Surgery Flashcards
Incidence of an emergency laparotomy
1:1000
30 day mortality of a laparotomy if over 80
25%
30 day mortality of a laparotomy if liver disease
75%
Components of the SORT score
ASA Age Urgency of Op Presence of malignancy Severity of op
Components of P-Possum
12 physiological
6 operative
problem is these operative ones are estimates pre op
does p-possum over or under predict mortality
over predict, though correlates well up to mortality of 15%
What has P-possum been replaced by for NELA
The NELA Risk Prediction Model
Does P-possum predict at population or individual level
population
should not be used alone for deciding to operative
What is the percentage cut off in p-possum that means the case needs consultant anaesthetic/surgical involvement
5%
What percentage cut off in p possum means the case needs direct consultant supervision
10% (also admit to ITU as routine above this level)
What does ASA I mean and its associated mortality
Normal healthy patient
0.1%
ASA2 definition and mortaity
Mild systemic disease without substantial functional limitation
0.7%
ASA3 definition and mortality
Severe systemic disease with substantial functional limits (poorly controlled COPD, DM etc)
3.5%
ASA 4 definition and mortality
Severe systemic disease which is a constant threat to life (recent MI<3/12, sepsis
18.3%
ASA 5 definition and mortality
Moribund patient who is not expected to survive wihtout the op
93.%
ASA 6 definition
BSD patient for organ retrieval
What is the anaerobic threshold that is associated with adverse outcomes
11ml/kg/min
Does anaeoribc threshold vary with patient effort
No
RCoS criteria of major GI surgery that has a predicted mortality of >5%
Age of 50 and:
Emergency or re-do surgery
AKI or CKD, creatinine >130
DM
CVD
OR
Over 65
Or
Shock of any cause
HES procedure groups that have mortality of greater than 10%
Laparotomy and peritonitis Bowel/rectal resection Therapeutic upper GI endoscopy Gastrectomy Ulcer surgery Splenectomy
NICE recommendations on EGDT
Use an oesophageal doppler to guide fluid therapy
What was the OPITIMISE study
Multi centre study
RCT
Protocolised cardiac output guided fluid and inotropes versus usual care
No reduction in complications or 30 day
BUT added to a meta analysis the rate of complications reduced
Pre Op enhanced recovery
Optimise condition and co-morbidities Correct anaemia after Ix Plan data of discharge and set criteria Carb loading Avoidance of bowel prep Admit on the day of surgery Hydrate and carb drinks
Intra op enhanced recov
Fluid and haemodynamic therapy guided by doppler
Balanced crystalloids, ringers hartmanns
Minimally invasive surgery
Avoid Hypothermia
Regional and epidural if possible
Post op enhanced recov
Avoid iv fluids Oral fluid and nutrition early avoid ng tube and drains avoid systemic opiates for simple analgesia early mobilisation remove catheter rehab
Risks of blood going through bypass circuit
Activates clotting
Precipation of inflammatory response
Fluid shifts
Risk of emboli
Anticoag risk
General rules of thumb for drain bleeding post cardiac surgery
400ml 1st hour
OR
200mls/hr for first 2 hours
OR
100mls/hr for first 4 hours
Coag features of heparinisation
Prolonged activated clotting time ACT
Prolonged APTT
Prolonged R time on teg
What causes thrombocytopenia in CPB
Process consumes platelets so expect a drop in absolute count
Previous antiplatelet agent use
Fluid shifts dilute clotting factors
How to minimise impact of ischaemia reperfusion
Cardioplegic solutions (high K, conserves ADP whilst asystolic)
Hypothermia Reduces metabolic demand
Hyperosmotic buffer cardioplegic solutions to minimise myocardial oedema and acidosis
Problems after bypass
SIRS
Arrhythmia (usually AF, use amiodarone and B blockers)
Tampanade
Hypothermia - shivering increases O2 demand and impairs coag
Pericarditis - global concave ST elevation
Atelectasis, ARDS, AKI, Delerium, CVA
Usual time to extubation in cardiac cases
6 hours
Features of a tampanade
Low BP, low CO, rising filling pressure (CVP and PAOP)
But conisder in any unstable patient
Transoesophageal echo is best way
Have a low threshold for sternotomy
Hb target for CPB
90
Causes of medical bleeding post CPB
Incomplete reversal of heparin
Thromobcytopenia
Peri op platelet drugs
Coag from liver
Features of medical/surgical bleeding
HR up
CVP/PAOP down
Cardiac index down
Blood in drains (surgical bleeding is more brisk)
Investigaton of bleeding after CPB
Activated clotting time
TEG
FBC
Coag
Surgical exploration
Causes of myocardial dysfunction after CPB
Post cariotomy stunning
Graft failure
Valve dysfunction
Pre existing dysfunction
Features of myocardial dysfunction
HR up
CVP PAOP up
CI down
Not much blood in draing
Ix of myocardial dysfunction
ECG
Echo both to look for regional ischaemia
Calcium level
Treatment of myocardia dysfunction
Electrolytes
Inotropes - milrinone
IABP
Correc the graft or valve
Complications of open AAA repair
AKI Spinal cord ischaemia - neuro defecit Bleeding and coagulaopathy Stroke MI
Mortality of emergency and elective AAA repair
36%
6%
Commplications of EVAR
Endoleak Covert to open Bleedind and coagulopathy Embolic event Rupture AKI - flow or contrast SIRS response - post implantation syndrome
Why does aortic surgery needs a spinal drain
drain CSF
decrease pressure on cord
maintain blood flow
Complications of intracranial surgery
Bleeding Haematoma Raised ICP Seizures Cerebral oedema Pneumocephalus CSF leak --> infection Neurogenic pulmonary oedema DI
Hypertension strategy
B blockers first line - do not affect ICP
Avoid GTN they increase flow
Is negative fluid balance good for traumatic brain injury
NO
This group should avoid negative balance
Why does free flap surgery fail
Thrombosis
Ischaemia/hypoperfusion - sedation, fluid loss, SIRS, vasoconstiction
Oedema - too much fluid, haemodilution, ischeamia
What is the optimal difference between peripheral ad core temperature in flap surgery
<1C
Hct target for flap surgery
30%
Mortality of pneumonectomy surgery
11%
Which side of pneumonectomy has higher mortality
Right (unclear why)
What is the immediate anatomical change after a pneumonectomy
Space fills with air
Is it routine to use drains in pneumonectomy
No
If you use a drain what would happen if you put in on suction
Air removed, mediastinal shift and haemodynamic compromise
What are the late anatomical changes after pneumonectomy
Raised hemi diaphragm
Mediastinal shift to the post pneumonectomy space
Other lung hyperinflates
CXR –> opacification of affected hemithorax at 4/12
How does lung function change after pneumonectomy
Volumes, FVC and TLCO all reduce by half
Complications of pneumonectomy
Pulm oedema of other lung - suddenly the entire CO goes through one lung
Haemothorax
Chylothorax
Bronchopleural fistula
Post pneumonectomy syndrome - breathlessness, infections and stridor (caused by compression of trachea and main stem bronchus)
Contralateral Ptx
Empyema in the pps
Cardiac herniation
Scoliosis
AKI
Who is at risk for problems after pneumonectomy
BMI>30
COPD
Current smoker
Co-morbid status
Normal time course for cardiac surgery post op
3 hours - warm to 36.5 6 hours - extubate overnight - wean pressors, ensure analgesia Next day - MDT, drains out, art line out Afternoon - ward or HDU
Optimal heart rate post op, and when are epicardial pacing wires removed
80 BPMM
day 4 - if not, PPM
BIggest risk to watch for after removing epicardial pacing wires
Tampanade
Is there evidence for whish inotrope to use post op
No
Inotropes to improve RV dysfunction
Inodilators - enoximone, milrinone, dobutamine
Improve RV perfusion pressure, reduce PVR
Improve RV afterload - avoid hypoxia, acidosis, hypercapnoea
Triad of tamponade
BP fall, CO fall, rising CVP
What to do in a cardiac arrest after bypass
Re-open the sternotomy
Consider epicardial wires
IABP - where does it go
Descnding aorta distal to left subclavian and proximal to renal arteries
How is the IABP balloon triggered
ECG or by BP
NOT time
Inflation of the ballon does what?
Increases diastolic pressure and improves coronary flow
Decreases LV afterload
Increases SV by 40ml
Indications for IABP
Cardiogenic shock (pap muscle rupture, mitral regurg) Post MI VSD Unstabel angina High risk cardiac surgery Difficult weaning from bypass
Contraindications to IABP
Moderate to severe AR
Aneurysm and dissection
PDA
Relative:
Bilatera peripheral arterial disease
Bleeding disorder
HOCM with LVOT
Complications of IABP
Stroke Bleeding Thrombocytopenia Pseudoaneurysm Renal hit Balloon rupture
When is the predictable peak of creatinine
day 3
Is there a risk of pancreatitis after cardiac surgery
Uncommon, but transient increases in amylase due to low CO, hypothermia and too much calcium
Is RRT usually needed after cardiac surgery
Not in the first 24 hours
Describe the 3 2 1 approach to acceptable bleeding in cardiac surgery
Hour 1 - 3ml/kg/hour
Hours 2 -4 2 mls/kg/hr
Hours 4-12 1ml/kg/hr
Causative organisms of sternal wound infections
S.aureus
S. epidermmidis
Coliforms
Drug re-introduction after cardiac surgery
Beta blockers on day 1 at half dose for rate control
Calcium channel blockers - rapid withdrawel can cause coronary artery spasm.
Digoxin on day 1
ACEi , A2 and spironolactone - delayed until inotropes off
What is Lee’s Revised Risk Index and what is it made up of
Risk of cardiac complications after NON cardiac surgery
High risk surgery IHD CCF U&Es (Cr>176) Previous Insulin for DM Stroke
0 - 0.4%
1 0.9%
2 6.6
>3 11%
