PREOPERATIVE EVALUATION

PREOPERATIVE EVALUATION

PREANESTHESIA EVALUATION • the process of clinical assessment that precedes the delivery of anesthesia care for surgery and for non-surgical procedures

Can or should the patient’s physical or mental condition be improved before surgery? Does the patient have any health problems or use any medications that could unexpectedly influence perioperative events? Is the patient in optimal health?

GOALS of preoperative evaluation • To reduce the morbidity of surgery • To increase the quality but decrease the cost of perioperative care • To educate the patient about anesthesia, perioperative care, and pain treatments • To reduce anxiety and facilitate optimal recovery

Routine Preoperative Evaluation • History • Physical examination • Laboratory evaluation • ASA physical status classification • Obtaining informed consent • Formulation of anesthetic plan

Routine Preoperative anesthetic evaluation History Current problem Other known problems Medication history Allergies Drug intolerances Present therapy (prescription, nonprescription) Nontherapeutic (alcohol, tobacco) Illicit Previous anesthetics, surgery, and obstetric deliveries Family history Review of organ systems General Neurologic Respiratory Endocrine Cardiovascular Psychiatric Renal Orthopedic Gastrointestinal Dermatologic Hematologic Last oral intake

History Routine Preoperative anesthetic evaluation Current problem determine surgical diagnosis indications for planned surgical procedure exact nature of comtemplated surgical procedure Other known problems Medication history Allergies Drug intolerances Present therapy (prescription, nonprescription) Nontherapeutic (alcohol, tobacco) Illicit Previous anesthetics, surgery, and obstetric deliveries Family history Review of organ systems General Neurologic Respiratory Endocrine Cardiovascular Psychiatric Renal Orthopedic Gastrointestinal Dermatologic Hematologic Last oral intake

History Routine Preoperative anesthetic evaluation Current problem Other known problems Medication history Allergies Drug intolerances Present therapy (prescription, nonprescription) Nontherapeutic (alcohol, tobacco) Illicit Previous anesthetics, surgery, and obstetric deliveries Family history Review of organ systems General Neurologic Respiratory Endocrine Cardiovascular Psychiatric Renal Orthopedic Gastrointestinal Dermatologic Hematologic Last oral intake

History Routine Preoperative anesthetic evaluation Current problem Other known problems Medication history Allergies Drug intolerances Present therapy (prescription, nonprescription) Nontherapeutic (alcohol, tobacco) Illicit Previous anesthetics, surgery, and obstetric deliveries Family history Review of organ systems General Neurologic Respiratory Endocrine Cardiovascular Psychiatric Renal Orthopedic Gastrointestinal Dermatologic Hematologic Last oral intake -- risk for aspiration of stomach contents when patient is rendered unconscious by anesthetics -- ‘NPO’ for at least 6 hrs prior to elective surgery -- delayed gastric emptying time expected in pregnancy, obesity, diabetics with autonomic dysfunction

Routine Preoperative anesthetic evaluation Physical examination Vital signs Airway Heart Lungs Extremities Neurologic examination

PREOPERATIVE TESTS May be indicated for various purposes, including but not limited to: 1)discovery or identification of a disease or disorder which may affect perioperative anesthetic care 2) verification or assessment of an already known disease, disorder, medical or alternative therapy which may affect perioperative anesthetic care 3) formulation of specific plans and alternatives for perioperative anesthetic care.

Routine battery of laboratory tests vs Problem directed, selective determination of laboratory tests

Routine Tests • A test ordered in the absence of a specific clinical indication or purpose

Indicated Tests • A test that is ordered for a specific clinical indication or purpose

ASA Practice Advisory for Preanesthesia Evaluation • A Report by the American Society of Anesthesiologists Task Force on Preanesthesia Evaluation

PRACTICE ADVISORIES • Systematically developed reports that are intended to assist decision-making in areas of patient care where scientific evidence is insufficient to develop an evidence-based model

PRACTICE ADVISORIES • In contrast to STANDARDS or GUIDELINES,practice advisories are not supported by sufficient numbers of controlled studies. • They may be adopted, modified or rejected according to clinical needs and constraints

ELECTROCARDIOGRAM • ECG abnormalities may be higher in older patients and in patients with multiple cardiac risk factors • No consensus regarding a minimum age for obtaining a preanesthesia ECG

ELECTROCARDIOGRAM • Important clinical characteristics that may warrant preop ECG: cardiocirculatory disease respiratory disease type or invasiveness of surgery

AMERICAN HEART ASSOCIATION/AMERICAN COLLEGE OF CARDIOLOGY • GUIDELINES FOR ELECTROCARDIOGRAPHY: ECG abnormalities rise exponentially with age. Patients who have no apparent heart disease but are older than 40 should have a preop ECG.

Preanesthesia Cardiac Evaluation Other than an ECG • Stress test, Echocardiogram, Radionucleotide imaging, cardiac catheterization Clinical characteristics to consider: cardiovascular risk factors type of surgery

Chest X-ray • Clinical chracteristics to consider: smoking recent URTI COPD cardiac disease

Preanesthesia Pulmonary Evaluation (other than X-ray) • Pulmonary function tests, spirometry, pulse oximetry, arterial blood gas Clinical considerations: type and invasiveness of the sx procedure interval from prior evaluation treated or symptomatic asthma symptomatic COPD scoliosis with restrictive function

IS THERE AN OPTIMAL PREOPERATIVE Hb/Hct? • 10g/dl rule??? There are no randomized prospective studies defining a specific minimum Hb conc as a risk factor for anesthesia and surgery. Came from older, anecdotal case series andn cohort studies

Preanesthesia Hemoglobin and Hematocrit • ROUTINE Hb, Hct is not advisable • Clinical considerations: type and invasiveness of sx procedure liver disease extremes of age history of anemia, bleeding, other hematologic disorders

Clinical considerations for preop Hb determination • Patients with significant cardiac and pulmonary disease will have a limited tolerance for perioperative anemia. • The decision for perioperative transfusion should be based on preop Hb conc, anticipated blood loss, and cardiorespiratory status

Preanesthesia Coagulation Studies • INR, PT, PTT, Platelets • Clinical considerations: bleeding disorders renal dysfunction liver dysfunction type and invasiveness of procedure

Routine coagulation tests prior to regional anesthesia? • The Task Force believes that there is not enough data to comment on the advisability of coagulation tests before regional anesthesia.

PreanesthesiaSerum Chemistries • Serum electrolytes, glucose, renal and liver function tests • Clinical considerations: perioperative therapies endocrine disorders risk of renal and liver dysfunction use of certain medications or alternative therapies

Preanesthesia Urinalysis • It is not indicated except for specific procedures (e.g. prosthesis implantation, urologic procedures) and when urinary tract symptoms are present

PreanesthesiaPregnancy Testing • Because history and PE may be insufficient for identification of early pregnancy, pregnancy testing must be OFFERED but not required for all females of childbearing age

SHOULD ALL ANTIHYPERTENSIVE AGENTS BE CONTINUED BEFORE SURGERY • BETA BLOCKERS and CLONIDINE: sequelae of abrupt discontinuation: withdrawal syndrome: rebound hpn advantage of continuation: cardiovascular risk reduction recommendation: continue

SHOULD ALL ANTIHYPERTENSIVE AGENTS BE CONTINUED BEFORE SURGERY • Calcium channel blockers: no withdrawal sequelae cardiovascular risk reduction perioperatively recommendation: continue

SHOULD ALL ANTIHYPERTENSIVE AGENTS BE CONTINUED BEFORE SURGERY • ACE inhibitors increased risk of intraoperative hypotension recommendation: discontinue at least 10 hrs before anesthesia and surgery

Preoperative physical status classification of patients according to the American Society of Anesthesiologists

Informed consent Preoperative visit culminates in giving the patient a reasonable explanation of the options available for anesthetic management

Informed consent written consent is advisable for medicolegal purposes any procedure performed without patient’s consent physician liable for assault and battery

How much of the risks should we tell? Only those that are realistic risks in similar patients with similar problems It is advisable to inform the patient that some complications may be life threatening

The anesthetic plan Premedication Type of anesthesia General Airway management Induction Maintenance Muscle relaxation Local or regional anesthesia Technique Agents Monitored anesthesia care Supplemental oxygen Sedation Intraoperative management Monitoring Positioning Fluid management Special techniques Postoperative management Pain control Intensive care Postoperative ventilation Hemodynamic monitoring

Good day!

PREOPERATIVE EVALUATION