Modified Aldrete Score

What Is It, How It’s Calculated, and More

Author:Lahav Constantini

Editors:Alyssa Haag,Stefan Stoisavljevic, MD,Kelsey LaFayette, DNP, ARNP, FNP-C

Illustrator:Jessica Reynolds, MS

Copyeditor:Stacy M. Johnson, LMSW

What is the Modified Aldrete score?

Aldrete score, also known as Post Anesthesia Recovery Score (PAR-Score), is one of several scoring systems that aid clinicians in ensuring individuals are safely discharged from the post-anesthesia care unit (PACU) after an intervention with local, regional, or general anesthesia. The original score from 1970 is based on five criteria, including respiration, circulation, consciousness, skin color, and level of activity. Patients in the recovery PACU are assessed on each of these parameters, receiving a score from 0 to 2 according to their status. The points are then summed up to determine the individual’s readiness for discharge from the unit.

In 1995, Jorge Antonio Aldrete, the Mexican anesthesiologist who developed the score, adapted it to keep up with advancements in medical knowledge and techniques. More specifically, he incorporated pulse oximetry into the score, creating the modified Aldrete scoring, which is more commonly used today. Instead of evaluating skin coloration, measuring oxygen saturation (i.e., SpO2) has allowed a more accurate assessment of blood oxygenation.

For individuals undergoing anesthesia on an ambulatory basis (i.e., same-day surgery), additional parameters, such as pain, ambulation, urinary output, feeding, nausea, and vomiting, may be assessed and graded zero to two to assess if the individual is ready to be discharged home. 

Furthermore, to determine the recovery time and discharge of the individual, other measures or scores, such as the ‘Post Anesthetic Discharge Scoring System’ (PADSS); the individual’s comorbidities; specific signs or symptoms, like unregulated temperature; complications, such as neuromuscular, respiratory, or cardiovascular functional alterations; the individual’s discharge plan; administrative limitations; and other factors, may be considered. 

Patient lying in hospital bed with oxygen mask.

How is the Modified Aldrete score calculated?

The modified Aldrete score is measured by evaluating five criteria, including the individual’s activity level, respiration, circulation, consciousness, and oxygen saturation. A score of “0”, “1”, or “2” is given for each category, two representing the ideal condition.

The activity parameter is based on the ability to move extremities voluntarily or on command. A score of “2” is given for moving all four extremities, “1” for moving just two extremities, and “0” if the individual can’t move any of their extremities. 

For respiration, an individual is given two points when being able to breathe deeply and cough freely; one, if there’s a respiratory effort, but breathing is limited, or dyspnea is recognized, and a score of zero if they’re apneic. 

The circulation score is based on the systemic blood pressure values compared to the pre-anesthetic level. A score of “2”, “1”, or “0” is given for blood pressure that is less than 20%, 20-49%, or more than 49%, from the pre-anesthetic level.

Consciousness is a score of two for fully awake individuals, one for those arousable on calling, and zero for non-responsive patients. 

Scores are also given for the oxygen saturation value, and the method needed to achieve it. A score of two is given if an individual can maintain oxygen saturation of more than 92% on room air; a score of one is assigned if supplemental oxygen is required to maintain more than 90%; and finally, a score of zero is given if saturation is lower than 90% even with supplemental oxygen.

Finally, the scores from each index are summed up to a total score that determines the status of the individual and contributes to the decision for discharging the patient from the PACU. 

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What do the Modified Aldrete scores mean?

The total Aldrete score helps clinicians determine the readiness of individuals to be safely discharged from the PACU to a recovery area, a different hospital ward, or a home. Given the five parameters, individuals can have a total score from zero to ten. A score of nine to ten generally allows individuals to leave the PACU. A score lower than nine typically means the individual's status is suboptimal, and further monitoring and management in the PACU are required to stabilize the individual.

What are the most important facts to know about the Modified Aldrete scoring?

Aldrete score aids in determining the discharge readiness of individuals recovering from anesthesia in the post-anesthesia care unit (PACU). It considers five different elements: activity (i.e., ability to move extremities on command), respiration, circulation (i.e., blood pressure), consciousness, and oxygen saturation. A score from zero to two is given for each parameter, and the final score is calculated by adding them all together. A final score of nine or greater means that the individual is fit enough to be discharged from the PACU. Nonetheless, additional considerations are often assessed with the Aldrete score to decide whether to discharge the individual or keep them in the PACU for further management.

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Related links

Postoperative evaluation: Clinical practice
Apnea, hypoventilation, and pulmonary hypertension: Pathology review
General anesthetics

Resources for research and reference

Aldrete, J. Antonio; Kroulik, Diane (November 1970). "A Postanesthetic Recovery Score." Anesthesia & Analgesia. 49(6): 924–934. ISSN 0003-2999.

Aldrete JA. The post-anesthesia recovery score revisited. J Clin Anesth 1995; 7:89.

Glick, D. B. (n.d.). Overview of post-anesthetic care for adult patients. UpToDate. Retrieved August 14, 2022, from 

Aldrete J. A. (1995). The post-anesthesia recovery score revisited. Journal of Clinical Anesthesia, 7(1), 89–91. 

Barash, P. G. (2013). Handbook of Clinical Anesthesia. Wolters Kluwer Health/Lippincott Williams & Wilkins.