Physicochemical evaluation of acid-base disorders after liver transplantation and the contribution from administered fluids

Perioperative anesthesia management in pediatric liver transplant recipient with atrial septal defect: A case report

BACKGROUND

Preoperative conditions in pediatric liver transplant recipients are understandably complex. Compared with adults, children have lesser compensatory abilities and demand greater precision during procedural executions. In the setting of end-stage liver disease, the heightened perioperative risk of coexistent cardiovascular pathology may impact graft survival as well. Requirements for anesthesia and perioperative management are thus more rigorous, calling for individualized treatments that reflect specific cardiovascular constraints and proposed surgical plans.

CASE SUMMARY

Reports of perioperative anesthesia management and liver transplant prognostication in pediatric patients with concurrent atrial septal defects are scarce. Herein, we detail the course of liver transplantation in a child with dual afflictions, focusing on perioperative anesthesia management and the important contributions of the anesthesiologist (pre- and perioperatively) to a positive therapeutic outcome, despite the clinical hurdles imposed.

CONCLUSION

Children with atrial septal defects bear substantially more than customary perioperative risk during orthotopic liver transplants, given their compromised cardiopulmonary reserves and functional states. Comprehensive preoperative cardiovascular assessments, including use of agitated-saline contrast echocardiography (to characterize intracardiac shunting) and multidisciplinary deliberation, may offer insights into structural cardiac pathophysiologic effects and transplant-related hemodynamic changes that impact new grafts. At the same time, active and effective monitoring and other measures should be taken to maintain hemodynamic stability in the perioperative period, avoid entry of bubbles into the circulation, and ease congestion in newly grafted livers. Such efforts are crucial for transplantation success and graft survival.

Primary Nonfunction of the Liver Allograft

Severe allograft dysfunction, as opposed to the expected immediate function, following liver transplantation is a major complication, and the clinical manifestations of such that lead to either immediate retransplant or death are the catastrophic end of the spectrum. Primary nonfunction (PNF) has declined in incidence over the years, yet the impact on patient and healthcare teams, and the burden on the organ pool in case of the need for retransplant should not be underestimated. There is no universal test to define the diagnosis of PNF, and current criteria are based on various biochemical parameters surrogate of liver function; moreover, a disparity remains within different healthcare systems on selecting candidates eligible for urgent retransplantation. The impact on PNF from traditionally accepted risk factors has changed somewhat, mainly driven by the rising demand for organs, combined with the concerted approach by clinicians on the in-depth understanding of PNF, optimal graft recipient selection, mitigation of the clinical environment in which a marginal graft is reperfused, and postoperative management. Regardless of the mode, available data suggest machine perfusion strategies help reduce the incidence further but do not completely avert the risk of PNF. The mainstay of management relies on identifying severe allograft dysfunction at a very early stage and aggressive management, while excluding other identifiable causes that mimic severe organ dysfunction. This approach may help salvage some grafts by preventing total graft failure and also maintaining a patient in an optimal physiological state if retransplantation is considered the ultimate patient salvage strategy.

Electrolyte and Acid-Base Disturbances in End-Stage Liver Disease: A Physiopathological Approach

Electrolyte and acid-base disturbances are frequent in patients with end-stage liver disease; the underlying physiopathological mechanisms are often complex and represent a diagnostic and therapeutic challenge to the physician. Usually, these disorders do not develop in compensated cirrhotic patients, but with the onset of the classic complications of cirrhosis such as ascites, renal failure, spontaneous bacterial peritonitis and variceal bleeding, multiple electrolyte, and acid-base disturbances emerge. Hyponatremia parallels ascites formation and is a well-known trigger of hepatic encephalopathy; its management in this particular population poses a risky challenge due to the high susceptibility of cirrhotic patients to osmotic demyelination. Hypokalemia is common in the setting of cirrhosis: multiple potassium wasting mechanisms both inherent to the disease and resulting from its management make these patients particularly susceptible to potassium depletion even in the setting of normokalemia. Acid-base disturbances range from classical respiratory alkalosis to high anion gap metabolic acidosis, almost comprising the full acid-base spectrum. Because most electrolyte and acid-base disturbances are managed in terms of their underlying trigger factors, a systematic physiopathological approach to their diagnosis and treatment is required.

Anion gap corrected for albumin, phosphate and lactate is a good predictor of strong ion gap in critically ill patients: a nested cohort study

Objective

Corrected anion gap and strong ion gap are commonly used to estimate unmeasured anions. We evaluated the performance of the anion gap corrected for albumin, phosphate and lactate in predicting strong ion gap in a mixed population of critically ill patients. We hypothesized that anion gap corrected for albumin, phosphate and lactate would be a good predictor of strong ion gap, independent of the presence of metabolic acidosis. In addition, we evaluated the impact of strong ion gap at admission on hospital mortality.

Methods

We included 84 critically ill patients. Correlation and agreement between the anion gap corrected for albumin, phosphate and lactate and strong ion gap was evaluated by the Pearson correlation test, linear regression, a Bland-Altman plot and calculating interclass correlation coefficient. Two subgroup analyses were performed: one in patients with base-excess <-2mEq/L (low BE group - lBE) and the other in patients with base-excess >-2mEq/L (high BE group - hBE). A logistic regression was performed to evaluate the association between admission strong ion gap levels and hospital mortality.

Results

There was a very strong correlation and a good agreement between anion gap corrected for albumin, phosphate and lactate and strong ion gap in the general population (r²=0.94; bias 1.40; limits of agreement -0.75 to 3.57). Correlation was also high in the lBE group (r²=0.94) and in the hBE group (r²=0.92). High levels of strong ion gap were present in 66% of the whole population and 42% of the cases in the hBE group. Strong ion gap was not associated with hospital mortality by logistic regression.

Conclusion

Anion gap corrected for albumin, phosphate and lactate and strong ion gap have an excellent correlation. Unmeasured anions are frequently elevated in critically ill patients with normal base-excess. However, there was no association between unmeasured anions and hospital mortality.