Usefulness of extracorporeal membrane oxygenation as a bridge to lung transplantation: a descriptive study.

BACKGROUND: This retrospective study investigated early outcome in patients with end-stage pulmonary disease bridged with extracorporeal membrane oxygenation (ECMO) with the intention of lung transplantation (LTx) in 2 Scandinavian transplant centers. METHODS: ECMO was used as a bridge to LTx in 16 patients between 2005 and 2009 at Sahlgrenska and Helsinki University Hospitals. Most patients were late referrals for LTx, and all failed to stabilize on mechanical ventilation. Thirteen patients (7 men) who were a mean age of 41 ± 8 years (range, 25-51 years) underwent LTx after a mean ECMO support of 17 days (range, 1-59 days). Mean follow-up at 25 ± 19 months was 100% complete. RESULTS: Three patients died on ECMO while waiting for a donor, and 1 patient died 82 days after LTx; thus, by intention-to-treat, the success for bridging is 81% and 1-year survival is 75%. All other patients survived, and 1-year survival for transplant recipients was 92% ± 7%. Mean intensive care unit stay after LTx was 28 ± 18 days (range, 3-53 days). All patients were doing well at follow-up; however, 2 patients underwent retransplantation due to bronchiolitis obliterans syndrome at 13 and 21 months after the initial ECMO bridge to LTx procedure. Lung function was evaluated at follow-up, and mean forced expiratory volume in 1 second was 2.0 ± 0.7 l (62% ± 23% of predicted) and forced vital capacity was 3.1 ± 0.6 l (74% ± 21% of predicted). CONCLUSION: ECMO used as a bridge to LTx results in excellent short-term survival in selected patients with end-stage pulmonary disease.

Comparison of the effect of 6% hydroxyethyl starch and gelatine on cardiac and stroke volume index: a randomized, controlled trial after cardiac surgery.

BACKGROUND AND AIMS: The objective of this study was to find out the effect of various doses of hydroxyethyl starch (HES), gelatine or Ringer's acetate on cardiac and stroke volume index after cardiac surgery. MATERIAL AND METHODS: Three consecutive boluses (each 7 mL·kg(-1)) of either 6% HES 130/0.4, 4% gelatine, or Ringer's acetate solutions were administered to 45 patients postoperatively. The rate of infusions was adjusted according to haemodynamic measurements. Thereafter, infusion of the study solution (7 mL·kg(-1)) was continued for the following 12 hours. The total dose of study solution was 28 mL·kg(-1). RESULTS AND CONCLUSION: Mean (SD) cardiac and stroke volume indices were greater in the HES group [2.8 L·min(-1)·m(-2) (0.7), 34.1 (6.7) ml·m( -2)] than in the gelatine group [2.2 L·min(-1)·m( -2) (0.6), 25.8 (7.2) ml·m(-2)] after completion of 7 mL·kg(-1) of study solution. At this stage, the effect of gelatine did not differ from Ringer's acetate. After completion of 14 mL·kg(-1) and 21 mL·kg(-1) of colloids, similar cardiac and stroke volume indices were observed and the haemodynamic response was better in both colloid groups than in the Ringer's acetate group. No differences between groups were detected on the first postoperative morning. In the early postoperative phase after cardiac surgery, the effect of a single dose of HES solution on the haemodynamics was superior to the effect of gelatine or Ringer's acetate. However, after repeated administration of the study solutions, the haemodynamics in the two colloid groups appeared to be similar, but superior to the Ringer's acetate group.

Natural course and risk factors for impaired renal function during the first year after heart transplantation.

BACKGROUND: Post-operative renal failure is a common and potentially hazardous complication after heart transplantation (HTx). In this study we characterized pre- and post-operative risk factors for acute renal failure requiring renal replacement therapy (RRT). METHODS: Ninety-three patients underwent orthotopic HTx between 2000 and 2007. The risk factors for RRT during the early post-operative period and predictors contributing to impaired renal function within the first post-transplant year were analyzed by regression analysis. The impact of pre-operative renal failure and early post-operative RRT on renal function within 1 year were studied. RESULTS: Before HTx, 55% of patients (51 of 93) had normal renal function or mild renal failure (glomerular filtration rate [GFR] >60 ml/min/1.73 m(2)). Before discharge from the hospital, 25% (23 of 93) developed acute renal failure and required RRT. Of these, 16% (8 of 51) had pre-operatively normal renal function or mild renal failure, and 36% (15 of 42) had moderate or severe renal failure (GFR <60 ml/min/1.73 m(2); p = 0.02). The prognosticators for early RRT were prolonged graft dysfunction, re-admission to the operating room due to post-operative bleeding, poor diuresis during surgery (<1,000 ml), pre-operative pacemaker implantation, intubation time >24 hours, pre-operative GFR <60 ml/min/1.73 m(2), post-operative troponin T >6 microg/liter and pre-operative use of angiotensin receptor blocker. CONCLUSIONS: Pre-operative renal failure is a significant risk factor for RRT during the immediate post-operative period and requires aggressive treatment. Patients with pre-operative renal failure secondary to severe heart failure and acute post-operative renal failure requiring RRT tend to recover within the first year post-HTx.

Rapidly degradable hydroxyethyl starch solutions impair blood coagulation after cardiac surgery: a prospective randomized trial.

BACKGROUND: There is continuing concern about the effect of hydroxyethyl starch (HES) solutions on blood coagulation. Rapidly degradable HES solutions with more favorable effects on clot strength have therefore been developed. Because the risk of bleeding is increased after cardiopulmonary bypass, we examined whether these types of HES solutions could be administered after cardiac surgery without an alteration of coagulation. METHODS: Two new rapidly degradable HES solutions were compared with human albumin in 45 patients scheduled for elective primary cardiac surgery. After admission to the cardiac surgical intensive care unit, the patients were allocated in random order to receive either 15 mL/kg of HES solution with low molecular weight and low molar substitution (either 6% HES200/0.5 or 6% HES130/0.4) or 4% human albumin solution as a short-time (70-240 min) infusion. RESULTS: Clot formation time was prolonged and maximum clot firmness was decreased in thromboelastometry tracings after infusion of both HES solutions. This impairment in thromboelastometry tracings partly recovered (using InTEM and ExTEM coagulation activators) at 2 h after the completion of the study infusion. Platelet contribution to maximum clot firmness remained unaffected in all of the study groups. HES did not induce fibrinolysis. No changes in thromboelastometry tracings were observed after human albumin infusion. Chest tube drainage was comparable in the study groups. CONCLUSIONS: We conclude that a short-time infusion of rapidly degradable HES solutions after cardiac surgery produces impairment in fibrin formation and clot strength in thromboelastometry tracings. In this clinical setting, human albumin does not impair hemostasis.

Heparin-induced thrombocytopenia following cardiac surgery is associated with poor outcome.

OBJECTIVE: The outcome of cardiac surgical patients with clinically diagnosed heparin-induced thrombocytopenia (HIT) was studied. DESIGN: Retrospective, observational study. SETTING: University hospital. PARTICIPANTS: All cardiac surgical patients with diagnosed HIT after cardiac surgery between January 2002 and December 2004, and concurrently, consecutive patients without HIT. INTERVENTIONS: None Measurements and Main Results: 3465 patients were treated postoperatively in the cardiac surgical intensive care unit during the study period. Clinical suspicion of HIT arose when platelet count markedly fell several days after surgery and HIT was proven by a positive enzyme immunoassay in 20 patients. Thrombocytopenia (35.5 [22] x 10(9)/L, median [interquartile range]) developed within 7 (6) days. HIT patients received significantly more platelet transfusions perioperatively than controls (p < 0.001). Thromboembolic complications occurred in 70% of HIT patients, but in none of non-HIT patients (14/20 v 0/20, p = 0.001). Intensive care unit stay was longer in HIT patients than in controls (16.5 [11.0] v 1.0 [3.0] days, p < 0.001). Nine HIT patients died (45%), while all control patients survived. Mortality was related to thrombotic complications in seven HIT patients (35%). CONCLUSIONS: The incidence of HIT in association with low-molecular-weight heparin use after cardiac surgery was low. HIT was associated with perioperative platelet transfusions and carried a remarkably high risk of thromboembolic complications and death. In order to reduce morbidity and mortality, early recognition of heparin-associated antiplatelet antibodies and alternative anticoagulation strategies need to be implemented.

Relation of the Sequential Organ Failure Assessment score to morbidity and mortality after cardiac surgery.

BACKGROUND: Organ dysfunction evaluation using Sequential Organ Failure Assessment (SOFA) has been shown to predict mortality and morbidity in adult cardiac surgical patients with prolonged recovery. The purpose of this study was to evaluate the utility of SOFA in prediction of mortality and morbidity in a cohort of heterogeneous consecutive adult cardiac surgical patients. METHODS: A prospective study of 857 consecutive patients entering in a single cardiac postoperative intensive care unit was assigned during the year 2004. The European System for Cardiac Operative Risk Evaluation (EuroSCORE) of each patient was assessed preoperatively. SOFA was calculated daily until intensive care unit discharge or for a maximum of 7 days. SOFA change between the first and the third postoperative day, maximum SOFA during the first 3 days, and maximal SOFA were calculated. Length of intensive care unit stay and 30-day mortality were assessed. RESULTS: Maximum SOFA during the first 3 days and maximal SOFA-predicted 30-day mortality (area under the curve, 0.763 and 0.779, respectively) also correlated with the length of intensive care unit stay (p < 0.001 and p < 0.001, respectively). The EuroSCORE predicted both mortality and intensive care unit stay (p < 0.0001 and p < 0.0001). The correlation coefficient between the EuroSCORE and maximum SOFA during the first 3 days or maximal SOFA was low (r = 0.34 and 0.33, respectively, p < 0.0001 and p = 0.0001). CONCLUSIONS: The SOFA score is an independent predictor of mortality and length of stay in cardiac surgical patients. The SOFA score is associated with mortality and morbidity even when assessed in the early postoperative period after adult cardiac surgery.

Tranexamic acid does not correct the haemostatic impairment caused by hydroxyethyl starch (200 kDa/0.5) after cardiac surgery.

We investigated the effect of intravenous tranexamic acid on hydroxyethyl starch (HES)-induced clot strength impairment after cardiac surgery. Patients were randomized to receive either 1 g tranexamic acid or the same volume of 0.9% saline after administration of 15 ml/kg of 6% HES (molecular weight, 200 kDa; degree of substitution, 0.5) in the immediate postoperative period. Modified thromboelastometry (ROTEM) using different activators [intrinsic ROTEM (InTEM), extrinsic ROTEM (ExTEM), fibrinogen ROTEM (FibTEM)] was carried out to evaluate clot formation and lysis. The clot formation time was prolonged, and the maximum clot firmness (MCF) and shear elastic modulus [G = 5000 x MCF / (100-MCF), dynes/cm(2)] decreased (all activators of ROTEM) after completion of HES (P < 0.001, two-factor analysis of variance). These abnormalities in blood coagulation persisted despite tranexamic acid. Maximal lysis (FibTEM), indicative of fibrinolytic activity, was increased after HES but no effect of tranexamic acid was observed. The cumulative chest tube drainage until the first postoperative morning was not different between the groups (1008 +/- 251 and 1081 +/- 654 ml, P = 0.698, respectively). We conclude that after cardiopulmonary bypass, HES-induced impairment in clot formation and strength, or increased fibrinolytic capacity, is not reversed by the administration of tranexamic acid.

Risk evaluation of cardiac surgery in octogenarians.

OBJECTIVE: To assess the predictive value of risk factors in the European System for Cardiac Operative Risk Evaluation (EuroSCORE) for cardiac surgery on octogenarians. DESIGN: An observational study of octogenarians undergoing cardiac surgery and average-aged controls matched according to the cardiac surgical procedure. SETTING: A university hospital. PARTICIPANTS: One hundred sixty-two consecutive patients 80 years or older who underwent cardiac surgery between January 1, 2001, and June 30, 2003, and 162 average-aged controls. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Risk factors according to the EuroSCORE (The European System for Cardiac Risk Evaluation) model and EuroScore algorithm without an age component (EuroSCOREex) were evaluated. The EuroSCORE model and EuroSCOREex predicted mortality (odds ratio 1.4) and morbidity (odds ratio 1.2 and 1.3, respectively) equally well in both age groups. Adding age group information into the EuroSCOREex model in combined data, the odds ratio estimate was 3.5 for age group. The 30-day mortality of octogenarians was 8.6% versus 1.9% in controls (p < 0.01). Incidences of organ-related complications were comparable. Octogenarians spent more days in the hospital's intensive care unit and surgical ward than did controls (3.4 +/- 3.3 days v 2.7 +/- 3.1 days, p < 0.01; 9.9 +/- 5.8 days v 8.6 +/- 3.8 days, p = 0.02). Only 31 (19.1%) octogenarians were discharged home, whereas the corresponding number was 66 (40.7%) in controls (p < 0.01). CONCLUSIONS: Risk factors other than age were not higher in octogenarians, and the EuroSCORE model predicted mortality and morbidity. Age was an important single risk factor predicting mortality.

Gelatin and hydroxyethyl starch, but not albumin, impair hemostasis after cardiac surgery.

We investigated the effect of postoperative administration of colloids on hemostasis in 45 patients after cardiac surgery. Patients were randomized to receive 15 mL kg(-1) of either 4% albumin, 4% succinylated gelatin, or 6% hydroxyethyl starch (molecular weight of 200 kDa/degree of substitution 0.5) as a short-term infusion. There was a comparable decrease in maximum clot firmness of thromboelastometry tracings in gelatin and hydroxyethyl starch groups immediately after completion of the infusion, whereas these values remained unchanged in the albumin group. The impairment in clot strength persisted up to 2 h, although the values partly recovered. Postoperative bleeding correlated inversely with the clot strength in pooled data of the artificial colloids. Fibrin formation (clot formation time, alpha-angle) and fibrinogen-dependent clot strength (maximum clot firmness and shear elastic modulus) were more disturbed in the hydroxyethyl starch group than in the gelatin group. We conclude that after cardiopulmonary bypass surgery, both gelatin and hydroxyethyl starch impair clot strength and fibrin buildup, which may predispose patients to increased blood loss. The greatest impairment in hemostasis was seen after hydroxyethyl starch administration, whereas albumin appeared to have the least effect on hemostatic variables.