Chapter 76: KEARNS-SAYRE SYNDROME

YOUR PATIENT

A 10-year-old female child with Kearns-Sayre syndrome is to undergo surgery to relieve bilateral ptosis.

OVERVIEW AND PREOPERATIVE CONSIDERATIONS

Kearns-Sayre syndrome (KSS), also known as oculocraniosomatic neuromuscular disease, is a rare mitochondrial myopathy that is characterized by chronic progressive external ophthalmoplegia (CPEO), retinitis pigmentosa, and cardiac conduction abnormalities. CPEO affects the muscles that control eyelid movement and eye movement. As it progresses, these patients develop ptosis and ophthalmoplegia. Often, the muscles affected are initially unilateral, but the disease will ultimately affect patients bilaterally. Other comorbidities include cerebellar ataxia, proximal muscle weakness, deafness, diabetes, and other endocrine disorders. These patients typically have a normal early development until their preadolescent years, when the progressive neurologic issues surface.

It is critical to obtain an electrocardiogram to look for conduction delays and heart block. Cardiomyopathies have also been seen in older patients with KSS, so an echocardiogram may be helpful if symptoms warrant it. Family history may be helpful. The majority of cases of mitochondrial myopathies are not familial, but rather have an unclear pattern of inheritance. However, when cases occur across generations in a family, maternal transmission is much more frequent.

ANESTHETIC MANAGEMENT

• Always consider using local or regional anesthesia in these patients, if feasible, to avoid administering drugs systemically that may have adverse effects.

• Avoid prolonged periods of taking nothing by mouth, given that these patients are prone to lactic acidosis during times of stress. Try to schedule the case as the first case, if possible.

• Consider placing an IV prior to induction of anesthesia to avoid the use of a high-dose volatile agent for induction and its effects on cardiac conduction.

• Volatile agents have generally been used safely in patients with mitochondrial disorders.

• Propofol has been associated with profound acidosis in patients with mitochondrial diseases and should be avoided.

• Avoid lactated Ringer’s for hydration, as it may increase lactic acidosis in these patients. Glucose-containing solutions have also been endorsed in patients with mitochondrial myopathy to prevent anaerobic metabolism and lactic acid production while taking nothing by mouth.

• If conduction defects exist, prepare an isoproterenol infusion and/or an external pacemaker prior to induction of anesthesia.

• Neuromuscular blockers have been shown to have no adverse sequelae in previous reports on KSS patients; however, given myopathy, it may be prudent to avoid them if they are not mandatory.

CONTROVERSIES

Volatile anesthetics have been shown to inhibit the electron transport chain in vitro; however, they have been used successfully in patients with mitochondrial disorders for many years without event.

FACTOID

The mutation ...