Crisis Management During Liver Transplant Surgery Liver and Intensive Care Group of Europe Newcastle upon Tyne 2005

Transcription

1 Crisis Management During Liver Transplant Surgery Liver and Intensive Care Group of Europe Newcastle upon Tyne 2005 M. Susan Mandell M.D. Ph. D. Department of Anesthesiology University of Colorado Health Sciences Center

2 Crisis Management During Liver Transplant Surgery Contents: 1. Cardiac Rhythm Disturbances 2. Hyperkalemia 3. Reperfusion Syndrome 4. Pulmonary Hypertension

3 Cardiac Rhythm Disturbances One of the most common complications during liver transplant surgery Etiology 1. Co morbid conditions 2. Autonomic dysfunction 3. Effects of Liver transplant surgery

4 Cardiac Rhythm Disturbances Co morbid Diseases Infiltrative Disease Hemochromatosis Primary Hyperoxalosis Collagen Vascular Diseases Amyloidosis Pediatric Metabolic Diseases

5 Murtagh et al Am J Cardiol 2005 Cardiac Rhythm Disturbances Infiltrative Co morbid Diseases Common Findings on the EKG Low voltage (46%) Infarct pattern (47%) Sinus arrhythmia (86%) 1 0 Atrial-ventricular block (21%)

6 Cardiac Rhythm Disturbances Infiltrative Co morbid Disease Persistent atrial fibrillation Complete heart block Caused by Direct infiltration of the conducting system Myocardial remodeling that disrupts conduction Leone et al, Eur Hear J 2004

7 Cardiac Rhythm Disturbances Co Morbid Disease Toxic Diseases Alcohol Fulminant Hepatic Failure (Viral and drug-induced)

8 Cardiac Rhythm Disturbances Alcohol Co Morbid Disease Common Findings on the EKG PR Prolongation Sinus Arrhythmia Poor R wave progression QTc prolongation

9 Cardiac Rhythm Disturbances Alcohol Co Morbid Disease Persistent Atrial Fibrillation Heart Block Ventricular tachycardia (mono and polymorphic) Ventricular fibrillation Caused by Dilative Cardiomyopathy that causes increased myocardial weight with diastolic and systolic dysfunction

10 Cardiac Rhythm Disturbances Alcohol Co Morbid Disease Improvement with abstinence At 23 months 50% have no improvement in cardiac function

11 Cardiac Rhythm Disturbances Autonomic Dysfunction Increase in QT interval (54% of listed patients) Caused by Decreased conductance of potassium channels Increases the time for repolarization Elevated norepinephrine levels are a marker Most patients improve following liver transplantation

12 Cardiac Rhythm Disturbances Effects of Liver Transplantation Dysrhythmogenic Factors Electrolytes (K, Mg, Ca) Suboptimal coronary perfusion Myocardial diameter (filling) Catecholamine stimulation Cold, Acidosis Donor organ

13 Hyperkalemia Renal Potassium Regulation Freely filtered by glomerulus and resorbed in the proximal loop of Henle 10% of the filtered load reaches the distal nephron Excretion regulated by 1) urinary [sodium] and 2) aldosterone

14 Hyperkalemia Causes of Hyperkalemia in Liver Disease Hepatorenal syndrome (Types I and II) Potassium-sparing sparing diuretics β-adrenergic blocking agents Insulin resistance Calcinurin inhibitors Co morbid conditions (age, diabetes)

15 Hyperkalemia Prevention Preoperative prevention of HRS Vasoconstrictors (Telripressin) and volume loading (Europe) Albumin and diuretics (United States) TIPS (Europe and United States)

16 Hyperkalemia Intraoperative Management Prevention: Fresh blood for transfusion (< 14 days old) Washed banked blood cells Dialysis (Hemo and Ultra filtration) Potassium Absorption units (sodium polystyrene) Knichwhitz et al Anesth Analg 2002 Inaba et al, Transfusion 2000

17 Hyperkalemia Intraoperative Management Emergency Treatment: Intracellular shift of K into cells Insulin-glucose Increase serum ph (hyperventilation and base equivalents) Calcium salts? Takas Neprol Dial Transplant 2004

18 Postreperfusion Syndrome A fall in mean blood pressure > 30% lasting for more than one minute following reperfusion 1 In reality A range of hemodynamic disturbances that can cumulate in asystole and cardiovascular collapse

19 Postreperfusion Syndrome What causes PRS? A primary and uncompensated fall in SVR Donor Graft function? Due to Patient baroreceptor dysfunction? A combination of patient and graft function? Garutti-Martinez et al, Anesth Analg 1997

20 Postreperfusion Syndrome Treatment Prophylaxis: Aprotinin (Increased conversion of HMWK to kalikrein) Treatment: Hemodynamic support (chronotropic, α,, and combined α,β inotropic support all reported as effective) Molenaar et al, Anesthesiology 2001

21 Portopulmonary Hypertension New Evian classification Pulmonary arterial hypertension Based upon similarities in 1) pathophysiology 2) clinical presentation 2) therapeutic options All diseases are chronic and progressive Includes PPH and collagen vascular disease and HIV associated PH

22 Portopulmonary Hypertension Mortality Risk and Disease Burden Is the mpap a marker of disease severity and thus risk of dying? Rule of 50s : pressures 25, 35 and 50 mm Hg were associated with an intraopertive mortality risk of 0%, 50% and 100% Krowka et al Liver Transpl 2000

23 Portopulmonary Hypertension There is sufficient evidence from both sides of the Atlantic to substantiate that No single hemodynamic variable can reliably predict outcome Starkel et al, Liver Transpl 2002 Krowka & Mandell Liver Transpl 2004

24 Portopulmonary Hypertension Factors that likely influence outcome Deductive Reasoning 1. Severity of PPHTN (physiological reserve) 2. Donor graft function (physiological challenge) 3. Anesthetic management (modifier)

25 Portopulmonary Hypertension Improving the Odds: Can we increase physiological reserve? Chronic treatment with vasodilators that induce remodeling in the pulmonary circulation Prostenoids, endothelin inhibitors and phosphodiesterase inhibitors

26 Portopulmonary Hypertension Improving the Odds: Modifying the interface between physiological reserve and challenge? Anesthetic Management

27 Summary Key strategies to the management of cardiac arrhythmias and hyperkalemia is identifying the patient at risk and instituting early pre-emptive emptive therapy Key strategies to the management of PRS and PPHTN are awaiting a better understanding of both syndromes