Desflurane

Comparative studies

In a systematic review of 25 published, randomized controlled comparisons of sevoflurane (746 patients) and desflurane (752 patients) there was no significant difference in the rates of postoperative nausea and vomiting [ ].

Cardiovascular

Desflurane increases the heart rate and reduces both mean arterial pressure and systemic vascular resistance while maintaining cardiac output [ , ]. In high concentrations it can cause transient activation of the sympathetic nervous system, predisposing to hypertension and dysrhythmias [ ].

Despite some coronary vasodilatation in dogs, there is no evidence of coronary steal in man. Desflurane may benefit elderly patients by allowing more rapid recovery from anesthesia [ ].

Cardiac arrest due to desflurane toxicity has been attributed to accidental delivery of a high concentration of desflurane due to vaporizer malfunction [ ].

• A healthy 36-year-old woman underwent anesthesia maintained with desflurane, which was delivered at 3.5% using a Tec 6 Plus Vaporizer (Datex Ohmeda, Steeton, England) via a partially closed circuit with a low flow of fresh gases (1 l/minute). Five minutes after induction, she developed hypoxia and bradycardia, rapidly followed by cardiac arrest with asystole. She was resuscitated and a chest X-ray showed pulmonary edema.

Examination of the memory of the halogenated anesthetic monitor (Viridia 24 C; Hewlett Packard, Boeblingen, Germany) showed a progressive increase in end-expiratory desflurane concentration up to 23%. There was an internal crack in the control dial, which normally regulates the control valve, but the damage did not limit the rotation of the control valve, which remained uncontrolled. The authors thought that this defect had been responsible for massive administration of desflurane in the inhalation circuit. Cardiac arrest was probably due to the negative inotropic effect of desflurane.

Duchenne’s muscular dystrophy can be associated with cardiac arrest during anesthesia, and this has been reported in a 16-year-old boy who was anesthetized with desflurane [ ].

Desflurane 6% prolonged the QT interval to over 440 ms until 30 minutes after the end of inhalational anesthesia in 20 children undergoing inguinal hernia repair, all of whom had a normal preoperative electrocardiogram [ ]. Sevoflurane 2% had no effect.

Respiratory

Desflurane is a mild respiratory irritant [ ]. Moderate to severe laryngospasm and moderate to severe coughing occurred often (50% of cases) during induction of anesthesia with desflurane in 206 children aged 1 month to 12 years; the authors concluded that the high incidence of these airway complications during induction limit the use of desflurane in children, but that anesthesia could be safely maintained with desflurane after induction with another anesthetic [ ].

The effects of 6% or 12% desflurane and 1.8% or 3.6% sevoflurane, which have markedly different pungencies, on airway reactivity have been tested in 60 patients breathing equivalent concentrations through a laryngeal mask airway [ ]. Compared with sevoflurane, desflurane titration to 12% increased heart rate, increased mean arterial blood pressure, and initiated frequent coughing (53% versus 0%) and body movements (47% versus 0%). During emergence, there was a two-fold greater incidence of coughing and a five-fold increase in breath holding with desflurane.

The effect of intravenous fentanyl given before thiopental induction on airway irritation caused by a stepwise increase in desflurane has been studied in 80 children aged 2–8 years in a double-blind, randomized, placebo-controlled study [ ]. Fentanyl reduced the incidence of airway irritation (cough 2.5% versus 43%; secretions 28% versus 83%; excitation 10% versus 83%; apnea 20% versus 65%). The mean expired desflurane concentration at which the first airway irritation symptom occurred was greater with fentanyl.

Nervous system

Increasing doses of desflurane caused no demonstrable fall in cerebral blood flow. Consequently, it can be advocated for patients undergoing neurosurgical procedures [ ].

Neuromuscular function

Depression of neuromuscular function occurred 10 minutes after the introduction of desflurane 1.3% in a 32-year-old man who had previously received midazolam, fentanyl, and thiopental for induction. On withdrawal his neuromuscular function returned to baseline [ ].