Pentobarbital

INTRODUCTION

Indications

Hypnotic agent (short-term). Preoperative sedation and other situations in which sedation is required. Treatment of seizures. Unlabeled Use: IV: Induction of coma in selected patients with cerebral ischemia and management of increased intracranial pressure (high doses).

Action

Depresses the CNS, probably by potentiating gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter. Produces all levels of CNS depression, including the sensory cortex, motor activity, and altered cerebellar function. Anticonvulsant effect due to decreased synaptic transmission and increased seizure threshold. May decrease cerebral blood flow, cerebral edema, and intracranial pressure (IV only). Therapeutic Effects: Sedation and/or induction of sleep.

Adverse Reactions/Side Effects

CNS: drowsiness, hangover, lethargy, delirium, excitation, mental depression, vertigo. Resp: respiratory depression. IV: LARYNGOSPASM, bronchospasm. CV: IV: hypotension. GI: constipation, diarrhea, nausea, vomiting. Derm: rashes, urticaria. Local: phlebitis at IV site. MS: arthralgia, myalgia, neuralgia. Misc: HYPERSENSITIVITY REACTIONS, INCLUDING ANGIOEDEMA AND SERUM SICKNESS, physical dependence, psychologic dependence.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Monitor signs of hypersensitivity reactions such as angioedema and serum sickness. Signs include laryngeal spasm and bronchospasm (tightness in the throat and chest, wheezing, cough, dyspnea) and skin reactions (rash, pruritus, urticaria, swelling in the face). Notify physician or nursing staff immediately if these reactions occur.

• Document the number, duration, and severity of seizures to help document whether this drug is effective in reducing seizure activity.

• Assess any breathing problems, and report signs of respiratory depression such as shortness of breath, reduced pulse oximetry values, cyanosis, and labored or difficult breathing. Severe respiratory depression requires emergency care.

• Assess dizziness and vertigo that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician and nursing staff, and caution the patient and family/caregivers to guard against falls and trauma.

• Monitor excitation, delirium, drowsiness, lethargy, mental depression, or symptoms resembling a “hangover.” Repeated or excessive symptoms may require change in dose or medication.

• Assess blood pressure after IV administration and compare to normal values (See Appendix F). Report low blood pressure (hypotension), especially if patient experiences dizziness or syncope.

• Assess any muscle, nerve, or joint pain to rule out neuromusculoskeletal pathology; that is, try to determine if pain is drug induced rather than caused by anatomic or neurologic problems.

• Assess injection site during and after IV administration, and report signs of phlebitis (local pain, swelling, inflammation).

Interventions

• Guard against falls and trauma (hip fractures, head injury, and so forth), especially if drowsiness, vertigo, or syncope affects gait and balance. Implement fall-prevention strategies, especially if balance is impaired (See ...