Question

CASE STUDY

Patient C is a high school senior. During the opening drive in the Friday night football game, Patient C is hit from behind. When he falls, he sustains open, comminuted fractures of his left tibia and fibula. Because he is unable to stand, an ambulance is brought onto the field to transport the young player to the hospital for evaluation.

Upon arrival at the emergency department, Patient C's leg is examined, x-rayed, and evaluated by the orthopedic surgeon on call. It is determined that prompt stabilization and cleansing of the wound would be optimal for the best possible outcome; thus, Patient C is prepared for surgery. His parents, who were at the game, arrive in the emergency department just moments after the ambulance and are available to give permission for the operative procedure. As Patient C has been medicated for pain, a history is obtained from the parents. There are no notable problems; Patient C is a healthy young man in excellent physical condition. He has not had previous operations and no previous exposure to anesthesia.

Patient C is transferred to the operating room. The anesthesiologist gives the patient a number of preoperative medications, including those to prevent PONV. The anesthesia of choice is ethrane, a volatile gas. The patient first receives succinylcholine prior to intubation, followed by the anesthetic gas. Within minutes, the anesthesiologist notes that Patient C's carbon dioxide levels are beginning to rise. Just as the surgeon is to begin, the patient sustains a cardiac arrest.

The anesthesiologist immediately stops the insufflation of the gas and begins to administer 100% oxygen. A code response is initiated by the remaining members of the operating team. The rescuer performing chest compressions notes that the patient's skin is warm. While resuscitative efforts continue, blood for laboratory evaluation is obtained. The arterial blood gas results demonstrate a pH of 6.9, partial pressure of oxygen (PaO₂) of 110 mm Hg, and a partial pressure of carbon dioxide (PaCO₂) of 55 mm Hg. At this point, the anesthesiologist's suspicions are confirmed; the patient is experiencing an episode of malignant hyperthermia.

As soon as the diagnosis is confirmed, the staff is ordered to administer dantrolene at a dose of 2 mg/kg. The operating room personnel contact the PACU to ask for assistance in drawing up and preparing the dantrolene. Only one nurse is available to leave the PACU, and she assists with mixing and administering the dantrolene as soon as it is prepared. Additionally, the patient requires repeat doses of sodium bicarbonate to combat the falling serum pH.

Within 15 minutes of administering the dantrolene, the patient begins to demonstrate a perfusing rhythm, although this is punctuated by frequent runs of premature ventricular contractions. Antiarrhythmics are administered to control the cardiac complications.

Simultaneously, the patient is cooled with external cold packs applied to the groin and axilla areas. The leg wound is dressed to prevent further contamination during the resuscitative efforts. Repeat blood is obtained for laboratory analysis. The patient's potassium is elevated, and the patient is started on a glucose-insulin drip.

After the patient's cardiac condition is stabilized, the operating room staff request transfer of the patient to the PACU for further management. The patient is moved, and the PACU staff becomes responsible for managing the patient. The antiarrhythmics, the glucose-insulin drip, and the cooling measures are continued. During the first 30 minutes in the PACU, the patient's urine is noted to be a deep red color, indicative of developing rhabdomyolysis and potential renal failure. The patient is given 100 mg furosemide, and fluids are increased to 150 mL/hour. Within 20 minutes, the urine lightens in color, although it retains a reddish tinge.

Approximately 3 hours after the first cardiac arrest, the patient suffers a second arrest with the development of ventricular fibrillation. A second code response is called, and the patient is again resuscitated with dantrolene, antiarrhythmics, and sodium bicarbonate. Once again, the patient responds to treatment and regains a perfusing cardiac rhythm.

The patient is ordered to receive dantrolene every 4 hours for the following 48 hours to ensure that another episode of malignant hyperthermia does not develop. The patient is subsequently stabilized and transferred to the ICU, where he remains for 72 hours.

Questions:

1. The patient was diagnosed with malignant hyperthermia. What is this illness and name 5 symptoms that you would look for?

2. What is dantrolene? Why is it used in this scenario? Does this medication have any side effects or risks that the nurse should be aware of?

3. If you were the charge nurse, how would you respond to the parents questions about how the surgery went?

4. The patient is started on an insulin-glucose drip in the PACU due to his high potassium levels. Why is this initiated? What should the PACU nurse monitor the patient for after this is given?

5. The patient now has blood tinged urine and has suspected rhabdomyolysis and possible renal failure. What is rhabdomyolysis? Why would he have developed kidney failure after this situation?

6. How would you respond to his parents questions about why this happened, his prognosis and his chances of developing this in the future?

Answer 1

1. The patient was diagnosed with malignant hyperthermia. What is this illness and name 5 symptoms that you would look for?

Malignant hyperthermia is the rise of body temperature as a result to a dose of anesthetics. This usually happens in individuals with some rare inherited muscular anomaly, and rarely the condition gets triggered by extreme exercise, heat stroke etc.

The people with this muscular abnormality have abnormal protein on the surface of muscle cells, which reacts on exposure to a drug, usually anesthetic type. The abnormally dangerous rise of temperature (upto 113 degree Farhenheit) and associated body changes may cause cardiac arrest. This condition may occur whenever anesthetic drugs are used in individuals with such muscular issues.

This muscular anomaly is usually the result of genetic mutation. A person with such mutated gene has 50% chance of passing the trait to his children. So always check for the family history of Malignant hyperthermia before the introduction of anesthetic medications.

Symptoms of Malignant hyperthermia:

Many people who carry the mutant gene may not present any symptoms. The symptoms usually seen in Malignant hyperthermia are:

• Dangerous rise in body temperature, sometimes as high as 113 degrees Fahrenheit
• Rigid or painful muscles, especially in the jaw.
• Flushed skin
• Sweating
• Arrhythmias (Abnormally rapid or irregular heartbeat )
• Fast breathing or uncomfortable breathing
• Brown or cola-colored urine
• Hypotension (shock)
• Confusion
• Muscular weakness

2. What is dantrolene? Why is it used in this scenario? Does this medication have any side effects or risks that the nurse should be aware of?

Dantrolene is a skeletal muscle relaxant that stops the dangerous increase of muscle metabolism. It decrease the release of Calcium from sarcoplasmic reticulum, and dissociates excitation –contraction coupling in skeletal muscles.

The common side effects for this medicine are:

• Dizziness
• Tiredness
• Nausea
• Vomiting
• Stomach pain and diarrhea
• Weakness

Also the patient may present with slurred speech, headache, vision problems, insomnia, constipation, polyuria etc.

3. If you were the charge nurse, how would you respond to the parents questions about how the surgery went?

As a nurse it is our responsibility to update the family, regarding the patient's condition. Initially the parents can be informed of the cancellation of surgery due to a serious drug reaction. The anesthetist and the surgeon can provide a detailed history of the incidents happened, and the nurse can provide psychological support to the parents.

4. The patient is started on an insulin-glucose drip in the PACU due to his high potassium levels. Why is this initiated? What should the PACU nurse monitor the patient for after this is given?

Hyperkalemia or increased serum Potassium levels beyond 5.5 meq/litre, is a life threatening condition and requires immediate and appropriate management. The best treatment is intra venous administration of 10 units of regular Insulin in 25% glucose, as the Insulin promotes shift of Potassium from the blood to the cells. This reduces the Potassium levels in the blood, preventing the lethal effects of Hyperkalemia. Dextrose is added to protect from the hypoglycemia caused by insulin.

The nurse must always monitor for signs and symptoms of hypoglycemia in a patient with glucose insulin infusion. Monitor blood glucose levels hourly in the beginning, and then continue as per the hospital policies. Keep ready dextrose 50 % to administer , in case of hypoglycemia.

5. The patient now has blood tinged urine and has suspected rhabdomyolysis and possible renal failure. What is rhabdomyolysis? Why would he have developed kidney failure after this situation?

Rhabdomyolysis is a syndrome which results from the break down or death of muscle fibers and the release of its content to blood stream. It can be the result of direct or indirect muscular injury. The classic triad of symptoms seen in Rhabdomyolysis are muscular pain in the shoulders, thighs or lower back, muscular weakness and inability to move legs and arms, and brown or dark red urine or decreased urine.

The break down waste of muscles have been in the circulatory system, and reaches the renal system for excretion, but the load of this is not excretable by kidneys, damaging the renal system leading to renal failure. This in turn increases the toxic contents of the blood and impairs the body functioning. The renal damage has to be managed immediately, and sometimes the patient need dialysis help to prevent the damage.

6. How would you respond to his parents questions about why this happened, his prognosis and his chances of developing this in the future?

The nurse can explain the condition Malignant hyperthermia and the related incidents happened. Also she can brief on the assumed reasons for this issue. since the patient has responded well to the resuscitation, and the patient is on continuous monitoring and care, the prognosis can be better and positive. If the muscular anomaly is present, the child may have chances of getting the same condition in the future too. So the history of malignant hyperthermia has to be included in his health history, and preventive measures need to be taken when he is exposed to anesthetic drugs. genetic mapping can further reveal the presence of mutated gene and can confirm the cause of the condition.