratio was for the postreperfusion phase.

CONCLUSIONS

Hypothermia was independently associated with the recipient's morphometric characteristics, emergency of end-stage liver disease, MELD score, and graft volume. These factors showed a cumulative effect, and the role of each factor was different according to the operative phase. These results should aid in the development of an optimal thermal strategy during LDLT.

Analysis of predictors for lactate elimination after reperfusion in recipients of living-donor liver transplantation

BACKGROUND

Graft-recipient weight ratio (GRWR) is the only documented predictor that influences the lactate elimination after reperfusion in living-donor liver transplantation (LDLT). This study was performed to investigate the predictors of lactate elimination after reperfusion in recipients of adult LDLT.

METHODS

The medical records of 159 patients who underwent LDLT were analyzed. Lactate level (mmol/L) was measured from just before the initiation of surgery (P0) and 5, 60, and 120 minutes after reperfusion of graft (R0, R1, and R2, respectively). The change of lactate level after reperfusion was defined as difference between lactate level measured at R0 and R2. Patients were divided into accumulation and elimination groups. Donor and recipient factors were compared between the 2 groups.

RESULTS

Lactate accumulation occurred in 80 of 159 recipients (50.3%), and elimination occurred in 79 (49.7%). GRWR and Model for End-Stage Liver Disease (MELD) score were higher in the elimination group. Lactate at R0 was lower in the elimination group.

CONCLUSIONS

Higher GRWR and MELD score and lower lactate level immediate after reperfusion of graft were predictors of lactate elimination after reperfusion during adult LDLT.

Factors associated with consciousness recovery time after liver transplantation in recipients with hepatic encephalopathy

BACKGROUND

Hepatic encephalopathy (HE) occurs as a result of liver failure and is often considered to be a clinical indication for liver transplantation (LT). An assessment of post-transplantation consciousness level in recipients with HE is crucial, because recovery of consciousness implies reestablishment of transplant liver function and lack of perioperative brain damage. The purpose of this study is to evaluate factors associated with consciousness recovery time after LT in recipients with HE.

METHODS

Out of 633 adult recipients who underwent LT, recipients who exhibited HE at the time of LT were analyzed retrospectively. The time between graft reperfusion and postoperative consciousness recovery was determined, and recipients were divided into 2 groups: group E with recovery of consciousness early (≤48 hours), and group L with recovery of consciousness late (>48 hours). Analyzed variables included recipient sex, age, graft type, Model for End-Stage Liver Disease score, HE history/duration/type/grade, and preoperative laboratory values, including blood ammonia concentration.

RESULTS

HE was present at the time of LT in 69 (10.9%) of 633 recipients. Among the 69 recipients, 11 recipients who died or underwent reoperation before consciousness recovery were excluded, and 58 recipients (group E: n = 32; group L: n = 26) were enrolled into analysis. Multivariate analysis showed that HE duration >5 days (odds ratio [OR], 15.58; 95% confidence interval [CI], 1.35-179.56; P = .028) and HE type C (OR, 30.90; 95% CI, 1.67-573.48; P = .021) were the independent factors associated with late recovery from HE after LT.

CONCLUSIONS

We suggest that recipients with long-duration or type C HE should be carefully managed during the post-transplantation period to prevent deterioration of HE.

The comparisons of hepatitis C virus RNA level between intraoperative blood salvage (cell saver) and systemic hepatitis C virus RNA kinetics during liver transplantation

BACKGROUND

Cell Saver (CS; Haemonemic Corp, Braintree, Mass, United States) is frequently used to decrease transfusion requirements of homologous blood during liver transplantation (OLT). However, the use of CS in hepatitis C virus (HCV)-infected recipients is still debated owing to the potential elevation of HCV RNA level. In this study, we compared HCV RNA levels of CS blood with a series of blood samples obtained from HCV-infected OLT recipients.

METHODS

Twelve HCV-infected patients with >50,000 copies/mL of HCV RNA were enrolled. HCV RNA was measured immediately after induction (I), at the end of anhepatic period (II), at the end of operation (III), and from the first returned blood in CS (CSb). HCV RNA level at each time period was compared.

RESULTS

HCV RNA levels ranged from 77,931 to 9,072,000 copies/mL at I. When compared to I, HCV RNA levels were reduced to 11.1% ± 13.0% and 0.7% ± 1.0% at II and III, respectively. Also, the RNA level reduced to 3.0% ± 2.0% of I after CS processing. The HCV RNA level at I was significantly higher than the levels at II, III, and CSb (P = .012, each), and the level at II was significantly higher than the level at III (P = .012). The HCV RNA level at CSb showed no statistical difference with the levels at II, but it was significantly higher than the level at III (P = .042).

CONCLUSIONS

The use of CS in HCV-infected OLT recipients seems to carry no additional risk with respect to intraoperative HCV RNA kinetics.

The comparison of femoral and radial arterial blood pressures during pediatric liver transplantation

BACKGROUND

Orthotopic liver transplantation (OLT) is frequently associated with dramatic hemodynamic changes; thus, it is critical to accurately monitor blood pressure. Although comparisons between femoral arterial blood pressure (FABP) and radial arterial blood pressure (RABP) have been reported in adult liver recipients, we compared FABP with RABP in pediatric recipients.

METHODS

Thirty-five pediatric liver recipients younger than 13 years of age were included in this prospective, observational study. We measured simultaneous FABP and RABP in the femoral and radial arteries at nine time points during the procedure, including: baseline (after anesthetic induction); 1 hour thereafter; 30 minutes after the beginning of the anhepatic period as well as 0, 1, 3, 5, 15, and 60 minutes after graft reperfusion.

RESULTS

Of the 35 pediatric liver recipients, 2 infants and 1 13-month-old child were excluded from the analysis because of radial arterial catheter malfunction. The remaining 32 patients including 16 infants and 16 children all showed significantly higher systolic and mean FABP than RABP during most stages of pediatric OLT. Overall diastolic FABP measurements were similar to diastolic RABP throughout the study.

CONCLUSIONS

Systolic and mean FABP were significantly higher than RABP during most stages of pediatric OLT. Radial arterial catheter malfunctions were not uncommon during pediatric OLT. Our results indicated that it is useful to cannulate the femoral artery to accurately and reliably measure arterial blood pressure to detect hemodynamic instability during pediatric OLT.

Comparison of mixed venous oxygen saturation after in vitro calibration of pulmonary artery catheter with that of pulmonary arterial blood in patients undergoing living donor liver transplantation

INTRODUCTION

Mixed venous saturation (SvO2) reflects the balance between oxygen delivery and consumption throughout the body. A multifunction pulmonary artery catheter (PAC) can monitor continuous SvO2 after in vitro calibration (CSvO2), obviating the need for in vivo calibration with pulmonary arterial blood. In critically ill patients CSvO2 has shown a good correlation with measured SvO2 of pulmonary arterial blood using co-oximetry (MSvO2). The aim of this study was to compare CSvO2 and MSvO2 in liver transplantation (OLT) recipients.

METHODS

We enrolled 44 OLT recipients for comparison with 24 coronary artery bypass graft (CABG) controls free of end-stage liver disease. After anesthetic induction, the PAC was inserted after in vitro calibration and CSvO2 and MSvO2 simultaneously measured. In OLT recipients, additional measurements of CSvO2 and MSvO2 were performed at anhepatic and postreperfusion phases. Pearson's correlation analysis was used to evaluate the correlation between the 2 measurements. A Bland-Altman analysis was used to determine precision of and bias between the 2 measurements. With ±3% regarded to be interchangeable.

RESULTS

Cardiac output and intrapulmonary shunt in CABG patients were lower than among OLT recipients. OLT recipients, showed a significant correlation between CSvO2 and MSvO2, but the coefficients were different during the three phases of OLT (r = 0.597, 0.753, and 0.756). In addition, bias values between the two measurements were 6.0%, 6.4%, and 2.9% for the preanhepatic, anhepatic, and postreperfusion phases, respectively, with 29.5%, 31.8%, and 50% of them being interchangeable. In contrast CABG patients showed bias in -0.17% with 75% of measurements interchangeable.

CONCLUSION

While in vitro calibration of the PAC can be used in CABG patients, MSvO2 is higher than CSvO2 in OLT recipients. Therefore, in vivo calibration with pulmonary arterial blood is necessary for accurate monitoring of SvO2 in OLT recipients.

Vecuronium requirements according to the operative phase during living donor liver transplantation under desflurane anesthesia

INTRODUCTION

The requirements of nondepolarizing neuromuscular blocking agent during liver transplantation show conflicting results. We sought to evaluate the requirements according to the operative phase and find extrahepatic factors that influence neuromuscular blocking agent requirements.

METHODS

We enrolled 35 patients undergoing living donor liver transplantation. Continuous infusion of vecuronium was adjusted every 15 minutes for consistent neuromuscular blockade aimed at T1/Tc of 0.10 monitored with a neuromuscular transmission module. We compared the mean infusion dose in each phase, and investigated whether it is correlated with preoperative Model for End-Stage Liver Disease (MELD) score, Child-Turcotte-Pugh (CTP) score, graft-recipient weight ratio (GRWR), or time to recovery of first twitch response to train-of-four (TOF) stimulation.

RESULTS

There was a significant difference between vecuronium doses during each phase (P < .001): 0.48 ± 0.16 μg/kg/min, preanhepatic; 0.38 ± 0.14 μg/kg/min, anhepatic and 0.26 ± 0.07 μg/kg/min, neohepatic phase. There was a significant positive correlation between vecuronium infusion dose in the preanhepatic phase and CTP scores (P = .006, correlation coefficient = 0.465). There was also a significant negative correlation between the time to recovery of first twitch response of TOF stimulation and vecuronium infusion dose in the preanhepatic phase (P = .001, correlation coefficient = -0.546). The infusion dose during the preanhepatic phase was not associated with the MELD score, and that of neohapatic phase not with GRWR.

CONCLUSIONS

The vecuronium infusion dose requirement during the anhepatic decreased compared with that in the preanhepatic phase. It further decreased during the neohepatic phase compared with the previous phases. Vecuronium infusion dose reduction is suggested especially during the neohepatic phase for early extubation. The dose during the preanhepatic phase is suggested to be determined considering the CTP score and the time to recovery of the TOF response.

Arthroscopic shoulder surgery under general anesthesia with brachial plexus block: postoperative respiratory dysfunction of combined obstructive and restrictive pathology

OBJECTIVE

Changes in respiratory parameters and pulmonary function tests were evaluated after shoulder arthroscopic surgery with brachial plexus block (BPB). The purpose of this study was to identify the mechanism of respiratory dysfunction after this type of surgery.

METHODS

Patients undergoing arthroscopic rotator cuff repair under general anesthesia (GA) with BPB were enrolled in the arthroscopy group (n = 30) while those undergoing open reduction of a clavicle or humerus fracture under GA were enrolled in the control group (n = 30). Forced vital capacity (FVC) and forced expiratory volume 1 s (FEV(1)) were measured at the outpatient clinic stage (#1) before (#2) and 20 min after BPB (#3) and 1 h after extubation (#4). Respiratory variable measurements along with the cuff leak test were performed 5 min after surgical positioning (T1) and at the start of skin closure (T2). Respiratory discomfort was evaluated after extubation. The upper airway diameters and soft tissue depth of chest wall were also measured by ultrasonography at stages #3 and #4.

RESULTS

Static compliance decreased significantly at T2 in the arthroscopy group (50 ± 11 at T1 vs. 44 ± 9 ml/cm H(2)O at T2, p =0.035) but not in the control group. The incidence of positive cuff leak tests at T2 was significantly higher in the arthroscopy group than in the control group (47% in the arthroscopy group vs. 17% in controls, p =0.010). While FEV(1) and FVC remained stable at stages #1 and #2, FVC and FEV(1) decreased at stages #3 and #4 only in the arthroscopy group (FVC in arthroscopy group, #2: 3.26 ± 0.77 l; #3: 2.55 ± 0.63 l, p =0.015 vs. #2; #4: 2.66 ± 0.41 l, p =0.040 vs. #2). The subglottic diameter decreased at #4 in the arthroscopy group, while no changes occurred in the control group (0.70 ± 0.21 cm vs. 0.85 ± 0.23 cm in the arthroscopy and control groups, respectively, p =0.011). Depth of skin to pleura increased at both intercostal spaces 1-2 and 3-4 in the arthroscopy group. There were three cases of hypoxia (S(p)O(2) < 95%) with room air in the arthroscopy group while none occurred in the controls.

CONCLUSION

Shoulder arthroscopic surgery under GA with BPB induced both restrictive and obstructive pathologies. It is important to maintain a high level of awareness for the potential negative respiratory effects of this surgery especially for subjects with pre-existing cardiopulmonary disease. The measurements in this study would be useful to monitor the risk of respiratory dysfunction in these patients.

Combined carbamazepine and pregabalin therapy in a rat model of neuropathic pain

BACKGROUND

Carbamazepine and pregabalin have proven effects against neuropathic pain. Carbamazepine blocks voltage-dependent Na(+) channels, whereas pregabalin blocks voltage-dependent Ca(2+) channels. The authors hypothesized that the co-administration of these drugs would synergistically reduce neuropathic pain.

METHODS

Neuropathic pain was induced by L5 nerve ligation in Sprague-Dawley rats. To determine their ED(50) values, carbamazepine and pregabalin were orally administered at 0.3, 3, 10, or 30 mg kg(-1). The drugs were then co-administered at 0, 1/4×ED(50), 1/2×ED(50), 1.5×ED(50), and 2×ED(50) to determine the ED(50) and ED(75) values of the drugs in combination. Allodynia was determined using the von Frey hair test and dose-effect curves and isobolograms were used to investigate drug interactions. Levels of the acute reactive protein c-Fos in the dorsal horn were evaluated as an indicator of pathological nerve excitation.

RESULTS

At ED(50) levels, carbamazepine and pregabalin did not exhibit synergism, but doses higher than ED(75) were found to be synergistic. The combination index was 0.18 (strong synergy) and dose reductions were 35.7-fold for carbamazepine and 6.8-fold for pregabalin when co-administered when compared with a single administration at ED(75). The percentage allodynia relief was only 60% for carbamazepine and 80% for pregabalin by single administration, whereas their co-administration relieved allodynia by 100%. Furthermore, treatment decreased c-Fos expression in the dorsal horn, but expressional differences between animals treated with carbamazepine plus pregabalin were not significantly different from those treated with single drug.

CONCLUSIONS

Carbamazepine and pregabalin ameliorate neuropathic pain synergistically at higher doses.

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.

Which score system can best predict recipient outcomes after living donor liver transplantation?

INTRODUCTION

Many scoring systems have been suggested to predict the outcomes of deceased donor liver transplantations. The aims of this study were to compare the Model for End-Stage Liver Disease (MELD) score with respect to other scores among patients who underwent living donor liver transplantation (LDLT) seeking to evaluate the best system to correlate with postoperative outcomes after LDLT.

METHODS

We analyzed retrospectively data from 202 adult patients who underwent LDLT from January 2008 to July 2010. We calculated preoperative MELD, MELD-sodium, MELD to serum sodium ratio (MESO), integrated MELD, United Kingdom MELD, Child-Turcotte-Pugh, Acute Physiology and Chronic Health evaluation II (APACHE II), and Sequential Organ Failure Assessment (SOFA) scores in all patients. We analyzed the correlation of each score with postoperative laboratory results, as well as survival at 1, 3, 6 and 12 months after LDLT.

RESULTS

There was significant positive correlation between all scores and peak total bilirubin during the first 7 days after LDLT. The MELD score showed the greatest correlation with peak total bilirubin (r=0.745). APACHE II and SOFA scores at 6 months and 1 year after LDLT and MESO score at 1 year after LDLT showed acceptable discrimination performance {area under the receiver operating characteristic curves (AUC)>0.7, while other scoring systems showed poor discrimination. However, the AUCs of each score were not significantly different from the MELD score AUC.

CONCLUSION

The MELD score most correlated with total bilirubin after LDLT, while the APACHE II and SOFA scores seemed to correlate with mortality after LDLT.

The Effect of Body Mass Index on Spinal Anaesthesia for Total Knee Replacement Arthroplasty: A Dose-response Study

The aim of this study was to compare the duration of spinal anaesthesia in obese and non-obese subjects. We also quantified the effect of body mass index (BMI) on spinal anaesthesia by comparing the median effective dose (ED50) of intrathecal hyperbaric bupivacaine required in the two cohorts. One hundred and eight patients undergoing elective total knee replacement arthroplasty under combined spinal-epidural anaesthesia were enrolled as a non-obese group (BMI <27.5 kg/m2) or obese (O) group (BMI ≤27.5 kg/m2). Each group was further subdivided by bupivacaine doses of 6, 7, 8, 9, 10 or 11 mg, respectively. Anaesthesia was deemed successful if a bilateral T12 sensory block occurred within 15 minutes of intrathecal drug administration and epidural supplementation was not required. The ED50 for successful anaesthesia and that for successful block of tourniquet pain were determined separately by probit regression analysis. Although the analgesic duration was prolonged with higher doses of bupivacaine in group O, the ED50 for successful anaesthesia did not differ between groups. However, the incidence of tourniquet pain was lower in group O and the ED50 for block of tourniquet pain was less in group O. This study suggests that bupivacaine dose reduction is not necessary, but analgesic duration may be prolonged in patients with higher BMI. These patients require careful consideration of spinal anaesthetic dose to minimise the risk of unnecessary prolongation of anaesthesia.

Predictors of high intraoperative blood loss derived by simple and objective method in adult living donor liver transplantation

We conducted a risk factor analysis for high intraoperative blood loss (IBL) in 555 living donor liver transplantation (LDLT) cases with a simple and objective method of IBL estimation based on the concept of red cell mass (RCM): Lost RCM (mL) = patient's estimated blood volume (mL) × (preoperative hematocrit in % - postoperative hematocrit in %) + (transfused leukocyte-depleted red blood cell in units × 213 × 70%) + (transfused Cell Saver blood in mL × 55%). Analysis of 33 preoperative variables revealed that Model for End-stage Liver Disease (MELD) score, albumin, the presence of ascites, and previous abdominal surgery were correlated with high IBL (lost RCM > 1000 mL) in multivariate logistical regression analysis. In conclusion, we found that MELD score, albumin, the presence of ascites, and previous abdominal surgery were significantly correlated with high IBL during adult LDLT.

Comparison of the prophylactic anti-emetic efficacy of ramosetron and ondansetron in patients at high-risk for postoperative nausea and vomiting after total knee replacement

We compared the prophylactic anti-emetic efficacy of ramosetron, a newly developed 5-HT(3) antagonist, and ondansetron in patients at high-risk for postoperative nausea and vomiting after total knee replacement. Eighty-four patients with three risk factors for postoperative nausea and vomiting (female, non-smoking and use of postoperative opioid use (ropivacaine and hydromorphone patient controlled epidural analgesia)) undergoing unilateral total knee replacement were randomly allocated to ramosetron 0.3 mg (n = 42) or ondansetron 4 mg (n = 42) groups. A complete response (no postoperative nausea and vomiting and no rescue anti-emetic) and the incidence of postoperative nausea and vomiting were assessed for 48 h after surgery at 0-2 h, 2-6 h, 6-24 h, and 24-48 h. More patients in the ramosetron group had a complete response between 2 and 48 h. The incidence of nausea between 2 and 24 h and the severity of nausea between 2 and 48 h were also less in the ramosetron group. Ramosetron was more effective than ondansetron in preventing postoperative nausea and vomiting in patients at high risk undergoing unilateral total knee replacement.

Peroneal neuropathy after liver transplantation

INTRODUCTION

The incidence of peroneal neuropathy (PN), occurring predominantly in the left leg, increases after the incorporation of intermittent pneumatic compression (IPC) devices among adult liver transplantation (OLT) recipients in our hospital. The aim of this study was to investigate the possible risk factors for PN and the reason for the left-leg predominance.

METHODS

We retrospectively reviewed the medical records of 501 OLT recipients. The patients were first divided into 2 groups, PN (n = 33) and non-PN (n = 468), to assess possible risk factors. The patients were then categorized into IPC (n = 262) and non-IPC (n = 239) groups according to the use of IPC devices. In a subsequent prospective study, we measured the degree and duration of the tilt of the operating table during OLT to investigate their relationship to the predominant left-leg PN.

RESULTS

The rate of IPC device use was significantly greater among the PN than non-PN group (78.8% vs 50.4%, P < .01). The incidence of PN was significantly higher among the IPC than non-IPC group (9.9% vs 2.9%, P < .01). The degree and duration of left tilt of the operating table were greater and longer than the right tilt.

CONCLUSIONS

The use of IPC devices during OLT increased the occurrence of PN and the left tilt of the operating table was strongly related to the predominant left-leg PN. Careful protection of the vulnerable point and minimization of the tilting of the operating table is advised during OLT, especially when IPC devices are used.

Comparison of femoral arterial blood pressure with radial arterial blood pressure and noninvasive upper arm blood pressure in the reperfusion period during liver transplantation

PURPOSE

The reperfusion period during liver transplantation is hemodynamically unstable. Accurate blood pressure measurements are the mainstay for the efficient management of abrupt cardiovascular changes. We sought to compare femoral arterial blood pressure (FABP) with radial arterial blood pressure (RABP) and noninvasive upper arm blood pressure (NIBP) in the reperfusion period.

METHODS

Thirty-six adult living donor liver recipients were enrolled in this prospective study. Blood pressures in 3 locations were simultaneously recorded from 1 minute before reperfusion to 15 minutes after reperfusion. We evaluated agreements between FABP and RABP and between FABP and NIBP using intraclass correlation coefficients. Also, we investigated the rates of postreperfusion syndrome (PRS) based on the measurements from 3 locations.

RESULTS

After reperfusion, the mean and diastolic RABP agreed more with the corresponding FABP than NIBP. However, systolic NIBP showed high agreement with FABP from 3 to 10 minutes after reperfusion in contrast with the moderate agreement between systolic RABP with FABP, and systolic values of NIBP than RABP were closer to FABP. The rates of PRS based on FABP, RABP, and NIBP measurements were 50.0% (18/36), 80.6% (29/36), and 50.0% (18/36), respectively.

CONCLUSIONS

We believe that NIBP in addition to RABP may be considered to be a reliable alternative when FABP is not available to evaluate hemodynamic instability in the reperfusion period during liver transplantation.

Evaluation of the Cobra perilaryngeal airway (CPLA) as an airway conduit

BACKGROUND AND OBJECTIVE

The effectiveness of the Cobra perilaryngeal airway as a routine airway device and as a conduit for tracheal intubation has not been prospectively studied to date. This study aimed to evaluate the Cobra perilaryngeal airway for its potential role in an emergency airway rescue, by analysing its use as a bridge to blind or fibre-optic-guided intubation.

METHODS

In 49 patients, the procedure was carried out as follows: fibre-optic view through the Cobra perilaryngeal airway was assessed after the insertion of the Cobra perilaryngeal airway, then blind intubation through the Cobra perilaryngeal airway was attempted. After evaluating the success of blind intubation, fibre-optic-guided intubation was performed through the Cobra perilaryngeal airway. The endotracheal tube was removed after evaluating the success of fibre-optic-guided intubation, and then conventional laryngoscopy was carried out to evaluate the Cormack & Lehane grade and airway trauma.

RESULTS

In all, 95.9% (47/49) of patients had adequate ventilation using the Cobra perilaryngeal airway; the success rates for the blind and fibre-optic-guided intubation were 36.2% and 83.0%, respectively. The patients were divided into two groups according to the fibre-optic view. Group 1 included patients with an obstructed view by an anterior grill of the Cobra perilaryngeal airway head, and a view of the anterior epiglottis (downfolded epiglottis) with or without a visible larynx (16/47, 34.0%). Group 2 included the remaining patients (31/47, 66.0%). The success rates of the blind and fibre-optic intubations were different between the two groups (blind intubation: 12.5% vs. 48.4%, fibre-optic intubation: 62.5% vs. 93.6%, P 0.05). 42.6% of patients had blood staining after removing the device and complications such as trauma and oedema were confirmed under direct laryngoscopy.

CONCLUSION

This study suggests that the Cobra perilaryngeal airway could be a useful airway device as a vehicle for fibre-optic-guided intubation; however, it needs caution against airway trauma.

The effects of the exaggerated lithotomy position for radical perineal prostatectomy on respiratory mechanics

The exaggerated lithotomy position is used during radical perineal prostatectomy to increase perineal exposure. The aim of this study was to evaluate the effects of the exaggerated lithotomy position on respiratory mechanics and arterial blood gases. In the exaggerated lithotomy position, dynamic compliance and static compliance were found to be significantly decreased by 27.4% and 34.8%, respectively, whilst peak, plateau, and mean airway pressures increased significantly by 34.0%, 45.8% and 31.7%, respectively. The physiological dead space/tidal volume ratio and total inspiratory work of breathing increased significantly by 11.1% and 33.7%, respectively. Arterial oxygen tension was significantly decreased by 26.9%; however, no significant differences were seen in end-tidal or arterial carbon dioxide tension. These results indicate that the exaggerated lithotomy position under general anaesthesia can cause significant effects on respiratory system mechanics and arterial oxygenation and highlights the need for careful monitoring of patients placed in this position for surgery.