The aim of this study is to determine the proportion of excellent tracheal intubation conditions at 60 seconds after administration of either rocuronium 1.0 mg/kg or suxamethonium 1 mg/kg in patients with age ≥ 80 years during rapid sequence induction.

Elderly patients are frail and susceptible to complications in the perioperative period. They are at higher risk of major morbidity and mortality and are characterized by a reduction in cardiac output, liver function and renal function. These physiological changes influence pharmacodynamics and pharmacokinetics of drugs administered during anesthesia as for example neuromuscular blocking agents (NMBA).

The number of elderly patients (>80 years) is increasing and a large proportion of these patients will require surgery and anesthesia with employment of rapid sequence induction (RSI) within the next decades. RSI and intubation is performed when there is an increased risk of pulmonary aspiration of gastric contents. Because of its fast onset time succinylcholine is often used to facilitate tracheal intubation during RSI. However, succinylcholine has certain side effects such as cardiac arrhythmia, hyperkalemia, muscle soreness, short duration of action and shorter time to desaturation.

It is therefore unknown if succinylcholine 1.0 mg/kg provides better intubating conditions compared to high dose rocuronium (1.0 mg/kg) in the elderly. In this matter, there remains a need for a study to investigate the optimal muscle relaxant during rapid sequence induction for facilitating tracheal intubation in the elderly.

Inclusion Criteria:

• Age ≥ 80
• Scheduled for surgery under general anesthesia with indication for rapid sequence induction
• American Society of Anesthesiologists physical status classification (ASA) I to IV
• Informed consent (see appendix 1)
• Body mass index (BMI) < 35 kg/m2
• Read and understand Danish

Exclusion Criteria:

• Neuromuscular disease
• Known allergy to rocuronium and/or suxamethonium
• Known hyperkalemia > 5 mM
• Previous malignant hyperthermia
• Known homozygote plasmacholinesterase gene mutation variant a or s
• Known impaired kidney function defined as estimated glomerular filtration rate (eGFR) < 30