The changes of intraoperative body temperature in adult liver transplantation: A retrospective study

Comparison of tracheal versus esophageal temperatures during laparoscopic surgery

PURPOSE

Recently, endotracheal tubes with an embedded temperature sensor in the inner surface of the tube cuff (temperature tracheal tubes) have been developed. We sought to assess whether temperature tracheal tubes show a good agreement with esophageal temperature probes during surgery.

METHODS

We enrolled 40 patients who underwent laparoscopic surgery in an observational study. The tracheas of all patients were intubated with a temperature tracheal tube, and an esophageal temperature probe was inserted into the esophagus. Tracheal and esophageal temperatures were recorded at 15-min intervals until the end of surgery. Temperatures from both devices were analyzed using Bland-Altman analysis, four-quadrant plots, and polar plots.

RESULTS

We analyzed 261 data points from 36 patients. Temperatures ranges were 34.2 °C to 36.6 °C for the tracheal temperature tube and 34.7 °C to 37.2 °C for the esophageal temperature probe. Bland-Altman analysis showed an acceptable agreement between the two devices, with an overall mean bias (95% limit of agreement) of -0.3 °C (-0.8 °C to 0.1 °C) and a percentage error of 3%; the trending ability (temperature changes over time) between the two devices showed a concordance rate of 94% in four-quadrant plot (cut-off ≥ 92%), but this was higher than the acceptable mean angular bias of 177° (cut-off <  ± 5°) and radial limits of agreement of 52° (cut-off <  ± 30°) in the polar plot. Bronchoscopy during extubation and patient interviews at six hours postoperatively revealed no serious injuries related to the use of the temperature tracheal tube.

CONCLUSION

The temperature tracheal tube showed an acceptable overall mean bias of -0.3 °C and a percentage error of 3%, but incompatible trending ability with the esophageal temperature probe.

STUDY REGISTRATION

cris.nih.go.kr (KCT0007265); 22 April 2022.

Utilization and outcomes of rescue hepatectomy among U.S. liver retransplant candidates

INTRODUCTION

The frequency and outcomes of anhepatic patients listed for transplantation in the United States have not been studied. The United Network for Organ Sharing (UNOS) records anhepatic status for patients listed as Status 1A for hepatic artery thrombosis (HAT) or primary non-function (PNF).

METHODS

Using the UNOS database from 2005 to 2020, demographics and waitlist outcomes of anhepatic candidates relisted as Status 1A for HAT or PNF were assessed.

RESULTS

Among 1364 adult Status 1A patients relisted for PNF or HAT across 120 distinct transplant centres, 75 (5.5%) patients were anhepatic and 1289 (94.5%) were non-anhepatic. A substantial number of centres (n = 51) had experience with ≥1 anhepatic patient relisted for either PNF or HAT, with individual centre rates ranging from 0% to 11.4%. Waitlist mortality was more than twice as high for anhepatic patients: 42.5% versus 17.0% non-anhepatic patients (p < .001). The post-transplant outcomes of anhepatic patients were markedly inferior to non-anhepatic patients. For example, 41.9% of anhepatic patients died during the index admission versus 23.4% of the non-anhepatic group (p = .006). Patient survival for the anhepatic and non-anhepatic groups was 48.3% versus 66.2% at 1-year and 29.3% versus 46.2% at 5-years, respectively (log-rank test for overall survival p = .014).

CONCLUSIONS

Rescue hepatectomy after initial liver transplantation is not only associated with high waitlist mortality, but also markedly worse post-transplant outcomes. With less than half of anhepatic patients surviving to the first year post-LT, further research is warranted to better delineate which patients should be considered for rescue hepatectomy.

Comparison of tracheal temperature and core temperature measurement in living donor liver transplant recipients: a clinical comparative study

BACKGROUND

Body temperature is a vital sign, and temperature monitoring during liver transplantation is important. Tracheal temperature can be measured via an endotracheal tube with a temperature sensor on the cuff of the tube. This study aimed to investigate the accuracy and trending ability of tracheal temperature measurement compared to those of the core temperature measured at the esophagus and pulmonary artery (PA) in living donor liver transplant recipients.

METHODS

Twenty-two patients who underwent living donor liver transplantation (LDLT) were enrolled. Patients were intubated using an endotracheal tube with a temperature sensor placed on the inner surface of the tube cuff. Tracheal, esophageal, and PA temperatures were recorded at five time points corresponding to the different phases of liver transplantation. The tracheal and esophageal, tracheal and PA, and esophageal and PA temperatures were compared using Bland-Altman analysis, four-quadrant plot/concordance analysis, and polar plot analysis.

RESULTS

Bland-Altman analysis showed an overall mean bias (95% limits of agreement) between tracheal and esophageal temperatures of -0.10 °C (-0.37 °C to 0.18 °C), with a percentage error of 0.27%; between tracheal and PA temperatures, -0.05 °C (-0.91 °C to 0.20 °C), with a percentage error of -0.15%; and between esophageal and PA temperatures, 0.04 °C (-0.27 °C to 0.35 °C), with a percentage error of 0.12%. The concordance rates between tracheal and esophageal temperatures, tracheal and PA temperatures, and esophageal and PA temperatures were 96.2%, 96.2%, and 94.94%, respectively. The polar plot analysis showed a mean angular bias (radial limits of agreement) of 4° (26°), -3° (13°), and 2° (21°).

CONCLUSIONS

Monitoring core temperature at the inner surface of the endotracheal tube cuff is accurate in all phases of LDLT with good trending ability; thus, it can be an excellent alternative for monitoring during LDLTs.

What is the optimal anesthetic monitoring regarding immediate and short-term outcomes after liver transplantation?-A systematic review of the literature and expert panel recommendations

BACKGROUND

Liver transplant centers vary in approach to intraoperative vascular accesses, monitoring of cardiac function and temperature management. Evidence is limited regarding impact of selected modalities on postoperative outcomes.

OBJECTIVES

To review the literature and provide expert panel recommendations on optimal intraoperative arterial blood pressure (BP), central venous pressure (CVP), and vascular accesses, monitoring of cardiac function and intraoperative temperature management regarding immediate and short-term outcomes after orthotopic liver transplant (OLT).

METHODS

Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel. Recommendations made for: (1) Vascular accesses, arterial BP and CVP monitoring, (2) cardiac function monitoring, and (3) Intraoperative temperature management (CRD42021239908).

RESULTS

Of 2619 articles screened 16 were included. Studies were small, retrospective, and observational. Vascular access studies demonstrated low rates of insertion complications. TEE studies demonstrated low rates of esophageal hemorrhage. One study found lower hospital-LOS and 30-day mortality in patients monitored with both PAC and TEE. Other monitoring studies were heterogenous in design and outcomes. Temperature studies showed increased blood transfusion and ventilation times in hypothermic groups.

CONCLUSIONS

Recommendations were made for; routine arterial and CVP monitoring as a minimum standard of practice, consideration of discrepancy between peripheral and central arterial BP in patients with hemodynamic instability and high vasopressor requirements, and routine use of high flow cannulae while monitoring for extravasation and hematoma formation. Availability and expertise in PAC and/or TEE monitoring is strongly recommended particularly in hemodynamic instability, portopulmonary HT and/or cardiac dysfunction. TEE use is recommended as an acceptable risk in patients with treated esophageal varices and is an effective diagnostic tool for emergency cardiovascular collapse. Maintenance of intraoperative normothermia is strongly recommended.

Safety of intraoperative hypothermia for patients: meta-analyses of randomized controlled trials and observational studies

BACKGROUND

Previous studies have shown that intraoperative hypothermia was associated with higher risks of clinical adverse events, but we found otherwise from recent evidences. This study aims to synthesize the existing evidence evaluating safety of intraoperative hypothermia.

METHODS

Articles, reviews, ongoing trials and grey literatures were retrieved from PubMed, The Cochrane Library, Clinical Trails and CNKI (a Chinese national database) till February 2nd, 2019. Both randomized controlled trials and observational studies compared incidences of all sorts of intra- and post-operative consequences between hypothermia and normothermia were included. Researches comparing different warming systems were excluded. We also examined risks of hypothermia using lowered standards (35.5 °C and 35 °C) from a Chinese trial (ChiCTR-IPR-17011099).

RESULTS

A total of 9 RCT studies and 11 observational studies were included. RCT-synthesized results showed that intraoperative hypothermia was associated with higher risks of bleeding (MD = 131.90, 95%CI: 117.42, 146.38), surgical site infection (RD = 0.14, 95%CI: 0.06, 0.21) and shivering (RD = 0.32, 95%CI: 0.06, 0.58) but with no significant differences in duration of surgery, hospital stay or mortality. Observational study-synthesized evidences showed that intraoperative hypothermia did not result in higher risks in any of these adverse events. Results didn't change even if the standard of hypothermia was lowered by 0.5-1.0 °C.

CONCLUSIONS

The study indicates that the synthesized risks resulted by intra-operative hypothermia might be overestimated and the eligibility of 36 °C to define hypothermia is not sensitive enough. Given body-temperature protection has not been popularized in China, it is still critical to normalize the hypothermia prevention at this stage.

Enhanced recovery after surgery protocols in patients undergoing liver transplantation: A retrospective comparative cohort study

INTRODUCTION

Enhanced Recovery after Surgery (ERAS) is a multimodal pathway to overcome the deleterious effect of perioperative stress, and has been applied to different surgeries including liver resection surgery. Explorative studies have shown the safety of some ERAS measures in liver transplantation patients, although no consensus was reached. This study aimed to evaluate the effect of ERAS protocols compared with conventional care in patients undergoing liver transplantation.

METHOD

All patients (aged 16-70) undergoing liver transplantation for their first time in our centers between January 2016 and July 2019 were retrospectively reviewed and included into this cohort study. They were divided into ERAS group and conventional group depending on the perioperative protocols. Operative time, anhepatic phase time, intraoperative blood loss, intraoperative hypothermia, Surgical Intensive Care Unit (SICU) stay, postoperative complications, pain score, postoperative hospital stay, and mortality were compared between the two groups.

RESULTS

A total of 40 and 53 patients were included in the ERAS and conventional groups, respectively. The ERAS group had shorter SICU stay (2 vs. 4 days, p < 0.001) and postoperative hospital stay (14.5 vs. 16 days, p < 0.001) compared with the conventional group. Intraoperative hypothermia rate, postoperative pulmonary complications rate, and postoperative pain score were lower in the ERAS group (p < 0.05). There were no differences in operative time, anhepatic phase time, blood loss, mortality, reintubation, lower extremity venous thrombosis and other complications incidence between the two groups.

CONCLUSION

ERAS procedures effectively improved the patients' recovery, alleviated the suffering and pulmonary complications, and reduced SICU stay and postoperative hospital stay, without increasing incidence of other complications or reintubation. As a safe and feasible choice, ERAS protocols may also have some socioeconomic advantages, which should be addressed in further prospective cohort or clinical trial studies.