Acute normovolemic red cell exchange for cardiopulmonary bypass in sickle cell disease

Sickle Cell-Related Complications in Patients Undergoing Cardiopulmonary Bypass

BACKGROUND

We aimed to describe our experience with patients with sickle cell trait (SCT) and undergoing surgery on cardiopulmonary bypass (CPB).

METHODS

Data on all patients with SCT or sickle-α thalassemia who underwent surgery on CPB were collected (1996-2017).

RESULTS

Overall, 46 patients were included, 37 (80%) had SCT and 9 (20%) had sickle-α thalassemia. A total of 4 (9%) developed a potential sickle cell-related complication. Patients with sickle cell-related complications were significantly older (median 14 years vs 14 months, P = .037) and heavier (median 54 kg vs 9 kg, P = .041). Complications occurred, although without statistical significance, in patients who underwent longer median CPB times (249 minutes vs 137 minutes, P = .069), lower median temperature (31.7 °C vs 33.3 °C, P = .094), and a higher percentage underwent deep hypothermic circulatory arrest (50% vs 7%, P = .053). A total of 30 (65%) patients underwent exchange transfusion (ET) pre-bypass. Patients who underwent ET were significantly older (median 4 years vs 7 months, P = .003) and heavier (median 16 kg vs 6 kg, P = .015) than patients who did not undergo ET. The incidence of complications was comparable between patients who underwent ET (10%) and those who did not (6%).

CONCLUSIONS

In this retrospective, single-center study, it has been shown that cardiac surgery requiring CPB in patients with SCT and sickle-α thalassemia had a low risk for sickle cell-associated complications. In this cohort of patients, older age, longer CPB times, lower median temperature, and the utilization of deep hypothermic circulatory arrest appear to play an important role in the development of complications.

Red blood cell exchange in patients with sickle cell disease-indications and management: a review and consensus report by the therapeutic apheresis subsection of the AABB

BACKGROUND

A prior practice survey revealed variations in the management of patients with sickle cell disease (SCD) and stressed the need for comprehensive guidelines. Here we discuss: 1) common indications for red blood cell exchange (RCE), 2) options for access, 3) how to prepare the red blood cells (RBCs) to be used for RCE, 4) target hemoglobin (Hb) and/or hematocrit (Hct) and HbS level, 5) RBC depletion/RCE, and 6) some complications that may ensue.

STUDY DESIGN AND METHODS

Fifteen physicians actively practicing apheresis from 14 institutions representing different areas within the United States discussed how they manage RCE for patients with SCD.

RESULTS

Simple transfusion is recommended to treat symptomatic anemia with Hb level of less than 9 g/dL. RCE is indicated to prevent or treat complications arising from the presence of HbS. The most important goals are reduction of HbS while also preventing hyperviscosity. The usual goals are a target HbS level of not more than 30% and Hct level of less than 30%.

CONCLUSION

Although a consensus as to protocol details may not be possible, there are areas of agreement in the management of these patients, for example, that it is optimal to avoid hyperviscosity and iron overload, that a target Hb S level in the range of 30% is generally desirable, and that RCE as an acute treatment for pain crisis in the absence of other acute or chronic conditions is ordinarily discouraged.

Sickle cell disease and complex congenital cardiac surgery: a case report and review of the pathophysiology and perioperative management

Sickle cell anemia and thalassemia are hemoglobinopathies rarely encountered in the United States. Compounded with congenital heart disease, patients with sickle cell disease (SCD) requiring cardiopulmonary bypass and open-heart surgery represent the proverbial “needle in the haystack”. As such, there is some trepidation on the part of clinicians when these patients present for complex cardiac surgery.

SCD is an autosomal, recessive condition that results from a single nucleotide polymorphism in the β-globin gene. Hemoglobin SS molecules (HgbSS) with this point mutation can polymerize under the right conditions, stiffening the erythrocyte membrane and distorting the cellular structure to the characteristic sickle shape. This shape change alters cellular transit through the microvasculature. As a result, circumstances such as hypoxia, hypothermia, acidosis or diminished blood flow can lead to aggregation, vascular occlusion and thrombosis. Chronically, SCD can give rise to multiorgan damage secondary to hemolysis and vascular obstruction.

This review and case study details an 11-year-old African-American male with known SCD who presented to the cardiothoracic surgical service with congenital heart disease consisting of an anomalous, intramural right coronary artery arising from the left coronary sinus for surgical consultation and subsequent surgical correction. This case report will include a review of the pathophysiology and current literature regarding preoperative, intraoperative and postoperative management of SCD patients.

Fast-track cardiac anesthesia in patients with sickle cell abnormalities

We conducted a retrospective review of 10 patients with sickle cell trait (SCT) and 30 patients (cohort control) without SCT undergoing first-time coronary artery bypass graft surgery with cardiopulmonary bypass. Demographic, perioperative management, and outcome data were collected. Both groups were matched according to age, weight, duration of surgery, and preoperative hemoglobin (Hb) concentration. Distribution of gender, medical conditions, pharmacological treatment, and preoperative left ventricular function were similar between the groups. The comparisons were analyzed in respect to postoperative blood loss and transfusion rates, as well as duration of intubation, intensive care unit, and hospital length of stay (LOS). All patients underwent fast-track cardiac anesthesia. A combination of cold crystalloid and blood cardioplegia was used. The lowest nasopharyngeal temperature was 33 degrees C. There were no episodes of significant hypoxemia, hypercarbia, or acidosis. None of the patients had sickling crisis during the perioperative period. The postoperative blood loss was 687 +/- 135 vs 585 +/-220 mL in the SCT and control groups, respectively. The trigger for blood transfusion during cardiopulmonary bypass was hematocrit <20% and Hb <75 g/L postoperatively. Three SCT patients (30%) and 10 control patients (33%) received a blood transfusion. Median extubation time was 4.0 vs 3.9 h; intensive care unit LOS was 27 vs 28 h; and hospital LOS was 6.0 vs 5.5 days in the SCT and control groups, respectively. There were no intraoperative deaths. One patient in the SCT group died from multiorgan failure 2 mo after surgery.

IMPLICATIONS

Fast-track cardiac anesthesia can be used safely in patients with sickle cell trait undergoing first-time coronary artery bypass graft surgery. Extubation time and intensive care unit and hospital length of stay are comparable to those of matched controls, and blood loss and transfusion requirements are not increased. A hematocrit of 20% seems to be a safe transfusion trigger during cardiopulmonary bypass in these patients.