Principles of Preoperative Assessment

By:Arravindh Vivekananthan

• Elective operation should be performed under optimal condition with full physical and psychological preparation of a fully informed patient.

• Emergency operation may have to be done in less than ideal circumstances .

The four legally-relevant criterion for decision-making capacity:

1. The patient can clearly indicate his or her treatment choice.

2. The patient understands the relevant information communicated by the physician.

3. The patient acknowledges his or her medical condition, treatment options, and the likely outcomes.

4. The patient can engage in a rational discussion about the treatment option

Rationale

• Identify the patient's pre-existing medical problems• Optimize comorbidities • Confirm the appropriateness of the planned

procedure.

• Planning to minimize risk and maximize benefit. Make advance preparation and organize facilities, equipment and expertise.

• Anticipate and plan for adverse events, inform everyone concerned.

Patient AssessmentObjective : Identify and manage risks.

Team involved

History TakingPhysical Examination

Relevant InvestigationsSpecific Problems

Severe comorbidities ReferralTo quantify risk, take appropriate measures to minimize operative morbidity.

Surgery cannot be made risk free, but risks must be known so that patient can make an informed decision.

Patient Assessment

Cognitive Ability

For any patient older than age 65 without a known history of cognitive impairment or dementia, a history and cognitive assessment, are essential.

• If the patient has experienced a decline primary care physician, geriatrician, or mental health specialist.

• The cognitive assessment should be performed early in the patient evaluation because any evidence of cognitive impairment or dementia may indicate that subsequent assessment of functional status and/or medication use may be unreliable.

Chief Complaint

History of presenting complaint• S : Symptoms• O : Onset• C : Character• R : Relieving factors• A : Aggravating Factors• P : Pain• E : Hopes and Expectations

Clarify diagnosisSeverity of symptoms

Fixed Questions: Comorbidities ‘Fitness’ for surgery

Cardiovascular System

Hypertension (<160/90 mmHg), chest pain, palpitations, syncope, dyspnea, poor exercise tolerance.High perioperative risk of MI.

Respiratory System Cough, wheeze, dyspneaAsthma : regular inhalers, extra steroid cover

Endocrine Diabetes

Past Medical History

Past previous history of thrombosis;deep vein thrombosis, stroke, acute coronary syndrome.

Risk factors for thrombosis

• Age>60• BMI >30 kg/m2

• Pregnancy/puerperium• Varicose veins with phlebitis• Drugs (OCP, HRT, smoking)• Previous ICU admission, known active cancer

or on treatment• Family/ personal history of thrombosis

Past Medical History

Past Surgical/Anaesthetic History

• Nature of previous operations• Abdominal adhesion, suxamethonium apneoa,

difficult intubation,

• Any previous complications (DVT, MRSA wound infection, wound dehiscence)

Allergic History

• Anesthetic agents• Antimicrobial drugs• Skin preparation substances; iodine• Wound dressings; Elastoplast

Medication HistoryPrinciple : Continue their medication in the immediate preoperative period, exceptions are:

Diabetic medications Diet, OAD, insulin

Anticoagulant Stop 5 days before, restart 2 days after surgeryTarget INR <1.4Convert to heparin infusion

DVT, PE: TED stockings, LMWH/ factor Xa inhibitor

Antiplatelet To stop at least 10 days prior to surgery

OCP DVT, pul. Emb. Stop 6 weeks prior to surgery. Counsel on appropriate alternative contraception

Steroid Steroid dependent patients, require extra hydrocortisone injections to overcome perioperative stress

Diuretics Thiazide and loop diuretics causes hypokalemia

Social History

Smoking (quit 8 weeks> prior to surgery)

Alcohol Recreational drugs

Social support, ability to communicate

History TakingPhysical Examination

Relevant InvestigationsSpecific Problems

• General Ex.• Airway –(Intubation)• Cardiovascular Ex. (JVP,

• Respiratory Ex.• Abdominal Ex.

• CNS • Musculoskeletal Ex

• Peripheral vasculature

InvestigationsFull Blood Count • Important in all patients prior to any surgery; TRO anemia.

• Major operations (EBL>500 mL), elderly, anemia, pathology with ongoing blood loss.

• Thalassemia screening

Urea and Electrolyte • Major operations, elderly patients, with CVS, renal, endocrine diseases, anticipated significant blood loss

• In those on medication eg; diuretics, I/V fluid, nutrition therapy

Coagulation Profile • History suggestive of bleeding diathesis, liver disease, anticoagulants, antiplatelet. Family history of bleeding disorders.

Liver Function Test • Patients with jaundice, known or suspected hepatitis, cirrhosis , malignancy, portal hypertension

Urinalysis • Urine dispstick urinary infections, glycosuria. Urine FEME; if indicated.

Renal Function Test • Baseline, watch for acute renal failure.

Beta –human chorionic gonadotrophin

• This may be tested in blood or urine to confirm pregnancy.

• It is essential in all females of child bearing age with abdominal pain to exclude an ectopic pregnancy .

Hepatits/ HIV serology • Testing should be undertaken in any patient with a past history of high-risk exposure to infected body fluids, hepatitis, or disorders associated with acquired immunodeficiency syndrome.

• Patients consent must be obtained before undertaking these test.

Blood glucose and HbA1c • In patients with diabetes mellitus, endocrine problems. Evaluates control of diabetes over 3 months.

Arterial Blood Gas • For detailed assessment of some respiratory conditions, especially when improvements are achievable preoperatively.

• Also important for acid base derangement.

Electrocardiography • Patient with underlying cardiac disease /risk factors like hypertension, diabetes mellitus or past history of angina or a myocardial infarction

Chest X-Ray • Not usually required unless the patient has a significant cardiac/respiratory history; CCF,COPD, acute respiratory symptoms, risk of TB, pulmonary cancer, metastasis, effusion.

Other Investigations• Flexion and extension lateral cervical spine radiographs (RA with unstable spine)• All other radiological investigations like CT , MRI are important for case to case basis

Preoperative Assessment in Emergency Surgery

Similar principles as in elective surgery. According to ATLS.

Constraints : Time, facilities availableConsent : May not be possible in emergency setting, procedure carried our ‘in the best interests of patient’

1. Preoperative Assessment (fit? Informed consent)

2. Preoperative Assessment by Anaes, Nursing Team

Verify, mark site of surgery, medications control, shower with special disinfecting soap, NO SHAVING.OT and staff arrangement.

3. Nil-by-mouth from midnight (6 hours on solids, 2 hours on liquid)

Surgical Chemoprophylaxis

• Considered when there is significant risk of post-operative infection.

• Ideally given intravenously as soon after induction.

• Dosages.

Thank You