How to prepare a patient for anesthesia

 

Introduction:

Preparing a patient for anesthesia is the most crucial and important thing as on the basis of this preparation we take a patient fit or not for anesthesia and so for surgery. Will discuss briefly all the requirements to prepare a patient for anesthesia.

A.   Medical history and physical examination:

In taking history from a patient always focus on about 7 types of medical histories which are briefly discussed below.

1)    History of present illness:

As its name indicates a patient should be deal according to their present illness for example if a patient has COPD then he will have difficulty for intubation so for that an anesthetist should do prepare his/her self accordingly and always remember to do awake intubation in patient with difficult airway as we might loss the airway after induction and then it will be difficult to access the airway again.

2)    History of past illness:

In the history patient should be asked about any past respiratory or cardiovascular disease by asking if he has dyspnea, Orthopnea, angina, dyspnea on exertion. Also check for any other diseases like renal, hepatic etc.

3)    Past surgical history:

In this patient should be asked about any past complications with anesthesia and surgery. Some complications are specific to anesthesia for example if there is past allergic reactions to intubation, nausea/vomiting, muscle paralysis, myalgia, sore throat etc.

4)    Family history:

Some genetic factors and diseases effect the anesthesia management also. For example myasthenia gravis, abnormality related with anti-cholinesterase, hemoglonopathies etc.

5)    Drug history:

Complete drug history like if a patient is taking anti-hypertensive i.e beta blockers etc. and they shouldn’t be stopped abruptly as complications can occur during anesthesia like the hypotensive effect can be potentiated. Also should look for drug abused users and regional anesthesia is given to them. Antihypertensive should be continued until the morning of the surgery with exception of renin angiotensin inhibitors which can be continued and not to be given on the day of surgery and can be resuming post-operatively.

6)    History of allergy:

Patient should be asked for allergy history if any like allergy due to food, drugs or due to past intubation mean previous anesthetic procedures and should be the exact signs and symptoms and causes of the allergy.

7)    History of addiction:

Patient should be asked for smoking addiction as  Long term effect of Smoking include cardiovascular disease, coronary and cerebral, chronic bronchitis and lung cancer  patient should also be asked for alcohol addiction as it can cause liver diseases like liver cirrhosis and other complications.

8)    History of pregnancy:

In case of female patients must asked about last menstrual cycle and gestation because in elective surgery should perform after the delivery.

9)    History of OSA:

Patients who is having obstructive sleep apnea has greater risk of airway obstruction and have difficult airway according to the current recommendations careful observation should be done postoperatively

The gold standard method for diagnosis is polysomnograpy. And STOP BANG questionnaire should be done
if yes to >3 questions then its having higher risk OSA

Yes to<3 questions then its having low risk for OSA

S (snorer) T(tired) O(observed) P(blood pressure) B(BMI) A(age= above 50years)  N(neck) G (gender)

B.    NBM/NPO status:

Preoperatively the patient should be instructed to have fast before surgery so as to avoid the complications of aspiration, that’s why the solid food should be stopped at least 6 hours before surgery and liquid food should 2 hours before surgery.

C.     Physical examination:

About physical examination I mean we should examine vital signs which are pulse, respiration, blood pressure, body temperature and most important all should be documented.

Look out for general appearance like body weight, weakness and nutritional balance etc.

Examine the airway which is the most important thing for preparing a patient for anesthesia as its too difficult to maintain saturation at difficult airway s  by doing the following tests we can examine airway and then accordingly we should manage it.

1)    Delikan test

2)    Upper lip/bite test

3)    Inter incisors gap distance

4)    Patils test/thyromental distance

5)    Sternomental/savva test (single best difficult laryngoscopy predictor)

6)    Calder test

7)    Malampati classification

8)    Cormack and lehane classification

9)    Palm print test

10) Lemon trial test

 Note: if you want the details of all the above tests just click here and you will have comprehensive detail with pictures of these tests

D.   Lab Investigations:

The investigations should be done according to the patient condition and procedure or surgery performing. All tests should be done only if the results improve patient information treatment and outcomes.

In 2002 the ASA developed some guidelines for surgeries requiring investigations’ and risks for heart complication.

Also some grading system has been developed too as shown below

Grade1 (minor surgeries)

Grade2 (intermediate)

Grade3 (major surgeries)

Grad4 (major plus)

American society of anesthesiology guidelines for investigations before anesthesia/surgery

1)    A healthy patient of any age doing a minimally invasive or low risk  surgery don’t need any lab investigations though it’s an exception to those who doing contrast MRI and CT for which creatinine level must be examine.

2)    Patients who are doing intermediate risk surgeries, they are healthy and have age less than 65 years they are considered to have no lab investigations. But here is an exception too if a patient has age greater than 64 and having some co diseases then chemistry panel is required.

3)    For high risk surgeries following investigations should be performed;

CBC

Chemistry panel

LFT’s

Coags study.
The former two is must.

4)    Routine pregnancy testing is NOT required for premenopausal women, BUT careful history regarding possible pregnancy is required and pregnancy test performed if indicated by history.

5)    The results of any investigations performed within 6 months are acceptable as long as the patient conditions haven’t changed significantly.

6)    Patients having respiratory diseases like COPD requires pre-operative chest x-ray

7)    Pulmonary function tests are also done for those who is having respiratory problems like COPD, orthopnea etc.

8)    Urinalysis is done for those who are having UTI or doing genitourologic procedures.

E.    Informed consent:

The consent from the patient should be informed mean the patient should be told about the procedure he is going to done and about the risk and benefits of anesthesia, try to make the patient relax and reduce his anxiety.

F.    Premedications:

The following drugs should be given before the procedure/anesthesia

1)    First go for a holistic approach and meditate the patient psychologically and emotionally so that he can’t feel anxiety or stress as discussed in informed consent.

2)    Give hypnotic agents

3)    Give anxiolytics

4)    Antiemetic’s

5)    Stabilized hemodynamics by giving anticholinergic agents

6)    Analgesics

G.   Some other preop preparation:

1)    Urinary bladder should be emptied before taking patient to OR

2)    False teeth, artificial limbs, artificial eyes, contact lenses, shoes, ornaments, etc. should be taken off

3)    Wear  comfortable and loose-fitting clothing that can be easily removed and will not interfere with any monitoring devices intraoperatively

4)    Arranging of transport for the patient pre and post operatively as both pre and post care is important for the patient.

5)    Anesthetics should be checked on label base as wrong agents can cause many problems.