Multi-disciplinary approach necessary in sickle cell surgeries
As the world observes Sickle Cell Awareness Month, Dr. G. Ashaini Knowles, consultant general and pediatric surgeon, says surgery in patients with sickle cell disease (SCD) is generally safe when performed by a multi-disciplinary team. However, he cautions that despite optimal care, there remains a substantial risk of morbidity, necessitating close cooperation among the medical, anesthesia and surgical teams.
SCD is a hereditary blood disorder affecting red blood cells. The cells can become sickle-shaped (hence the name of the disease), making it difficult for them to pass through small blood vessels. When those blood cells get trapped, they can’t carry oxygen to all parts of the body and this is what causes the pain and complications associated with SCD. People with sickle cell can experience anemia, jaundice and gallstones as well as acute pain in the arms, legs, chest and abdomen. Prolonged blockages can also cause damage to most organs, including the spleen, kidneys and liver.
The disease is passed genetically from parents to child. It is not contagious — but it is a life-long illness. The severity of the disease varies from person to person.
According to the United States National Heart, Lung and Blood Institute ((NHLBI), in high-income countries like the United States (US), the life expectancy of a person with SCD is now about 40 to 60 years due to advances in the diagnosis and care of SCD. In 1973, the average lifespan of a person with SCD in the U.S. was only 14 years.
SCD is associated with an increased risk of perioperative complications that can be decreased by a multi-disciplinary approach that includes surgical, hematology and anesthesiology components, according to Dr. Knowles. Knowles spoke at a recent Doctors Hospital Distinguished Lecture Series in advance of the disease’s awareness month.
Common indications of SCD include splenectomy, cholecystectomy, hip replacement and other surgeries.
“Most sicklers have had splenic crisis, where you have sickling of the cells and sequester in the spleen [sickled red blood cells become trapped in the spleen which can enlarge, get damaged and not work as it should] and it’s very painful. One of the things that happens is it drops your hemoglobin, so that’s a real challenge,” said Dr. Knowles.
The most common operation performed for SCD, according to the doctor is cholecystectomy, the removal of the gallbladder for gallstones. He said sicklers might also need hip replacement later in life; other common surgeries include those to address colon cancer and thyroid disease. According to Knowles, there is a certain approach that medical practitioners have to adhere to when it comes management of patients with sickle cell disease.
“The one thing you see a lot of is recurrent acute splenic sequestration crisis (ASSC), another indication is hypersplenism, which is a bit different than crisis, [in that] you have a hyper active spleen, so your platelets, hemoglobin and white cells drop. Another indication for surgery in sicklers is splenic abscess, which is an abscess with a lot of puss; so you have a spleen filled with puss. You could have a massive splenic infarction, which means a heart attack of the spleen.”
To reduce the complications, the recommendation is a splenectomy, which Dr. Knowles said is safe in children, and reduces the patient’s transfusion requirements eliminating the risks of ASSC.
In the two years since his return home, medical teams have performed about three splenectomies, which he said eliminated the discomfort and mechanical pressure of the patients’ enlarged spleen.
Cholecystectomy is another common operation performed on sickle cell patients with gallstones. Up to 70 percent of patients with sickle cell disease might have gallstones, the problem may not be symptomatic. According to the doctor, it is the complications that arise from having gallstones that cause problems. They include acute cholecystitis (inflammation of the gallbladder).
“The big one we want to avoid is acute cholangitis [bacterial infection], that can be very deadly,” said Dr. Knowles.
In the perioperative management of surgery for sickle cell patients, because of the increased risk of morbidity, the doctor said patients are admitted to hospital 12 to 24 hours before surgery to allow for optimal hydration with intravenous fluids. A diverse medical team performs pulmonary function testing and treats any obstructive disease with a bronchodilator. They also start the incentives spirometer pre-operatively to help the patient’s keep lungs clear and active. A blood transfusion is also given to increase the patient’s hematocrit to 30 percent before all operations except minor procedures performed under local anesthesia.
“There’s nothing left untouched. We adhere to pretty much the protocol worldwide,” he said.
There is no specific anesthetic technique used with sickle cell patients. The doctor said the most important areas are the maintenance of hydration, pre-oxygenation, monitoring oxygen therapy, preventing hypothermia, preventing venous stasis (slow blood flow in the veins) and monitoring blood loss.
Dr. Knowles said post-operative is where they have the most challenges. In a perfect world he said all sickle cell patients would go to the intensive care unit (ICU) following surgery, but he said there are only so many ICU beds. If doctors can’t get patients into ICU, he said, they ensure that the team watches the patient around the clock.
“Since acute chest syndrome has its peak occurrence 48 hours after a major operation, a prolonged observation is desirable,” he said. “Even if you’ve done a laparoscopic splenectomy and everything went well, you have to know that there is a risk of acute chest, so we tend to keep them about two days.”
At Doctors Hospital he said post-op patients go into an IMCU (intermediate care unit) where they are observed overnight.
Dr. Knowles said effective analgesia is also important in pain management. People with SCD do not have the same response to narcotics/opiates as normal people due to their pain tolerance level.
“We have to monitor them, because the risk with narcotics is they can have respiratory depression and we have to keep an eye on that,” he said.
Blood transfusion versus exchange transfusion
Whether medical practitioners should be aggressive and exchange transfuse their patients, or do a simple transfusion is a “controversial” issue, according to Dr. Knowles.
“With exchange transfusion you’re trying remove the sickled blood and put in normal blood. The initial aggressive guys were basically trying to get less than 30 percent of sickled red blood cells within circulation and felt that when they did that, the morbidity of the surgery was less. However, a study in the New England Journal of Medicine compared conservative [topping you up with blood] versus aggressive [exchange transfusion], and there conclusion was a conservative transfusion regimen is as effective as an aggressive regimen and the one thing is you have less transfusion-related complications.”
Dr. Knowles said there is no consensus on the best regimen of transfusions for this purpose. He said a conservative transfusion regiment is as effective as an aggressive regimen in preventing perioperative complications, and reduces the risk of transfusion-associated complications by 50 percent.
Citing a Jamaican paper with only 29 patients, they found that with selective transfusion the morbidity was acceptable, and there were no perioperative mortalities.
“It was retrospective, and did show that in this cohort you could get away with being a bit more conservative,” said the surgeon.