Acute Care & Trauma Flashcards
Define acute kidney injury (AKI)
An abrupt loss of kidney function resulting in the retention of urea and nitrogenous waste products and the dysregulation of extracellular volume and electrolytes. KDIGO Classification of AKI: Increase in serum creati• An abrupt loss of kidney function resulting in the retention of urea and other nitrogenous waste products and the dysregulation of extracellular volume and electrolytes.
o NOTE: this can occur in patients with previously normal kidneys or in patients with pre-existing renal disease
• KDIGO Classification of AKI
o Increase in serum creatinine > 26 mol/L within 48 hrs
o Increase in serum creatinine to > 1.5 times baseline within the preceding 7 days
o Urine volume < 0.5 ml/kg/hr for 6 hours nine >26 umol/l within 48 hours/ to >1.5 times baseline within the preceeding 7 days/ urine volume <0.5 ml/kg/hr for 6 hours
Explain the aetiology / risk factors of acute kidney injury (AKI)
Pre renal (90%) - Hypovolaemia (e.g. haemorrhage, severe vomiting), heart failure, cirrhosis, nephrotic syndrome, hypotension (e.g. shock, sepsis, anaphylaxis), renal hypoperfusion (e.g. NSAIDs, ACE inhibitors, ARBs, renal artery stenosis). Intrinsic renal - glomerular - glomerulonephritis, haemolytic yuraemic syndrome, Tubular - acute interstitial necrosis, Interstitial (e.g. NSAIDs, autoimmune), Vasculitides (e.g. Wegener’s granulomatosis), Eclampsia. Post renal (due to obstruction) - Calculi, Urethral Structure, Prostatic hypertrophy or malignancy, Bladder tumour. Risk Factors: Age, CKD, Comorbidities (e.g HF), Sepsis, Hypovolaemia, Use of nephrotoxis medications, Emergency surgery, Diabetic mellitus
Summarise the epidemiology of acute kidney injury (AKI)
15% of adults admitted to hospital. Most common in the elderly.
Recognise the presenting symptoms of acute kidney injury (AKI)
Dependent on the underlying cause. Oligura/anuria (abrupt anuria suggests post-renal obstruction. Nausea/vomiting, dehydration, confusion
Recognise the signs of acute kidney injury (AKI) on physical examination
Hypertension, distended bladder, dehydration - postural hypotension, fluid overload (in HF, cirrhosis, nephrotic syndrome), - raised JVP, pulmonary and peripheral oedema, pallor, rash, bruising (vascular disease)
Identify appropriate investigations for acute kidney injury (AKI) and interpret the results
Urinalysis - blood (suggests nephritic cause), Leucocyte esterase and nitrites - UTI, Glucose, Protein, Urine osmolality. Bloods - FBC, Blood Film, U & Es, Clotting, CRP, Immunology - • Serum immunoglobulins and protein electrophoresis - for multiple myeloma - Also check for Bence-Jones proteins in the urine
• ANA - associated with SLE - Also check anti-dsDNA antibodies (high in active lupus)
• Complement levels - low in active lupus
• Anti-GBM antibodies - Goodpasture’s syndrome
• Antistreptolysin-O antibodies - high after Streptococcal infection . Virology- Hep & HIV, Ultrasound - Post renal cause - look for hydronephrosis, CXR - Pulmonary Oedema, AXR - Renal stones
Generate a management plan for acute kidney injury (AKI)
Treat the cause
FOUR main components to management:
o Protect patient from hyperkalaemia (calcium gluconate)
o Optimise fluid balance
o Stop nephrotoxic drugs
o Consider for dialysis
Monitor serum creatinine, sodium, potassium, calcium, phosphate and glucose
Identify and treat infection
Urgent relief of urinary tract obstruction
Refer to nephrology if intrinsic renal disease is suspected
Renal Replacement Therapy (RRT) considered if:
o Hyperkalaemia refractory to medical management
o Pulmonary oedema refractory to medical management
o Severe metabolic acidaemia
o Uraemic complications
Identify the possible complications of acute kidney injury (AKI) and its management
- Pulmonary oedema
- Acidaemia
- Uraemia
- Hyperkalaemia
- Bleeding
Summarise the prognosis for patients with acute kidney injury (AKI)
Inpatient mortality varies depending on cause and comorbidities Indicators of poor prognosis: o Age o Multiple organ failure o Oliguria o Hypotension o CKD Patients who develop AKI are at increased risk of developing CKD
Define acute respiratory distress syndrome
• A syndrome of acute and persistent lung inflammation with increased vascular permeability. Characterised by:
o Acute onset
o Bilateral infiltrates consistent with pulmonary oedema
o Hypoxaemia
o No clinical evidence of increased left arterial pressure (pulmonary capillary wedge pressure)
o ARDS is the severe end of the spectrum of acute lung injury
Explain the aetiology / risk factors of acute respiratory distress syndrome
Severe insults to the lungs and other organs leads to the release of inflammatory mediators. These lead to increased capillary permeability, pulmonary oedema, impaired gas exchange and reduced lung compliance . Causes o Sepsis o Aspiration o Pneumonia o Pancreatitis o Trauma/burns o Transfusion o Transplantation (bone marrow and lung) o Drug overdose/reaction There are THREE pathological stages of ARDS: o Exudative o Proliferative o Fibrotic
Summarise the epidemiology of acute respiratory distress syndrome
1 in 6000
Recognise the presenting symptoms of acute respiratory distress syndrome
- Rapid deterioration of respiratory function
- Dyspnoea
- Respiratory distress
- Cough
- Symptoms of CAUSE
Recognise the signs of acute respiratory distress syndrome on physical examination
- Cyanosis
- Tachypnoea
- Tachycardia
- Widespread inspiratory crepitations
- Hypoxia refractory to oxygen treatment
- Signs are usually bilateral but may be asymmetrical in early stages
Identify appropriate investigations for acute respiratory distress syndrome and interpret the results
• CXR - bilateral alveolar infiltrates and interstitial shadowing
• Bloods - to figure out the cause (FBC, U&Es, LFTs, ESR/CRP, Amylase, ABG, Blood Culture)
o NOTE: plasma BNP < 100 pg/mL could distinguish ARDS from heart failure
• Echocardiography
o Check for severe aortic or mitral valve dysfunction
o Low left ventricular ejection fractions = haemodynamic oedema rather than ARDS
• Pulmonary Artery Catheterisation
o Check pulmonary capillary wedge pressure (PCWP)
• Bronchoscopy
o If the cause cannot be determined from the history
Define adrenal insufficiency
Deficiency of adrenal cortical hormones (e.g. mineralocorticoids, glucocorticoids and androgens)
Explain the aetiology / risk factors of adrenal insufficiency
Primary Adrenal Insufficiency o Addison's disease (usually autoimmune) Secondary Adrenal Insufficiency o Pituitary or hypothalamic disease Infections o Tuberculosis o Meningococcal septicaemia (Waterhouse-Friderichsen Syndrome) o CMV o Histoplasmosis Infiltration o Metastasis (mainly from lung, breast, melanoma) o Lymphomas o Amyloidosis Infarction o Secondary to thrombophilia Inherited o Adrenoleukodystrophy o ACTH receptor mutation Surgical o After bilateral adrenalectomy Iatrogenic o Sudden cessation of long-term steroid therapy
Summarise the epidemiology of adrenal insufficiency
- Most common cause is IATROGENIC
* Primary causes are rare
Recognise the presenting symptoms of adrenal insufficiency
• Chronic Presentation - the symptoms tend to be VAGUE and NON-SPECIFIC o Dizziness o Anorexia o Weight loss o Diarrhoea and Vomiting o Abdominal pain o Lethargy o Weakness o Depression • Acute Presentation (Addisonian Crisis) o Acute adrenal insufficiency o Major haemodynamic collapse o Precipitated by stress (e.g. infection, surgery)
Recognise the signs of adrenal insufficiency on physical examination
• Postural hypotension • Increased pigmentation o More noticeable on buccal mucosa, scars, skin creases, nails and pressure points • Loss of body hair in women (due to androgen deficiency) • Associated autoimmune condition (e.g. vitiligo) • Addisonian Crisis Signs o Hypotensive shock o Tachycardia o Pale o Cold o Clammy o Oliguria
Identify appropriate investigations for adrenal insufficiency and interpret the results
To confirm the diagnosis
9 am Serum Cortisol (< 100 nmol/L is diagnostic of adrenal insufficiency)
• > 550 nmol/L makes adrenal insufficiency unlikely
Short Synacthen Test
• IM 250 g tetrocosactrin (synthetic ACTH)
• Serum cortisol < 550 nmol/L at 30 mins indicates adrenal failure
Identify the level of the defect in the hypothalamo-pituitary-adrenal axis
o HIGH in primary disease
o LOW in secondary
Long Synacthen Test
• 1 mg synthetic ACTH administered
• Measure serum cortisol at 0, 30, 60, 90 and 120 minutes
• Then measure again at 4, 6, 8, 12 and 24 hours
• Patients with primary adrenal insufficiency show no increased after 6 hours
Identify the cause
o Autoantibodies (against 21-hydroxylase)
o Abdominal CT or MRI
o Other tests (adrenal biopsy, culture, PCR)
Check TFTs
Investigations in Addisonian crisis
o FBC (neutrophilia –> infection)
o U&Es
• High urea
• Low sodium
• High potassium
o CRP/ESR
o Calcium (may be raised)
o Glucose - low
o Blood cultures
o Urinalysis
o Culture and sensitivity
Generate a management plan for adrenal insufficiency
Addisonian Crisis
o Rapid IV fluid rehydration
o 50 mL of 50% dextrose to correct hypoglycaemia
o IV 200 mg hydrocortisone bolus
o Followed by 100 mg 6 hourly hydrocortisone until BP is stable
o Treat precipitating cause (e.g. antibiotics for infection)
o Monitor
Chronic Adrenal Insufficiency
o Replacement of:
• Glucocorticoids with hydrocortisone (3/day)
• Mineralocorticoids with fludrocortisone
o Hydrocortisone dosage needs to be increased during times of acute illness or stress
o NOTE: if the patient also has hypothyroidism, give hydrocortisone BEFORE thyroxine (to prevent precipitating an Addisonian crisis)
Advice
o Have a steroid warning card
o Wear a medic-alert bracelet
o Emergency hydrocortisone on hand
Identify the possible complications of adrenal insufficiency and its management
HYPERKALAEMIA
Death during Addisonian crisis
Summarise the prognosis for patients with adrenal insufficiency
• Adrenal function rarely recovers • Normal life expectancy if treated Autoimmune Polyendocrine Syndrome Type 1 - autosomal recessive disorder caused by mutations in the AIRE gene. Consists of the following diseases: • Addison's disease • Chronic mucocutaneous candidiasis • Hypoparathyroidism Type 2 - also known as Schmidt's Syndrome • Addison's disease • Type 1 Diabetes • Hypothyroidism • Hypogonadism