A comparison of pediatric liver transplant anesthesia practices with new organ procurement and transplant network pediatric policy requirements: A report from the society for the advancement of transplant anesthesia and the society for pediatric anesthesia

INTRODUCTION

Organ Procurement and Transplant Network (OPTN) pediatric policies on knowledge and skill requirements for key personnel failed to address the Director of Anesthesia for Pediatric Liver Transplantation. A Joint Committee representing the Society for the Advancement of Transplant Anesthesia and Society for Pediatric Anesthesia (SPA) surveyed all pediatric anesthesia liver transplant practices to determine if practices were aligned with policies and what changes would be needed for compliance.

METHODS

A survey of the Director or equivalent at each program collected data about specialized knowledge and skill sets. Questions focused on (1) skill and knowledge of the Director and team, (2) requirements for appointment, (3) experience in pediatrics, and (4) characteristics of the program including the availability of pediatric resources.

RESULTS

Response rate was 73% (n = 63). Most responding programs had a Director (67%) with certification, selection committee, and continuing education credits outlined in existing policies. Team members met similar requirements. Alternate pathways for acquiring knowledge and skill sets were identified between programs.

CONCLUSIONS

Pediatric liver transplant anesthesiologists use knowledge and skill pathways that align with the new pediatric policies. We suggest that collaborative work with oversight agencies is needed to resolve high case volume requirements originally designed for adult programs.

SUMMARY

Most pediatric liver transplant anesthesiologists in the US have specialized knowledge and skills for expert care consistent with current oversight policies. Differences in pathways to acquire knowledge and skill sets were still aligned with the new policies for pediatric transplant surgeons and bylaws for the Director of Transplant Anesthesia. We conclude that minimal changes in case volume requirements to the existing Pediatric Transplant Anesthesiology Directorship criteria that authenticates the pediatric anesthesia Director's position would improve the safety of care without limiting access to transplantation.

Recommendations From the Society for the Advancement of Transplant Anesthesiology Fellowship Committee: Core Competencies and Milestones for the Kidney/Pancreas Component of Abdominal Organ Transplant Anesthesia Fellowship

The Society for the Advancement of Transplant Anesthesia (SATA) is dedicated to improving patient care in all facets of transplant anesthesia. The anesthesia fellowship training recommendations for thoracic transplantation (heart and lungs) and part of the abdominal organ transplantation (liver) have been presented in previous publications. The SATA Fellowship Committee has completed the remaining component of abdominal transplant anesthesia (kidney/pancreas) and has assembled core competencies and milestones derived from expert consensus to guide the education and overall preparation of trainees providing care for kidney/pancreas transplant recipients. These recommendations provide a comprehensive approach to pre-operative evaluation, vascular access procedures, advanced hemodynamic monitoring, assessment of coagulation and metabolic abnormalities, operative techniques, and post-operative pain control. As such, this document supplements the current liver/hepatic transplant anesthesia fellowship training programs to include all aspects of "Abdominal Organ Transplant Anesthesia" recommended knowledge.

Intraoperative Cardiac Arrest During Adult Liver Transplantation: Incidence and Risk Factor Analysis From 7 Academic Centers in the United States

BACKGROUND

Intraoperative cardiac arrest (ICA) has a reported frequency of 1 in 10,000 anesthetics but has a much higher estimated incidence in orthotopic liver transplantation (OLT). Single-center studies of ICA in OLT are limited by small sample size that prohibits multivariable regression analysis of risks.

METHODS

Utilizing data from 7 academic medical centers, we performed a retrospective, observational study of 5296 adult liver transplant recipients (18-80 years old) between 2000 and 2017 to identify the rate of ICA, associated risk factors, and outcomes.

RESULTS

ICA occurred in 196 cases (3.7% 95% confidence interval [CI], 3.2-4.2) and mortality occurred in 62 patients (1.2%). The intraoperative mortality rate was 31.6% in patients who experienced ICA. In a multivariable generalized linear mixed model, ICA was associated with body mass index (BMI) <20 (odds ratio [OR]: 2.04, 95% CI, 1.05-3.98; P = .0386), BMI ≥40 (2.16 [1.12-4.19]; P = .022), Model for End-Stage Liver Disease (MELD) score: (MELD 30-39: 1.75 [1.09-2.79], P = .02; MELD ≥40: 2.73 [1.53-4.85], P = .001), postreperfusion syndrome (PRS) (3.83 [2.75-5.34], P < .001), living donors (2.13 [1.16-3.89], P = .014), and reoperation (1.87 [1.13-3.11], P = .015). Overall 30-day and 1-year mortality were 4.18% and 11.0%, respectively. After ICA, 30-day and 1-year mortality were 43.9% and 52%, respectively, compared to 2.6% and 9.3% without ICA.

CONCLUSIONS

We established a 3.7% incidence of ICA and a 1.2% incidence of intraoperative mortality in liver transplantation and confirmed previously identified risk factors for ICA including BMI, MELD score, PRS, and reoperation and identified new risk factors including living donor and length of surgery in this multicenter retrospective cohort. ICA, while rare, is associated with high intraoperative mortality, and future research must focus on therapy to reduce the incidence of ICA.

Anesthetic management of lung transplantation: Results from a multicenter, cross-sectional survey by the society for advancement of transplant anesthesia

BACKGROUND

Current protocols for the perioperative care of lung transplant (LTX) recipients lack rigorous evidence and are often empiric, based upon institutional preferences. We surveyed LTX anesthesiologists to determine the most common practices.

METHODS

We developed a survey of 40 questions regarding perioperative care of LTX recipients using Qualtrics software. The survey was sent out to members of the Society of Cardiovascular Anesthesiologists performing LTX at geographically diverse sites to facilitate data collection for as many practices as possible.

RESULTS

The responses were center-weighed (127 responses, 85% from academic settings). The clamshell approach was commonly used (70%). Cardiopulmonary bypass was preferred by 56%, ex vivo lung perfusion utilized by 43%, and 49.4% indicated they use lungs from donation after circulatory determination of death. Most (69%) used oximetric pulmonary artery catheters, 60% used tissue oximetry, and 89.3% utilized transesophageal echocardiography. Inhaled nitric oxide was preferred by 48%, restrictive fluid management by 48%, and systemic analgesia advocated by 49% of participants. Inspired oxygen concentration <30% was applied to the new lung on reperfusion by 28% of the respondents.

CONCLUSION

Variations in healthcare delivery and utilization for LTX recipients indicate gaps in knowledge and potential opportunities to improve the quality of care.

Service Requirements of Liver Transplant Anesthesia Teams: Society for the Advancement of Transplant Anesthesia Recommendations

There are disparities in liver transplant anesthesia team (LTAT) care across the United States. However, no policies address essential resources for liver transplant anesthesia services similar to other specialists. In response, the Society for the Advancement of Transplant Anesthesia appointed a task force to develop national recommendations. The Conditions of Transplant Center Participation were adapted to anesthesia team care and used to develop Delphi statements. A Delphi panel was put together by enlisting 21 experts from the fields of liver transplant anesthesiology and surgery, hepatology, critical care, and transplant nursing. Each panelist rated their agreement with and the importance of 17 statements. Strong support for the necessity and importance of 13 final items were as follows: resources, including preprocedure anesthesia assessment, advanced monitoring, immediate availability of consultants, and the presence of a documented expert in liver transplant anesthesia credentialed at the site of practice; call coverage, including schedules to assure uninterrupted coverage and methods to communicate availability; and characteristics of the team, including membership criteria, credentials at the site of practice, and identification of who supervises patient care. Unstructured comments identified competing time obligations for anesthesia and transplant services as the principle reason that the remaining recommendations to attend integrative patient selection and quality review committees were reduced to a suggestion rather than being a requirement. This has important consequences because deficits in team integration cause higher failure rates in service quality, timeliness, and efficiency. Solutions are needed that remove the time-related financial constraints of competing service requirements for anesthesiologists. In conclusion, using a modified Delphi technique, 13 recommendations for the structure of LTATs were agreed upon by a multidisciplinary group of experts.

Anesthesia Management and Perioperative Infection Control in Patients With the Novel Coronavirus

Anesthesiologists have a high risk of infection with COVID-19 during perioperative care and as first responders to airway emergencies. The potential of becoming infected can be reduced by a systematic and integrated approach that assesses infection risk. The latter leads to an acceptable choice of materials and techniques for personal protection and prevention of cross-contamination to other patients and staff. The authors have presented a protocolized approach that uses diagnostic criteria to clearly define benchmarks from the medical history along with clinical symptoms and laboratory tests. Patients can then be rapidly assigned into 1 of 3 risk categories that direct the choice of protective materials and/or techniques. Each hospital can adapt this approach to develop a system that fits its individual resources. Educating medical staff about the proper use of high-risk areas for containment serves to protect staff and patients.

Enhanced recovery after surgery and practical application to liver transplantation

There is a growing support for the use of protocols that incorporate multiple steps aimed at reducing the time patients require to regain health. A recurring limitation is the variable outcomes of these protocols with more or less success at the sites at which they are instituted. This review examines the essential building blocks needed to launch a successful ERAS protocol. It addresses why there are differences in outcome measures between centers such as the length of stay and the cost of care even if the protocols and patient populations are similar.

Recommendations From the Society for the Advancement of Transplant Anesthesiology: Liver Transplant Anesthesiology Fellowship Core Competencies and Milestones

Liver transplantation is a complex procedure performed on critically ill patients with multiple comorbidities, which requires the anesthesiologist to be facile with complex hemodynamics and physiology, vascular access procedures, and advanced monitoring. Over the past decade, there has been a continuing debate whether or not liver transplant anesthesia is a general or specialist practice. Yet, as significant data have come out in support of dedicated liver transplant anesthesia teams, there is not a guarantee of liver transplant exposure in domestic residencies. In addition, there are no standards for what competencies are required for an individual seeking fellowship training in liver transplant anesthesia. Using the Accreditation Council for Graduate Medical Education guidelines for residency training as a model, the Society for the Advancement of Transplant Anesthesia Fellowship Committee in conjunction with the Liver Transplant Anesthesia Fellowship Task Force has developed the first proposed standardized core competencies and milestones for fellowship training in liver transplant anesthesiology.

Unexpected Complication of Hydroxocobalamin Administration for Refractory Vasoplegia in Orthotopic Liver Transplant: A Case Report

A 40-year-old male with alcoholic cirrhosis and end-stage renal disease presented for simultaneous liver and kidney transplantation. Hemodialysis was utilized intraoperatively during liver transplantation. During the procedure, the patient developed refractory hypotension and ultimately received hydroxocobalamin for vasoplegia. Shortly after administration, the hemodialysis machine ceased working after a "blood leak" alarm developed. Without the ability to continue intraoperative dialysis, the kidney transplantation portion of his surgery was postponed. The patient was transferred to the intensive care unit, where he underwent continuous renal replacement therapy overnight, and his kidney transplant proceeded the following morning.

Rapid Recovery of Liver Transplantation Recipients by Implementation of Fast-Track Care Steps: What Is Holding Us Back?

A body of scientific studies has shown that early extubation is safe and cost-effective in a large number of liver transplant (LT) recipients including pediatric patients. However, fast-track practices are not universally accepted, and debate still lingers about whether these interventions are safe and serve the patients' best interest. In this article, we focus on reasons why physicians still have a persistent, although diminishing, reluctance to adopt fast-track protocols. We stress the importance of collection/analysis of perioperative data, adoption of a consensus-based standardized protocol for perioperative care, and formation of LT anesthesia focused teams and leadership. We conclude that the practice of early extubation and fast-tracking after LT surgery could help improve anesthesia performance, safety, and cost-effectiveness.

Use, Training, and Opinions About Effectiveness of Transesophageal Echocardiography in Adult Liver Transplantation Among Anesthesiologists in the United States

Study Objective. Describe transesophageal echocardiography (TEE) use, preparatory training and opinions about clinical importance, and future training pathways in a sample of liver transplant anesthesiologists. Design. Online survey questionnaire. Setting. Liver Transplant Centers in the United States. Participants. Director of Liver Transplant Anesthesia or designated alternate respondent. Results. A total of 79 Directors or alternates from 111 (71%) centers were identified. There were 56 responses (71%) representing 433 transplant anesthesiologists who cared for 63.3% of liver transplant cases performed in 2015. Basic TEE certification was reported more frequently (64%) than advanced (53.6%). At least one team member used TEE in over 90% of responding centers. Most respondents (83.9%) agreed TEE provided unique and valuable clinical information but were equally divided about future training pathways (on the job learning vs basic TEE certification). Conclusion. TEE use in liver transplantation is growing with a substantial increase in basic TEE certified users. Transplant anesthesiologists support basic certification but an equal number believe there should be more applied training at the site of care.

Society for the Advancement of Transplant Anesthesia: Liver Transplant Anesthesia Fellowship—White Paper Advocating Measurable Proficiency in Transplant Specialties Training

The anesthesia community has openly debated if the care of transplant patients was generalist or specialist care ever since the publication of an opinion paper in 1999 recommended subspecialty training in the field of liver transplantation anesthesia. In the past decade, liver transplant anesthesia has become more complex with a sicker patient population and evolving evidence-based practices. Transplant training is currently not required for accreditation or certification in anesthesiology, and not all anesthesia residency programs are associated with transplant centers. Yet there is evidence that patient outcome is affected by the experience of the anesthesiologist with liver transplants as part of a multidisciplinary care team. Requests for a formal review of the inequities in training opportunities and requirements led the Society for the Advancement for Transplant Anesthesia (SATA) to begin the task of developing post-graduate fellowship training recommendations. In this article, members of the SATA Working Group on Transplant Anesthesia Education present their reasoning for specialized education and conclusions about which pathways can better prepare trainees to care for complex transplant patients.

Social and Financial Outcomes of Living Liver Donation: A Prospective Investigation Within the Adult-to-Adult Living Donor Liver Transplantation Cohort Study 2 (A2ALL-2)

Because results from single-center (mostly kidney) donor studies demonstrate interpersonal relationship and financial strains for some donors, we conducted a liver donor study involving nine centers within the Adult-to-Adult Living Donor Liver Transplantation Cohort Study 2 (A2ALL-2) consortium. Among other initiatives, A2ALL-2 examined the nature of these outcomes following donation. Using validated measures, donors were prospectively surveyed before donation and at 3, 6, 12, and 24 mo after donation. Repeated-measures regression models were used to examine social relationship and financial outcomes over time and to identify relevant predictors. Of 297 eligible donors, 271 (91%) consented and were interviewed at least once. Relationship changes were positive overall across postdonation time points, with nearly one-third reporting improved donor family and spousal or partner relationships and >50% reporting improved recipient relationships. The majority of donors, however, reported cumulative out-of-pocket medical and nonmedical expenses, which were judged burdensome by 44% of donors. Lower income predicted burdensome donation costs. Those who anticipated financial concerns and who held nonprofessional positions before donation were more likely to experience adverse financial outcomes. These data support the need for initiatives to reduce financial burden.

Small-for-Size Syndrome: Bridging the Gap Between Liver Transplantation and Graft Recovery

In living donor liver transplantation, optimal graft size is estimated from values like graft volume/standard liver volume and graft/recipient body weight ratio but the final functional hepatic mass is influenced by other donor and recipient factors. Grafts with insufficient functional hepatic mass can produce a life-threatening condition with rapidly progressive liver failure called small-for-size syndrome (SFSS). Diagnosis of SFSS requires careful surveillance for signs of inadequate hepatocellular function, residual portal hypertension, and systemic inflammation that suggest rapidly progressive liver failure. Early diagnosis, symptom control, and addressing the cause of SFSS may prevent the need for retransplantation. With increased attention to avoiding donor risk, intensivists will be confronted with more SFSS recipients. In this review, we aim to outline a systematic approach to the medical management of patients with SFSS by providing a concise synopsis of general supportive care—neurological, cardiovascular, and renal support, mechanical ventilation, nutritional support, infection control, and tailored immunosuppression—with an aim to avoid end-organ damage or death and a review of current interventions including liver support devices, portal flow modulating drugs, and other experimental interventions that aim to preserve existing hepatic mass and improve conditions for hepatic regeneration. We examine evidence for SFSS interventions to provide the reader with information that may assist in clinical decision making. Points of controversy in care are purposefully highlighted to identify areas where additional experimental work is still needed. A full understanding of the pathophysiology of SFSS and measures to support liver regeneration will guide effective management.

Early Postoperative Pain and its Predictors in the Adult to Adult Living Donor Liver Transplantation Cohort Study

BACKGROUND

Little is known about how well postoperative pain is managed in living liver donors, despite pain severity being the strongest predictor of persistent pain with long-lasting disability.

METHODS

We conducted a prospective multicenter study of 172 living liver donors. Self-reported outcomes for pain severity, activity interference, affective (emotional) reactions, adverse effects to treatment, and perceptions of care were collected using the American Pain Society Patient Outcomes Questionnaire-Revised. Mixed-effects linear regression was used to identify demographic and psychosocial predictors of subscale scores.

RESULTS

Donors were young (36.8 ± 10.6) and healthy. Of 12 expert society analgesic recommendations for postoperative pain management, 49% received care conforming to 3 guidelines, and only 9% to 4 or 5. More than half reported adverse effects to analgesic treatment for moderate to severe pain that interfered with functional activity; however, emotional distress to pain was unexpectedly minimal. Female donors had higher affective (β = 0.88, P = 0.005) and adverse effects scores (β = 1.33, P < 0.001). Donors with 2 or more medical concerns before surgery averaged 1 unit higher pain severity, functional interference, adverse effects, and affective reaction subscale scores (β range 1.06-1.55, all P < 0.05). Receiving information about pain treatment options increased perception of care subscale scores (β = 1.24, P = 0.001), whereas depressive symptoms before donation were associated with lower scores (β = -1.58, P = 0.01).

CONCLUSIONS

Donors have a distinct profile of pain reporting that is highly influenced by psychological characteristics. Interventions to improve pain control should consider modifying donor behavioral characteristics in addition to optimizing pain care protocols.

Donor preoperative oxygen delivery and post-extubation hypoxia impact donation after circulatory death hypoxic cholangiopathy

AIM: To evaluate donation after circulatory death (DCD) orthotopic liver transplant outcomes [hypoxic cholangiopathy (HC) and patient/graft survival] and donor risk-conditions.

METHODS: From 2003-2013, 45 DCD donor transplants were performed. Predonation physiologic data from UNOS DonorNet included preoperative systolic and diastolic blood pressure, heart rate, pH, SpO₂, PaO₂, FiO₂, and hemoglobin. Mean arterial blood pressure was computed from the systolic and diastolic blood pressures. Donor preoperative arterial O₂ content was computed as [hemoglobin (gm/dL) × 1.37 (mL O₂/gm) × SpO₂%) + (0.003 × PaO₂)]. The amount of preoperative donor red blood cell transfusions given and vasopressor use during the intensive care unit stay were documented. Donors who were transfused ≥ 1 unit of red-cells or received ≥ 2 vasopressors in the preoperative period were categorized as the red-cell/multi-pressor group. Following withdrawal of life support, donor ischemia time was computed as the number-of-minutes from onset of diastolic blood pressure < 60 mmHg until aortic cross clamping. Donor hypoxemia time was the number-of-minutes from onset of pulse oximetry < 80% until clamping. Donor hypoxia score was (ischemia time + hypoxemia time) ÷ donor preoperative hemoglobin.

RESULTS: The 1, 3, and 5 year graft and patient survival rates were 83%, 77%, 60%; and 92%, 84%, and 72%, respectively. HC occurred in 49% with 16% requiring retransplant. HC occurred in donors with increased age (33.0 ± 10.6 years vs 25.6 ± 8.4 years, P = 0.014), less preoperative multiple vasopressors or red-cell transfusion (9.5% vs 54.6%, P = 0.002), lower preoperative hemoglobin (10.7 ± 2.2 gm/dL vs 12.3 ± 2.1 gm/dL, P = 0.017), lower preoperative arterial oxygen content (14.8 ± 2.8 mL O₂/100 mL blood vs 16.8 ± 3.3 mL O₂/100 mL blood, P = 0.049), greater hypoxia score >2.0 (69.6% vs 25.0%, P = 0.006), and increased preoperative mean arterial pressure (92.7 ± 16.2 mmHg vs 83.8 ± 18.5 mmHg, P = 0.10). HC was independently associated with age, multi-pressor/red-cell transfusion status, arterial oxygen content, hypoxia score, and mean arterial pressure (r² = 0.6197). The transplantation rate was greater for the later period with more liberal donor selection [era 2 (7.1/year)], compared to our early experience [era 1 (2.5/year)]. HC occurred in 63.0% during era 2 and in 29.4% during era 1 (P = 0.03). Era 2 donors had longer times for extubation-to-asystole (14.4 ± 4.7 m vs 9.3 ± 4.5 m, P = 0.001), ischemia (13.9 ± 5.9 m vs 9.7 ± 5.6 m, P = 0.03), and hypoxemia (16.0 ± 5.1 m vs 11.1 ± 6.7 m, P = 0.013) and a higher hypoxia score > 2.0 rate (73.1% vs 28.6%, P = 0.006).

CONCLUSION: Easily measured donor indices, including a hypoxia score, provide an objective measure of DCD liver transplantation risk for recipient HC. Donor selection criteria influence HC rates.

Portable optical epidural needle-a CMOS-based system solution and its circuit design

Epidural anesthesia is a common anesthesia method yet up to 10% of procedures fail to provide adequate analgesia. This is usually due to misinterpreting the tactile information derived from the advancing needle through the complex tissue planes. Incorrect placement also can cause dural puncture and neural injury. We developed an optic system capable of reliably identifying tissue planes surrounding the epidural space. However the new technology was too large and cumbersome for practical clinical use. We present a miniaturized version of our optic system using chip technology (first generation CMOS-based system) for logic functions. The new system was connected to an alarm that was triggered once the optic properties of the epidural were identified. The aims of this study were to test our miniaturized system in a porcine model and describe the technology to build this new clinical tool. Our system was tested in a porcine model and identified the epidural space in the lumbar, low and high thoracic regions of the spine. The new technology identified the epidural space in all but 1 of 46 attempts. Experimental results from our fabricated integrated circuit and animal study show the new tool has future clinical potential.

Director of anesthesiology for liver transplantation: existing practices and recommendations by the United Network for Organ Sharing

A new Organ Procurement and Transplantation Network/United Network for Organ Sharing bylaw recommends that all centers appoint a director of liver transplant anesthesia with a uniform set of criteria. We obtained survey data from the Liver Transplant Anesthesia Consortium so that we could compare existing criteria for a director in the United States with the current recommendations. The data set included responses from adult academic liver transplant programs before the new bylaw. The respondent rates were within statistical limits to exclude sampling bias. All centers had a director of liver transplant anesthesia. The criteria varied between institutions, and the data suggest that the availability of resources influenced the choice of criteria. The information suggests that the criteria used in the new bylaw reflect existing practices. The bylaw plays an important role in supporting emerging leadership roles in liver transplant anesthesia and brings greater uniformity to the directorship position.

Fluid management guided by stroke volume variation failed to decrease the incidence of acute kidney injury, 30-day mortality, and 1-year survival in living donor liver transplant recipients

BACKGROUND

Low central venous pressure (CVP) produced by fluid restriction has been applied to liver transplant recipients in order to decrease blood loss. However, CVP is not reliable for monitoring intravascular volume and ventricular filling. In addition, doubts remain over the association between fluid restriction and acute kidney injury (AKI). We tested the utility of stroke volume variation (SVV), derived from the FloTrac/Vigileo system, as a decision-making tool in fluid management. We examined the differences in fluid administration, urine output, postoperative AKI, and 30-day and 1-year survival rates between liver transplant recipients with fluid management guided by SVV and CVP.

METHODS

We retrospectively collected data on our liver transplant recipients with a Model for End-stage Liver Disease score less than 30 and serum creatinine lower than 1.5 mg/dL from 2007 to 2010. Recipients in 2007 and 2008 who received CVP-guided fluid management served as the control group. Recipients in 2009 and 2010 who received fluid administration triggered by SVV were recruited as the study group. The estimated blood loss, urine output, and fluid administered during the operation were recorded. Renal function was assessed using the RIFLE criteria on postoperative days 1 and 5. We also recorded the 30-day and 1-year survival.

RESULTS

Significantly more diuretic use and urine output were noted in the control group in spite of similar fluid administration. However, there was no significant difference in blood loss, AKI, or 30-day and 1-year survival rates.

CONCLUSION

The outcomes of living donor liver transplant patients who had fluid therapy guided by an SVV less than 10% were similar to those of patients who were given fluids to reach a CVP of 10 mmHg. Our findings suggest that the two measures of vascular filling are similar in liver transplant recipients with demographic characteristics similar to those of our patients.

Use of higher thromboelastogram transfusion values is not associated with greater blood loss in liver transplant surgery

Plasma-containing products are given during the pre-anhepatic stage of liver transplant surgery to correct abnormal thromboelastogram (TEG) values and prevent blood loss due to coagulation defects. However, evidence suggests that abnormal TEG results do not always predict bleeding. We questioned what effect using higher TEG values to initiate treatment would have on blood loss. A single transfusion protocol was used for all patients who underwent liver transplantation between 2007 and 2010. Thirty-eight patients received coagulation products when standard TEG cutoff values were exceeded, whereas another 39 patients received coagulation products when the TEG values were 35% greater than normal. The results of postoperative coagulation tests for total blood loss and the use of blood products were compared for the 2 groups. When the critical TEG values for transfusion were higher, significantly fewer units of fresh frozen plasma (5.58 ± 6.49 versus 11.53 ± 6.66 U) and pheresis platelets (1.84 ± 1.33 versus 3.55 ± 1.43 U) were used. There were no differences in blood loss or postoperative blood product use. In conclusion, the use of higher critical TEG values to initiate the transfusion of plasma-containing products is not associated with increased blood loss. Further testing is necessary to identify what TEG value predicts bleeding due to a deficit in coagulation factors.

Anesthesia for liver transplantation in US academic centers: institutional structure and perioperative care

Investigators at a single institution have shown that the organization of the anesthesia team influences patient outcomes after liver transplant surgery. Little is known about how liver transplant anesthesiologists are organized to deliver care throughout the United States. Therefore, we collected quantitative survey data from adult liver transplant programs in good standing with national governing agencies so that we could describe team structure and duties. Information was collected from 2 surveys in a series of quantitative surveys conducted by the Liver Transplant Anesthesia Consortium. All data related to duties, criteria for team membership, interactions/communication with the multidisciplinary team, and service availability were collected and summarized. Thirty-four of 119 registered transplant centers were excluded (21 pediatric centers and 13 centers not certified by national governing agencies). Private practice sites (26) were later excluded because of a poor response rate. There were minimal changes in the compositions of the programs between the 2 surveys. All academic programs had distinct liver transplant anesthesia teams. Most had set criteria for membership and protocols outlining the preoperative evaluation, attended selection committees, and were always available for transplant surgery. Fewer were involved in postoperative care or were available for patients needing subsequent surgery. Most trends were associated with the center volume. In conclusion, some of the variance in team structure and responsibilities is probably related to resources available at the site of practice. However, similarities in specific duties across all teams suggest some degree of self-initiated specialization.

Discriminant analysis for anaesthetic decision-making: an intelligent recognition system for epidural needle insertion

BACKGROUND

Incorrect placement of epidural catheters causes medical complications. We used linear discriminant analysis (LDA) to develop an intelligent recognition system (i-RS) in order to guide epidural placement and reduce physician error.

METHODS

We analysed real-time dual-wavelength fibreoptic data recorded from the end of an epidural needle in a live porcine model. Two categories of tissue layers were necessary for correct placement of catheter: epidural space and ligamentum flavum. The data were tested using linear, quadratic and logistic parametric analysis to identify which method could distinguish the two anatomical structures.

RESULTS

LDA was the best fit for our model. There was ∼80% sensitivity and specificity for correct anatomical identification. Error rates based on cross-validation were 17.0% for the epidural space and 18.6% for ligamentum flavum. Error rates were greater with the 532 nm compared with 650 nm wavelength.

CONCLUSIONS

The sensitivity and specificity of LDA for identifying the correct anatomical structure was similar to a physician who is an expert in epidural placement. Overall performance of an i-RS could be improved by expanding the database for decision-making and adding a category of uncertainty. This would reduce complications caused by incorrect epidural placement.

A multicenter evaluation of safety of early extubation in liver transplant recipients

Small single-institutional studies performed prior to the introduction of organ allocation using the Model for End-Stage Liver Disease (MELD) suggest that early airway extubation of liver transplant recipients is a safe practice. We designed a multicenter study to examine adverse events associated with early extubation in patients selected for liver transplantation using MELD score. A total of 7 institutions extubated all patients meeting study criteria and reported adverse events that occurred within 72 hours following surgery. Adverse events were uncommon: occurring in only 7.7% of 391 patients studied. Most adverse events were pulmonary or surgically related. Pulmonary complications were usually minor, requiring only an increase in ambient oxygen concentration. The majority of surgical adverse events required additional surgery. Analysis of a limited set of perioperative variables suggest that blood transfusions and technical factors were associated with an increased risk of adverse events. In conclusion, while early extubation appears to be safe under specified circumstances, there are performance differences between institutions that remain to be explained.

Clinical controversies surrounding the diagnosis and treatment of hepatopulmonary syndrome

Hepatopulmonary syndrome (HPS) is a clinical syndrome which complicates liver disease but remains poorly defined. To date there is no consensus on the definition of hypoxemia or the best diagnostic test that provides evidence of intrapulmonary shunting. Furthermore, it is reasonable to question whether the role of intrapulmonary shunting has been overplayed in the etiology of HPS and if echocardiographic intrapulmonary shunts could simply be nonspecific markers of the hyperdynamic circulation of liver disease. These inquiries lend support to theories that HPS is primarily a manifestation of profound pulmonary vascular autoregulatory failure that occurs in predisposed patients. Because there is little experience with clinical interventions for HPS other than liver transplantation, there are few accepted, efficacious therapeutic options for these patients. Because liver transplantation remains the only treatment known to effectively ''treat'' HPS, many medical communities have increased the priority of HPS patients over others who are waiting for life saving organs. Until there is further evidence that effectively identifies patients with HPS and that predicts outcomes, the preferential allocation of organs to patients with suspected HPS may unjustly cause the death of others waiting for transplantation.

Hepatopulmonary syndrome and portopulmonary hypertension

The incidence of pulmonary vascular disorders is significantly increased in patients with liver disease. Intrapulmonary shunting with hypoxemia in patients with liver disease is diagnosed as hepatopulmonary syndrome (HPS), whereas precapillary pulmonary vessel obliteration is identified as portopulmonary hypertension (PPHTN). Because the symptoms of liver disease can mimic those of pulmonary vascular disease, all patients with hepatic failure should be screened for these two diseases. Pulse oximetry effectively screens for hypoxemia associated with HPS, whereas an elevated right ventricular systolic pressure estimated by echocardiography identifies patients at risk of having PPHTN. Liver transplantation is the only effective medical therapy for HPS. However, those who have a resting arterial oxygenation less than 50 mm Hg or a shunt measured by scintigraphic perfusion greater than 20% have an unacceptably high mortality rate following surgery. Compared with HPS, there are more therapeutic options that can bridge patients with PPHTN to transplantation. Drugs used to manage idiopathic pulmonary hypertension have shown promise in the treatment of PPHTN. Prostanoids, endothelin receptor antagonists, and phosphodiesterase-5 inhibitors have improved transplant survival. Despite treatment, however, perioperative mortality for patients with PPHTN remains high. Even with successful transplantation, HPS and PPHTN can persist or develop de novo. Long-term follow-up and surveillance of liver transplant recipients is thus indicated to identify HPS and PPHTN following surgery.

Early detection of graft failure using the blood metabolic profile of a liver recipient

In this case report we describe the blood metabolic profile ("metabolomics") by nuclear magnetic resonance (NMR) spectroscopy and principle component analysis (PCA) from a patient who underwent two consecutive liver transplantations. The first graft from a living-related donor failed and was followed by a second successful transplant from a deceased donor. Using quantitative high-resolution H-NMR spectroscopy, 48 endogenous metabolites were analyzed in whole blood samples at baseline and different time points after each transplantation. From 48 analyzed metabolites, six metabolites were identified by PCA as metabolic markers consistent with a non-functional liver after first transplantation. Importantly, this distinctive metabolic profile was present as early as two hours after first transplant surgery when no other variable or conventional laboratory tests indicated poor graft function. This article reports the potential usefulness of quantitative H-NMR based metabolomics to diagnose early graft dysfunction in liver transplantation.

National evaluation of healthcare provider attitudes toward organ donation after cardiac death

OBJECTIVE

Organ donation after cardiac death will save lives by increasing the number of transplantable organs. But many healthcare providers are reluctant to participate when the withdrawal of intensive care leads to organ donation. Prior surveys indicate ethical concerns as a barrier to the practice of organ donation after cardiac death, but the specific issues that characterize these concerns are unknown. We thus aimed to identify what barriers healthcare providers perceive.

DESIGN

We conducted a qualitative analysis of focus group transcripts to identify issues of broad importance.

SETTING

Healthcare setting.

PARTICIPANTS

Participants included 141 healthcare providers representing critical care and perioperative nurses, transplant surgeons, medical examiners, organ procurement personnel, neurosurgeons, and neurologists.

INTERVENTIONS

Collection and analysis of information regarding healthcare providers' attitudes and beliefs.

MEASUREMENTS AND MAIN RESULTS

All focus groups agreed that increased organ availability is a benefit but questioned the quality of organs recovered. Study participants identified a lack of standards for patient prognostication and cardiopulmonary death and a failure to prevent a conflict between patient and donor interests as obstacles to acceptance of organ donation after cardiac death. They questioned the practices and motives of colleagues who participate in organ donation after cardiac death, apprehensive that real or perceived impropriety would affect public perception.

CONCLUSIONS

Healthcare providers are uncomfortable at the clinical juncture where end-of-life care and organ donation interface. Our findings are consistent with theories that care providers are hesitant to perform medical tasks that they consider to be outside the focus of their practice, especially when there is potential conflict of interest. This conflict appears to impose moral distress on healthcare providers and limits acceptance of organ donation after cardiac death. Future research is warranted to examine the effect of standardized procedures on reducing moral distress. The hypothesis generated by this qualitative study is that use of neutral third parties to broach the subject of organ donation may improve acceptance of organ donation after cardiac death.

The diagnosis and treatment of hepatopulmonary syndrome

Few prognostic indicators and outcomes reported for patients who have hepatopulmonary syndrome can be consistently reproduced between institutions. The lack of practice recommendations based upon consistent and predictable outcomes creates uncertainty for physicians trying to make the best patient choices. With the scarcity of donor organs, these issues are of particular importance when transplantation in considered as a treatment option. Much uncertainty arises from the basic tasks of making an accurate diagnosis in patients who have symptoms suggestive of hepatopulmonary syndrome. This article focuses on problems that underlie diagnostic accuracy and uses this information to appraise critically outcomes literature.

Hepatopulmonary syndrome and portopulmonary hypertension in the model for end-stage liver disease (MELD) era

1. How do physicians decide which patients with pulmonary vascular disease will benefit from liver transplantation? 2. Studies on patients with pulmonary vascular disease are limited and the findings and recommendations may not apply to all practice sites. 3. All patients with hypoxemia, liver disease, and pulmonary vasodilation do not have hepatopulmonary syndrome (HPS). 4. Not all patients with hepatopulmonary syndrome will benefit from liver transplantation. 5. The mean pulmonary artery pressure (mPAP) may not be an accurate predictor of mortality in patients with portopulmonary hypertension. 6. The effects of pulmonary vasodilators on the outcome of patients with portopulmonary hypertension (PPHTN) is still unconfirmed but promising.

Hepatopulmonary syndrome and portopulmonary hypertension: a report of the multicenter liver transplant database

Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PortoPH) are pulmonary vascular consequences of advanced liver disease associated with significant mortality after orthotopic liver transplantation (OLT). Data from 10 liver transplant centers were collected from 1996 to 2001 that characterized the outcome of patients with either HPS (n = 40) or PortoPH (n = 66) referred for OLT. Key variables (PaO2 for HPS, mean pulmonary artery pressure [MPAP], pulmonary vascular resistance [PVR], and cardiac output [CO] for PortoPH) were analyzed with respect to 3 definitive outcomes (those denied OLT, transplant hospitalization survivors, and transplant hospitalization nonsurvivors). OLT was denied in 8 of 40 patients (20%) with HPS and 30 of 66 patients (45%) with PortoPH. Patients with HPS who were denied OLT had significantly worse PaO2 compared with patients who underwent transplantation (47 vs. 52 mm Hg, P <.005). Transplant hospitalization survival was associated with higher pre-OLT PaO2 (55 vs. 37 mm Hg; P <.005). MPAP was significantly higher (53 vs. 45 mm Hg; P <.015) and PVR was significantly worse (614 vs. 335 dynes. s. cm(-5); P <.05) in patients with PortoPH who were denied OLT compared with patients who underwent transplantation. Transplant hospitalization mortality was 16% (5/32) in patients with HPS and 36% (13/36) in patients with PortoPH. All of the deaths in patients with PortoPH occurred within 18 days of OLT; 5 of the 13 deaths in patients with PortoPH occurred intraoperatively. We concluded that patients with HPS (based on a combination of low PaO2 and nonpulmonary factors) and patients with PortoPH (based on pulmonary hemodynamics) were frequently denied OLT because of pre-OLT test results and comorbidities. For patients who subsequently underwent OLT, transplant hospitalization mortality remained significant for both those with HPS (16%) and PortoPH (36%).

The effects of desflurane and propofol on portosystemic pressure in patients with portal hypertension

Physicians perform hepatic venous pressure measurements to guide medical therapy aimed at reducing portal hypertension. These measurements are frequently performed during general anesthesia. Since most general anesthetic drugs reduce liver blood flow, it is likely that hepatic venous pressures will be altered. We therefore examined the effects of two frequently used anesthetic drugs on hepatic venous pressure in a prospective randomized study to determine if pressure measurements taken during general anesthesia were similar to awake values. We studied 21 patients with hepatitis C, excluding patients with hepatofugal flow and portal vein thrombosis. All patients had free and wedged hepatic venous pressures measured awake with sedation and after anesthesia with either propofol or desflurane. Desflurane significantly increased free hepatic venous pressure (11.9 +/- 4.4 to 23.5 +/- 4.1 mm Hg; P < 0.05) and decreased hepatic venous pressure gradient (21.6 +/- 7.4 to 14.7 +/- 5.2 mm Hg; P < 0.05), whereas propofol did not change these variables. We conclude that desflurane, but not propofol, alters hepatic venous pressure measurements from the awake state, significantly increasing free hepatic venous pressure and decreasing the hepatic venous pressure gradient, an indirect measure of portosystemic pressure. Changes in the hepatic venous pressure gradient must be interpreted with caution during desflurane general anesthesia.

IMPLICATIONS

Desflurane reduces the blood pressure difference between the portal and systemic circulations. This can cause errors in assessment of the success of medical therapy of portal hypertension. Propofol has less effect on the difference between the portal and systemic circulation.

Executive summary from the Intraoperative Advisory Council on Donation After Cardiac Death of the United Network for Organ Sharing: practice guidelines

The number of organs recovered from asystolic donors is less than anticipated and is explained partially by negative attitudes held by health care providers. To understand the reasons for these beliefs and find solutions, the United Network for Organ Sharing under contract with the Department of Health and Human Services convened the Intraoperative Advisory Council on Donation After Cardiac Death in September, 2001. The Council found that, unlike other medical specialties, operating room health care providers were uncertain of their roles and duties in the care of donors declared dead with cardiopulmonary criteria, known as donation after cardiac death. They were reluctant to care for terminally ill patients in whom death was an expected outcome. Council members deliberated these issues, seeking solutions to repatriate operating room health care providers with the national effort to provide reliable and compassionate care to organ donors and their families. The Council requested the construction of practice guidelines, believing that the structure provided by guidelines will improve health provider confidence in donation after cardiac death and thus improve the quality of care. Physician and nonphysician health care providers from the operating room met to create the Guidelines for the United Network for Organ Sharing, which they believe will improve the quality of care of asystolic organ donors.

Elimination of indocyanine green in the perioperative evaluation of donor liver function

IMPLICATIONS

The authors describe the intraoperative use of indocyanine green dye elimination to detect critical reductions in donor liver function.

Reduced use of intensive care after liver transplantation: influence of early extubation

Postoperative ventilation and admission to the intensive care unit (ICU) is the standard of care in liver transplantation and comprises a significant proportion of transplantation costs. Because immediate postoperative extubation has been reported previously in a selected group of liver transplant recipients, we questioned whether this protocol could be extended to a larger group of patients. We also sought to determine the proportion of patients extubated immediately after surgery that could be transferred to the surgical ward without intervening ICU care. Of 147 patients studied in a prospective trial of sequential liver transplant recipients (who were not second-transplant recipients, United Network for Organ Sharing status 1, living donor transplant recipients, or dead before the end of surgery), 13 patients did not meet postsurgical criteria for early extubation and 111 patients were successfully extubated. Eighty-three extubated patients were transferred to the surgical ward after a routine admission to the postoperative care unit. Only 3 patients who were transferred to the surgical ward experienced complications that required a greater intensity of nursing care. A learning curve detected during the 3-year study period showed that attempts to extubate increased from 73% to 96% and triage to the surgical ward increased from 52% to 82% without compromising patient safety. The use of this protocol in our institution resulted in a 1-day reduction in ICU use in 75.5% of study subjects. We therefore conclude that the majority of liver transplant recipients can be extubated safely and admitted to the surgical ward after liver transplantation surgery, thus decreasing the cost associated with ICU care.

Reduced use of intensive care after liver transplantation: patient attributes that determine early transfer to surgical wards

Part 1 of our report, presented in the same issue of the Journal, shows that immediate postoperative extubation and direct transfer to the surgical ward is safe and reduces reliance on the intensive care unit in most liver transplant recipients. However, there is no method to preoperatively predict which patients will need ventilatory support after surgery. To address this issue, we examined the relationship between perioperative patient attributes and extubation outcome in patients entered into our immediate postoperative extubation study from 1996 to 1998. Variables chosen stemmed from considerations in the literature. We examined the influence of 13 preoperative and 6 intraoperative factors on extubation outcome. Preoperative attributes included sex, race, diagnosis, United Network for Organ Sharing status, Child-Pugh score, presence of a portosystemic shunt, ascites, encephalopathy, coagulation, age, body mass index (BMI), creatinine level, and year of surgery. Intraoperative factors were type of surgery, surgeon, anesthesiologist, number of red blood cells administered, length of surgery, and surgical start time. Female sex (P =.02), BMI of 32 or greater (P =.015), portosystemic shunt (P =.022), and encephalopathy (P =.041) were associated with no attempt by the physician to extubate, whereas encephalopathy (P =.01) and BMI of 34 or greater (P =.002) were associated with failure to meet criteria for postoperative extubation (described in part 1 of this study). We conclude there are limited factors that predict an increased risk for postoperative respiratory failure in liver transplant recipients. Our results indicate that physicians are conservative in their approach to extubation immediately after surgery, and sole reliance on physician judgment to determine suitability for postoperative extubation leads to unnecessary use of postoperative cardiopulmonary support.

Adult living donor liver transplantation using a right hepatic lobe

BACKGROUND

Living donor liver transplantation has gained wide acceptance as an alternative for children with end-stage liver disease. The standard left lateral segment used in this operation does not provide adequate parenchymal mass to broaden its application to larger children or adults.

METHODS

We report two cases of adult to adult living donor liver transplantation using a right hepatic lobe in patients with chronic liver disease.

RESULTS

Both recipients experienced excellent initial graft function and have normal liver function 4 and 9 months postoperatively. Both donors are alive and well and returned to normal life 4 weeks postoperatively.

CONCLUSIONS

Our initial experience suggests that this technique is a safe and reliable option for adults with chronic end-stage liver disease. A conservative application of this procedure in the adult population could significantly reduce the mortality on the adult waiting list.