Evaluating the Patient Before Anesthesia

PENG ShulingSecond Affiliated HospitalSun Yat-sen University

1846 年 10 月 16日乙醚第一次用于临床麻醉

What is anesthesia?

Anesthesiology definitionThe management of procedures for rendering a patient insensible to pain and emotional stress during surgical, obstetrical, and certain medical

procedures.

The support of life functions under the stress of anesthesia and surgical manipulations.

Anesthesiology

• Clinical anesthesia

• Pain management

• First-aid and resuscitation

• Intensive care

Anesthesiology Classification

• General anesthesia: A. Inhalation anesthesia B. Intravenous anesthesia ( intramuscular )

• Regional anesthesia: spinal (subarachnoid) block epidural block (caudal block) nerve (brachial) plexus block local infiltration

Others

• Deliberate hypotension

• Deliberate hypothermia

• Acute normovolemic hemodilution

Anesthesia procedures

1. Preoperative evaluation and

premedication

2. Anesthesia induction

3. Anesthesia maintenance

4. Anesthesia termination

5. Recovery period

Why should we perform a preoperative evaluation?

Patient evaluated in PreOp Clinic

Basic effects of anesthesia on the body

• Depression on ascending reticular activating system

• Depression on medullar ( Res. and Cardiovas. center )

The purposes and procedures of the preoperative visit(evaluation)

• Establish rapport with the patient.• Obtain a history and perform a physical

examination.• Assess the risks of anesthesia and

surgery. To reduce perioperative morbidity and mortality.

• Institute preoperative management. Order investigations and prescribe premedication.

• Obtaining informed consent .

History.

• Present surgical illness, presumptive diagnosis, initial treatment, and responses.

• Coexisting medical illnesses. • Medications.• Allergies and drug reactions. • Anesthetic and surgical history.• Social history and habits. Smoking, drugs and alcohol.

The physical examination

• Vital signs: Height and weight, blood pressure, resting pulse, respirations.

• Head and neck. • Heart & lungs. • Abdomen. • Back and extremities.

• Neurologic examination.

Special investigations

• Urinalysis

• Hemoglobin, platelet and coagulation.

• Serum electrolytes and urea

• Chest X- ray and/or echocardiography

• Electrocardiography

• Respiratory function test

• Blood gas analysis

Review of systems.

• A recent history of an upper respiratory infection. Asthma and COPD.

• Cardiovascular system.

• Hepatic and renal status.

• Endocrine status.

• Neurologic status.

ASA Classification ( physical status index )

• Normal,healthy Ⅰ• Mild systemic disease Ⅱ• Severe systemic disease that limits

activity but is not incapacitating Ⅲ• Incapacitating systemic disease that is constant

threat to life Ⅳ

• Moribund; not expected to survive 24 hours with or without operation Ⅴ

Talk with the patient and family

• Anesthetic plan and Alternatives.

• Plan for postoperative pain control.

• Special IV or other manipulation.

• Risks associated with anesthesia-related procedures.

• Blood transfusion.

Drugs used for remedication

• sedatives and analgesics • Anticholinergics • Antiemetic agents • Medicine for preexisting medical

conditions

Sedation, hypnosis and amnesia , analgesia,

reducing salivation and bronchial secreton,

blocking vagal reflex

ASA guidelines for NPO status preoperatively

• Fasting for 6 hours preoperatively• No clear liquid drinking for 2 hours

preoperatively• No milk for children 4 hours

preoperatively• No meat 8 hours preoperatively

Two broad questions

• Is the patient in optimum condition for anesthesia?

• Is the patient in hi-risk in anticipated surgery or anesthesia?

Common causes for delaying surgical procedures.

• Acute upper respiratory tract infection ( common cold ).

• Existing medical disease which is not under optimum control.

• Recent ingestion of food or liquid.

Active cardiac conditions

Clinical risk factors