Perioperative Management

The stress of surgery, even if minor, may induce a sickle crisis. It is therefore important for the otolaryngologist to be aware of the perioperative management of a patient with sickle cell disease.

Sickle cell trait does not cause an increase in operative morbidity. On the other hand, sickle cell disease has a high incidence of perioperative problems. Complications related to sickle cell events, such as acute pain syndrome, are increased after surgery. Sickle cell disease may not increase the risk of common complications such as fever, infection, and bleeding; however, these events may increase stress such that they may in themselves induce sickle crises.

Preoperative assessment is critical for these patients. They should be managed in the perioperative period by the primary hematologist as well as an anesthesiologist. Predictors of perioperative complications include type of surgery, increased age, previous history of complications, history of ACS, and preexisting infection (11,13,16).

Tonsillectomies and ventilating tubes are considered low-risk procedures. High-risk procedures include intra-abdominal and neurological surgery. The incidence of perioperative events for tonsillectomy and for myringotomy tube insertion were 0% and 2.9%, respectively, compared with 16% for cesarean section (18). History of several acute pain crises within the last year and/or ACS appears to be among the most significant findings of perioperative risk. Patients with end-organ damage (e.g., lung, kidney, etc.) would also be at a higher risk for complications (12).

Preoperative assessment of patients with sickle cell should include hematocrit, blood urea nitrogen, creatinine, urine dipstick, chest film, and pulse oximetry. One may also consider blood cross match, pulmonary function testing, and liver function tests, if clinically warranted.

The adage "an ounce of prevention is worth a pound of cure" is especially true in the perioperative management of these patients. Interestingly, there is mixed evidence regarding the efficacy of various treatments for prevention of sickle cell events. Prophylactic blood transfusion to prevent sickle cell events was once popular; however, evidence-based reviews of the literature did not support this practice. The current recommendations for transfusion are based on the patient's preoperative risk. Patients undergoing low-risk operations such as tonsillectomy do not routinely need transfusion therapy. High-risk operations require a thorough assessment of the risk and benefits of transfusion therapy with a multidisciplinary hematology team. If indicated, the transfusion goal is to reduce the Hb-S concentration to less than 30% (19).

Other measures to reduce perioperative risk include increasing oxygen-carrying capacity, hydration, body temperature, and anesthetic technique, all of which are controversial. Patients with anemia should probably be transfused, although a concentration of Hb that should initiate transfusion is not agreed upon in the literature (12).

Events that are presumed to cause dehydration, for example, exposure to high altitude, are associated with sickle cell events; therefore, it is recommended that sickle cell patients be kept well hydrated. This issue can be especially problematic for patients undergoing tonsillectomy, which can cause severe dehydration. These patients should be hospitalized to ensure adequate hydration before discharge (12).

Theoretically, hypothermia may cause a sickle cell event; however, there is insufficient evidence in clinical practice to support this concept. Also, hyperthermia (pyrexia) is common after surgery in sickle cell patients. It does not appear to increase their risk of acute events and should be managed in a manner similar to that for a non-sickle cell patient.

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