Perioperative Medicine Introduction Flashcards
Perioperative medicine - what is it?
“Medical side of surgery”
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 …-… weeks before the date of their surgery.
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.
What is the basic structure of a periop pathway?
Pre-op
Intra-op
Post-op
Perioperative pathways (3 pathways)
Elective
Urgent
Emergency
What happens before an emergency op?
Presentation Assessment Investigations Decision Booking Anaesthetists assessment Theatre
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; the process takes around 40 minutes and no blood is issued
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
This process also takes ~40 minutes (in addition to the 40 minutes required to G&S the blood, which must be done first), and should be done pre-emptively if blood loss is anticipated
What is a CEPOD list?
Dedicated theatre lists for emergencies during normal working hours were introduced into UK hospitals in the early 1990s as a result of recommendations of the National Confidential Enquiries into Perioperative Deaths (NCEPOD). These lists are commonly known as CEPOD lists.
Key points for urgent surgery
Booked directly with theatres
Emergency list available 24/7
Urgency has to be assessed to confirm order of operating with the CEPOD criteria
There is limited theatre space - robust assessment of urgency and good communication between teams is needed
Surgical teams usually more involved in emergency work up than in elective cases
Pre-op investigations
Communication Blood tests (FBC, U+Es, LFTs, HbA1C/TFTs, clothing, G+S+/-Cross match) Pregnancy tests Sickle cell disease or trait tests Urine tests CXR Echocardiography
Cardiac Investigations pre-op
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 ischaemia.
An echocardiogram (ECHO) provides very useful information for the anaesthetist as it helps to risk stratify and tailor the intra-operative care of the patient. It may be considered if the person has (1) a heart murmur (2) ECG changes (3) signs or symptoms of heart failure.
For patients with untreated ischaemic heart disease, or symptoms of angina, myocardial perfusion scans are often performed to look for inducible ischaemia.
Respiratory Investigations for pre-op
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.
Plain film chest radiographs (CXR) are less commonly performed routinely pre-operatively and should be used only when necessary
When is a urinalysis indicated pre-op?
Especially for urological procedures, a urinalysis must be performed to assess if there is any evidence or suspicion of ongoing urinary tract infection
Do all patients have an MRSA swab pre-op?
All patients will have swabs taken from the nostril and perineum for MRSA colonisation. If this is isolated, decontamination hair and body wash, along with topical ointment applied to the nostrils, will be given.
Cardiopulmonary Exercise Testing pre-op - when is this indicated?
Cardiopulmonary Exercise Testing
High-risk patients undergoing major surgery may be referred for cardiopulmonary exercise testing (CPET). This usually involves a graded intensity period on a stationary bicycle whilst wearing a mask, as well as ECG monitoring. It provides useful information, such as the VO2max and anaerobic threshold, which can be used to risk-stratify patients for post-operative complications and need for higher level care environments
On all anaesthetic charts, a patient will be given an … grade after their pre-operative assessment, which has been subjectively assessed and based on the criteria below. A patient’s …. grade directly correlates with their risk of post-operative complications and absolute mortality.
On all anaesthetic charts, a patient will be given an American Society of Anaesthesiologists (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.
Recommendations for specific surgery and ASA grades:
ASA 1 ASA 2 ASA 3 ASA 4 - define each
I - A normal healthy patient
2 - A patient with mild systemic disease
3 - A patient with severe systemic disease
4 - A patient with severe systemic disease that is a constant threat to life
Post operative nausea & vomiting - how is this managed?
This is a relatively common side effect of general anaesthesia. It is important to ask about this and if the patient is concerned, to reassure them that there are specific steps that can be taken to reduce the chance of it happening. These steps include using regional anaesthesia where possible, use of more than one antiemetic and use of TIVA (total intravenous anaesthesia).
Difficult airway pre-op - how is this managed?
It is important to ask patients about this and also review old anaesthetic charts to see if airway management has been an issue and if so what approach worked and what didn’t. Patients who have difficult airways may have an alert in the notes and also carry around a card to give to healthcare professionals.
Mallampati score: This is arguably the most recognized and most performed test for preoperative airway assessment.
… score: This is arguably the most recognized and most performed test for preoperative airway assessment.
Mallampati score: This is arguably the most recognized and most performed test for preoperative airway assessment.
Pre-op assessment for elective patient pathway
Nurse led proforma
Aimed at identifying any co-existing medical problems
Routine investigations, dependent on the type of surgery planned
Screening
Discussion about peri-op period - Starvation guidelines (Food 6 hours, drink 2 hours), anaesthetic, DVT/PE prevention
Elective patient pathway - day case vs inpatient
Day cases usually within 24 hours
Inpatient cases - may stay if bleeding, pain, high risk
AAGBI - what are these guidelines?
Association of Anaesthetists of Great Britain and Ireland
Patient needs to meet criteria for discharge…
Pain and nausea under control
Maintaining oral intake
Mobilising
Discharge summary completed
Malignant hyperthermia - what is this?
Malignant hyperthermia is a severe reaction to certain drugs used for anesthesia. This severe reaction typically includes a dangerously high body temperature, rigid muscles or spasms, a rapid heart rate, and other symptoms. Without prompt treatment, the complications caused by malignant hyperthermia can be fatal.
Suxamethomium apnoea - What is it?
Suxamethonium (succinylcholine) is a drug used in anaesthesia to produce relaxation of the muscles (paralysis). It is normally broken down very rapidly in the body by a substance
in the blood, an enzyme called plasma cholinesterase. The effects of suxamethonium normally wear off within a few minutes.
SA occurs when there are abnormalities in this enzyme and the body has difficulties in breaking down this drug. This means the muscles will stay relaxed (paralysed) for longer than expected
It is important to ask about family history of any adverse reactions to anaesthesia particularly for patients who have not had anaesthetics in the past. Patients should be asked about a family history of … apnoea or malignant ….
It is important to ask about family history of any adverse reactions to anaesthesia particularly for patients who have not had anaesthetics in the past. Patients should be asked about a family history of suxamethonium apnoea or malignant hyperthermia.
Gastrointestinal system pre-op. What is important to ask about?
Gastro-oesophageal reflux disease: This is important in regards to airway management. It is important to find out if it is well controlled or not by asking how often this affects the patient, what triggers it (e.g. certain foods or lying flat), whether does acidic fluid or food actually come up into the mouth and how bad has it been recently. Patients may be on a proton pump inhibitor or H2 receptor antagonists, if they are, make sure they have had their regular dose.
Bowel obstruction: Patients with bowel obstruction should have an NG tube placed and fully aspirated prior to induction of general anaesthesia.
What GI condition is really important in regards to airway management?
Gastro-oesophageal reflux disease: This is important in regards to airway management. It is important to find out if it is well controlled or not by asking how often this affects the patient, what triggers it (e.g. certain foods or lying flat), whether does acidic fluid or food actually come up into the mouth and how bad has it been recently. Patients may be on a proton pump inhibitor or H2 receptor antagonists, if they are, make sure they have had their regular dose.
Patients with … obstruction should have an NG tube placed and fully aspirated prior to induction of general anaesthesia.
Patients with bowel obstruction should have an NG tube placed and fully aspirated prior to induction of general anaesthesia.
In women of childbearing age - what do we ask pre-operatively? (2)
If of childbearing age ask if they could be pregnant (informed consent is required for pregnancy tests). Ask if they are on any hormonal therapies which has increased associated DVT/PE risk (e.g. combined oral contraceptive pill, HRT).
What medications may be held/reduced pre-op (day of surgery)
ACE-inhibitors
Certain insulin types & oral hypoglycaemics (dose day before surgery may be adjusted)
Drugs held for variable length of time pre-operatively (when indicated):
Clopidogrel (5 days)
Ticagrelor (5 days)
Aspirin (7 days)
DOACs (depends on agent, surgical bleeding risk and renal function, may be on LMWH bridging therapy)
Warfarin (5-7 days, may be on LMWH bridging therapy)
LMWH (depends on the dose, renal function and indication)
Combined oral hormonal contraceptive & hormonal replacement therapy (4 weeks if indicated to reduce VTE risk)
Allergies to medications, l.., f… and all other substances should be checked pre-operatively
Allergies to medications, latex, food and all other substances should be checked pre-operatively
Pre-op assessment - GASPORT
Ga - any previous gas/issues/FH of problems
Allergies - any known drug/food/other
Starved - last time eating/drinking
PMH - past medical history with emphasis on CVS/Resp/PE
Oral/airway - dental work/airway assessment
Rex - medications NB anti-coag/CVS drugs
Tests - Bloods, G+S etc
Pre-medications are commonly used to aid with pain-control or reduce the risk of aspiration before operations - what may be given?
Analgesia: Most patients will be given at least paracetamol pre-operatively. If there are no contra-indications and low risk of bleeding or acute kidney injury, NSAIDs are also given. Opioids and neuroleptics are sometimes also used in specific clinical scenarios (e.g. chronic pain, neuropathic pain, specific operations).
Managing regurgitation and aspiration risk: Proton pump inhibitor (e.g. omeprazole) or H2 receptor antagonists (e.g. ranitidine) are commonly used for high risk patients. Acid neutralisers such sodium citrate and prokinetics such as metoclopramide may also be used in some scenarios.
Anxiolytics: These are not routinely used peri-operatively. For very anxious patients midazolam is the most common drug used. It is usually given in oral or buccal forms around 30 minutes prior to anaesthesia. Patients need to be in a safe monitored environment especially if buccal preparations are used.
Antimuscarinics: These are infrequently used but may be considered either to reduce airway secretions in certain patient groups or prevent bradycardia in paediatric patients undergoing general anaesthesia.
Fasting pre-op
Advice may vary somewhat from hospital to hospital or operation to operation. Standard advice would be:
No food for 6 hours prior to surgery
Clear fluids until 2 hours prior to surgery
Nil by mouth from that point on
NICE advise considering stopping oestrogen containing hormone replacement therapy (HRT)… …prior to elective surgery to reduce the risk of venous thromboembolism.
NICE advise considering stopping oestrogen containing hormone replacement therapy (HRT) 4 weeks prior to elective surgery to reduce the risk of venous thromboembolism.
In certain settings the COCs need to be stopped pre-operatively to reduce the risk of venous thromboembolism. NICE CKS advise COC should be stopped 4 weeks prior to:
Major surgery (including any operation lasting longer than 30 minutes) Any operation on the legs Any procedure involving prolonged immobilisation of legs
Modifiable risk factors pre-operatively …
Smoking cessation
Weight loss advised in obese patients
Reduce alcohol consumption
Driving post- op - advice
Being safe to drive depends on the surgical procedure and the anaesthetic provided. This information should be given to patients at pre-assessment as it will allow them to make appropriate plans. From a general anaesthetic point of view the recommended time to abstain from driving is between 1 to 4 days depending on which drugs are used.
Social considerations with day-case surgery patients
There are social considerations with day-case patients needing a responsible adult to take them home and stay with them for 24 hours after surgery. In addition they need access to basic facilities such as a toilet and telephone and also be close to a hospital that can treat potential complications.
HbA1C aim within 3 months of surgery in elective setting?
If a patient’s diabetes is poorly controlled they will be referred to their GP or diabetes team for optimisation of this. A HbA1c < 69mmol/mol within 3 months of surgery is the aim in the elective setting. However if an operation is more urgent a clinical decision of risk versus benefit needs to be made with the patient.
AAGBI hypertension guidelines: aim for primary care
Systolic <160, diastolic <100
If no readings - proceed if 180/100
Spurious high readings and white coat syndrome need to be excluded.
… are usually omitted on the day of surgery to reduce severe hypotension associated with concomitant general anaesthesia, regional anaesthesia and operative blood loss. Most other antihypertensives can be continued in stable patients having elective surgery.
ACE-inhibitors are usually omitted on the day of surgery to reduce severe hypotension associated with concomitant general anaesthesia, regional anaesthesia and operative blood loss. Most other antihypertensives can be continued in stable patients having elective surgery.
From an anaesthetic viewpoint aim is for patients to have a systolic blood pressure < …/…mmHg in everyday life
From an anaesthetic viewpoint aim is for patients to have a systolic blood pressure < 160/100mmHg in everyday life
Where possible patients with … are put first on the list to prevent prolonged starvation, hypoglycaemic or hyperglycaemic episodes and limit interruptions to their management regimen.
Where possible patients with diabetes are put first on the list to prevent prolonged starvation, hypoglycaemic or hyperglycaemic episodes and limit interruptions to their management regimen.
Changes to … and oral … depend on the drug and timing of surgery and so are made on an individual patient basis. When the process is managed well variable rate insulin infusions are rarely required and usually reserved for patients who have prolonged peri-operative starvation or poorly controlled diabetes.
Changes to insulin and oral hypoglycaemics depend on the drug and timing of surgery and so are made on an individual patient basis. When the process is managed well variable rate insulin infusions are rarely required and usually reserved for patients who have prolonged peri-operative starvation or poorly controlled diabetes.
Patients who are undergoing surgical procedures with a risk of >…ml blood loss should be screened for anaemia. Other indications for a FBC can be seen in the investigations section above. Ideally this is done around 4-6 weeks prior to surgery so that if anaemia is identified its cause can be investigated (which may include upper and lower GI endoscopy) and treated.
Patients who are undergoing surgical procedures with a risk of >500ml blood loss should be screened for anaemia. Other indications for a FBC can be seen in the investigations section above. Ideally this is done around 4-6 weeks prior to surgery so that if anaemia is identified its cause can be investigated (which may include upper and lower GI endoscopy) and treated.
Iron deficiency is a common cause of anaemia and oral iron supplementation is usually effective after 2-3 weeks of therapy; if there is not sufficient time or oral iron has been ineffective, IV iron can be given. Generally for elective operating a haemoglobin level > …g/dL for men and women is the aim and surgery may be delayed to allow time to reach these targets. However it is not always possible to get to these targets, as anaemia is often multi-factorial in aetiology and may not respond to iron, vitamin B12 or folate.
Iron deficiency is a common cause of anaemia and oral iron supplementation is usually effective after 2-3 weeks of therapy; if there is not sufficient time or oral iron has been ineffective, IV iron can be given. Generally for elective operating a haemoglobin level > 130g/dL for men and women is the aim and surgery may be delayed to allow time to reach these targets. However it is not always possible to get to these targets, as anaemia is often multi-factorial in aetiology and may not respond to iron, vitamin B12 or folate.
Patients with chronic kidney disease and anaemia can be referred to specialist tertiary clinics to see if they would benefit from . Blood transfusion should not be required in the elective setting as patients should be able to be optimised by the previously described methods.
Patients with chronic kidney disease and anaemia can be referred to specialist tertiary clinics to see if they would benefit from EPO. Blood transfusion should not be required in the elective setting as patients should be able to be optimised by the previously described methods.
Obstructive Sleep Apnoea:
Patients at risk should be screened for OSA using scores such as:
…-… score
… … scale
Patients at risk should be screened for OSA using scores such as:
STOP-BANG score
Epworth Sleepiness scale
Depending on OSA scores patients may need to be referred for formal investigation for OSA and potentially have … treatment initiated. This should be implemented pre-operatively and is a reason to delay purely elective surgery that can otherwise wait.
Depending on the scores patients may need to be referred for formal investigation for OSA and potentially have CPAP treatment initiated. This should be implemented pre-operatively and is a reason to delay purely elective surgery that can otherwise wait.
Anticoagulants & antiplatelets - pre op
Patients require clear plans for their anticoagulants & antiplatelets to prevent cancellations and allow for safe surgery.
The management of anticoagulation and antiplatelets during the peri-operative period is complex. Both local and national guidelines exist
It is generally wise to refer to local guidance and expertise when considering peri-operative use of anticoagulants. There is a balance of risk between … and complications of this if the drugs are continued versus the risk of complications of … if the drugs are stopped.
It is generally wise to refer to local guidance and expertise when considering peri-operative use of anticoagulants. There is a balance of risk between surgical bleeding and complications of this if the drugs are continued versus the risk of complications of thrombosis if the drugs are stopped.
Warfarin has a half-life of around 36 hours. It is usually stopped … … days prior to surgery and INR is checked on the day of surgery to ensure it is within normal range (normally ≤ 1.4). If patients are significant risk of thrombosis they are given bridging therapy usually in the form of LMWH either at prophylactic or treatment doses depending of the degree of VTE risk.
Warfarin has a half-life of around 36 hours. It is usually stopped 5-7 days prior to surgery and INR is checked on the day of surgery to ensure it is within normal range (normally ≤ 1.4). If patients are significant risk of thrombosis they are given bridging therapy usually in the form of LMWH either at prophylactic or treatment doses depending of the degree of VTE risk.
Warfarin has a half-life of around 36 hours. It is usually stopped 5-7 days prior to surgery and INR is checked on the day of surgery to ensure it is within normal range (normally ≤ …). If patients are significant risk of thrombosis they are given bridging therapy usually in the form of LMWH either at prophylactic or treatment doses depending of the degree of VTE risk.
Warfarin has a half-life of around 36 hours. It is usually stopped 5-7 days prior to surgery and INR is checked on the day of surgery to ensure it is within normal range (normally ≤ 1.4). If patients are significant risk of thrombosis they are given bridging therapy usually in the form of LMWH either at prophylactic or treatment doses depending of the degree of VTE risk.
Different DOACs have different half-lives that are somewhat dependent on renal function. They are usually stopped pre-operatively at a point in time determined by the exact DOAC, patients’ renal function and operative/anaesthetic risk of bleeding, typically being held for … days pre-operatively. Like for patients on warfarin bridging therapy with LMWH may be used depending on thrombosis risk.
Different DOACs have different half-lives that are somewhat dependent on renal function. They are usually stopped pre-operatively at a point in time determined by the exact DOAC, patients’ renal function and operative/anaesthetic risk of bleeding, typically being held for 1-3 days pre-operatively. Like for patients on warfarin bridging therapy with LMWH may be used depending on thrombosis risk.
LMWH: Prophylactic doses are safe … hours pre-procedure, treatment doses are safe 24-48 hours pre-procedure.
LMWH: Prophylactic doses are safe 12 hours pre-procedure, treatment doses are safe 24-48 hours pre-procedure.
LMWH: … doses are safe 12 hours pre-procedure, … doses are safe 24-48 hours pre-procedure.
LMWH: Prophylactic doses are safe 12 hours pre-procedure, treatment doses are safe 24-48 hours pre-procedure.
Aspirin monotherapy for primary prevention: This is generally safe to stop …. days prior to the procedure. In some settings it may be continued.
Aspirin monotherapy for primary prevention: This is generally safe to stop 7 days prior to the procedure. In some settings it may be continued.
Aspirin monotherapy for … prevention: This is generally thought to be safer to continue with the risk of cardiac events outweighing the risk of bleeding events except for certain operations where there is the risk of bleeding into closed space and the consequences of this would be catastrophic (e.g. intracranial surgery, spinal surgery, posterior eye chamber surgery).
Aspirin monotherapy for secondary prevention: This is generally thought to be safer to continue with the risk of cardiac events outweighing the risk of bleeding events except for certain operations where there is the risk of bleeding into closed space and the consequences of this would be catastrophic (e.g. intracranial surgery, spinal surgery, posterior eye chamber surgery).
Dual antiplatelet therapy with recent ACS or coronary stent: In low risk cases (from a … viewpoint) these may be continued. Other elective cases should be deferred. Where deferral is not possible discussion should be had with haematology, cardiology, anaesthetics and the operating team. Generally … should be continued whilst the other agent is stopped. If … or ticagrelor its stopped 5 days prior, if … its stopped 7 days prior.
Dual antiplatelet therapy with recent ACS or coronary stent: In low risk cases (from a bleeding viewpoint) these may be continued. Other elective cases should be deferred. Where deferral is not possible discussion should be had with haematology, cardiology, anaesthetics and the operating team. Generally aspirin should be continued whilst the other agent is stopped. If clopidogrel or ticagrelor its stopped 5 days prior, if prasugrel its stopped 7 days prior.
Dual anti platelet therapy with recents ACS or coronary stent - Generally aspirin should be continued whilst the other agent is stopped. If clopidogrel or ticagrelor its stopped … days prior, if prasugrel its stopped … days prior.
Generally aspirin should be continued whilst the other agent is stopped. If clopidogrel or ticagrelor its stopped 5 days prior, if prasugrel its stopped 7 days prior.
High-risk anaesthetic clinics are run by anaesthetists with a special interest in peri-operative medicine for patients at greater peri- or post-operative risk.
There are a number of reasons (or combination of reasons) a patient may be referred to the high-risk clinic, these include:
Type of procedure
Co-morbidities / fitness
History of anaesthetic problems
Medications
What is a POSSUM/P-POSSUM score?
POSSUM overpredicts mortality in low-risk patients and underpredicts mortality in elderly and emergency patients. P-POSSUM was developed to compensate for these weaknesses.
The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) assesses morbidity and mortality for general surgery. It can be used for both emergency and elective surgery.
What is the NELA risk calculation tool?
The NELA risk calculation tool provides an estimate of the risk of death within 30 days of emergency abdominal surgery
Your … score will tell you whether you are at low, moderate or high risk of developing CVD in the next 10 years. This means that you have less than a one in ten chance of having a stroke or heart attack in the next 10 years.
Your QRISK score will tell you whether you are at low, moderate or high risk of developing CVD in the next 10 years. This means that you have less than a one in ten chance of having a stroke or heart attack in the next 10 years.
Levels of care - ITU?
L0,L1,L2,L3
L3 vs L2 patient - nurse ratio
1:1 L3, L2 1:2
HDU
High dependency unit
L0 care
Basic patient needs
ITU - what 3 things do we do for patients
Support, monitoring, complex nursing requirements
Smoking cessation pre surgery - ideal time frame?
6 weeks prior
Assessing perioperative risk
Pt factors, effectiveness of care, variation, outcome
Outcome - periop risks
30 day, 90 day mortality Length of stay Adverse event rate Incidence of specific complications Re-admission rate
Type of surgery - risk categories
Low risk - breast, thyroid, dental
Intermediate - carotid, head and neck, neuro, major urology
High risk - open aortic, major vascular, peripheral vascular, urgent body cavity
ASA classification
1-6 - graded description
E after procedure = emergency
