Pre-operative assessment in anaesthesia.pptx

Notes

1. MOUNTAINS OF THE MOON UNIVERSITY FACULTY OF HEALTH SCIENCES INDIVIDUAL COURSE WORK. NAME; BYARUHANGA MIKE Reg. no.; 2022/U/MMU/BNSD/013 TOPIC; P reoperative assessment and preparation in anesthesia

2. OVERVIEW. P reoperative assessment and preparation are crucial steps in patient care before surgery, aiming to reduce risks associated with anesthesia and the surgical procedure itself. the primary goal is to ensure the patient is in the best possible condition for a safe and effective outcome.

3. The pre-operative assessment The pre-operative assessment is an opportunity to identify co-morbidities that may lead to patient complications during the anesthetic, surgical, or post-operative period. Patients scheduled for elective procedures will generally attend a pre-operative assessment 2-4 weeks before the date of their surgery. The components are: an effective pre-operative history, examination, and routine investigations.

4. Pre-Operative History The pre-operative history follows the same structure as typical history taking, with the addition of some anesthetic and surgery specific topics.

5. History of the Presenting Complaint A brief history of why the patient first attended and what procedure they have subsequently been scheduled for. One should also confirm the side on which the procedure will be performed (if applicable) There may be aspects of the disease or condition requiring surgery that are important for the anesthetist to be aware of; for example, head and neck surgery may indicate the presence of abnormal airway anatomy.

6. Past Medical History A full past medical history is required, with the following specifically asked about; Cardiovascular disease , including hypertension; exercise tolerance is a useful indicator of cardiovascular fitness and, particularly for patients undergoing major surgery, can help predict their risk of post-operative complications and level of care needed post-operatively Respiratory disease, as adequate oxygenation and ventilation is essential in reducing the risk of acute ischemic events in the peri-operative period Questions including whether the patient is able to lie flat for a prolonged period or has a chronic cough are key as these may preclude spinal anesthesia.

7. Past Medical History… Renal disease , including their baseline renal function and any renal-specific medications Endocrine disease , specifically diabetes mellitus and thyroid disease Gastro-esophageal reflux , as the aspiration of gastric contents can potentially be fatal and the presence of GORD will likely alter anesthetic technique

8. Past Surgical History Has the patient had any previous operations? If so, what, when, and why? If the patient is having a repeat procedure, this can significantly change both the surgical time and ease of operation, and hence influence the anesthetic technique used

9. Past Anesthetic History Has the patient had anesthesia before? If so, for what operation and what type of anesthesia? Were there any problems? Did the patient experience any post-operative nausea and vomiting? Drug History A full drug history is required, as some medications require stopping or altering prior to surgery. Ask about any known allergies, both drug and non-drug allergies

10. Family History Whilst most hereditary conditions relating to anesthesia are extremely rare, such as malignant hyperthermia, it is important to ask about any known family history of problems with anesthesia Social History Ensure to ask the patient about smoking history, alcohol intake, and any recreational drug use Other important social factors to make note of include: Language spoken and the need for an interpreter. Living situation, as the absence of an adult at home may require an admission overnight

11. Pre-Operative Examination In the pre-operative examination, two distinct examinations are performed; the general examination to identify any underlying undiagnosed pathology present and the airway examination to predict the difficulty of airway management e.g. intubation. If appropriate, the area relevant to the operation can also be examined. The Mallampati score is a common tool used to classify the airway based on the visibility of the soft palate, uvula, and tonsillar pillars. This is critical for predicting potential difficulties with airway management and intubation. It involves assessing the patient's mouth opening, jaw size, neck mobility, and tongue size .

12. American Society of Anesthesiologists Grade On all anesthetic charts, a patient will be given an American Society of Anesthesiologists (ASA) grade after their pre-operative assessment, which has been subjectively assessed and based on the criteria below. A patient’s ASA grade directly correlates with their risk of post-operative complications and absolute mortality .

13. American Society of Anesthesiologists Grade… ASA Definition Absolute Mortality% Grade I Normal healthy patient 0.1 II Mild systemic disease 0.2 III Severe systemic disease 1.8 IV Severe systemic illness that is a constant threat to life 7.8 V Moribund, who is not expected to survive without the operation 9.4 E Suffix added if an emergency operation

14. Pre-Operative Investigations Full Blood Count Most patients will get a full blood count, predominantly used to assess for any anemia or thrombocytopenia, as this may require correction pre-operatively to reduce the risk of cardiovascular events or allow for preparation of blood products Urea & Electrolytes To assess the baseline renal function, which help inform fluid management and drug decisions, both for anesthesia Liver Function Tests (LFTs) Important in the assessing liver metabolism and synthesizing function, useful for peri-operative management; if there is suspicion of liver impairment, LFTs may help direct medication choice and dosing Clotting Screen Any indication of deranged coagulation, such as iatrogenic causes (e.g. warfarin), inherited coagulopathies (e.g. hemophilia A/B), or liver impairment, will need identifying and correcting or managing appropriately in the peri-operative period

15. Pre-operative investigations … Group and Save (G&S) and cross-matching Group and Save (G&S) and Cross-Match (X-match) are two tests that are slightly different in their aims: A G&S determines the patient’s blood group (ABO and RhD) and screens the blood for any atypical antibodies A G&S is recommended if blood loss is not anticipated, but blood may be required should there be greater blood loss than expected A cross-match involves physically mixing the patient’s blood with the donor’s blood, in order to see if any immune reaction takes places; if it does not, the donor blood is issued and can be transfused in to the patient, otherwise alternative blood is trialled

16. Pre-operative investigations … Cardiac Investigations An ECG is often performed in individuals with a history of cardiovascular disease or for those undergoing major surgery. It can indicate any underlying cardiac pathology and provide a baseline for comparison if there are post-operative concerns for cardiac ischemia.   Respiratory Investigations If a patient has a chronic lung condition e.g. COPD, spirometry may be of use in assessing current baseline and predicting post-operative pulmonary complications in these patients. Patients may also be referred for spirometry if there are symptoms and signs of undiagnosed pulmonary disease. Urinalysis Especially for urological procedures, a urinalysis must be performed to assess if there is any evidence or suspicion of ongoing urinary tract infection

17. Preoperative Preparation Once the assessment is complete, the patient receives instructions to prepare for surgery. This preparation is tailored to the individual and the procedure. Fasting : To prevent the aspiration of stomach contents into the lungs during anesthesia, patients are instructed not to eat or drink for a specific period before the operation. These are known as NPO (nil per os) guidelines. Solids: No solid food after midnight before surgery .   Clear Liquids: A small amount of clear liquids (water, black coffee, or clear juice) can be consumed up to a few hours before the scheduled surgery. Medication Management : Patients are given specific instructions on which medications to continue, stop, or adjust. For example, some blood thinners may need to be stopped several days before surgery to reduce the risk of bleeding.

18. Preoperative Preparation… Premedication: In some cases, patients may receive premedication to help with anxiety or to prepare them for anesthesia. This can include: Anxiolytics: Medications to reduce preoperative anxiety.  Smoking Cessation and Alcohol Intake : Patients are advised to stop smoking and avoid alcohol for a period before the procedure to improve respiratory function and reduce the risk of complications.   Informed Consent: The anesthesiologist discusses the planned anesthetic technique, including potential risks and alternatives, with the patient. The patient must give their informed consent for the anesthesia plan .

19. REFERENCES Barash, P. G., Cullen, B. F., & Stoelting, R. K. (2013). _Clinical anesthesia_. Lippincott Williams & Wilkins. (Chapter on Preoperative Evaluation)   Koch , C. G., & Li, L. (2014). Preoperative evaluation and risk management. In _Anesthesia and perioperative care_ (pp. 15-28). Springer .