1. CASE PRESENTATION: 81 yr old African-American male was referred from hemo-dialysis center to the hospital for abdominal pain and vomiting associated with melena during the last 30 minutes of dialysis. It was noted that the pressures across the dialysis circuit ware high during this period. The trans- membrane pressure was noted to be 355 mmHg. It was also noted that the dialysis tubing was kinked, leading to very high arterial pressures ( up to 450 mm Hg ). The past medical history was significant for Diabetes Mellitus-type 2, hypertension, End Stage Renal Dialysis on maintenance hemodialysis., S/P nephrectomy ( for reasons not clear ), gout, S/P pulmonary embolism (1999 ), coronary artery disease, and history of diverticular GI bleeding. His medications include hydralazine, irbesartan, Renovite, metoprolol, & iron. Family history was significant for a son who died of colon cancer. On examination, he was an elderly, cachectic gentleman. BP recorded in the dialysis unit prior to termination of dialysis was 202/110. At the time of admission to the hospital, the BP was 142/51 mmHg, Pulse 112/min, RR 30/min, and Temp 101. Abdomen was soft, with mild peri-umbilical tenderness, no organomegaly, & normal bowel sounds. Rectal examination showed black-colored hemoccult positive stools. Other systems were within normal limits. LABORATORY INVESTIGATIONS: On admission : Hgb 12.1, Hct 38.3, Wbc 10.4, Platelets 374K, Na 136, K 4.2, Cl 95, HCO3 22, Urea 99, Creatinine 11.5,Glucose 115 mg%, Retics 2.9%, Rbc morphology: anisocytosis, polychromasia ovalocytes and schistocytes seen. Iron studies: Serum Iron 26, TIBC 152, %Sat 17, LDH 3799. LFTs: total bilirubin 1.5, direct bilirubin 1.1, alkaline phosphatase 112, AST 1582, ALT 132. Macroscopic evidence of hemolysis ( pink serum ) was reported from the lab. X-Ray of chest showed minimal air space disease at the left base. CT Abdomen & Pelvis showed distended gall bladder with stones. HOSPITAL COURSE: The patient was admitted to the Intensive Care Unit and managed conservatively for presumed lower GI bleed, manifesting with a fall in hematocrit and heme positive stools. Because hemolysis was reported by the laboratory, hemolytic parameters were also obtained. His hemoglobin dropped to 8.7 from 10.1 and Hematocrit to 21 from 38.3, and he was transfused with 2 units of packed RBCs. The serum haptoglobin levels were undetectable. The hematocrit level was thereafter stable with no evidence of increasing hemolysis. It was presumed that the inciting factor for hemolysis was the high circuit pressure during the dialysis. The serum bilirubin level climbed to 11.8, with predominantly unconjugated hyperbilirubinemia, before starting to decline to normal by discharge. The LDH levels peaked at 6450 and declined to normal. The AST levels increased to 1582 and ALT to 132 before declining to normal. Subsequent dialyses were conducted with extra precautions to maintain normal circuit pressure and no further hemolytic episodes were noted. DISCUSSION: Some degree of hemolysis occurs in all extracorporeal circuits using pumps. The higher the blood flow, the greater the degree of hemolysis. High pressure gradients and velocities in the blood lines cause increased shear forces, which can result in hemolysis. Arterial chamber pressures more than 350 mmHg are usually associated with significant hemolysis. Initial diagnosis is made by a Port Wine color of the blood in the venous line. The symptoms include malaise, nausea, chest pain, dyspnea, abdominal pain, back pain, emesis, cyanosis, headache and high blood pressure. Massive hemolysis is associated with a positive PINK TEST ( pink appearance of plasma in a centrifuged sample of blood) due to the presence of free hemoglobin, fall in the Hematocrit, very high serum LDH, and an almost complete absence of Haptoglobin in blood. Initial treatment consists of immediate cessation of hemodialysis. At the same time, the blood lines are to be clamped and all extracorporeal blood is to be discarded to prevent the occurence of severe hyperkalemia. The patient should be treated symptomatically with specific attention to hyperkalemia and anemia. The patient should be hospitalized for close observation. There was an epidemic of hemodialysis-associated hemolysis in 1998 in 3 states – Nebraska, Maryland and Masschusetts ( Kidney International 2000). Examination of the tubing cartilage showed a narrowing of the aperture through which the blood was pumped before entering the dialysers. The hemolysis was caused by increased pressure on the RBCs as they passed through the partially occluded tubing. The causes of hemolysis on hemodialysis can be grouped into 5 categories: (1) Toxins in the dialysate Ex: Chloramine, Zinc, Copper, Nitrates, Formaldehyde etc. (2) Patient factors: Microangiopathic vasculitis etc. (3) Medications: Alpha-methyldopa, procainamide etc. (4) hypo and hypertonic dialysate fluids, (5) Faulty equipment: Improperly calibrated blood pumps, crimped or obstructed tubings, low flow with high speeds causing negative pressures and over heated (>47 degrees) or underheated (<35 degrees) dialysates, or high speed flow through narrow gauge needles. Some degree of hemolysis, though not of immediate clinical significance, happens with all extracorporeal shunts. Massive hemolysis associated with hemodialysis is fortunately not very common. However the exact incidence is not known. This is probably because the hemolysis occurs in clusters related to the occurrence of faulty dialysis tubing or dialysate fluid most of the time. One such cluster was in 1998, as noted above, followed by a recall of the tubing by the particular company. In our clinical vignette too, the fault was in the cartridge as we subsequently received a communication by the company later recalling the tubing. REFERENCES : (1) Bergman, Daugirdas : Hand book of Dialysis, Little Brown NY 1994 (2) McCarthy, Steingart, Callahan : American Journal of Kidney Diseases. 1996, Feb 27 (2) : 262-2 (3) Multi state outbreak of hemolysis in HD patients traced to faulty tubing sets. Duffy, Tomashek, Spangenberg, Spry et al. Kidney International.. 2000. April: 57 (4) 1668-74. MASSIVE HEMOLYSIS ON HEMODIALYSIS : CASE REVIEW SAYED KAZI, MD (ACP Associate Member) AND ELIAS GHANDOUR, MD FACP Good Samaritan Hospital, Baltimore, Maryland PINK TEST LOCATION A- OBSTRUCTED TUBING