Volatile Gases

Authors: Billy Sun Reviewers: Joseph Tropiano Melinda Davis, MD
Volatile Gases e.g. desflurane, sevoflurane, isoflurane
Abbreviations GABA — Gamma-aminobutyric acid CNS — Central nervous system NDNMB — Non-depolarizing neuromuscular blocking agents
Quick Facts 1° Indication = Facilitates induction and maintenance of general anesthesia
Route of Administration = Inhalation
Metabolism & Excretion = Minimal metabolism, excretion by exhalation
Legend: Pathophysiology Mechanism
Potentially interacts with GABA activated chloride channels to induce hyperpolarization and CNS depression
Potentially inhibits excitatory presynaptic channel activity mediated by neuronal nicotinic, serotonergic, and glutaminergic receptors
Loss of Consciousness
Potentially interacts with two-pore domain potassium channels to alter resting membrane potential of neurons
Specific mechanism of action unclear
CNS 4, Cerebral metabolic rate 4, Cerebral oxygen consumption
Sign/Symptom/Lab Finding
Cardiovascular 4, Systemic vascular resistance Hypotension Tachycardia Prolong QT interval (esp. sevoflurane)
Respiratory 4, Hypoxic and hypercapnic respiratory drive 4, Tidal volume 4, Alveolar ventilation Hypercapnia
1 t Respiratory rate
Neuromuscular blockade and potentiation of NDNMBs
Muscle Relaxation
Malignant Hyperthermia (See Slide)
Complications I Published March 3, 2018 on www.thecalgaryguide.com
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