Learning objective: Surgery: Principles of surgery and peri-operative care: Flashcards
Learning objectives: Principles of surgery and perioperative care:
What is informed consent? What does valid consent involve? - list 4 features
What are the goals of the pre-operative assessment?
What acronym can be used to give informed consent in a surgical patinet? (BRABAD)
Outline a pre-operative history:
HPC, female, pmhx, surgical, medications, allergies, immunizations, social, family hx: Outline
Outline a preoperative examination: : what are two components of pre-op examination: + Airway examination: (LEMON)
What is mallampati score?
What is ASA grading? give examples:
What are pre-op investigations to consider? Minor surgery vs major surgery? Imaging and bedside tests?
Pre-operative management (OPTIMIZATION) = ADSO
Fasting?
Drugs to stop? (CHOW)
Drugs to start? (think teds, LMWH, prophylactic antibiotics) 2.5 marks (non-pharm as well)
Special considerations pre-op:
What is medical optimisation? Diabetes and surgery? Oral hypoglycemics?
IDDM? How much should you reduce it prior to surgery (INSULIN)
What use does a sliding scale have? What is it?
Respiratory optimisation?
Bowel preparation?
Other?
History of presenting complaint:
Past medical history? (think specific diseases)
Past surgical history? (whats relevant)
Past anaesthetic history?
Drug history? Family history? Social history?
The pre-operative assessment is an opportunity to identify co-morbidities that may lead to patient complications during the anaesthetic, 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.
In this article, we shall look at the components of an effective pre-operative history, examination, and routine investigations that can be performed.
Pre-Operative History
- The pre-operative history follows the same structure as typical history taking, with the addition of some anaesthetic and surgery specific topics.
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 anaesthetist to be aware of; for example, head and neck surgery may indicate the presence of abnormal airway anatomy.
Past Medical History
- A full past medical history (PMH) 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
- Screening questions may elucidate undiagnosed disease and prompt further investigation, e.g. the presence of exertional chest pain, syncopal episodes, or orthopnoea
Respiratory disease, as adequate oxygenation and ventilation is essential in reducing the risk of acute ischaemic 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 anaesthesia; also screen for symptoms and signs of obstructive sleep apnoea, if the patient has any risk factors
Renal disease, including their baseline renal function and any renal-specific medications
Endocrine disease, specifically diabetes mellitus and thyroid disease
Gastro-oeseophageal reflux (GORD), as the aspiration of gastric contents can potentially be fatal and the presence of GORD will likely alter anaesthetic technique
- Whilst this may be overlooked as a diagnosis or in their past medical history, particularly if patient managed with over-the-counter medicines, it is important to ask about at the pre-operative assessment
- Other specific questions it may be useful to ask themselves the following questions:
Pregnancy – as part of the pre-operative checklist on the day of surgery, for females of reproductive age a urinary pregnancy test is mandatory in the majority of hospitals
Sickle Cell Disease – could they have undiagnosed sickle cell disease, especially if their country of birth does not have routine screening for sickle cell
Past surgical history:
- Previous surgery?
- Previous complications? Previous abdominal surgery?
Past anaesthetic history:
- Has the patient had it any prior anesthetic? If so; what for? indication? complications? Were there any issues? Did the patient experience any post-operative nausea and vommitting?
Drug History:
- A full drug history is required, as some medications require stopping or altering prior to surgery
- Allergies
Family history:
- family hx of malignant hyperthermia? known family hx of any anaesthetic issues
Social history:
- SNAP
- recreational drugs
- occupation
- living conditions
Anticoagulants and surgery: What is bridging therapy?
What is the principle of management?
NOACs? (low risk of bleeding, high risk of bleeding?
Warfarin and surgery prinicples?
What are contraindications to mechanical prophylaxis? List 4
What are contraindications to pharmalogical anticoagulation? List 4
Anticoagulants and surgery
Principle - cannot be anti-coagulated during operation but want the shortest possible duration pre-op where they aren’t anticoagulated. Warfarin has unpredictable onset/offset of action so bridge with more reliable LMWH
NOACs
Low risk of bleeding - stop 24h prior
High risk of bleeding - stop 48h prior
WARFARINWarfarin with low risk of thrombosis
Who - low risk AF (CHADSVA 0-2), DVT >12 months ago
Stop warfarin 5 days prior to surgery + bridging not required
Measure INR day of surgery - must be <1.5 otherwise defer surgery
After surgery - start day of surgery if there is no evidence of bleeding
Employ LMWH thromboprophylaxis until INR is therapeutic
Warfarin with high risk of thrombosis (high risk AF, VTE)
- Stop warfarin 5 days prior
- Bridge with heparins - start either LMWH or UFH infusion 3 days before surgery at treatment doses
- Stop LMWH 24h before surgery and stop UFH infusion 6 hours prior to surgery
- Check INR day of surgery - must be <24h
- Start warfarin and enoxaparin again after surgery if no evidence of bleeding
- Keep enoxaparin thromboprophylaxis until warfarin in therapeutic range
Urgent surgery
- Check INR
- Give Prothrombinex dose depending on INR
Contra-indications
Mechanical prophylaxis
- CIs - severe PVD or ulcers, peripheral arterial bypass graft, severe leg edema or pulmonary edema, severe local leg disease (infection, dermatitis etc.), hypersensitivity
Pharmacological
- Active major bleeding or recent (<48hrs) clinically significant bleed
- Bleeding diathesis - already anticoagulated, thrombocytopenia, inherited or acquired bleeding disorders (e.g. haemophilia, liver failure)
- Intracranial - recent stroke, TBI, tumour, bleed
- Conditions with significant bleeding risk - peptic ulcer etc.
Pre-operative nutritional support:
Indications? (what conditions and state)
Outline the hierachy of feeding: If unable to eat sufficient calories?
When is parenteral nutrition indicated?
What is ERAS? Explain:
What role does post-op nutrition play?
What is an “high output stoma”? What defines this? what are complications of this? How do you manage it?
OSCE case: Assessing VTE prophylaxis for surgery: outline approach:
Hx, Exam, Weighing risks vs benefits (what is this based on)
What are the different catergories of risk and the management: E.g Low, medium, high
How is VTE managed?
Non-pharm? List 5
Pharmacological? When? What?
Intraoperative management: Prevention? Impact? Management?
Hypothermia? Hyperthermia?
HR: cardiac arrest- What are the 5 Hs, 5 Ts for reversible causes of cardiac arrest?
Intraoperative tachycardia?
Intraoperative HTN?
Antibiotic prophylaxis:? Choice? When?
Goals of oxygen therapy:
What are different delivery systems?
