Preoperative hyperlactatemia and early mortality after liver transplantation: selection of important variables using random forest survival analysis

Background@#Generally, lactate levels > 2 mmol/L represent hyperlactatemia, whereas lactic acidosis is often defined as lactate > 4 mmol/L. Although hyperlactatemia is common finding in liver transplant (LT) candidates, association between lactate and organ failures with Acute-on-chronic Liver Failure (ACLF) is poorly studied. We searched the important variables for pre-LT hyperlactatemia and examined the impact of preoperative hyperlactatemia on early mortality after LT. @*Methods@#A total of 2,002 patients from LT registry between January 2008 and February 2019 were analyzed. Six organ failures (liver, kidney, brain, coagulation, circulation, and lung) were defined by criteria of EASL-CLIF ACLF Consortium. Variable importance of preoperative hyperlactatemia was examined by machine learning using random survival forest (RSF). Kaplan-Meier Survival curve analysis was performed to assess 90-day mortality. @*Results@#Median lactate level was 1.9 mmol/L (interquartile range: 1.4, 2.4 mmol/L) and 107 (5.3%) patients showed > 4.0 mmol/L. RSF analysis revealed that the four most important variables for hyperlactatemia were MELD score, circulatory failure, hemoglobin, and respiratory failure. The 30-day and 90-day mortality rates were 2.7% and 5.1%, whereas patients with lactate > 4.0 mmol/L showed increased rate of 15.0% and 19.6%, respectively. @*Conclusion@#About 50% and 5% of LT candidates showed pre-LT hyperlactatemia of > 2.0 mmol/L and > 4.0 mmol/L, respectively. Pre-LT lactate > 4.0 mmol/L was associated with increased early post-LT mortality. Our results suggest that future study of correcting modifiable risk factors may play a role in preventing hyperlactatemia and lowering early mortality after LT.

Effect of two-week continuous epidural administration of 2% lidocaine on mechanical allodynia induced by spinal nerve ligation in rats

Background@#Lidocaine is an effective against certain types of neuropathic pain. This study aimed to investigate whether timing of initiating continuous epidural infusion of lidocaine affected the glial activation and development of neuropathic pain induced by L5/6 spinal nerve ligation (SNL) in rats. @*Methods@#Following L5/6 SNL, rats were epidurally infused 2% lidocaine (drug infusion initiated on days 1, and 7 post SNL model establishment) or saline (saline infusion initiated on day 1 post SNL model establishment) continuously for 14 days. Mechanical allodynia of the hind paw to von Frey filament stimuli was determined prior to surgery, postoperative day 3, and once weekly after SNL model establishment. At 7 days after the infusion of saline or lidocaine ended, spinal activation of proinflammatory cytokines and astrocytes was evaluated immunohistochemically, using antibodies to interleukin-6 (IL-6) and glial fibrillary acidic protein (GFAP). @*Results@#Continuous epidural administration of 2% lidocaine for 14 days increased the mechanical withdrawal threshold regardless of the difference in timing of initiating lidocaine administration. Epidurally infusing 2% lidocaine inhibited nerve ligation-induced IL-6 and GFAP activation. In the 2% lidocaine infusion group, rats maintained the increased mechanical withdrawal threshold even at 7 days after the discontinuation of 2% lidocaine infusion. @*Conclusions@#Continuous epidural administration of 2% lidocaine inhibited the development of SNL-induced mechanical allodynia and suppressed IL-6 and GFAP activation regardless of the difference in timing of initiating lidocaine administration.

Intraoperative airway obstruction caused by dissection of the internal wall of a reinforced endotracheal tube: A case report

Endotracheal intubation is the gold standard for airway management in general anesthesia. However, airway patency is not guaranteed by keeping the endotracheal tube (ETT) in place. Sometimes, the ETT itself may become a cause of airway obstruction; there are some reports on airway obstruction related to reinforced tube malfunction. We report a rare case with an obstruction of reinforced endotracheal tubes caused by dissection of the internal wall. Recognition of the possibility of airway obstruction due to a rare cause and monitoring patients vigilantly during anesthesia is very important for patient safety.

Intraoperative airway obstruction caused by dissection of the internal wall of a reinforced endotracheal tube: A case report

Endotracheal intubation is the gold standard for airway management in general anesthesia. However, airway patency is not guaranteed by keeping the endotracheal tube (ETT) in place. Sometimes, the ETT itself may become a cause of airway obstruction; there are some reports on airway obstruction related to reinforced tube malfunction. We report a rare case with an obstruction of reinforced endotracheal tubes caused by dissection of the internal wall. Recognition of the possibility of airway obstruction due to a rare cause and monitoring patients vigilantly during anesthesia is very important for patient safety.

Bloody cerebrospinal fluid during replacement of descending thoracic aorta: A case report / 대한마취과학회지

Cerebrospinal fluid (CSF) drainage is a routinely used adjunct to thoracoabdominal aortic surgery which may reduce the incidence of preoperative paraplegia by improving spinal cord perfusion. However, this procedure infrequently causes complications. Bloody or bloody-tinged CSF may be associated with intracranial or spinal hematoma. We present herein a case of bloody CSF during the replacement of the descending thoracic aorta.