The pathophysiology of the sickle hemoglobinopathies and implications for perioperative management

Perioperative care of children with sickle cell disease: A systematic review and clinical recommendations

Children with sickle cell disease (SCD) require specific perioperative care, and clinical practice in this area remains poorly defined. We aimed to conduct a systematic, PRISMA-based review of the literature, available clinical guidelines and practice recommendations. We also aimed to extract any valuable information for the "best of available-evidence"-based prevention of perioperative adverse events in children with SCD, and highlight the most urgent priorities in clinical research. As data sources, US National Library of Medicine, Medline, National Guideline Clearinghouse, International Guideline Network, TRIP databases were searched for any content until January 2019. We also included institutional, consortia and expert group guidelines. Included were reports/guidelines in English, French, German, and Italian. Excluded were reports on obstetrical and fetal management. We identified 202 reports/guidelines fulfilling the criteria outlined above. A majority focused on visceral, cardiovascular and orthopedic surgery procedures, and only five were multicenter randomized controlled trials and two prospective randomized studies. After grading of the quality of the evidence, the extracted data was summarized into clinical recommendations for daily practice. Additionally, we designed a risk-grading algorithm to identify contexts likely to be associated with adverse outcomes. In conclusion, we provide a systematic PRISMA-based review of the existing literature and ancillary practice and delineate a set of clinical recommendations and priorities for research.

Effectiveness of preoperative screening for sickle cell disease in a population with a newborn screening program: a cohort study

PURPOSE

Published clinical practice guidelines recommend that all patients from ethnic groups with a high prevalence of sickle cell disease (SCD) undergo preoperative screening for this hemoglobinopathy. Newborn Screening Ontario initiated a universal sickle hemoglobinopathy screening program in 2006 as part of its regional newborn screening program. The primary objective of this study was to determine the effectiveness of selective preoperative screening for SCD based on at-risk ethnicity in Ontario, a region that has a universal newborn sickle hemoglobinopathy screening program.

METHODS

The hematology laboratory database at our hospital was searched to identify all children who underwent preoperative sickle cell screening in the 42-month period starting in November 2006 (when the newborn sickle hemoglobinopathy screening program was introduced) and ending in April 2010. Medical records of all children testing positive on hemoglobin analysis were reviewed to determine perioperative outcomes.

RESULTS

Our search strategy identified 710 children who were born after the introduction of newborn screening and who underwent preoperative screening. Thirty-five of these children had abnormal sickle solubility tests - one (0.14%) was a new diagnosis (not identified by newborn screening), one had been diagnosed previously, and 33 (4.65%) were identified as having sickle cell trait. Sixty children had more than one preoperative screening test performed (range, 2-4). Six of the 35 children with abnormal sickle solubility results underwent repeated testing.

CONCLUSIONS

Preoperative screening based on at-risk ethnicity alone is an ineffective method of identifying additional children with SCD in Ontario, a population with universal newborn sickle hemoglobinopathy screening. In an effort to avoid unnecessary repeat testing, we propose an algorithm to help physicians decide whether to initiate preoperative sickle cell screening for children.

Preoperative screening for sickle cell disease in children: clinical implications

PURPOSE

Preoperative screening of at-risk patients for sickle cell disease (SCD) is recommended as a method to decrease perioperative morbidity. However, the effectiveness of pre-operative screening in accomplishing this goal has never been demonstrated. We undertook a retrospective study to determine the prevalence of positive test results among those screened preoperatively at our institution and to determine whether amendments to present screening guidelines can be recommended.

METHODS

The hematology laboratory database of a university teaching hospital was searched to identify all patients who underwent preoperative screening for SCD from October 1999 to October 2003. The medical records of those patients testing positive were reviewed.

RESULTS

Of 1,906 children screened preoperatively, 79 (4.1%) were diagnosed as having sickle cell trait and three (0.16%) as having some form of SCD: one had homozygous hemoglobin S and two had sickle-hemoglobin C disease. Two of the three had a family history for SCD and none had a preoperative hemoglobin concentration < 10 g.dL(-1). No patient developed perioperative sickle-related complications.

CONCLUSION

Preoperative screening of 1,906 children identified only one asymptomatic child with undiagnosed SCD and a negative family history, suggesting that routine preoperative screening for SCD is rarely of significant clinical value in our population. Had preoperative screening not been performed, no child requiring preoperative transfusion would have been missed, representing a long-run probability of at least 99.84% that no at-risk child would require transfusion. We recommend that preoperative screening for SCD be undertaken selectively, giving consideration to the risks and benefits of screening to the individual patient.

Anaesthetic management of the child with sickle cell disease

Sickle cell disease (SCD) is a relatively common inherited disorder of haemoglobin with significant morbidity and mortality. This review describes the epidemiology and pathophysiology of the disease, and discusses the clinical manifestations found in children with SCD. A discussion of the evidence concerning the perioperative management of such children is presented.

A retrospective observational study of pre-operative sickle cell screening

The aim of this study was to determine the ethnic mix of those patients being pre-operatively screened for sickle cell disease in a London teaching hospital and to determine the rate of carriage of sickle haemoglobin amongst those tested. We retrospectively studied 1879 patients undergoing surgery over a 2-month period. Two hundred and thirteen (11%) were screened for sickle cell disease and of these, 12 (5%) tested positive for sickle cell trait (HbAS). There were no patients homozygous for sickle cell disease (HbSS) or with haemoglobin SC disease (HbSC). Screening rates varied widely in different ethnic groups from 0% of the Chinese population to 85.2% of the Afro-Caribbean population. We conclude that at present there is no coherent pre-operative screening policy for sickle cell disease in our institution. Sickle cell disease poses unique anaesthetic risks and with a rapidly expanding 'mixed race' population high-risk patients are difficult to identify phenotypically. We propose a universal screening policy be implemented in high-risk areas.

Acute chest syndrome in the postoperative sickle cell patient

BACKGROUND/PURPOSE

Acute chest syndrome (ACS), a phenomenon of pulmonary sequestration in sickle cell disease (SCD) patients, is frequently missed in the postoperative SCD child. The constellation of symptoms range from fever and respiratory distress to abdominal discomfort. In its most fulminate state, the syndrome has been reported in some series to carry almost a 25% to 50% mortality rate in the postoperative patient. The incidence in pediatric patients in the era of minimally invasive surgery is unknown.

METHODS

Since December 1995, 63 episodes of ACS have been documented in the nearly 500 SCD children seen at our institution. Six of 63 episodes occurred within 2 weeks after a surgical procedure under general anesthesia. During this period, 59 operations were performed by the pediatric surgery service on SCD patients with an ACS incidence of 10.2%. Careful review of the preoperative, intraoperative, and postoperative management of these patients was performed.

RESULTS

All six received preoperative oxygen saturation monitoring and intravenous fluid (IVF) hydration. One half of these patients required transfusion to achieve a hemoglobin level of greater than 10 mg/dL. Documentation of intraoperative temperature, hypoxia, volume status, and hypercarbia as well as any atypical perioperative events were monitored and reviewed. All patients received postoperative oxygen supplementation and IVF hydration. Onset of ACS ranged from 1 hour to 7 days postoperatively. Only one of six was thought to be of microbial etiology (elevated mycoplasma titers), and all patients received prophylactic antibiotic and aggressive pulmonary therapy. Overall length of hospitalization was increased with an average stay of 6.1 days. There were no postsurgical ACS deaths.

CONCLUSIONS

Despite close attention and avoidance of known risk factors for development of postoperative SCD complications, ACS occurred with an incidence much higher than previously reported in the literature (0.4% v 10.2%). Interestingly, five of six cases were after laparoscopic procedures suggesting that the advantages of laparoscopy, such as reduced postoperative pain, do not extrapolate to decreased incidence of ACS.

Successful surgical outcome in children with sickle hemoglobinopathies: the Duke University experience

BACKGROUND/PURPOSE

Surgery in patients with sickle hemoglobinopathies can be problematic because of the potential for sickling events in the perioperative and postoperative period. The authors and others have previously reported successful surgical outcomes using an aggressive erythrocyte transfusion regimen, designed to alleviate anemia and to reduce the percentage of sickle hemoglobin to below 30%. Recently, a randomized trial compared this aggressive regimen with a more conservative transfusion regimen and found no differences in perioperative complications. The incidence of complications, however, was very high in each group (31% to 35%).

METHODS

The authors therefore analyzed retrospectively their surgical experience in children with sickle hemoglobinopathies over the past 10 years to determine the efficacy of an aggressive transfusion regimen and skilled perioperative care in their patient population.

RESULTS

A total of 130 surgical procedures were performed on 92 children including 54 cholecystectomies (42%), 23 splenectomies (18%), 12 ENT procedures (9%), 11 central line placements and removals (8%), 7 herniorrhaphies (5%), 7 appendectomies (5%), and 16 miscellaneous operations (13%). The mean age of the children was 10 years (range, 1 to 22 years), and the mean weight was 32.1 kg (range, 9.9 to 76.8 kg). The average hemoglobin (mean +/- 1 SD) at the time of surgery was 11.2+/-1.3 g/dL, and the average percent hemoglobin S was 21+/-11%.

CONCLUSIONS

Relatively few transfusions were required to achieve these endpoints, and the complications resulting from transfusions were minimal. Similarly, the number of perioperative and postoperative events was very low.