Screening and diagnosis

Classification and risk stratification

Perioperative care

Quality improvement

Patient education

Nonpharmacologic interventions

Therapeutic procedures

Respiratory support

Follow-up and surveillance

Specific circumstances

Preventative measures

Medical management

Surgical interventions

Inpatient care

Diagnostic procedures

Diagnostic investigations

Insufficient evidence to make a recommendation.

Strongly favor this test or intervention.

The American Society of Anesthesiologists (ASA) classification system is a tool used to assess a patient's preoperative condition in terms of systemic health. This system helps determine the associated risk with anesthesia and surgical procedures by categorizing patients into different classes based on their health status and the urgency of the surgery.

To use the ASA score calculator, follow these steps:

1. **Select the patient's health description** from one of the following options:
   - Absence of systemic disease
   - Mild systemic disease without functional limitations
   - Moderate systemic disease with functional limitations
   - Severe systemic disease that is a constant threat to life
   - A moribund patient who is not expected to survive without the operation
   - Brain-dead patient whose organs are being removed for donor purposes

2. **Indicate if the surgery is an emergency** by choosing either "No" or "Yes".

These selections align the patient with a specific ASA score:

- **ASA 1**: For patients with an absence of systemic disease undergoing non-emergency surgery.
- **ASA 1E**: Same condition as ASA 1 but involving emergency surgery.
- **ASA 2**: For patients with mild systemic disease without functional limitations and no emergency surgery.
- **ASA 2E**: Mild systemic disease with an emergency condition.
- **ASA 3**: Those with moderate systemic disease with functional limitations, non-emergency surgery.
- **ASA 3E**: Same health condition as ASA 3, with the need for emergency surgery.
- **ASA 4**: Individuals with severe systemic disease posing a constant threat to life, non-emergency surgery.
- **ASA 4E**: When the same severe health condition requires emergency surgery.
- **ASA 5**: For patients who are moribund and not expected to survive without the operation, non-emergency context.
- **ASA 5E**: Similar dire condition of ASA 5, requiring emergency surgery.
- **ASA 6**: Reserved for brain-dead patients whose organs are being removed for donor purposes, non-emergency.
- **ASA 6E**: Organ donation from brain-dead patients in an emergency context.

Through this classification, the ASA score provides a numeric and alphanumeric representation, from ASA 1 (healthiest) to ASA 6 (least viable). Scores suffixed with 'E' indicate emergency surgical procedures. This system assists medical professionals in understanding the patient's health risks and guides decisions before surgery.

The American Society of Anesthesiologists score (ASA score) is a preoperative assessment tool used to evaluate a patient's overall health status prior to undergoing anesthesia for surgery. It is applicable to all patients who are scheduled for surgery, regardless of their age or type of surgery. 

The ASA score is used to predict perioperative risks and potential complications, helping clinicians to plan appropriate anesthetic management and postoperative care. It ranges from ASA I (a healthy patient) to ASA VI (a declared brain-dead patient whose organs are being removed for donor purposes). 

There are no specific exclusion criteria for the ASA score, but it should be noted that it is a subjective assessment and may vary between clinicians. It does not take into account the type or complexity of the surgery, and it is not designed to predict long-term prognosis or survival.

American Society of Anesthesiologists score (ASA score)

The 4 'A's Test (4AT) is a straightforward and efficient tool used to screen for delirium and assess cognitive impairment. It involves evaluating four key components: alertness, cognitive orientation (AMT 4), attention, and recent changes in cognitive state. Each response is given a specific score that contributes to an overall total, which informs the interpretation of the patient's condition.

- **Alertness**: Evaluate the patient's alertness and categorize it as:
  - Normal: Score 0
  - Mild sleepiness for less than 10 seconds after waking, then normal: Score 0
  - Clearly abnormal: Score 4

- **AMT 4 (Cognitive Orientation)**: Ask the patient to state their age, date of birth, the name of the hospital or place, and the current year. Score based on the number of mistakes:
  - No mistakes: Score 0
  - 1 mistake: Score 1
  - Two or more mistakes, or if untestable: Score 2

- **Attention**: Ask the patient to list the months of the year in reverse order, starting from December:
  - Lists 7 or more months correctly: Score 0
  - Starts but lists fewer than 7 months, or refuses to start: Score 1
  - Untestable or cannot start because unwell: Score 2

- **Acute Change or Fluctuating Course**: Determine if the patient has experienced an acute change or fluctuation in mental state over the last two weeks, which persists in the last 24 hours:
  - No: Score 0
  - Yes: Score 4

Once all the responses are scored, sum these scores to get a total between 0 and 12. This total is then interpreted:

- A total score of 0 indicates that delirium or severe cognitive impairment is unlikely.
- Scores between 1 and 3 suggest possible cognitive impairment. 
- A score of 4 or higher indicates possible delirium and/or cognitive impairment.

The 4 A's Test, also known as the 4AT, is a clinical calculator used for delirium screening in patients. It is applicable to a wide range of patient populations, particularly those in acute hospital settings, intensive care units, and long-term care facilities. The 4AT is designed to quickly and accurately identify patients who may be suffering from delirium, a common and serious cognitive disorder. The test assesses four areas: alertness, AMT4 (a brief memory test), attention, and acute change or fluctuating course. The 4AT is particularly useful because it does not require any special training to administer and can be completed in under 2 minutes. There are no specific exclusion criteria for its use, making it a versatile tool for healthcare professionals.

4 'A's Test (4AT) for delirium screening

The Richmond Agitation-Sedation Scale (RASS) assigns a numerical score to a patient's level of agitation or sedation based on their behavior. The patient's behavior is assessed using predefined descriptions, and each description corresponds to a specific RASS score.

To determine the RASS score:

1. The calculator receives an input which is the patient's description based on observed behavior.
2. The available options for patient description range from combative behavior to unarousable sedation.
3. Each description is mapped to a corresponding RASS score as follows:

   | Patient Description                                                                              | RASS Score |
   |--------------------------------------------------------------------------------------------------|------------|
   | Combative: overtly combative or violent; immediate danger to staff                               | RASS +4    |
   | Very agitated: pulls on or removes tube(s) or catheter(s) or has aggressive behavior             | RASS +3    |
   | Agitated: frequent non-purposeful movement or patient-ventilator dyssynchrony                    | RASS +2    |
   | Restless: anxious or apprehensive, but movements not aggressive or vigorous                      | RASS +1    |
   | Alert and calm                                                                                   | RASS 0     |
   | Drowsy: not fully alert, but has sustained (> 10 seconds) awakening, with eye contact, to voice  | RASS -1    |
   | Light sedation: briefly (< 10 seconds) awakens with eye contact to voice                         | RASS -2    |
   | Moderate sedation: any movement (but no eye contact) to voice                                    | RASS -3    |
   | Deep sedation: no response to voice, but any movement to physical stimulation                    | RASS -4    |
   | Unarousable sedation: no response to voice or physical stimulation                               | RASS -5    |

4. For the computation process, the patient's description is checked against each possible condition. When a match is found, the corresponding RASS score is assigned..

The Richmond Agitation-Sedation Scale (RASS) is a clinical tool used primarily in intensive care units (ICUs) to assess the level of sedation and agitation in patients. It is particularly useful in monitoring the sedation status of mechanically ventilated patients, helping to guide sedation therapy and ensure optimal patient comfort without over-sedation. The RASS score ranges from -5 (indicating unarousable sedation) to +4 (indicating combative agitation). It is not applicable to patients who are not in an ICU setting or those who are not at risk of over- or under-sedation.

Richmond Agitation-Sedation Scale (RASS)

The Charlson Comorbidity Index (CCI) is a tool used to predict a patient's 10-year survival by taking into account age and various medical conditions. Each component of the index is assigned a score based on the presence or absence of specific conditions and the patient's age. These scores are then summed to produce a total CCI score, which provides an estimate of long-term survival.

- Age is scored as:
  - Less than 50 years: 0 points
  - 50 to 59 years: 1 point
  - 60 to 69 years: 2 points
  - 70 to 79 years: 3 points
  - 80 years or older: 4 points

- Medical conditions are scored as follows:
  - Myocardial infarction, congestive heart failure, peripheral vascular disease, cerebrovascular disease, dementia, chronic pulmonary disease, connective tissue disease, and ulcer disease each contribute 1 point if present.
  - Liver disease scores 0 for none, 1 for mild chronic hepatitis or cirrhosis without portal hypertension, and 3 for moderate to severe cirrhosis with or without variceal bleeding.
  - Diabetes mellitus contributes 0 points if absent, 1 point for uncomplicated diabetes, and 2 points for diabetes with end-organ damage.
  - Hemiplegia and moderate to severe chronic kidney disease each add 2 points if present.
  - Solid tumors add 0 points if absent, 2 points if localized, and 6 points if metastatic.
  - Leukemia and lymphoma each contribute 2 points if present.
  - AIDS contributes 6 points if present.

The CCI score is the sum of these individual scores and can range from 0 to 37. The total score correlates with an estimated 10-year survival probability, which is interpreted as follows:

- A score of 0 suggests an estimated 10-year survival rate of 98%.
- A score of 1 corresponds to a 96% survival rate.
- A score of 2 indicates a 90% survival rate.
- With a score of 3, the survival rate is estimated at 77%.
- A score of 4 corresponds to a survival rate of 53%.
- A score of 5 suggests a survival rate of 21%.
- Scores of 6 or higher indicate a survival probability of less than 21%.

This scoring system helps healthcare providers assess long-term mortality risk in patients with multiple comorbidities based on their health conditions and age.

The Charlson Comorbidity Index (CCI) is a clinical calculator used to predict the ten-year mortality for a patient who may have a range of comorbid conditions. Each condition is assigned a score of 1, 2, 3, or 6, depending on the risk of dying associated with each one. Conditions include heart disease, AIDS, and cancer among others. The scores are summed to provide a total score to predict mortality. 

This calculator is applicable to a wide range of patients, particularly those with multiple comorbid conditions. It is often used in research settings to control for the confounding effect of comorbidities. 

The CCI is not recommended for use in patients without any comorbid conditions, as the score would be zero and not provide any additional prognostic information. It also may not be as accurate in populations with conditions not included in the original index, or in those with very high levels of comorbidity.

Charlson Comorbidity Index (CCI)

Postoperative delirium

Haloperidol

As per AAST/GAIS/SIAARTI/WSES 2022 guidelines, 

Pharmacological prophylaxis

Nonpharmacological prevention program

Monitoring depth of anesthesia

Benzodiazepines

General principles

Preoperative risk assessment

Electroencephalogram

Dexmedetomidine

Initial assessment

Added 2024 ESICM, 2022 WSES/GAIS, 2019 SIGN, and 2015 AGS guidelines for the prevention and management of postoperative delirium


Postoperative delirium

Guidelines

Key sources