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Evaluation of an uncalibrated arterial pulse contour cardiac output monitoring system in cirrhotic patients undergoing liver surgery

BACKGROUND The pulmonary artery catheter is invasive and may cause serious complications. A safe method of cardiac output (CO) measurement is needed. We have assessed the accuracy and reliability of a recently marketed self-calibrating arterial pulse contour CO monitoring system (FloTrac/Vigileo) in end-stage liver failure patients undergoing liver transplant. The pattern of alterations known as cirrhotic cardiomyopathy, and the transplant procedure itself, provided an evaluation under varying clinical conditions. METHODS The cardiac index was measured simultaneously by thermodilution (CI(TD): mean of four readings) using a pulmonary artery catheter and pulse contour analysis (CI(V): mean value computed by the FloTrac/Vigileo over the same time period). Readings were made at 10 time-points during liver transplant surgery (T1-T5) and on the intensive care unit (T6-T10). CI(V) was computed using the latest Vigileo software version 01.10. RESULTS A total of 290 paired readings from 29 patients were collected. Mean (SD) CI(TD) was 5.2 (1.3) and CI(V) was 3.9 (0.9) litre min(-1) m(-2), with a corrected for repeated measures bias between readings of 1.3 (0.2) litre min(-1) m(-2) and 95% limits of agreement of -1.5 (0.2) to 4.1 (0.3) litre min(-1) m(-2). The percentage error (2SD(Bias)/meanCI(TD)) was 54%, which exceeded a 30% limit of acceptance. Low peripheral resistance and increasing bias were related (r=0.69; P<0.001). The Vigileo system failed to reliably trend CI data, with a concordance compared with thermodilution below an acceptable level (at best 68% of sequential readings). CONCLUSIONS In cirrhotic patients with hyperdynamic circulation, the Vigileo system showed a degree of error and unreliability higher than that considered acceptable for clinical purposes.

Evaluation of a new software version of the FloTrac/Vigileo (version 3.02) and a comparison with previous data in cirrhotic patients undergoing liver transplant surgery.

BACKGROUND: Reliable cardiac output monitoring is particularly useful in the cirrhotic patient undergoing liver transplant surgery, because cirrhosis of the liver is associated with a vasodilated and high output state, known as cirrhotic cardiomyopathy, that challenges the reliability of pulse contour cardiac output technology. The contractility of the ventricle in cirrhosis is impaired, which is tolerated even though the ejection fraction and cardiac output are elevated because of the low peripheral resistance. However, during surgery the cirrhotic patient can decompensate because of the physiological changes and stress of surgery. Recently, we showed that the FloTrac/Vigileo™ failed to perform in cirrhotic patients undergoing transplant surgery. In response, the company upgraded their software. Therefore, we have assessed the accuracy and reliability of this new third-generation (version 3.02) FloTrac/Vigileo algorithm software in the same setting. METHODS: The cardiac index was measured simultaneously by single-bolus thermodilution (CITD), using a pulmonary artery catheter, and pulse contour analysis, using the FloTrac/Vigileo (CIV). Readings were made at 10 time points during and after liver transplant surgery in 21 patients. Comparisons with data from our 2009 study, which used second-generation (version 01.10) software, were also made. RESULTS: Our new data show that version 3.02 software significantly reduced the adverse effect on pulse contour cardiac output reading bias in low peripheral resistance states, and thus improves the overall precision and trending ability of the system. Regression analysis between CITD and CIV showed that the correlation was moderate (r =0.67, 95% confidence interval, 0.40 to 0.86). The Bland and Altman analysis showed that bias was 0.4 L.min−1 · m−2, and the percentage error was 52% (95% confidence interval, 49% to 55%). Trending ability of the new software also was improved but was still well below the current benchmarks. CONCLUSION: The new software (version 3.02) provided substantial improvements over the previous versions with better overall precision and trending ability. Further algorithm refinements will increase this technology’s reliability to be extensively used in the highly complex setting of cirrhotic patients undergoing liver transplantation.

Fast track in liver transplantation: 5 years' experience.

Background and objective: Reducing postoperative mechanical ventilation in patients undergoing liver transplantation may have clinical and organizational advantages. On the basis of our experience, we here evaluate the possibility of practising immediate tracheal extubation in the operating theatre. Methods: In this prospective study, patients consecutively undergoing liver transplantation between 1 June 1999 and 31 May 2004 were extubated in the operating theatre at the end of surgery on the basis of standardized and universally accepted criteria, under conditions of haemodynamic and metabolic stability. Results: Two hundred and seven of the 354 patients (58.5%) were extubated immediately after the completion of the surgical procedure (mean time between end of surgery and extubation: 0.4 ± 1.4 min); two were re‐intubated. In the last of the 5 yr of the study, the percentage of immediate extubations increased to 82.5%. During the study period, there was a progressive increase in the number of immediate extubations per individual member of the team of anaesthetists. The pre‐transplant Child‐Pugh severity of the underlying liver disease did not predict rapid extubation, but the Model for End‐stage Liver Disease score of <11 did (receiver operator characteristic area under the curve = 0.61; P < 0.05). Conclusions: Immediate extubation after liver transplantation is possible in a substantial percentage of cases; confidence, habit and a spirit of emulation are decisive factors in encouraging anaesthetists to extend this practice to the largest possible number of patients. A successful immediate extubation may be an important indicator of perioperative quality of care in liver transplantation.

Solvent detergent vs. fresh frozen plasma in cirrhotic patients undergoing liver transplant surgery: a prospective randomized control study

Although orthotopic liver transplantation (OLT) is nowadays considered standard practice at experienced centres, it can still be affected by a significant risk of massive bleeding and its related complications. Solvent/detergent plasma (S/D Plasma) has been proposed as an alternative to fresh frozen plasma (FFP) to curtail such complications. This study aimed at evaluating the efficacy of S/D Plasma in OLT patients by comparing it to FFP.

Octogenarian donors in liver transplantation grant an equivalent perioperative course to ideal young donors

BACKGROUND Use of grafts from very old donors for liver transplantation is controversial. AIM To compare the perioperative course of patients receiving liver grafts from young ideal vs octogenarian donors. METHODS Analysis of the perioperative course of patients receiving liver grafts from young, ideal (18-39 years) vs octogenarian (≥80years) deceased donors between 2001 and 2014. RESULTS 346 patients were studied: 179 (51.7%) received grafts aged 18-39 years whereas 167 (48.3%) received a graft from a donor aged ≥80years. Intra-operative cardiovascular (p=0.2), coagulopathy (p=0.5) and respiratory (p=1.0) complications and incidence of reperfusion syndrome (p=0.3) were similar. Patients receiving a young graft required more fresh frozen plasma units (p≤0.03) but did not differ for the need of packed red cells (p=0.2) and platelet (p=0.3) transfusions. Median ICU stay was identical (p=0.4). Patients receiving octogenarian vs young grafts did not differ in terms of death or re-transplant (p=1.0) during the ICU stay. Similar cardiovascular, respiratory, renal, infectious and neurological postoperative complication rates were observed in the two groups. CONCLUSIONS Octogenarian donors in liver transplantation grant an equivalent perioperative course to ideal young donors.

A single-staggered dose of calcineurin inhibitor may be associated with neurotoxicity and nephrotoxicity immediately after liver transplantation

Abstract:  The aim of the present work was to assess the incidence of neuro‐nephrotoxicity after a single‐staggered dose of calcineurin inhibitors (CI) with different immunosuppressive approaches. From January to December 2006, all liver transplantation (LT) recipients at risk of renal or neurological complications treated with extracorporeal photopheresis (ECP) + mycophenolate mofetil + steroids and staggered introduction of CI (ECP group) were compared with a historical control group on standard CI‐based immunosuppression. The ECP group included 24 patients with a mean model for end‐stage liver disease (MELD) score of 19.9 ± 11.1. The control group consisted of 18 patients with a mean MELD score of 12.5 ± 5.2 (p = 0.012). In the ECP group CI were introduced at a mean of 9.2 ± 6.2 d (4–31 d) after LT. Five patients in the ECP group presented acute neuro‐nephrotoxicity after the first CI administration on post‐transplant d 4, 5, 6, 6, and 14. Overall patient survival at one, six, and 12 months was 100%, 95.8%, and 95.8% in the ECP group vs. 94.4%, 77.7%, and 72.2% in the control group (p < 0.001). In conclusion, we showed that CI toxicity may occur after a single‐staggered dose administration, ECP seems to be a valuable tool for managing CI‐related morbidity regardless of the concomitant immunosuppressive regimen, being associated with a lower mortality rate in the early post‐transplant course.

The challenges of diagnosing thrombotic thrombocytopenic purpura in the critically ill. A case report

Thrombotic thrombocytopenic purpura (TTP) is associated with high mortality rates. TTP may have various and different presentations depending on the organs involved. It is now recognized to be the consequence of reduction of blood levels of the disintegrin and metalloprotease with thrombospondin motifs (ADAMTS)-13. Prompt diagnosis of TTP is paramount, because plasma exchange is the only treatment capable of improving patients survival with a dual mechanism: removal of anti-ADAMTS-13 auto-antibodies and infusion of the active protease available in the fresh frozen plasma. We report herein on the challenges in diagnosing TTP-like complications of post-surgical facial surgery in a young male patient.