CARDIAC ARREST DURING A PEDIATRIC TONSILLECTOMY

Physician anesthesiologist at Stanford at Associated Anesthesiologists Medical Group
Richard Novak, MD is a Stanford physician board certified in anesthesiology and internal medicine.Dr. Novak is an Adjunct Clinical Professor in the Department of Anesthesiology, Perioperative and Pain Medicine at Stanford University, the Medical Director at Waverley Surgery Center in Palo Alto, California, and a member of the Associated Anesthesiologists Medical Group in Palo Alto, California.
emailrjnov@yahoo.com
THE ANESTHESIA CONSULTANT

A 12-year-old boy and his mother walk into a surgery center. The child is scheduled for a tonsillectomy, and is otherwise healthy. The anesthesiologist induces general anesthesia, and ten minutes later the patient has ventricular arrhythmias which descend into a cardiac arrest. Advanced Cardiac Life Support (ACLS) measures are applied, but the child cannot be resuscitated, and is declared dead. What caused this cardiac arrest during a pediatric tonsillectomy?

This is an actual closed malpractice case which I was asked to review. The anesthesiologist induced general anesthesia with propofol and a paralytic drug called succinylcholine (sux-in-ol-KOH-leen), and then inserted a breathing tube successfully into the patient’s windpipe. All vital signs were normal. Sevoflurane, nitrous oxide, and 50% oxygen were ventilated into the patient’s lungs. The surgeon began the tonsillectomy. One minute later the cardiac arrest occurred. The anesthesiologist followed ACLS guidelines, but standard ACLS treatments and hyperkalemia (elevated potassium concentration) treatments were unsuccessful.

Succinylcholine is an intravenous muscle relaxant (paralytic) drug commonly used in the United States. Succinylcholine is an old drug—available since 1951—which has the distinction of being the most rapid-acting intravenous muscle relaxant, and also the shortest-acting muscle relaxant. Succinylcholine is an important drug in an anesthesiologist’s toolkit. When an airway emergency threatens a patient’s life, such as the unexpected occurrence of laryngospasm, succinylcholine is the emergency drug of choice to paralyze the patient, relax the spasm of the vocal cords, and enable the anesthesiologist/emergency room physician/acute care physician to insert a life-saving breathing tube into the trachea.

But succinylcholine can be a dangerous drug. The Food and Drug Administration (FDA) placed a Black Box Warning on succinylcholine in 1994. The current succinylcholine warning in the PDR (Prescribers’ Digital Reference) reads:

Succinylcholine is contraindicated in patients with a personal or familial history of malignant hyperthermia and/or skeletal muscle myopathy. Malignant hyperthermia may be precipitated by succinylcholine; concomitant use of volatile anesthetics may further increase this risk. 

In neonates, infants, children, and adolescents, reserve the use of succinylcholine for emergency intubation or instances where immediate securing of the airway is necessary (e.g., laryngospasm, difficult airway, full stomach, or lack of intravenous access). 

There have been rare reports of ventricular dysrhythmias and fatal cardiac arrest secondary to rhabdomyolysis with hyperkalemia, primarily in healthy-appearing pediatric patients who were subsequently found to have undiagnosed skeletal muscle myopathy, most frequently Duchenne’s muscular dystrophy. 

Affected pediatric patients are typically, but not exclusively, males 8 years or younger. Although some patients have no identifiable risk factors, a careful history and physical exam may identify developmental delays suggestive of myopathy, and a preoperative creatinine kinase could identify patients at risk. 

Closely monitor body temperature, expired CO2, heart rate, blood pressure, and electrocardiogram in pediatric patients to help detect early signs of malignant hyperthermia and/or hyperkalemia. 

The rhabdomyolysis syndrome often presents as peaked T-waves and sudden cardiac arrest within minutes of succinylcholine administration. If cardiac arrest occurs immediately after succinylcholine administration, institute treatment for hyperkalemia (e.g., intravenous calcium, bicarbonate, glucose with insulin, hyperventilation). If malignant hyperthermia is suspectedinitiate appropriate treatment (e.g., dantrolene, supportive care) concurrently.”

Per the Black Box warning, succinylcholine has the potential for inducing life threatening hyperkalemia in children with undiagnosed skeletal muscular dystrophies. Severe hyperkalemia and ventricular arrhythmias followed by cardiac arrest may occur in apparently healthy children who have an occult muscular dystrophy (usually Duchenne’s muscular dystrophy). An occult muscular dystrophy is a rare inherited disease. The global prevalence of Duchenne’s muscular dystrophy is 7.1 cases per 100,000 males, and 2.8 cases per 100,000 in the general population. The Black Box warning on succinylcholine recommends to “reserve use in children for emergency intubation or need to immediately secure the airway.”

The Black Box warning applies to neonates, infants, children and adolescents. No parent wants their son or daughter under the age of 18 to electively receive a drug which has an FDA Black Box Warning for use in adolescents. No parent wants their neonate, infant, child, or adolescent to have a risk of sudden cardiac arrest under general anesthesia for a common elective surgery.

In 1994 the Anesthesia Patient Safety Foundation (APSF) published a sentinel article about the risks of succinylcholine in pediatric anesthesia. The article reviews the history of the succinylcholine warning: “In 1992, Drs. H. Rosenberg and G. Gronert published a letter in Anesthesiology briefly reviewing four deaths in male children under the age of eight who had received halothane and then succinylcholine. These cases were identified through the Malignant Hyperthermia (MH) Hotline. Reference was also made to ‘11 similar cases’ identified through the German MH Hotline. Their letter concluded with the statement: ‘We have notified the Food and Drug Administration of this potential problem and recommended that anesthesiologists carefully consider the indications for use of succinylcholine in young children.’ This letter was accepted for publication August 24,1992.” The article goes on to emphasize “the need for prompt and appropriate treatment should hyperkalemic arrest occur. This treatment involves the intravenous administration of calcium. With proper treatment, approximately 50% of patients have survived this catastrophic hyperkalemia.” The Black Box warning specifically states, “If cardiac arrest occurs immediately after succinylcholine administration, institute treatment for hyperkalemia (e.g., intravenous calcium, bicarbonate, glucose with insulin, hyperventilation).”

Despite the Black Box warning, how often is succinylcholine still used for non-emergency pediatric anesthetics in the United States? No one knows. I can attest that during a recent Quality Assurance review in the Northern California, I saw anesthetic records from a board-certified anesthesiologist who administered succinylcholine to a 14-year-old boy for elective ear surgery. I discussed this with the anesthesiologist, who was unaware they were doing anything dangerous.

There is an excellent alternative to the elective use of succinylcholine. For most cases, pediatric or adult, the muscle relaxant rocuronium is a superior alternative to succinylcholine. Succinylcholine is the IV muscle relaxant with the most rapid onset, but large doses (0.9 mg/kg) of rocuronium are nearly as rapid as succinylcholine, without any of succinylcholine’s risks.   Succinylcholine is also the IV muscle relaxant which wears off the fastest, but since the year 2015 FDA approval of the muscle relaxant reversal drug sugammadex (Bridion), an intubating dose of rocuronium can be rapidly reversed within 3 minutes by administering 16 mg/kg of sugammadex

Succinylcholine remains an important drug for the treatment of airway emergencies. I would never begin a general anesthetic if I did not have a vial of succinylcholine immediately available in case of an airway emergency. In addition, succinylcholine is important because it can be administered intramuscularly (in a patient who has no IV). For example, if a child is undergoing an inhalational induction of general anesthesia with sevoflurane vapor prior to a surgery, and the child suddenly goes into laryngospasm before any IV can be started, (this does occur, not uncommonly, and is a true emergency), the appropriate treatment is an intramuscular injection of 4 mg/kg of succinylcholine. The child will become paralyzed within minutes, and the anesthesiologist can then insert a life-saving breathing tube. (The mean onset of paralysis with 4 mg/kg intramuscular succinylcholine in children ages 1 to 10 ranges from 2.9 to 3.9 minutes.)

I’ve written about the advantages and risks of succinylcholine previously in the article, “Succinylcholine: Vital Drug or Obsolete Dinosaur?”  

I also refer you to the published article, “Is There Still a Role for Succinylcholine in Contemporary Clinical Practice?

The take home messages from this case study of a cardiac arrest during a pediatric tonsillectomy are:

  • If you’re an anesthesia provider, do not administer succinylcholine to a neonate, infant, child, or adolescent for an elective surgery. The Black Box warning on succinylcholine recommends to “reserve use in children for emergency intubation or need to immediately secure the airway.”
  • If you’re a parent, prior to your son or daughter’s surgery, be empowered to ask your child’s anesthesiologist if they’re aware of the Black Box warning on succinylcholine. 
  • Nobody wants a death brought on by an elective anesthetic.

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The most popular posts for laypeople on The Anesthesia Consultant include:
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READ ABOUT RICK NOVAK’S FICTION WRITING AT RICK NOVAK.COM.

ANESTHESIA FACTS FOR NON-MEDICAL PEOPLE: WHAT IS MALIGNANT HYPERTHERMIA?

Physician anesthesiologist at Stanford at Associated Anesthesiologists Medical Group
Richard Novak, MD is a Stanford physician board certified in anesthesiology and internal medicine.Dr. Novak is an Adjunct Clinical Professor in the Department of Anesthesiology, Perioperative and Pain Medicine at Stanford University, the Medical Director at Waverley Surgery Center in Palo Alto, California, and a member of the Associated Anesthesiologists Medical Group in Palo Alto, California.
emailrjnov@yahoo.com
THE ANESTHESIA CONSULTANT

What is Malignant Hyperthermia? Patients frequently have concerns and misunderstandings.  Patients wonder what the disease is, if it could possibly strike them during anesthesia, and how the disease would be treated.

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The word “malignant” in Malignant Hyperthermia has nothing to do with malignancy or cancer. Hyperthermia is the medical term for high temperature, and Malignant Hyperthermia, or MH, refers to an acute medical disorder associated with dangerously elevated body temperature. MH is rare, life threatening, and triggered by general anesthetic drugs. The disease runs in families. For this reason, if any of your ancestors or relatives died during anesthesia it’s important you reveal that fact to your anesthesiologist.

The inheritance is autosomal dominant, which means one of your parents must have had the disease for you to inherit it. To manifest MH, you must have both the gene for MH and also be exposed to one of the triggering anesthetic drugs. The triggering drugs are succinylcholine (a paralyzing drug/muscle relaxant) and the potent inhaled anesthetic gases sevoflurane, desflurane, isoflurane, or halothane.

The incidence of MH varies from 1:5000 to 1:100,000 anesthetics. Most MH cases appear during a patient’s first anesthetic, therefore most MH cases appear in children or young adults. I’ve performed 25,000 anesthetics over 30+ years, and none of my patients have developed MH. Nonetheless, every anesthesiologist must be knowledgeable and ready to diagnose and treat an MH crisis should one occur.

The clinical signs of MH are increased temperature, increased heart rate, increased breathing rate, and increased carbon dioxide production. These changes are caused by increased metabolism within muscle cells. The onset of MH causes individual muscle cells to become hypermetabolic, which leads to increased heat, increased carbon dioxide production, and acidosis in the bloodstream. As temperature increases, the heart beats faster and the lungs hyperventilate to blow off the excessive carbon dioxide and acid production from the muscle cells.

Early diagnosis can be difficult. There is no specific blood test to diagnose the disease. If a child receiving his first anesthetic develops a temperature of 104 degrees Fahrenheit, a heart rate of 180 beats per minute, and a respiratory rate of 60 breaths per minute, the diagnosis is apparent. As well, the patient’s jaw, trunk, or total body may become rigid. However, in some patients the initial presentation may only include increases in heart rate and respiratory rate, and high temperature may be a late sign.

A hallmark of diagnosis is evidence of increased carbon dioxide production. During surgery, anesthesiologists measure the carbon dioxide concentration of every breath you inhale and exhale. If the carbon dioxide concentration increases steadily in the context of increased heart rate and respiratory rate, with or without an increase in temperature, the anesthesiologist must suspect MH. Late clinical findings include hypertension, abnormal heart rhythms, poor blood supply to the extremities (skin turning bluish in color), and sudden unexpected cardiac arrest in children.

Blood tests drawn during MH show low pH (both metabolic and respiratory acidosis), elevated potassium, and elevated muscle enzymes (elevated CPK). The urine will become cola-colored (colored by myoglobin in the urine).

The emergency treatment for MH:

  1. Notify the surgeon. Stop the surgery as soon as possible.
  2. Call for help from all available MDs and RNs in the vicinity.
  3. Stop the triggering anesthetic drug(s).
  4. Administer dantrolene. Dantrolene is a specific inhibitor of the MH cascade within the muscle cells. All anesthetizing locations are required to have a supply of dantrolene on site. The drug is manufactured in a powdered form, and must be mixed with sterile water to form an injectable solution. Large doses of dantrolene (2.5 mg/kg, which is 8 vials of dantrolene powder for an average-sized man) must be given IV as soon as possible. Doses may be repeated as needed, for a total dose up to 30 mg/kg if necessary.
  5. Administer sodium bicarbonate IV to buffer acidosis.
  6. Cool the patient. This can be done by applying bags of cold fluid to the skin surface, administering cold IV fluids, or by immersion of the body into an ice bath if available.
  7. Treat abnormal heart rhythms with appropriate IV cardiac drugs.
  8. Treat elevated potassium levels with hyperventilation, and empiric administration of calcium chloride, insulin, and glucose IV.
  9. Draw blood tests for electrolyte levels/arterial blood gas determinations, insert a catheter into the bladder to monitor urine output, and insert a catheter into the radial artery at the wrist to monitor blood pressure and for intravascular access for rechecking the levels of acidosis and potassium in the blood.
  10. Prepare for transfer to an intensive care unit.

If a family member of yours died during anesthesia and you don’t know if they died because of MH, your doctor may advise you to have a muscle biopsy to determine if you are MH susceptible. This biopsy of the anterior thigh muscle (quadriceps) is done under local anesthesia. You are not at risk of developing MH during local anesthesia.

If a family member of yours died during anesthesia and you don’t know if they died because of MH, and you choose not to undergo a muscle biopsy, you should wear a MedicAlert bracelet that states that you are susceptible to Malignant Hyperthermia, and all your anesthetic care should be done with trigger-free anesthetics (as listed below).

If you have a positive muscle biopsy test for MH, or if a family member of yours had well-documented MH, you should wear a MedicAlert bracelet that states you are susceptible to Malignant Hyperthermia, and all your anesthetic care should be done with trigger-free anesthetics (as listed below).

A trigger-free anesthetic includes no succinylcholine, sevoflurane, isoflurane, desflurane, or halothane. A trigger-free anesthetic includes any of the following:

  1. Local anesthesia, with or without sedation with IV drugs such as Versed, fentanyl, or propofol.
  2. Regional anesthesia, such as spinal anesthesia, epidural anesthesia, or a regional nerve block, with or without sedation with IV drugs such as Versed, fentanyl, or propofol.
  3. A general anesthetic without succinylcholine, sevoflurane, isoflurane, or desflurane. A typical recipe would include all intravenous drugs, e.g. Versed as a premed, propofol for anesthetic induction, rocuronium for paralysis/muscle relaxation, fentanyl or remifentanil infusion for pain relief, and possibly ketamine. The gas nitrous oxide can also be used.

In the 1980’s, prior to the availability of dantrolene, the mortality from an MH episode was greater than 80%. In the 21st century, the mortality from an MH episode should be less than 5%.

For further information, I refer you to http://www.mhaus.org, the website of the Malignant Hyperthermia Association of the United States.

 

The most popular posts for laypeople on The Anesthesia Consultant include:

How Long Will It Take To Wake Up From General Anesthesia?

Why Did Take Me So Long To Wake From General Anesthesia?

Will I Have a Breathing Tube During Anesthesia?

What Are the Common Anesthesia Medications?

How Safe is Anesthesia in the 21st Century?

Will I Be Nauseated After General Anesthesia?

What Are the Anesthesia Risks For Children?

 

The most popular posts for anesthesia professionals on The Anesthesia Consultant  include:

10 Trends for the Future of Anesthesia

Should You Cancel Anesthesia for a Potassium Level of 3.6?

12 Important Things to Know as You Near the End of Your Anesthesia Training

Should You Cancel Surgery For a Blood Pressure = 178/108?

Advice For Passing the Anesthesia Oral Board Exams

What Personal Characteristics are Necessary to Become a Successful Anesthesiologist?

 

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Published in September 2017:  The second edition of THE DOCTOR AND MR. DYLAN, Dr. Novak’s debut novel, a medical-legal mystery which blends the science and practice of anesthesiology with unforgettable characters, a page-turning plot, and the legacy of Nobel Prize winner Bob Dylan.

KIRKUS REVIEW

In this debut thriller, tragedies strike an anesthesiologist as he tries to start a new life with his son.

Dr. Nico Antone, an anesthesiologist at Stanford University, is married to Alexandra, a high-powered real estate agent obsessed with money. Their son, Johnny, an 11th-grader with immense potential, struggles to get the grades he’ll need to attend an Ivy League college. After a screaming match with Alexandra, Nico moves himself and Johnny from Palo Alto, California, to his frozen childhood home of Hibbing, Minnesota. The move should help Johnny improve his grades and thus seem more attractive to universities, but Nico loves the freedom from his wife, too. Hibbing also happens to be the hometown of music icon Bob Dylan. Joining the hospital staff, Nico runs afoul of a grouchy nurse anesthetist calling himself Bobby Dylan, who plays Dylan songs twice a week in a bar called Heaven’s Door. As Nico and Johnny settle in, their lives turn around; they even start dating the gorgeous mother/daughter pair of Lena and Echo Johnson. However, when Johnny accidentally impregnates Echo, the lives of the Hibbing transplants start to implode. In true page-turner fashion, first-time novelist Novak gets started by killing soulless Alexandra, which accelerates the downfall of his underdog protagonist now accused of murder. Dialogue is pitch-perfect, and the insults hurled between Nico and his wife are as hilarious as they are hurtful: “Are you my husband, Nico? Or my dependent?” The author’s medical expertise proves central to the plot, and there are a few grisly moments, as when “dark blood percolated” from a patient’s nostrils “like coffee grounds.” Bob Dylan details add quirkiness to what might otherwise be a chilly revenge tale; we’re told, for instance, that Dylan taught “every singer with a less-than-perfect voice…how to sneer and twist off syllables.” Courtroom scenes toward the end crackle with energy, though one scene involving a snowmobile ties up a certain plot thread too neatly. By the end, Nico has rolled with a great many punches.

Nuanced characterization and crafty details help this debut soar.

Click on the image below to reach the Amazon link to The Doctor and Mr. Dylan:

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LEARN MORE ABOUT RICK NOVAK’S FICTION WRITING AT RICK NOVAK.COM BY CLICKING ON THE PICTURE BELOW:

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