ABSTRACT
Objective To analyze clinical prognosis, risk factors and predictive indexes of hyperkalemia in recipients after heart transplantation. Methods Clinical data of 158 recipients were retrospectively analyzed. According to the serum potassium levels within postoperative 1-year follow-up, all recipients were divided into the normal serum potassium level group (n=83), hyperkalemia group (n=43) and severe hyperkalemia group (n=32). The incidence and prognosis of hyperkalemia after heart transplantation were summarized. The risk factors and predictive indexes of hyperkalemia after heart transplantation were identified. Results The incidence of hyperkalemia and severe hyperkalemia within postoperative 1 year was 47.5%(75/158) and 20.3%(32/158), respectively. In the severe hyperkalemia group, the fatality was 16%(5/32), higher than 8%(7/83) in the normal serum potassium level group and 7%(3/43) in the hyperkalemia group. The mean serum creatinine (Scr) within 6 months before heart transplantation, the final total bilirubin level before heart transplantation, postoperative hemodialysis time, the Scr level and N-terminal pro-brain natriuretic peptide level at postoperative 1 d were the independent risk factors for hyperkalemia following heart transplantation (all P < 0.05). The mean Scr level within 6 months before heart transplantation, postoperative hemodialysis time, and Scr levels at postoperative 1 and 7 d could be used to predict postoperative severe hyperkalemia. Conclusions The recipients with severe hyperkalemia after heart transplantation obtain poor prognosis. The mean Scr level within 6 months before heart transplantation, the final total bilirubin level before heart transplantation, postoperative hemodialysis time, and the Scr level and N-terminal pro-brain natriuretic peptide level at postoperative 1 d are the independent risk factors for hyperkalemia after heart transplantation. Perioperative Scr level and postoperative hemodialysis time may be used to predict the incidence of severe hyperkalemia within 1 year after heart transplantation.
ABSTRACT
BACKGROUND: Sheep are a primary model of mechanical circulatory support (MCS) with heparin anticoagulation therapy frequently being monitored by activated clotting time (ACT) due to ease and cost. In patients undergoing long-term heparin therapy, other anticoagulation monitoring strategies, such as activated partial thromboplastin time (aPTT), have proven to be more reliable indicators for the adequacy of anticoagulation, frequently determined by heparin concentration. As there is a paucity of similar studies in sheep, we sought to investigate the correlation between heparin concentration and ACT and aPTT using whole sheep blood in an ex vivo model. METHODS: Fresh whole blood was serially drawn from an adult female Dorset-hybrid sheep and aliquots were placed into tubes containing heparin saline solutions with concentrations ranging from 0 to 7.81 U heparin per mL of whole blood. ACT and aPTT values were measured on each of the samples. The experiment was performed four times with the same animal. A simple linear regression was performed to determine correlation, and subgroup analysis was performed on low versus high heparin concentrations typically seen in human patients on long-term MCS, such as extracorporeal membrane oxygenation (ECMO), versus cardiopulmonary bypass, respectively. RESULTS: aPTT measurements versus the heparin concentration had an R2 = 0.7295. ACT measurements versus the heparin concentration had a R2 = 0.4628. aPTT measurements versus the ACT measurements had a R2 = 0.2974. The strength of the correlation between aPTT and heparin concentration increased at low heparin concentrations (R2 = 0.8392). CONCLUSION: aPTT had a more reliable correlation to heparin concentration and thus anticoagulation level than ACT. This was particularly true at lower heparin concentrations, similar to ranges seen for patients on ECMO. The correlation between aPTT and ACT values was poor. Further in vivo studies should be performed to confirm our results.
Subject(s)
Anticoagulants/administration & dosage , Heparin/administration & dosage , Partial Thromboplastin Time , Whole Blood Coagulation Time , Animals , Dose-Response Relationship, Drug , Linear Models , Models, Animal , SheepABSTRACT
OBJECTIVE: Leukocytes play an important role in the body's immune system. The aim of this study was to assess alterations in neutrophil phenotype and function in pump-assisted circulation in vitro. METHODS: Human blood was circulated for four hours in three circulatory flow loops with a CentriMag blood pump operated at a flow of 4.5 L/min at three rotational speeds (2100, 2800, and 4000 rpm), against three pressure heads (75, 150, and 350 mm Hg), respectively. Blood samples were collected hourly for analyses of neutrophil activation state (Mac-1, CD62L, CD162), neutrophil reactive oxygen species (ROS) production, apoptosis, and neutrophil phagocytosis. RESULTS: Activated neutrophils indicated by both Mac-1 expression and decreased surface expression of CD62L and CD162 receptors increased with time in three loops. The highest level of neutrophil activation was observed in the loop with the highest rotational speed. Platelet-neutrophil aggregates (PNAs) progressively increased in two loops with lower rotational speeds. PNAs peaked at one hour after circulation and decreased subsequently in the loop with the highest rotational speed. Neutrophil ROS production dramatically increased at one hour after circulation and decreased subsequently in all three loops with similar levels and trends. Apoptotic neutrophils increased with time in all three loops. Neutrophil phagocytosis capacity in three loops initially elevated at one hour after circulation and decreased subsequently. Apoptosis and altered phagocytosis were dependent on rotational speed. CONCLUSIONS: Our study revealed that the pump-assisted circulation induced neutrophil activation, apoptosis, and functional impairment. The alterations were strongly associated with pump operating condition and duration.
