AKI (Part V) Flashcards
Fluid administration in sepsis as per surviving sepsis guidelines?
At least 30ml/kg
Risk & benefits of administration of normal saline?
- Hyperchloremic acidosis
- Beneficial in traumatic brain injury
Action of Furosemide on the kidney?
- Renal protection by decreasing renal tubular oxygen demand
- Expedites renal function recovery by washing out necrotic debris blocking the tubule
RBF ?
- It is constant due to autoregulation
- Dependent on arterial blood pressure
Norad?
- Alpha and beta agonist effects
- Increases contractility
Adrenaline?
- Increases CO & perfusion pressures
Metabolic side effects of Adrenaline administration?
- Hyperglycaemia
- Acidosis
- Hyperlactataemia
- Deleterious effect on splanchnic circulation
- Proarrhythmogenic
Dopamine?
- Dopaminergic effect - Direct renal vasodilation
- Stronger beta effect
- Not recommended in septic shock
Phenylephrine ?
- Synthetic pure alpha agonist
- No beta effect
- Effect is dependent on preload status
- Induces increased venous resistance
- increases CO only
Vasopressin?
- Potent vasopressor
- Action on the mesenteric compartment
- Pure vasoconstrictor w/o inotropic effect
- Useful in septic shock
- May prevent progression of AKI
Vasopressin deficiency ?
- Septic shock induced reduced vascular tone
Effects of various vasopressors?
See attached image
Drugs to avoid in order to prevent AKI?
- NSAIDs
- ACE inhibitors
- ARBs
- Contrast agents
- Aminoglycosides
What is the chemical name for statins ?
3-hydroxy-3-methylglutaryl-CoA reductase inhibitor
Useful effects of statins?
- Anti-inflammatory
- Endothelial stabilizer
What are the hallmarks of critical illness?
- Alteration in fluid status
- Absolute volume depletion (Hypovolaemic or haemorrhagic)
- Relative volume depletion ( page 9
How does renal blood flow remain constant?
Autoregulation
What does renal blood flow depend on ?
Arterial pressure
What is the target MAP for patients with chronic HTN?
80-85mmHg as this is renal protective and reduces the need for RRT
Are alpha-receptors present in the renal vessels?
Their density here is relatively high
What occurs when the MAP is below the autoregulatory threshold ?
Increasing the MAP will directly increase Renal Blood Flow
What does the threshold and slope of the autoregulatory curve depend on?
Comorbidities;
- HTN
- Vascular disease
What is the target MAP for critically unwell patients?
This depends on the prior presence or absence of chronic HTN
What are the effects of vasopressors on renal vasculature?
- Increases MAP & RBF
- Glomerular filtration - Effect on afferent & efferent arterioles
Effects of vasoactive drugs
See attached image
Effects of vasopressors?
See attached image
What are the effects of Norepinephrine?
- Alpha-agonist
- Beta-agonist
- Increased contractility
What are the effects of epinephrine?
- Increased CO & perfusion pressures
What are the metabolic side-effects of epinephrine (Adrenaline)?
- Hyperglycaemia
- Hyperlactataemia
- Acidosis
- Pro-arrhythmogenic
- Impairment of splanchnic circulation
Effect of low dose Dopamine?
- Direct renal vasodilation
Properties of Dopamine ?
- Weak vasoconstrictor effect
- Predominant Beta-effect
- Not recommended for sepsis
Properties of phenylephrine?
- Pure alpha-agonist
- Effect depends on preload & LV function
Characteristics of Vasopressin?
- Potent vasopressor
- It is non-catecholamine
- Pure vasoconstrictor
- No inotropic effect
- Prevents progression of AKI
What is the relationship between septic shock and vasopressin?
- During septic shock there might be vasopressin deficiency
- Decrease in vessel tone
Review vasoactive drugs alongside their renal and systemic effects ?
See image attached
Nephrotoxic drugs to avoid?
- NSAIDs
- Contrast
- ACEi / ARBs
- Aminoglycosides
What is the full name for statins?
3-Hydroxy-3-Methylglutaryl-CoA reductase inhibitor
What are the effects of statins?
- Lowering cholesterol levels
- Anti-inflammatory
- Endothelial stabilization
Major mechanisms of development of AKI?
- Inflammatory pathways
- Endothelial dysfunction
Characteristics of iodinated contrast agents ?
- Iso-osmolality
- Reduced risk of AKI
Alkaline phosphatase?
- Endogenous enzyme
- Detoxifying effect
- Renoprotective effect
Nephrotoxicity can be caused by ?
- Hyperglycaemia
Resuscitation using goal directed therapy ?
See image attached
What are the absolute indications for RRT ?
- Hyperkalaemia
- Metabolic acidosis
- Pulmonary oedema
- BUN > 140mg/dL
- Pericarditis
Furosemide stress test ?
- High sensitivity & specificity
- Predicts progression of AKI
Conditions potentiating the harmful effect of hyperkalemia?
- Acidosis
- Hypocalcemia
- Hyponatremia
Systemic effects of hyperkalemia ?
- Muscle weakness
- Shortened QT interval
- Tall T-waves
- Progressive lengthening of QRS & PR intervals
- VF is a possibility
What is the role of B2-Adrenergic agonist in Mx hyperkalemia ?
- Acts directly on Na/K-ATPase
- Avoid in individuals with coronary disease
What is the role of calcium chloride/gluconate in hyperkalemia?
- Antagonizes cardiac membrane excitability and onset of effect is within minutes.
- Beneficial when ECG changes are present
What is the role of insulin in hyperkalemia ?
- Stimulates Na/K-ATPase activity
- Shift of potassium into the cell
- Approx. 0.5-1.5mmol/L fall in potassium within 15 mins & peak effect observed in about 60 mins
What is the typical ECG for hyperkalemia?
See image attached
What are the causes of metabolic acidosis in AKI?
- Increased acid production
- Increased acid retention
- Decreased bicarbonate reabsorption
Uraemic complications ?
- Observed in 10% of patients with ESRF
- It is rarely encountered in AKI
- ## Inflammation of visceral & parietal membrane of pericardial sac
What is the characteristic presentation of pericarditis in AKi?
- Fever
- Pleuritic chest pain
- Unable to lay flat
- Pericardial rub
What are the early clinical signs of uremic encephalopathy?
- Rambling speech
- Disorientation
- Lethargy
- Irritability
- Hallucination
- Coma
What are the commonly encountered signs of encephalopathy ?
- Tremors
- Myoclonus
- Asterixis
