The period immediately following surgery and anesthesia is vulnerable, requiring close medical supervision. Anesthetic medications and surgical stress can temporarily depress normal bodily functions, particularly breathing and circulation. Healthcare providers needed a uniform, objective method to track a patient’s return to a stable condition before moving them from the recovery area. This led to the development of a standardized assessment tool used globally to ensure patient safety.
Defining the Aldrete Score and Its Clinical Goal
The Aldrete Score is a post-anesthesia recovery scoring system designed to quantify a patient’s physical readiness for discharge from the Post-Anesthesia Care Unit (PACU). Its primary goal is to provide a clear, objective measure that determines when a patient has recovered sufficiently to be safely transferred to a less intensive setting. The score was originally devised in 1970 by Mexican anesthesiologist Dr. Jorge Aldrete.
The original scale used five criteria, including a subjective assessment of skin color. Modern practice relies on the Modified Aldrete Score (MAS), introduced in 1995 to incorporate more objective technology. The MAS replaces the subjective “color” criterion with a measurement from a pulse oximeter, making the assessment more accurate and reliable for evaluating recovery status. This modification helps reduce the risk of complications being missed before transfer.
The Five Measured Physiological Criteria
The Modified Aldrete Score evaluates five specific physiological parameters. Each category is assigned a score of 0, 1, or 2 points, resulting in a maximum total score of 10. These parameters focus on the patient’s neurological, respiratory, and circulatory functions, which are the most likely to be affected by anesthesia.
Consciousness
This criterion assesses the patient’s level of wakefulness and orientation. A score of 2 points is assigned if the patient is fully awake and oriented. If the patient responds to verbal commands only, 1 point is given. If the patient is unresponsive to any stimuli, they receive 0 points.
Activity
Activity measures the patient’s voluntary muscle function, indicating the reversal of any neuromuscular blocking drugs used during the procedure. To earn the full 2 points, the patient must be able to move all four extremities on command or voluntarily. If they can only move two extremities, they are given 1 point, and if they are unable to move any extremities, the score is 0.
Respiration
The respiration score evaluates the patient’s ability to breathe without assistance. A score of 2 points is achieved if the patient can breathe deeply and cough freely, indicating a clear and protected airway. If the patient exhibits shallow or limited breathing, or requires assistance to maintain their airway, they receive 1 point. If the patient is apneic (not breathing), they are scored 0.
Circulation
Circulation is assessed by monitoring the patient’s blood pressure against their pre-anesthetic baseline levels. A full score of 2 points is given if the patient’s blood pressure is within 20% of their documented pre-anesthetic value. If the blood pressure differs by 20% to 49% from the baseline, 1 point is assigned. Any deviation of 50% or more from the baseline blood pressure results in a score of 0 points.
Oxygen Saturation
This parameter uses pulse oximetry to measure the percentage of hemoglobin carrying oxygen in the blood. A patient receives 2 points if their oxygen saturation (SpO2) is 92% or greater while breathing room air. If the SpO2 is below 92% but can be maintained at or above this level with supplemental oxygen, 1 point is awarded. A score of 0 is given if the saturation remains below 92%, even with supplemental oxygen.
Scoring and Determining Post-Anesthesia Recovery
The final Aldrete Score is the summation of the five criteria, providing a total score between 0 and 10. This number serves as the primary data point for clinicians to make decisions about the patient’s next phase of care. Generally, a patient is considered ready for discharge from the PACU once they achieve a total score of 9 or 10.
A score of 8 or lower indicates the patient requires continued close observation and monitoring in the recovery unit. The score is typically checked and documented at regular intervals (often every 5 to 15 minutes) to track the physiological trend. Demonstrating a consistently improving score over time is more informative than a single snapshot reading. This systematic approach ensures recovery is stable before the patient is moved to an area with less intensive nursing supervision.