Aortic stenosis and fluid overload Flashcards
Scenario: elective TURBT, pt has history of aortic stenosis
What is the pathophysiology of aortic stenosis, what are the problems you might face?
-Pt has fixed cardiac output–> limited coronary blood supply –> cannot respond to decreased afterload which may occur with anaesthesia or blood loss
How could you calculate coronary perfusion pressure/
-Coronary perfusion pressure = systemic diastolic arterial pressure - LVED presure`
What does left axis deviation look like on an ecg?
Deflection in lead 1: positive
Deflection in lead 2 and 3: negative
How do you calculate HR based on this ECG?
-300/no of large squares between two R-R intervals
What would you do with this patient?
Scenario: elective TURBT, pt has history of aortic stenosis
Inform consultant and anaesthetist
-Cancel the operation
-Call operating theatre to cancel listing
-Explain to the patient
-Discuss in MDT
If the patient had a bladder cancer, will you proceed to bladder surgery or valve surgery first/
-This will depend on the severity of aortic stenosis
-Normal aortic valve area is 3.0-4.0cm2
-<1cm2 = severe stenosis = transvalvular gradient >40mmhg (differnece between peak left ventricular pressure and peak aortic pressure)
If the operation was cancelled, what are you worried about?
-Spread of cancer
And if you proceed to surgery?
-salah’s says preoperative antibiotics: but nice guidelines don’t recommend antibiotics for procedures in GU tract
Post-operative patient. Fluid chart + vitals chart inside the station. Patient has taken crystalloids and colloids about 7 litres, 4 litres of them are normal saline, now he is tachycardic, hypertensive, desaturating and oliguric
What are your expected physical findings?
Congested neck veins
Puffiness of face
Lung crepitations
Confusion
Interpret this chest XR?
Pulmonary oedema, loss of cardiophrenic angle, cardiomegaly
What chest x ray findings are often evident in pulmonary oedema?
-Alveolar oedema (bat wing or butterfly)
-Kerley B lines
-Cardiomegaly
-Dilated prominent upper lobe vessels
Post-operative patient. Fluid chart + vitals chart inside the station. Patient has taken crystalloids and colloids about 7 litres, 4 litres of them are normal saline, now he is tachycardic, hypertensive, desaturating and oliguric
Why is this patient at high risk of MI?
-Tachycardia leads to reduced diastolic time which reduces coronary filling
-Also it increases cardiac load
What is the minimal acceptable urine output?
In adults, the minimum acceptable urine output is 0.5ml/kg/hr
Can you explain why the patient is oliguric?
-The most common cause is due to the physiological stress response to surgery in the first 24-36 hrs post operatively. This is due to circulating glucocorticoids and mineralocorticoids inducing salt and water retention
-Surgical trauma and various anaesthetic gases also stimulate the release of vasopressin from the posterior pituitary, stimulating post-operative solute free water retention
-Congestive heart failure with low renal perfusion
Explain what are the fluids given to this patient?
-Crystalloids and colloids
-Amount of na_ in 0.9% saline: 150mmol/L
-Amount of na+ in hartmann’s solution: 131mmol/L
