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Calcimator

Rapid Sequence Intubation Calculator

RSI drug dosing for induction agents, paralytics, and pretreatment with ET tube sizing.

Inputs

Results

Induction Dose (mg)

21

Paralytic Dose (mg)

105

Lidocaine Pretreatment (mg)105
Fentanyl Pretreatment (mcg)140
ET Tube Size (mm ID)7.5
Tube Depth at Lip (cm)22.5
Agent Selected (1=Etom, 2=Ket, 3=Prop)1
How to Use This Calculator
  1. Enter Patient Weight (kg) and Age (years).
  2. Select the Induction Agent (Etomidate, Ketamine, or Propofol) based on hemodynamic status.
  3. Select Paralytic (Succinylcholine or Rocuronium) — use rocuronium if succinylcholine is contraindicated.
  4. Review Induction Dose (mg), Paralytic Dose (mg), Lidocaine Pretreatment, and Fentanyl Pretreatment doses.
  5. Confirm ET Tube Size (mm ID) and Tube Depth at Lip (cm) before intubation attempt.

How the result changes with Patient Weight (kg)

Patient Weight (kg)Induction Dose (mg)Paralytic Dose (mg)
319.346.5
10631.8159
19558.5292.5
27081405

What each input means

Patient Weight (kg)
Patient weight in kilograms.
Patient Age (years)
Age in years. Used for ET tube sizing.
Induction Agent (1=Etomidate, 2=Ketamine, 3=Propofol)
1 = Etomidate 0.3 mg/kg, 2 = Ketamine 1.5 mg/kg, 3 = Propofol 1.5 mg/kg.
Paralytic Agent
Select paralytic agent for RSI.

What each result means

Induction Dose (mg)
Weight-based induction agent dose.
Paralytic Dose (mg)
Weight-based neuromuscular blocking agent dose.
Lidocaine Pretreatment (mg)
1.5 mg/kg IV, given 3 min before induction (optional).
Fentanyl Pretreatment (mcg)
2 mcg/kg IV, given 3 min before induction (optional).
ET Tube Size (mm ID)
Cuffed tube size. Age-based for pediatrics, standard for adults.
Tube Depth at Lip (cm)
Estimated insertion depth (3 × tube size for age ≥ 2).
Agent Selected (1=Etom, 2=Ket, 3=Prop)
Echo of selected induction agent for reference.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Patient Weight (kg) = 70, Patient Age (years) = 30, Induction Agent (1=Etomidate, 2=Ketamine, 3=Propofol) = 1, Paralytic Agent = 1 = 4 input(s) provided
  2. Calculate Induction Dose
    21 = 21
  3. Calculate Paralytic Dose
    105 = 105
  4. Calculate Lidocaine Pretreatment
    Lidocaine Pretreatment = round(weight * 1.5 * 10) / 10
    105 = 105
  5. Calculate Fentanyl Pretreatment
    Fentanyl Pretreatment = round(weight * 2 * 10) / 10
    140 = 140

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