preoperative evaluation of a patient
TRANSCRIPT
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