The Surgical Apgar Score calculator evaluates postoperative risk by utilizing three critical inputs related to the patient's intraoperative status: estimated blood loss, lowest mean arterial pressure, and lowest heart rate. Each of these parameters is assigned a score based on predefined scales, which collectively determine the overall Surgical Apgar Score. The patient's responses are mapped to numerical scores as follows:

1. Estimated blood loss:
   - "> 1,000 mL" = 0
   - "601-1,000 mL" = 1
   - "101-600 mL" = 2
   - "<= 100 mL" = 3

2. Lowest mean arterial pressure:
   - "< 40 mmHg" = 0
   - "40-54 mmHg" = 1
   - "55-69 mmHg" = 2
   - ">= 70 mmHg" = 3

3. Lowest heart rate:
   - "> 85 bpm" = 0
   - "76-85 bpm" = 1
   - "66-75 bpm" = 2
   - "56-65 bpm" = 3
   - "<= 55 bpm" = 4
   - "Pathologic bradyarrhythmia or asystole" = 0

The total Surgical Apgar Score is the sum of the scores from these three parameters, with a possible range from 0 to 10. This total score provides an interpretation regarding the patient's risk of mortality and major complications or death. Here are the interpretation criteria based on score:

- A score of 0 to 2 indicates a 14% risk of mortality and a 75% risk of major complications or death.
- A score of 3 to 4 indicates a 14% risk of mortality and a 56% risk of major complications or death.
- A score of 5 to 6 indicates a 4% risk of mortality and a 16% risk of major complications or death.
- A score of 7 to 8 indicates a 1% risk of mortality and a 6% risk of major complications or death.
- A score of 9 to 10 signifies a 0% risk of mortality and a 4% risk of major complications or death.

The calculator processes the inputs by assigning scores according to the tables above, summing the scores, and then using the total to provide an interpretation of the patient's postoperative risk. The output consists of the calculated score and its corresponding interpretation.

| Input Parameter               | Options                | Score |
|-------------------------------|------------------------|-------|
| Estimated blood loss          | > 1,000 mL             | 0     |
|                               | 601-1,000 mL           | 1     |
|                               | 101-600 mL             | 2     |
|                               | <= 100 mL              | 3     |
| Lowest mean arterial pressure | < 40 mmHg              | 0     |
|                               | 40-54 mmHg             | 1     |
|                               | 55-69 mmHg             | 2     |
|                               | >= 70 mmHg             | 3     |
| Lowest heart rate             | > 85 bpm               | 0     |
|                               | 76-85 bpm              | 1     |
|                               | 66-75 bpm              | 2     |
|                               | 56-65 bpm              | 3     |
|                               | <= 55 bpm              | 4     |
|                               | Pathologic bradyarrhythmia or asystole | 0 |

The Surgical Apgar Score (SAS) is a clinical calculator used to assess the risk of postoperative complications in patients undergoing surgery. It is applicable to a wide range of surgical patients, including those undergoing general, vascular, thoracic, and orthopedic surgeries. The SAS is based on three intraoperative parameters: lowest heart rate, lowest mean arterial pressure, and estimated blood loss. The score ranges from 0 to 10, with lower scores indicating a higher risk of postoperative complications such as major morbidity or mortality. The SAS is particularly useful in guiding postoperative management and informing discussions about prognosis with patients and their families. However, it may not be applicable to patients undergoing certain types of surgery, such as cardiac or neurosurgery, where these parameters may be intentionally manipulated as part of the surgical procedure.

Surgical Apgar Score for postoperative risk (SAS score)