SAQ Flashcards
14B5 Outline the principles of cardiopulmonary exercise testing (50%) b) Evaluate the role of cardiopulmonary exercise testing in a patient who is scheduled for oesophagectmony (50%)
a) Principles of Cardiopulmonary Exercise Testing (CPET)
Non invasive quantitative measurement of functional capacity
* Incremental Exercise Protocol: A graded exercise test (treadmill or bike) where workload increases progressively to maximal effort or symptom limitation.
* Measurement of Gas Exchange: Real time VO2, VCO2 and MV.
* Anaerobic Threshold: where lactate production exceeds clearance
* Peak Oxygen Uptake VO2 max
* Ventilatory Efficiency: MV/VCO2
* HR and BP Response:
* Exercise Limitation: Cardiac (angina), Vascular (claudication), Resp (dyspnoea), MSK (back/joint pain)
b) Role of CPET in a Patient Scheduled for Oesophagectomy
* Risk Stratification:
○ Identifies high risk of cardiopulmonary morbidity and mortality.
○ VO2 (<15 mL/kg/min) indicates poor functional reserve.
* Optimization of Preoperative Care:
○ Prehabilitation, including physical conditioning and nutritional support.
○ Book HDU/ICU bed
* Decision-Making:
○ Weigh risks versus benefits of surgery
○ Improves interdisciplinary communication
○ May influence the choice of surgical approach (e.g., minimally invasive vs. open vs palliative/medical/conservative)
* Prognostication:
○ Correlates with long-term outcomes, such as survival and recovery.
○ Helps predict the likelihood of prolonged mechanical ventilation or delayed return to baseline function.
* Limitations:
○ Not universally available
○ Resource-intensive.
○ Interpretation requires expertise
○ May not always align with clinical outcomes.
19A5 Alcoholism
A 61-year-old man presents with a large haematemesis. He has known alcoholic liver disease and sedation is requested for an urgent gastroscopy.
Outline your peri-procedural concerns
Unfasted/High aspiration risk - requires RSI, not for sedation
Co-operation/Consent - may need substitute consent if intoxicated/encephalopathic or implied consent if life-saving.
Hypovolemia (haemorrhagic) shock - with potential coagulopathy/thrombocytopenia may also have preexisting macrocytic anaemia (b12 deficiency)
- requires resuscitation and ROTEM/TEG guided transfusion prior to RSI - induce with vasopressor, art line
Alcohol complications
Acute intoxication - less anaesthetic requirement
Chronic = more -titrate to BIS/Entropy
AF - check ECG, optimise K>4.0, Mg>1.0, withhold anticoagulation
Dilated Cardiomyopathy - check previous TTEs
Preload - maintain. Rate - low normal 50-70, Rhythm - sinus. Contractility -maintain. Afterload - avoid increasing
Gastric ulcer - Pantoprazole 80mg bolus then 80mg/12hr
Alcohol withdrawal - at risk of seizures/delirium tremens (benzodiazepine load), Wernickes/Korsakoffs (thiamine load)
Chronic liver disease complications - cirrhosis, portal hypertension
Varices - octreotide infusion 50mcg bolus then 50mcg/hr
Ascites - abdominal distension can compromise respiratory compliance - may require drainage prior to RSI
Labile BSL
Post-op HDU
Alcohol withdrawal scale
22A03 Hypoxemia in Chronic Liver Disease
Interpret this ABG.
List the causes of hypoxia in patients with chronic liver disease.
Describe how you would differentiate between the causes of hypoxia in patients with chronic liver disease.
- Resp Alkalosis with metabolic compensation (likely acute)
Hypoxemia
A-a gradient =
FiO2 (Patm - PH2O) - PCO2/R - PaO2
0.21 (760-47) - 25/0.8 - 55
150-30-55 = 65- Hypoxia in CLD
a. Hypoventilation (encephalopathy, drug intoxication 2* ↓clearance)
b. Diffusion (Pulmonary odema - APO, ETOH cardiomyopathy, fibrosis - a1 antitrypsin def)
c. V-Q mismatch (hepatopulmonary syndrome ↑Q, portopulmonary sydnrome ↓Q, Pulmonary embolism)
d. Shunt (atelectasis - ascites, hepatosplenomegaly, hepatic hydrothorax, pneumonia/pleural efffusion) - History
a. Onset (acute, delayed, chronic)
b. Infective Sx (cough, fever, sputum = pneumonia)
c. Associated Sx (chest pain = MI , ↓LOC = encephalopathy)
d. Context (recent drugs/anaesthesia, overseas travel/exposure to sick contacts)
Exam
a. Platypnea (hepatopulmonary)
b. Vitals (↓BP, ↑HR = MI, Fever = sepsis)
c. Signs of cardiac failure (creptitations, ↑JVP, displaced apex beat, peripheral odema/orthopnea/PND)
d. Ausculation - ↓AE = pleural effusion/hydrothorax
e. Abdomen - palpate heptalosplenomegaly, percuss shifting dullness - ascites
Investigations
a. Bloods
i. FBC - neutrophilia, ↑WCC = sepsis
ii. EUC - ↑Cr Urea hepatorenal syndrome/fluid overload
iii. Ammonia -encephalopathy
iv. Trop/BNP - cardiac dysfxb. CXR - APO
c. TTE - MI/cardiac dysfx,
d. US abdo - volume ascites
e. Bubble TTE study - HPS
f. CTPA - PE
- Hypoxia in CLD
23B06 Chronic Heart Failure
Outline the treatment strategies for chronic heart failure
HFrEF <40% and still symptomatic
African American = Hydralazine + ISMN (1)
NYHA I-III, LVEF <35% = ICD if >1y survival (1)
NYHA II-III, ambulatory IV, LVEF<35%, LBBB QRS>150ms, sinus = CRT-D (1)
Maximal Beta blocker, HR>70 sinus =Ivabradine (2a)
Recent decompensation or IV diuretics = Vericiguat (2b)
Ongoing symptoms = Digoxin (2b)
NYHA II-IV = Fish oil (2b)
Refractory HF
Consider LVAD, cardiac transplant or palliative care
ARNi = Angiotensin Receptor blocker + Neprilysin receptor inhibitor (valsartan/sacubitril)
Treat underlying cause
Non-pharm
Smoking cessation
Reduce alcohol
Low salt diet
Fluid restriction
Exercise/cardiac rehab
Other
Vaccination (pneumococcal/influenza/COVID)
HTN/T2D as per guidelines
AF → ablation or anticoagulation
OSA → CPAP
IDA → Fe infusion
