Intraoperative lactic acid concentration during liver transplantation and cutoff values to predict early mortality: a retrospective analysis of 3,338 cases

We aimed to explore the distribution of intraoperative lactic acid (LA) level during liver transplantation (LT) and determine the optimal cutoff values to predict post-LT 30-day and 90-day mortality. Methods: Intraoperative LA data from 3,338 patients were collected between 2008 to 2019 and all-cause mortalities within 30 and 90 days were retrospectively reviewed. Of the three LA levels measured during preanhepatic, anhepatic, and neohepatic phase of LT, the peak LA level was selected to explore the distribution and predict early post-LT mortality. To determine the best cutoff values of LA, we used a classification and regression tree algorithm and maximally selected rank statistics with the smallest P value. Results: The median intraoperative LA level was 4.4 mmol/L (range: 0.5–34.7, interquartile range: 3.0–6.2 mmol/L). Of the 3,338 patients, 1,884 (56.4%) had LA levels > 4.0 mmol/L and 188 (5.6%) had LA levels > 10 mmol/L. Patients with LA levels > 16.7 mmol/L and 13.5–16.7 mmol/L showed significantly higher 30-day mortality rates of 58.3% and 21.2%, respectively. For the prediction of the 90-day mortality, 8.4 mmol/L of intraoperative LA was the best cutoff value. Conclusions: Approximately 6% of the LT recipients showed intraoperative hyperlactatemia of > 10 mmol/L during LT, and those with LA > 8.4 mmol/L were associated with significantly higher early post-LT mortality.

Serious acid-base disorder or life-threatening arrhythmia in patients with ABO-incompatible liver transplantation who received therapeutic plasma exchange - A report of two cases -

Background@#Excessive citrate load during therapeutic plasma exchange (TPE) can cause metabolic alkalosis with compensatory hypercarbia and electrolyte disturbances. If TPE is required immediately before ABO-incompatible (ABOi) liver transplant (LT) surgery, metabolic derangement and severe electrolyte disturbance could worsen during LT anesthesia.Case: We report two ABOi LT cases who received TPE on the day of surgery because isoagglutinin titers did not be dropped below 1:8. One case had a surprisingly high metabolic alkalosis with a pH of 7.73 immediately after tracheal intubation because of hyperventilation during mask bagging. The other experienced sudden ventricular tachycardia and blood pressure drop after surgical incision accompanied with severe hypokalemia of 1.8 mmol/L despite supplementation with potassium. @*Conclusions@#Special attention should be paid to patients who just completed TPE the operative day morning as they are vulnerable to severe acid-base disturbances and life-threatening ventricular arrhythmias in ABOi LT.

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.

Pretransplant diastolic wall strain assessed by transthoracic echocardiography and its implication on posttransplant survival rate in liver transplantation

BACKGROUND: In cirrhotic patients, left ventricular diastolic dysfunction is associated with poor outcomes. Diastolic wall strain (DWS) is a new index of left ventricular diastolic function that correlates with the myocardial stiffness. In this study, we aimed to determine whether DWS calculated from preoperative transthoracic echocardiography can predict the survival of liver transplantation recipients. METHODS: A total of 981 patients who underwent liver transplantation were enrolled. We collected the clinical, laboratory and echocardiographic data retrospectively. The left ventricular posterior wall thickness at end-systole (LVPWs) and end-diastole (LVPWd) were measured using M-mode imaging. DWS was calculated as follows: DWS = (LVPWs – LVPWd) / LVPWs. As previously reported, DWS ≤ 0.33 was defined as low DWS and DWS > 0.33 was defined as normal DWS. The primary outcome of this study was 2-years survival after liver transplantation. RESULTS: The 2-years mortality rate following liver transplantation was higher in low DWS group than normal DWS group (14.6% vs.10.0%, P = 0.038). In univariate Cox regression analysis, age, model for end-stage liver disease score, Child-Turcotte-Pugh score, creatinine, b-type natriuretic peptide, heart rate, left ventricular end-diastolic volume index, left ventricular stroke volume index, left ventricular ejection fraction, E/A ratio, e′, E/e′ ratio, and DWS were associated with 2-years survival after liver transplantation. In multivariate Cox regression analysis, DWS was an independent predictor of 2-years survival after adjusting significant univariate covariates. CONCLUSIONS: This study results indicated that the DWS is an independent prognostic predictor in liver transplantation recipients.

Thalamic Pain Misdiagnosed as Cervical Disc Herniation

Thalamic pain is a primary cause of central post-stroke pain (CPSP). Clinical symptoms vary depending on the location of the infarction and frequently accompany several pain symptoms. Therefore, correct diagnosis and proper examination are not easy. We report a case of CPSP due to a left acute thalamic infarction with central disc protrusion at C5-6. A 45-year-old-male patient experiencing a tingling sensation in his right arm was referred to our pain clinic under the diagnosis of cervical disc herniation. This patient also complained of right cramp-like abdominal pain. After further evaluations, he was diagnosed with an acute thalamic infarction. Therefore detailed history taking should be performed and examiners should always be aware of other symptoms that could suggest a more dangerous disease.

Arrhythmogenic potential develops rapidly at graft reperfusion before the start of hypotension during living-donor liver transplantation / 대한마취과학회지

BACKGROUND: Detailed profiles of acute hypothermia and electrocardiographic (ECG) manifestations of arrhythmogenicity were examined to analyze acute hypothermia and ventricular arrhythmogenic potential immediately after portal vein unclamping (PVU) in living-donor liver transplantation (LT). METHODS: We retrospectively analyzed electronically archived medical records (n = 148) of beat-to-beat ECG, arterial pressure waveforms, and blood temperature (BT) from Swan-Ganz catheters in patients undergoing living-donor LT. The ECG data analyzed were selected from the start of BT drop to the initiation of systolic hypotension after PVU. RESULTS: On reperfusion, acute hypothermia of < 34degrees C, < 33degrees C and < 32degrees C developed in 75.0%, 37.2% and 11.5% of patients, respectively. BT decreased from 35.0degrees C +/- 0.8degrees C to 33.3degrees C +/- 1.0degrees C (range 35.8degrees C-30.5degrees C). The median time to nadir of BT was 10 s after PVU. Difference in BT (DeltaBT) was weakly correlated with graft-recipient weight ratio (GRWR; r = 0.22, P = 0.008). Compared to baseline, arrhythmogenicity indices such as corrected QT (QTc), Tp-e (T wave peak to end) interval, and Tp-e/QTc ratio were prolonged (P < 0.001 each). ST height decreased and T amplitude increased (P < 0.001 each). However, no correlation was found between DeltaBT and arrhythmogenic indices. CONCLUSIONS: In living-donor LT, regardless of extent of BT drop, ventricular arrhythmogenic potential developed immediately after PVU prior to occurrence of systolic hypotension.

Measurement of respiratory pulse transit time variation as an intravascular volume index in simulated hemorrhage / 대한마취과학회지

BACKGROUND: We examined the usefulness of respiratory pulse transit time (PTT) variation as an intravascular volume index in young, healthy, spontaneous, paced breathing volunteers exposed to simulated central hypovolemia by lower body negative pressure (LBNP). METHODS: With paced breathing at 0.25 Hz, beat-to-beat finger blood pressure (BP), heart rate (HR), cardiac output (CO), stroke volume (SV), total peripheral resistance (TPR), and PTT were measured non-invasively in 18 healthy volunteers. Graded central hypovolemia was generated using LBNP from 0 to -20, -30, -40, and -50 mmHg. Respiratory PTT variation (PTTV) was calculated as the difference of maximal and minimal values divided by their respective means. Respiratory-frequency PTT variability (PTTRF) using power spectral analysis was also estimated. RESULTS: During LBNP, SV, CO and PTTRF decreased, but PTT, PTTV and TPR increased significantly. PTTV did not correlate with SV changes (r = -0.08, P = 0.52), but PTTRF (r = 0.58, P < 0.01) and PTT (r = 0.43, P < 0.01) did during progressive hypovolemia. CONCLUSIONS: PTTRF is more applicable to the changes in intravascular volume than PTT and PTTV, suggesting spectral analysis of PTT might be used as a dynamic preload index in patients with spontaneous and paced breathing condition, which needs further studies.

Effects of magnesium infusion on hemodynamic and autonomic changes in healthy volunteers / 대한마취과학회지

BACKGROUND: Magnesium has been used for treatments and preventions of various situations, such as cardiovascular disease and pre-eclampsia. And it also used for decreasing demands of anesthetics and analgesics during anesthesia. Activity of autonomic nervous system has important roles for homeostasis of cardiovascular system, and its dysfunction affects mortality and morbidity. Because there are few reports about effects of magnesium infusion on autonomic nervous system, we investigated effects of magnesium infusion on hemodynamic and autonomic changes using variable autonomic function tests in healthy volunteers. METHODS: Hemodynamic parameters, heart rate variability, blood pressure variability, and baroreflex sensitivity were evaluated before and after magnesium infusion of 30 mg/kg during 20 min in twenty healthy volunteers. Cold face test, valsalva maneuver were also performed before and after magnesium infusion. RESULTS: Low-frequency components of blood pressure variability decreased after magnesium infusion (P = 0.026). There were no significant differences in blood pressure, heart rate, cardiac output, stroke volume, total peripheral resistance, heart rate variablility and baroreflex sensitivity between before and after magnesium infusion. Increases of diastolic blood pressure during cold face test decreased significantly after magnesium infusion (P = 0.022). In addition, no significant hemodynamic and autonomic changes were found during valsalva maneuver. CONCLUSIONS: Central sympathetic vasomotor tone decreased after magnesium infusion of 30 mg/kg during 20 min in healthy volunteers. However, it had no effects on parasympathetic system and baroreflex sensitivity.

Asymptomatic Severe Dilutional Hyponatremia during Transurethral Resection of the Prostate: A case report / 대한마취과학회지

The transurethral resection of the prostate (TURP) syndrome is caused by intravascular absorption of an electrolyte-free irrigating fluid during TURP for benign prostatic hypertrophy or prostatic carcinoma. The clinical symptoms and signs include hypertension, bradycardia, respiratory distress, hypotension, nausea, vomiting, confusion, blindness, seizure, coma, hyponatremina, and hypoosmolality. In this case, we incidentally detected very severe dilutional hyponatremia (99 mmol/L) without any symptoms during TURP and immediately took measures to treat TURP syndrome. On the third postoperative day, the hyponatremia had resolved within the normal range.