From the Guidelines
The recommended dosage of succinylcholine for rapid sequence intubation (RSI) in adult patients is 1-2 mg/kg administered intravenously as a single bolus. This dosage is based on the most recent and highest quality study available, which was published in 2023 1. For an average adult, this typically translates to about 70-100 mg total dose. Onset of action is extremely rapid (30-60 seconds), with complete paralysis typically achieved within 1 minute, and the duration of action is short (4-6 minutes). Succinylcholine should be administered after a sedative agent (such as etomidate, propofol, or ketamine) to prevent awareness during paralysis. Prior to administration, ensure the patient has no contraindications such as hyperkalemia, personal or family history of malignant hyperthermia, neuromuscular disorders, or penetrating eye injuries.
The choice of succinylcholine as the first-line agent for RSI is supported by several studies, including a guideline published in 2017 1, which recommends succinylcholine as the first-line agent for RSI in patients with vital signs of distress. However, the 2023 study 1 provides more recent and relevant guidance on the dosage of succinylcholine for RSI. The rapid onset of succinylcholine is due to its mechanism as a depolarizing neuromuscular blocking agent that binds to acetylcholine receptors at the neuromuscular junction, causing initial depolarization followed by paralysis. The short duration results from rapid hydrolysis by plasma pseudocholinesterase. Common side effects include fasciculations, myalgia, increased intraocular pressure, and transient hyperkalemia (0.5-1.0 mEq/L rise), which is usually clinically insignificant in patients without underlying potassium abnormalities.
Some key points to consider when using succinylcholine for RSI include:
- Ensuring the patient has no contraindications to succinylcholine
- Administering succinylcholine after a sedative agent to prevent awareness during paralysis
- Monitoring for common side effects such as fasciculations, myalgia, and increased intraocular pressure
- Being aware of the potential for transient hyperkalemia and taking steps to mitigate this risk if necessary.
From the FDA Drug Label
The average dose required to produce neuromuscular blockade and to facilitate tracheal intubation is 0.6 mg/kg Succinylcholine Chloride Injection given intravenously. The optimum dose will vary among individuals and may be from 0.3 to 1.1 mg/kg for adults.
The recommended dosage of succinylcholine for Rapid Sequence Intubation (RSI) in adult patients is 0.6 mg/kg given intravenously, with an optimum dose ranging from 0.3 to 1.1 mg/kg 2.
From the Research
Recommended Dosage of Succinylcholine for Rapid Sequence Intubation (RSI) in Adult Patients
- The recommended dosage of succinylcholine for RSI in adult patients is typically in the range of 0.9-1.2 mg/kg 3 or 1 mg/kg 4, 5.
- However, a study found that a dose of 0.45 mg/kg provides an optimal intubation condition in ASA III & IV emergency non-prepared patients 6.
- Another study compared the effect of 0.6 mg/kg, 0.45 mg/kg, and 1 mg/kg of succinylcholine on intubation conditions and found that increasing the succinylcholine dosage shortened the onset time, prolonged the duration of action, and prolonged the duration of abdominal fasciculation significantly 6.
- The choice of dosage may depend on the specific clinical situation and the patient's individual characteristics.
Comparison with Other Muscle Relaxants
- Rocuronium has been compared to succinylcholine in several studies, with some finding that rocuronium may be a suitable alternative to succinylcholine for RSI 3, 5, 7.
- However, another study found that rocuronium failed to demonstrate noninferiority with regard to first-attempt intubation success rate compared to succinylcholine 4.
Clinical Considerations
- The dosage of succinylcholine should be carefully considered in each individual patient, taking into account factors such as the patient's weight, medical history, and the specific clinical situation.
- The use of succinylcholine should be balanced against the potential risks and benefits, including the risk of adverse events such as hypoxemia and hypotension 4, 7.