Ketamine

INTRODUCTION

Indications

Anesthesia for short-term diagnostic and surgical procedures. As induction before the use of other anesthetics. As a supplement to other anesthetics. Unlabeled Use: Provides sedation and analgesia.

Action

Blocks afferent impulses of pain perception. Suppresses spinal cord activity. Affects CNS transmitter systems. Therapeutic Effects: Anesthesia with profound analgesia, minimal respiratory depression, and minimal skeletal muscle relaxation.

Adverse Reactions/Side Effects

CNS: emergence reactions, elevated intracranial pressure. EENT: diplopia, increased intraocular pressure, nystagmus. Resp: laryngospasm, respiratory depression and apnea (rapid IV administration of large doses). CV: hypertension, tachycardia, arrhythmias, bradycardia, hypotension. GI: excessive salivation, nausea, vomiting. Derm: erythema, rash. Local: pain at injection site. MS: increased skeletal muscle tone.

PHYSICAL THERAPY IMPLICATIONS*

^*Implications refer primarily to any residual effects that occur typically within 24 hr after anesthesia.

Examination and Evaluation

• Assess respiration and notify physician immediately if patient exhibits any interruption in respiratory rate (apnea) or signs of respiratory depression, including decreased respiratory rate, confusion, bluish color of the skin and mucous membranes (cyanosis), and difficult, labored breathing (dyspnea). Monitor pulse oximetry and perform pulmonary function tests (See Appendix I) to quantify suspected changes in ventilation and respiratory function. Apnea or excessive respiratory depression requires emergency care.

• Monitor signs of laryngeal spasm, including tightness in the throat and chest, wheezing, cough, and severe shortness of breath. Notify physician or nursing staff immediately if these reactions occur.

• Assess signs of increased intracranial pressure, including decreased consciousness, headache, lethargy, seizures, and vomiting (See Appendix D). Notify physician or nursing staff immediately of these signs.

• Be alert for signs of emergence reactions, including nightmares, hallucinations, and other changes in mood and behavior. Report these signs to the physician or nursing staff.

• Assess blood pressure (BP) and compare to normal values (See Appendix F). Report changes in BP, either a problematic decrease in BP (hypotension) or a sustained increase in BP (hypertension).

• Assess heart rate, ECG, and heart sounds, especially during exercise (See Appendices G, H). Report abnormal heart rhythms or symptoms of arrhythmias, including palpitations, chest discomfort, shortness of breath, fainting, and fatigue/weakness.

• Be alert for residual muscle rigidity and increased skeletal muscle tone. Report a sustained increase in muscle tone.

• Monitor injection site for pain, swelling, and irritation. Report prolonged or excessive injection site reactions to the physician.

Interventions

• Implement breathing activities and other therapeutic exercises to encourage ventilation and help overcome any residual effects of the anesthetic.

• Because of the risk of respiratory depression, arrhythmias, and abnormal BP responses, use caution during aerobic exercise and other forms of therapeutic exercise. Assess exercise tolerance frequently ...