M. Susan Mandell

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%). (Liver Transpl 2004;182:10.)

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.

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. Liver Transpl 13:1557–1563, 2007.

A New Technique to Assist Epidural Needle Placement Fiberoptic-guided Insertion Using Two Wavelengths

Background:Up to 10% of epidurals fail due to incorrect catheter placement. We describe a novel optical method to assist epidural catheter insertion in a porcine model. Methods:Optical emissions were tested on ex vivo tissues from porcine paravertebral tissues to identify optical reflective spectra. The wavelengths of 650 and 532 nm differentiated epidural space from the ligamentum flavum. We then used a hollow stylet that contained optical fibers to place epidural needles in anesthetized pigs. Real-time data were displayed on an oscilloscope and stored for analysis. A total of 50 punctures were done in four laboratory pigs. Data were expressed as mean ± SD. Results:Paired t test shows significant optical differences between the epidural space and the ligamentum flavum at both 650 nm (P < 0.001) and 532 nm (P = 0.014). Mean magnitudes for 650 nm, 532 nm, and their ratio were 3.565 ± 0.194, 2.542 ± 0.145, and 0.958 ± 0.172 at epidural space and 3.842 ± 0.191, 2.563 ± 0.131, and 1.228 ± 0.244 at ligamentum flavum, respectively. There were no differences in the optical characteristics of the ligamentum flavum and epidural space at different levels in the lumbar and thoracic region (two-way ANOVA P > 0.05). Conclusions:This is the first study to introduce a new optical method to localize epidural space in a porcine model. Epidural space could be identified by the changes in the reflective pattern of light emitted at 650 nm, which were specific for the ligamentum flavum and dural tissue. Real-time optical information successfully guided a modified Tuohy needle into the epidural space.

Anesthesia for liver transplantation in United States academic centers: intraoperative practice

STUDY OBJECTIVE To determine current practice patterns for patients receiving liver transplantation. DESIGN International, web-based survey instrument. SETTING Academic medical centers. MEASUREMENTS Survey database responses to questions about liver transplant anesthesiology programs and current intraoperative anesthetic care and resource utilization were assessed. Descriptive statistics of intraoperative practices and resource utilization according to the size of the transplant program were recorded. MAIN RESULTS Anesthetic management practices for liver transplantation varied across the academic centers. The use of cell salvage (Cell Saver®), transesophageal echocardiography, thrombelastography, and ultrasound guidance for catheter placement varies among institutions. CONCLUSION Effective practices and more evidence-based intraoperative management have not yet been applied in many programs. Many facets of perioperative liver transplantation anesthesia care remain underexplored.

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

Key Points 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. (Liver Transpl 2004;10:S54–S58.)

Eyes in the needle: novel epidural needle with embedded high-frequency ultrasound transducer--epidural access in porcine model.

Background:Epidural needle insertion is usually a blind technique where the rate of adverse events depends on the experience of the operator. A novel ultrasound method to guide epidural catheter insertion is described. Methods:An ultrasound transducer (40 MHz, a −6 dB fractional bandwidth of 50%) was placed into the hollow chamber of an 18-gauge Tuohy needle. The single crystal was polished to a thickness of 50 &mgr;m, with a width of 0.5 mm. Tissue planes were identified from the reflected signals in an A-mode display. The device was inserted three times into both the lumbar and thoracic regions of five pigs (average weight, 20 kg) using a paramedian approach at an angle of 35–40°. The epidural space was identified using signals from the ligamentum flavum and dura mater. Epidural catheters were placed with each attempt and placement confirmed by contrast injection. Results:The ligamentum flavum was identified in 83.3% of insertions and the dura mater in all insertions. The dura mater signal was stronger than that of the ligamentum flavum and served as a landmark in all epidural catheter insertions. Contrast studies confirmed correct placement of the catheter in the epidural space of all study animals. Conclusions:This is the first study to introduce a new ultrasound probe embedded in a standard epidural needle. It is anticipated that this technique could reduce failed epidural blocks and complications caused by dural puncture.

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. Liver Transpl 18:1254–1258, 2012.

Donor Complications Following Laparoscopic Compared to Hand-Assisted Living Donor Nephrectomy: An Analysis of the Literature

There are two approaches to laparoscopic donor nephrectomy: standard laparoscopic donor nephrectomy (LDN) and hand-assisted laparoscopic donor nephrectomy (HALDN). In this study we report the operative statistics and donor complications associated with LDN and HALDN from large-center peer-reviewed publications. Methods. We conducted PubMed and Ovid searches to identify LDN and HALDN outcome studies that were published after 2004. Results. There were 37 peer-reviewed studies, each with more than 150 patients. Cumulatively, over 9000 patients were included in this study. LDN donors experienced a higher rate of intraoperative complications than HALDN donors (5.2% versus. 2.0%, P < .001). Investigators did not report a significant difference in the rate of major postoperative complications between the two groups (LDN 0.5% versus HALDN 0.7%, P = .111). However, conversion to open procedures from vascular injury was reported more frequently in LDN procedures (0.8% versus 0.4%, P = .047). Conclusion. At present there is no evidence to support the use of one laparoscopic approach in preference to the other. There are trends in the data suggesting that intraoperative injuries are more common in LDN while minor postoperative complications are more common in HALDN.

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. Liver Transpl, 2012.