1. What is the METs Equation for Surgery?

The METs (Metabolic Equivalents) equation for surgery estimates the metabolic cost of surgical procedures based on their duration. It helps in assessing the physiological stress of different surgical interventions.

2. How Does the Calculator Work?

The calculator uses the METs equation:

Where:

• \( T \) — Time in minutes

Explanation: The equation provides a cubic relationship between surgical duration and metabolic demand, accounting for the increasing physiological stress with longer procedures.

3. Importance of METs Calculation

Details: METs calculation helps in preoperative risk assessment, especially for patients with cardiovascular conditions. Higher METs values indicate greater physiological stress.

4. Using the Calculator

Tips: Enter the duration of the surgical procedure in minutes. The calculator will estimate the metabolic equivalent of the procedure.

5. Frequently Asked Questions (FAQ)

Q1: What is a MET in physiology?
A: One MET is defined as the amount of oxygen consumed while sitting at rest and is equal to 3.5 ml O₂ per kg body weight per minute.

Q2: How are METs used in preoperative assessment?
A: Patients who can tolerate >4 METs generally have lower perioperative cardiovascular risk. Procedures >10 METs are considered high risk.

Q3: What factors affect METs during surgery?
A: Procedure type, duration, blood loss, patient positioning, and temperature management all influence the metabolic demand.

Q4: Are there limitations to this equation?
A: The equation provides an estimate and doesn't account for individual patient factors or specific surgical techniques.

Q5: How does this compare to other METs calculations?
A: This is specific to surgical stress. Other METs calculations exist for different activities (walking, climbing stairs, etc.).