DESFLURANE

Method of administration Desflurane is administered by inhalation. Desflurane should only be administered by persons trained in the administration of general anaesthesia using a vaporizer specifically designed and designated for use with desflurane.

Premedication Premedication should be selected according to the needs of the individual patient taking into account that salivary secretions are stimulated. The use of anticholinergic drugs is a matter of choice for the anaesthetist.

Individualization The administration of general anaesthesia must be individualized based on the patient's response. Effects on Concomitant Therapy Opioids or benzodiazepines decrease the amount of desflurane required to produce anaesthesia.

5). If added relaxation is required, supplemental doses of muscle relaxants may be used. 5) Dosage The minimum alveolar concentration (MAC) of desflurane decreases with increasing patient age. The dose of desflurane should be adjusted accordingly.

The MAC has been determined as listed in Table 1. 0% increments every 2 to 3 breaths. Inspired concentrations of 4-11% of desflurane usually produce surgical anaesthesia in 2-4 minutes. Higher concentrations up to 15% may be used. Such concentrations of desflurane will proportionately dilute the concentration of oxygen and commencing administration of oxygen should be 30% or above.

5-1 MAC, whether the carrier gas is O2 or N2O/O2. 8 MAC or less, and in conjunction with a barbiturate induction and hyperventilation (hypocapnia) until cerebral decompression in patients with known or suspected increases in CSFP. Appropriate attention must be paid to maintain cerebral perfusion pressure.

4). During induction in adults, the overall incidence of oxyhemoglobin desaturation (SpO2 < 90%) was 6%. High concentrations of desflurane may induce upper airway adverse events. 8. 5 % may be required when administered using oxygen or oxygen enriched air.

In adults, surgical levels of anaesthesia may be sustained at a reduced concentration of desflurane when nitrous oxide is used concomitantly. Maintenance of Anaesthesia in Children Desflurane is indicated for maintenance of anaesthesia in infants and children.

2 to 10% desflurane with or without the concomitant use of nitrous oxide. Although endtidal concentrations of up to 18% desflurane have been administered for short periods of time, if high concentrations are used with nitrous oxide it is important to ensure that the inspired mixture contains a minimum of 25% oxygen.

If added relaxation is required, supplemental doses of muscle relaxants may be used. Blood Pressure and Heart Rate During Maintenance Blood pressure and heart rate should be monitored carefully during maintenance as part of the evaluation of depth of anaesthesia.

4) Dosage in Renal and Hepatic Impairment Concentrations of 1-4% desflurane in nitrous oxide/ oxygen have been used successfully in patients with chronic renal or hepatic impairment and during renal transplantation surgery. Because of minmal metabolism, a need for dose adjustment in patients with renal and hepatic impairment is not to be expected.

8. 5 % may be required when administered using oxygen or oxygen enriched air. In adults, surgical levels of anaesthesia may be sustained at a reduced concentration of desflurane when nitrous oxide is used concomitantly. Maintenance of Anaesthesia in Children Desflurane is indicated for maintenance of anaesthesia in infants and children.

2 to 10% desflurane with or without the concomitant use of nitrous oxide. Although endtidal concentrations of up to 18% desflurane have been administered for short periods of time, if high concentrations are used with nitrous oxide it is important to ensure that the inspired mixture contains a minimum of 25% oxygen.

If added relaxation is required, supplemental doses of muscle relaxants may be used. Blood Pressure and Heart Rate During Maintenance Blood pressure and heart rate should be monitored carefully during maintenance as part of the evaluation of depth of anaesthesia.

4) Dosage in Renal and Hepatic Impairment Concentrations of 1-4% desflurane in nitrous oxide/ oxygen have been used successfully in patients with chronic renal or hepatic impairment and during renal transplantation surgery. Because of minmal metabolism, a need for dose adjustment in patients with renal and hepatic impairment is not to be expected.

g. jaundice associated with fever and/or eosinophilia) after anaesthesia with a halogenated inhalational anaesthetic Desflurane is contraindicated for use as an inhalation induction agent in paediatric patients because of the frequent occurrence of cough, breath holding, apnea, laryngospasm and increased secretions.

4). 4 Special warnings and precautions for use Desflurane should only be administered by persons trained in the administration of general anaesthesia using a vaporizer specifically designed and designated for use with desflurane. Facilities for maintenance of a patent airway, artificial ventilation, oxygen enrichment and circulatory resuscitation must be immediately available.

Warnings:

Malignant Hyperthermia (MH) In susceptible individuals, potent inhalation anaesthetic agents may trigger a skeletal muscle hypermetabolic state leading to high oxygen demand and the clinical syndrome known as malignant hyperthermia.

Desflurane was shown to be a potential trigger of malignant hyperthermia. The clinical syndrome is signaled by hypercapnia, and may include muscle rigidity, tachycardia, tachypnea, cyanosis, arrhythmias, and/or unstable blood pressure.

Some of these non-specific signs may also appear during light anaesthesia: acute hypoxia, hypercapnia, and hypovolemia. Treatment of malignant hyperthermia includes discontinuation of triggering agents, administration of intravenous dantrolene sodium, and application of supportive therapy.

Renal failure may appear later, and urine flow should be monitored and sustained if possible. Desflurane should not be used in subjects known to be susceptible to MH. Fatal outcome of malignant hyperthermia has been reported with desflurane.

Perioperative Hyperkalemia Use of inhaled anaesthetic agents, has been associated with very rare increases in serum potassium levels that have resulted in cardiac arrhythmias, and death in children during the postoperative period. The condition has been described in patients with latent as well as overt neuromuscular disease, particularly Duchenne muscular dystrophy.

Use of suxamethonium has been associated with most, but not all, of these cases. These patients showed evidence of muscle damage with increased serum creatinine kinase concentration and myoglobinuria. Despite the similarity in presentation to malignant hyperthermia, none of these patients exhibited signs or symptoms of muscle rigidity or hypermetabolic state.

Prompt and vigorous treatment for hyperkalaemia and arrhythmias is recommended. Subsequent evaluation for latent neuromuscular disease is indicated. Paediatric Inhalation Induction Desflurane is not indicated for use as an inhalation induction agent in children and infants because of the frequent occurrence of cough, breath holding, apnoea, laryngospasm and increased secretions.

Use in Children with Bronchial Hyperreactivity Desflurane should be used with caution in children with asthma or a history of recent upper airway infection due to the potential for airway narrowing and increases in airway resistance.

Maintenance of Anaesthesia in Children Desflurane is not approved for maintenance of anaesthesia in non-intubated children under the age of 6 years due to an increased incidence of respiratory adverse reactions. g. coughing and laryngospasm, especially with […]

Desflurane should only be administered by persons trained in the administration of general anaesthesia using a vaporizer specifically designed and designated for use with desflurane. Facilities for maintenance of a patent airway, artificial ventilation, oxygen enrichment and circulatory resuscitation must be immediately available.

Warnings:

Malignant Hyperthermia (MH) In susceptible individuals, potent inhalation anaesthetic agents may trigger a skeletal muscle hypermetabolic state leading to high oxygen demand and the clinical syndrome known as malignant hyperthermia.

Desflurane was shown to be a potential trigger of malignant hyperthermia. The clinical syndrome is signaled by hypercapnia, and may include muscle rigidity, tachycardia, tachypnea, cyanosis, arrhythmias, and/or unstable blood pressure.

Some of these non-specific signs may also appear during light anaesthesia: acute hypoxia, hypercapnia, and hypovolemia. Treatment of malignant hyperthermia includes discontinuation of triggering agents, administration of intravenous dantrolene sodium, and application of supportive therapy.

Renal failure may appear later, and urine flow should be monitored and sustained if possible. Desflurane should not be used in subjects known to be susceptible to MH. Fatal outcome of malignant hyperthermia has been reported with desflurane.

Perioperative Hyperkalemia Use of inhaled anaesthetic agents, has been associated with very rare increases in serum potassium levels that have resulted in cardiac arrhythmias, and death in children during the postoperative period. The condition has been described in patients with latent as well as overt neuromuscular disease, particularly Duchenne muscular dystrophy.

Use of suxamethonium has been associated with most, but not all, of these cases. These patients showed evidence of muscle damage with increased serum creatinine kinase concentration and myoglobinuria. Despite the similarity in presentation to malignant hyperthermia, none of these patients exhibited signs or symptoms of muscle rigidity or hypermetabolic state.

Prompt and vigorous treatment for hyperkalaemia and arrhythmias is recommended. Subsequent evaluation for latent neuromuscular disease is indicated. Paediatric Inhalation Induction Desflurane is not indicated for use as an inhalation induction agent in children and infants because of the frequent occurrence of cough, breath holding, apnoea, laryngospasm and increased secretions.

Use in Children with Bronchial Hyperreactivity Desflurane should be used with caution in children with asthma or a history of recent upper airway infection due to the potential for airway narrowing and increases in airway resistance.

Maintenance of Anaesthesia in Children Desflurane is not approved for maintenance of anaesthesia in non-intubated children under the age of 6 years due to an increased incidence of respiratory adverse reactions. g. coughing and laryngospasm, especially with removal of the LMA under deep anaesthesia.

Obstetrics Due to the limited number of patients studied, the safety of desflurane has not been established for use in obstetric procedures. Desflurane is a uterine-relaxant and reduces the uterine-placental blood-flow. 8). g. patients with congenital or acquired Long QT Syndrome, hypokalemia, congestive heart failure or patients taking drugs that can prolong with QT interval).

Precautions:

With the use of halogenated anaesthetics, disruption of hepatic function, icterus and fatal liver necrosis have been reported: such reactions appear to indicate hypersensitivity. As with other halogenated anaesthetic agents, desflurane may cause sensitivity hepatitis in patients who have been sensitized by previous exposure to halogenated anaesthetics.

Cirrhosis, viral hepatitis or other pre-existing hepatic disease may be a reason to select an anaesthetic other than a halogenated anaesthetic. Desflurane, as other volatile anaesthetics, may produce a dose-dependent increase in cerebrospinal fluid pressure (CSFP) when administered to patients with space occupying lesions.

8 MAC or less, and in conjunction with a barbiturate induction and hyperventilation (hypocapnia) until cerebral decompression in patients with known or suspected increases in CSFP. Appropriate attention must be paid to maintain cerebral perfusion pressure.

In patients with coronary artery diseases, maintenance of normal hemodynamics is important to avoid myocardial ischemia. Marked increases in pulse rate, mean arterial pressure and levels of epinephrine and norepinephrine are associated with a rapid increase in desflurane concentrations.

Desflurane should not be used as the sole agent for anaesthetic induction in patients at risk of coronary artery disease or in patients where increases in the heart rate or blood pressure are undesirable. It should be used with other medications, preferably intravenous opioids and hypnotics.

During maintenance of anaesthesia, increases in heart rate and blood pressure occurring after rapid incremental increases in end-tidal concentration of desflurane may not represent inadequate anaesthesia. The changes due to sympathetic activation resolve in approximately 4 minutes.

Increases in heart rate and blood pressure occurring before or in the absence of a rapid increase in desflurane concentration may be interpreted as light anaesthesia. Hypotension and respiratory depression increase as anaesthesia is deepened.

Use of desflurane in […]

g. jaundice associated with fever and/or eosinophilia) after anaesthesia with a halogenated inhalational anaesthetic Desflurane is contraindicated for use as an inhalation induction agent in paediatric patients because of the frequent occurrence of cough, breath holding, apnea, laryngospasm and increased secretions.

4).