preoperative evaluation of a patient

PREOPERATIVE

EVALUATION

Vaishali Syal

Moderator - Prof. J. R. Thakur

Introduction

Preoperative evaluation of a patient is

necessary to ensure that patient is

asymptomatic from the anaesthetic risk

point of view before surgery by

physiological and psychological

preparation.

What is Anestheia?

Triad of

Amnesia (reversible loss of consciouness)

Analgesia (pain relief)

Areflexia (muscle relaxation)

Purpose of effective Pre op

Evaluation

to identify those few patients whose outcomes likely will be improved by implementation of a specific medical treatment (which in rare circumstances

may require that the planned surgery be rescheduled).

to identify patients whose condition is so poor that the proposed surgery might only hasten death without improving the quality of life.

Identify patients with specific characteristics that likely will influence the proposed anesthetic plan

to provide the patient with an estimate of anesthetic risk.

an opportunity for the anesthesiologist to

describe the proposed anesthetic plan in

the context of the overall surgical and

postoperative plan

Provide the patient with psychological

support

obtain informed consent for the proposed

anesthetic plan from the surgical patient.

Effective preoperative

evaluation include :-

history and physical examination

a complete account of all medications taken by

the patient in the recent past

all pertinent drug and contact allergies

responses and reactions to previous

anesthetics.

any indicated diagnostic tests, laboratory

investigations, imaging procedures, or

consultations from other physicians.

Source- Morgan and Mikhail Clinical Anesthesiology 5th edition

Elements of Pre Op History

Patients presenting for elective surgery and anesthesia

typically require a focused preoperative medical history

emphasizing :-

cardiac and pulmonary function

kidney disease, endocrine and metabolic diseases

musculoskeletal and anatomic issues relevant to

airway management and regional anesthesia, and

history of responses and reactions to previous

anesthetics/drugs.

family/personal history

Any coexisting illness

Exercise tolerance

Elements of Physical Pre op

Evaluation

measurement of vital signs (blood pressure,

heart rate, respiratory rate, and temperature)

examination of the airway, heart, lungs,

and musculoskeletal system

standard techniques of inspection,

auscultation, palpitation are used.

Breath holding time should be assessed in

every patient(normal value >25 seconds ; 15-

20seconds is considered borderline).

Proper examination of patient’s airway

Inspection of loose or chipped teeth,

caps, bridges, or dentures.

Micrognathia (a short distance between

the chin and the hyoid bone), prominent

upper incisors, a large tongue, limited

range of motion of the temporo

mandibular joint or cervical spine, or a

short or thick neck

Investigations

Routine investigations vary from hospital

to hospital, state to state and country to

country.

ECG : should be performed for every patient

aged between 40-50 years.

RFT : recommended for every patient aged

> 40 years.

Chest X-ray : done as a routine practice

Blood glucose measurement for diabetic

patient

Urine analysis

Coagulation profile for patients with suspected

coagulopathy.

By convention, physicians in many countries use the American

Society of Anesthesiologists’ (ASA) classification to define relative

risk prior to conscious sedation and surgical anesthesia

Source- Morgan and Mikhail Clinical Anesthesiology 5th edition

Cardiovascular issues

The core goals of preoperative cardiac assessment are to :

o determine the status of the patient's cardiac conditions

o to provide an estimate of risk

o to determine if further testing is warranted

o and to determine if interventions are warranted to reduce perioperative cardiac risk.

In general, the indications for cardiovascular investigations are the same in surgical patients as in any other patient.

Pulmonary issues

Cases where there is markedly increased risk of pulmonary complications :

ASA Class 3 and Class 4 patients as compared to Class 1 patients.

Cigarette smoking

Longer surgeries(>4 h)

Certain types of surgery(abdominal, thoracic, aortic aneurysm, head and neck, and emergency surgery)

General Anesthesia(compared with cases in which GA was not used)

Efforts required for prevention of pulmonary

complications

focus on cessation of cigarette smoking prior to surgery and on lung expansion techniques (eg, incentive spirometry) after surgery in patients at risk.

Patients with asthma, have a greater risk for bronchospasm during airway manipulation.

Appropriate use of analgesia and monitoring are key strategies for avoiding postoperative respiratory depression in patients with obstructive sleep apnea.

Coagulation issues

to manage patients who are taking warfarin on

a long-term basis;

to safely provide regional anesthesia to patients

who either are receiving long-term

anticoagulation therapy or who will receive

anticoagulation perioperatively.

patients deemed at high risk for thrombosis

(eg, those with certain mechanical heart valve

implants or with atrial fibrillation and a prior

thromboembolic stroke), warfarin should be

replaced by intravenous heparin or, more

commonly, by intramuscular heparinoids to

minimize the risk.

Gastro intestinal issues

the risk of aspiration is increased in

certain groups of patients :-

o pregnant women in the second and third

trimesters,

o those whose stomachs have not emptied after

a recent meal,

o and those with serious gastroesophageal

reflux disease (GERD).

Treatment of GERD :

to treat patients with consistent symptoms

(multiple times per week) with medications

(eg, nonparticulate antacids such as sodium

citrate) and techniques (eg, tracheal

intubation rather than laryngeal mask airway)

as if they were at increased risk for aspiration.

Fasting

recommendations

Ingested material

Clear liquids

Breast milk

Infant formula

Non human milk

Light meal (toast &

clear liquids)

Minimum fasting

period(in hrs)

2

4

6

6

6

Airway assessment

Predictors of difficult intubation Mallampati classification

ULBT

Measurements (IID, TMD, SMD)

Movement of the neck

Deformities

Thyromantal distance

Upright, neck extension, mouth closed,

distance < 6.5 cm is difficult intubation

Sternomantal distance

Extended head & neck, mouth closed,

distance < 12.5 cm is a difficult intubation

Movement of neck

Craniofacial deformities

Why would this patient’s

airway be difficult to manage?

Why would this patient’s

airway be difficult to manage?

Conclusion

Preoperative evaluation is scenario which utilizes vast scales anaesthesiologistsknowledge in a limited span to ensure

Increased quality of preoperative care

Reduced mortality and morbidity of surgery

Reduced cost of preoperative care

Reduced anxiety

Thank you