Aki Flashcards

1
Q

What is AKI

A

Abrupt disruption of kidney function including but not limited to acute renal failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which kidney is higher?

A

Left

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which peritoneal section are the kidneys

A

Retroperitoneal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Functions of the kidney

A

Acid base balance
Hormone regulation
Electrolyte balance
Blood pressure regulation
Toxin removal
Water balance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where is both H+ and HC03- secreted in the kidney?

A

Proximal tubule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where is H+ secreted in the kidney?

A

Proximal tubule and collecting ducts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What electrolyte determines ECF volumeV

A

Sodium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Perfusion of what allows the functioning of RAAS

A

Juxtaglomerular apparatus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does the kidney regulate BP?

A

Volume of ECF (with sodium)
RAAS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What causes ADH secretion

A

Detection of increased plasma osmolality by hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where is ADH secreted from

A

Posterior pitusitarh gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What toxins does the kidney remove?

A

Urea
Creatinine
Drug metabolites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How are toxins filtered by the kidney?

A

Glomerular filtration
Passive diffusion
Active transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What can high urea cause

A

Uraemia encephalopathy
Uraemia pericarditis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the criteria for an AKI?

A

Rise in serum creatinine 26micromol/L or greater in 48 hours
50% greater rise in serum creatinine (more than 1.5x baseline) in last 7 days
Fall in urine output <0.5ml/kg/hour for > 6 hours - catheterised

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What signs and symptoms should u suspect AKI in

A

N+V, diarrhoea, signs dehydration
Reduced urine output or colour change
Confusion, fatigue, drowsiness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are methods of staging for AKI?

A

RIFLE criteria
KDIGO system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is second stage AKI defined by?

A

100-199% creatinine rise from baseline in 7 days
Urine output <0.5ml in 12 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What criteria is 3rd stage AKI?

A

200% creatinine rise, 354 micro mil/L or more with acute rise
Urine output <0.3ml/kg/hr 24 hours, anuria for 12 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Risk factors for AKI

A

Diabetes
Emergency surgery
Intraperitoneal surgery
CKD if eGFR <60
Heart failure
Age over 65
Liver
Use nephrotoxic drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

drugs need to stop in AKI

A

DAMN
Diuretics
ACEis/ARBs
Metformin
NSAIDs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Causes of loss of glomerular filtration rate (features of AKI)

A

Circulating volume overload
Hyperkalaemia
Acidosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What reduces hydrostatic pressure in the glomerulus?

A

Hypotension
Renal artery stenosis
ACEi - efferent arteriole dilation
NSAIDs - afferent arteriole dilation
(NSAID +ACEi BAD)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What increases hydrostatic pressure in glomerulus

A

Urinary tract obstruction, hypertension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What do kidneys vitally control in the short term?
Maintenance of electrolyte homeostasis Fluid homeostasos Excretion of toxins Regulation of acid base balance
26
Long term kidney functions
Hormone production -> anaemia, renal bone disease
27
Pre-renal causes of AKI
Blood supple - hypovolaemia (haemorrhage), hypotension (sepsis, dehydration, shock) Decreased circulating volume = cirrhosis, congestive HF Medications - NSAIDs Third space loss/intersitiial fluid loss Narrowing of renal artery - thrombosis, stenosis Hepatorenal syndrome
28
What is hepatorenal syndrome?
Rapid deterioration in kidney function in people with fulminant or fulminant hepatic failure. Caused due to back up in splanchic circulation, portal veins. Need liver transplant, otherwise manage with dialysis.
29
Investigations pre renal cause of AKI
Bloods, U+Es, LFTs, bone profile, CK, FBC, CRP Dipstick analyisis ECG CXR Urinary creatinine/serum creatinine Urine osmolarity Sediment Renal doppler US Fractional excretion of Na
30
Renal causes of AKI
Acute tubular necrosis Acute intersistitial nephritis Glomerular disease Glomerulonephritis Intratubular obstruction Polycystic kidney disease
31
What is acute tubular necrosis?
Death of epithelial cells of renal tubules Most common cause of AKI Reversible - cells can regenerate. Week to a month recovery
32
Cuaes of acute tubular necrosis
Ischamia secondary to hypoperfusion -shcok, sepsis, dehydration Direct damage from toxins -Gentomycin, radiology contrast dye, NSAIDs
33
What do you find on urinalysis in acute tubular necrosis?
Muddy brown cast
34
What is acute interstitial nephiritis and what causes it?
Inflammation of nephrons - hypersensitivity reaction atypical -Autoimmune -Drugs - NSAIDs, penicillin Infection - TB, pneumonia Sarcoidosis
35
What often presents alongside acute interstiial nephritis if caused by NSAIDs?
Nephrotic syndrome
36
Nephrotic vs nephritic syndromes
Both glomeruklar diseases Nephrotic is a loss of protein -> hypoalbuniaemia -> oedema Nephritic - lose blood, cause HPTN https://geekymedics.com/nephrotic-vs-nephritic-syndrome/
37
What is goopasteurs syndrome?
Rare autoimmune disease where antibodies attack basement membrane in kidney andlungs leading to haemoptysis, glomerulonephritis and acute renal failure. anti-GBM antibody https://rarediseases.info.nih.gov/diseases/2551/goodpasture-syndrome/
38
Glomerular diseases causes of AKI
Nephrotic and nephritic syndrome Good pastuers syndrome Systemic autoimmune eg IgA vasculitis, granulomatosis with polyangitis Inflammation of glomeruli and small blood vessels
39
What is intratubular obstruction?
Increase tubular pressure by increasing eGFR Large protein deposits eg rhabdomyolysis and myeloma cuase blockage
40
Investigations renal causes of AKI
History and exam Bloods Urinalysis US Nephrology for biopsy
41
Post renal causes of AKI
Urinary retnetion - obstruction Renal calculus Pyelonephrosis Pelvic mass Enlarged prostate Carcinomas Blood clot in ureter - catheter trauma, cancer Stricture Neurogenic bladder - ketamine
42
Investigations post renal causes
CT no contrast CTKUB for renal calculi = gold standard.
43
What does dilatation of the ureters on CT suggest?
Hydronephrosis
44
What calculi will not show up on CT?
Uric acid - not radioopaque
45
What presentation suggests an AKI?
N+V or diarrhoea, evidence of dehydration Reduced urine output or change colour Confusion, fatigue, drowsiness
46
How do you stage an AKI?
RIFLE criteria KDIGO system AKIN
47
RIFLE staging
RISK - 1.5 x creatinine / GFR decrease >25% / <0.5ml x 6 hrs INJURY- 2 x creatinine / >50% decline GFR, <0.5ml/kg/hr urine in 12hrs FAILURE - 3x SCR or >75% decreased GFR or if baseline SCR >353.6umol/L or increased by >44.2 <0.3mol/kg/hr, 24 hrs or anuria x 12hrs Persistent ARF = Loss of kidney function Complete loss >4 weeks End stage kidney disease >3 months
48
Risks for AKI
Emergency surgery INtraperitoneal surgery CKD ie eGFR < 60 Diabetic HF >65 liver Nephrotoxic drug use
49
What to look for in bloods AKI
- Anaemia - Biochem - Increase UR + Cr - Increased potassium, phosphate - Decrease Ca, HC03, albumin - ABGs go deeper - anion gal = sodium -(chloride and HC03-) - Normal = 4-13 - Higher anion gap >12
50
Management on AKI
Stop offending drugs - DAMN IV fluids Improve renal perfusion Treat precipitants Monitor U+Es and fluid balance closely
51
Indications fro renal replacement therapy
AEIOU Acidosis Electrolytes - refractory hyperkalaemia Intoxication Overload - pulm oedema Uraemia - encephalopathy, pericarditis
52
What can use to monitor kidney function
eGFR CrCl 0 estimation of eGFR, slightly higher than true value, some creatinine secreted in porximal tubule adds to calue
53
DAMN drugs
Diuretics - exacerbate dehydration and hypopefusion ACEis/ARBs → vasodilation efferent arteriole, hypoperfusion, aspirin (aminoglycosides - gentomycin) Metformin → lactic acidosis, methotrexate NSAIDs → prostaglandin vasodilation reduced, renal hypopeefysion
54
Other offending drugs
Statins, CCBs,
55
Summary of causes of acute kidney injury
Pre-renal (most common) — due to reduced perfusion of the kidneys and leading to a decreased glomerular filtration rate (GFR). Intrinsic renal — structural damage to the kidney, eg tubules, glomeruli, interstitium, and intrarenal blood vessels. damaging renal cells Post-renal — acute obstruction of urine flow resulting in increased intratubular pressure and decreased GFR
56
Groups at higher risk of AKI
>65 Prev AKI CKD Symptoms or history urological obstruction - at risk conditions HF, liver disease, DM Sepsis., Hypovolaemia. Oliguria Cancer and cancer therapy Immunocompromise Toxins In last week: Nephrotoxic drug - (NSAIDs), (ACE) inhibitors, (ARBs), and diuretics. Exposure to iodinated contrast agents
57
Complications of AKI
Hyperkalaemia Electolyte imbalances - hyperphosphatemia, magnesaemia, hypnatremia, calcemia Metabolic acidosis Volume overload - peripheral and pumonary oedema Uraemia CKD and end stage renal disease
58
Predictors for CKD after AKI
older age, lower baseline eGFR, higher baseline albuminuria, and higher stages of AKI
59
Symtpoms of uraemia and how treat
Confusion, lethargy, altered LOC Dialysis
60
Presentation of metabolic acidosis
altered LOC, circulatory collapse, hyperventialtion
61
Hyperkalaemia presentation
Asymptomatic until severe Muscle weakness, paralysus, cardiac arrhytmias, cardiac arrest
62
When there is an illness with no clear acute componenet, which features would make you suspect an AKI?
Chronic kidney disease (stage 3B, 4, or 5), or urological disease. New onset or significant worsening of urological symptoms. Symptoms or signs of multi-system disease - kidneys and other organ systems Symptoms of complications of AKI
63
What test can flag AKIs early?
AKI warning stage test result from electronic detection systems in a lab 3 stages measuring creatinine levels Determines how quickly admit/patient is monitored how often
64
What to do if no creatinine prev abailvabe
Repeat within 48-72 hours and compare
65
What to consider in people who take trimethoprin?
False positives for serum creatinine - increases but does not affect eGDR
66
Volume status assessment
Fluid intake and losses. Peripheral perfusion (capillary refill time). Heart rate/blood pressure (and any postural changes). Jugular venous pressure. Moistness of mucous membranes, skin turgor. Changes in urination pattern. For peripheral oedema and pulmonary crackles
67
Questions to ask about possible underlying causes
Current symptoms, if the person is unwell underlying obstructive cause History of CVSD increasing the risk of impaired renal perfusion. Symptoms of an underlying inflammatory process Drug history Possibility of rhabdomyolysis
68
What does a negative urinalysis but AKI symptoms indicate?
Pre renal cause
69
Symptoms of urinary obstruction
(for example lower urinary tract symptoms, bloating from a pelvic mass, renal colic).
70
Symptoms of underlying inflammatory process
(for example vasculitic rash, arthralgia, epistaxis, or haemoptysis).
71
Causes of rhabdomyolysis
skeletal muscle injury, muscle overexertion, crush injury, prolonged immobility.
72
Why are patients with neuroglogical deficits more likely to get an AKI?
fLUID INTAKE more difficult to regulate themselves or regulated by a carer
73
WHat is oliguria
(urine output less than 0.5mL/kg/hour).
74
COmplications of UTI
Hyperkalaemia + other electrolyte disturbances Pulmonary oedema Metabolic acidosis Uraemic pericarditis, encephalopathy
75
electrolyte disturbances caused by AKI
Hyperkalaemia Hyperphosphatemia Hypermagenesiumia Hyponatremia Hypocalcemia
75
Pre renal causes AKI
Hypovolaemia Decreased cardiac output Drugs that reduce BP
76
Renal causes AKI
Drugs Vascular Glomerular - nephritits, good pasteur Tubular - ischaemia, meyloma, contrast agent Interstitiatl - interstitial nephritis eg ascending UTI
77
Obstructions that can cause AKI
Renal stones, pyelonephrosis, blocked cathertet, pelvic mass, enlarged prostate, cervical carcinoma, ,retroperitoneal fibrosis
78
Urine investgiatones - bedside AKI
Dipstick Microscopy, culture and sensitivity Electrolytes abd somolalilty
79
What test for on dipstick for AKI
Blood Protein Leucocytes Nitrities Glucose Detects glomerulonephritis, acute pyelonephritis and intersitital nephritits
80
Bloods in AKI
FBC U+Es LFTs Creatinine kinase Immunology CRP/ESR Virology ABG Blood culture - sepsis
81
What can increased eosinophils suggest in AKI>
Acute intertitial nephritis, cholesterol embolisation and vasculitis
82
What suggests thrombocytic microangiopathy in bloods
Decreased platelets Haemolytic anaemia
83
Why chcek for creatinine kinase in AKI
Rhabdomyolysis
84
Immunology tests in SLE
ANA, anti-DsDNA, decreased C3, C4
85
What condition suggests ANCA
Granulomatosis with polyangitis
86
Imaging for AKI adn why
CXR - rule out oedema US KUB - urinary retention Doppler US - assess renal artery MRA - renal vascular occlusion
87
Presentation of AKI
Nausea, vomitting, dehydration, confusion, oliguria or anuria
88
AKI warning stage 1
Creatinine >1.5 x baseline OR >26mol<48 hrs
89
AKI warning stage 2
Current creatinine >2 x baseline level
90
AKI warning stage 3
Current creatinine >3 x baseline OR 1.5 x baseline and >354 umol/L
91
What is azotemia
High levels of nitrogenous compounds in the blood
92
Neurogenic causes of postrenal AKI
DM MS Spinal cord compression Cauda equina Anticholinergics Sympathomimetic drugs
93
Clinical signs of AKI
Oliguria, anuria Hypovolaeia signs Volume overload - HPTN, pulmonary/peripheral oedema Uraemia - encephalopathy, ecchymosis (platelet dysfunction) Post renal obstrucution - tender/palpable bladder
94
Bedside investigations AKI
Urine dipstick Urine micoscopy Urine osmolality and electrolytes ECG
95
Urine studies
Urinalysis Urinary PCR or nephritic screen Urine volume/output Microscopy and sediment - cast, crystals Urine osmolarity and specific gravity Urine eosiniphil count - AIN evaluation
96
Bloods in AKI
FBC - Hb, platelets, WCC U+Es - Creatnine, urea, potassium, sodium ABG/VBG For intrinsic: CK Vasculitis screen - ANCA, ANA Clotting Blood film Complement Immunoglobulins Serum electrophroesus Virology (hep B/C)
97
Imaging for AKI
US - key fo robstructive pathology non contrast CT for urinary stones CXR Renal dopplers MR angiography CT urogram
98
Indications for renal biopsy
Intra renal AKI cause or sus rapid progressive glomerulonephritis - Unexplained renal impairment - Unexplained glomerular haematuria - Renal masses - urology - Renal transplant - Rejection - Dysfunction - Connective tissue diseases - Treatment monitoring/research
99
General management AKI
Withdrawal nephrotoxic meds (DAMN) + adjust renally cleared drug doses Fluid resus + monitoring Catheterise to monitor output Evidence of spesis Daily U+Es Treat causes and complications
100
What to do in pulmonary oedema patients with AKI
Can give diuretics - weigh up benefits and risks
101
What is considered in AIN or RPGN to slow progression
Immunosupression
102
Indications for renal replacement therapy
A - acid 0- Metabolic acidosis <7.15 or worsening E - electrolytes - Refractory electrolyte abnormalities - hyperkalemia >6.5 I - intoxication - Presence of dialysable toxins O - Overload - Refractory fluid overload U -Uraemia - End organ uraemic complications - pericarditis, encephalopathy
103
What substances are dialysable in intoxication
Methanol, ethylene glycol, lithium, ASA Any severe posisonning or drug overdose suitable
104
Types of continious renal replacement therapy
Cont. venovenous haemodialysis - CVVHD Cont, venovenous haemofiltration - CVVHF Cont venovenous haemodiafiltration - CVVHDF
105
Complications AKI
Fluid overload Electrolyte derangement Metabolic acidosis End organ complications CKD End stage renal disease
106
Treatment for rhabdomyolysis
IV fluids - 0.9% sodium chloride at 10-15ml/kg/hr to achieve urine (>100ml/hr),adding f sodium bicarbonate 1.4% to maintain urinary pH> 6.51. AND regularly monitor CK and U+Es
107