Acute Care and Trauma Flashcards
Define diabetic ketoacidosis
DKA is an acute metabolic complication of type 1 diabetes mellitus that is potentially fatal and requires prompt medical attention. It is characterised by absolute insulin deficiency.
What is the biochemical triad of diabetic ketoacidosis and describe the onset?
Hyperglycaemia
Ketonaemia
Acidaemia
There is RAPID onset.
Summarise the epidemiology of diabetic ketoacidosis?
In DKA, there is a reduction in the net effective concentration of circulating insulin and an elevation of counter-regulatory hormones (glucagon, catecholamines, cortisol, and growth hormone).
This leads to metabolic derangements and ketone production.
What are common precipitating events of DKA and risk factors?
Two most common precipitating factors:
Inadequate insulin therapy
Infection
Other risk factors: Underlying medical conditions eg MI or stroke - release of counter-regulatory hormones Drugs that affect carbohydrate metabolism (corticosteroids, thiazides, pentamidine, sympathomimetic agents, second-generation antipsychotic agents) SGLT-2 inhibitors Pancreatitis Acromegaly Hyperthyroidism Cushing's Syndrome
Summarise the epidemiology of DKA
Less common with increasing age
0-128 per 1000 people
What are the presenting symptoms of DKA?
Polyuria Polyphagia Polydipsia Weight loss Weakness Nausea and vomiting Abdominal pain Drowsiness Confusion Coma
What are the signs on physical examination of DKA?
Signs of dehydration - dry mucous membranes, poor skin turgor, sunken eyes
Tachycardia
Hypotension
Kussmal respiration - rapid and deep respiration due to acidosis
Acetone breath
Hypothermia
What are appropriate investigations for DKA?
Bloods: PLASMA GLUCOSE - high (>13.9mmol/L) Capillary or serum KETONES - BOHB >3.8mmol/L SERUM UREA - elevated due to volume depletion SERUM CREATININE - elevated Serum sodium - low Serum potassium - elevated FBC - elevated WCC
ABG - acidosis, low bicarbonate
URINALYSIS - positive for glucose and ketones, in presence of infection positive for leukocytes and nitrites
What is the management of DKA?
Intravenous fluids (0.9% saline)
Supportive care (ICU admission)
Potassium therapy if hypokalaemic (often caused by insulin therapy and correction of acidaemia)
IV dextrose when glucose reaches 15mmol/L
Intravenous insulin once serum potassium normalises
Add vasopressors, bicarbonate therapy and phosphate therapy
Monitor blood glucose, ketones, urine output and VBG
What are the possible complications of DKA?
Hypoglycaemia if excessive insulin therapy
Hypokalaemia due to bicarbonate and insulin therapy
Thromboembolic events - give heparin prophylaxis
Non-anion gap hypercholaraemic acidosis – due to urinary loss of ketoanions
Cerebral oedema
Acute Respiratory Distress Syndrome
What is the prognosis of DKA?
Mortality rate of 5%
Prognosis worse at age extremes or in presence of coma or hypotension
Define anaphylaxis
A severe hypersensitivity reaction characterised by rapidly developing life-threatening breathing or circulation problems and an associated urticarial skin rash.
Summarise the aetiology of anaphylaxis
Hypersensitivity of the immune system to a non-harmful antigen resulting in mast cell and basophil degranulation
Histamine causes bronchi and GI smooth muscle constriction and blood vessel dilation and permeability
Mainly IgE antibody mediated
In rare cases, immune complex mediated (opioids, contrast medium)
Can be non-immunologic
Causes: Food allergy - shellfish, peanuts, eggs Bee sting Drugs - antibiotics eg penicillin, NSAIDs Latex
Summarise the epidemiology of anaphylaxis
Food allergy anaphlyaxis most common in young children
Food allergy affects both sexes equally
Medication most common cause in adults
What are the presenting symptoms of anaphylaxis?
Angioedema - swelling of face, eyes, mouth Utricarial rash - red, itchy, blotchy rash with central white papule Shortness of breath Cough Wheeze Abdominal cramping Vomiting Diarrhoea Pruritis
What are the signs on physical examination of anaphylaxis?
Hypotension Tachycardia Use of accessory muscles Wheeze Stridor and hoarse voice Chest hyperinflation Cyanosis Pale clammy skin
What are the appropriate investigations for anaphylaxis?
Mainly a clinical diagnosis
Serum tryptase, histamine and IgE will be raised
ABG - metabolic acidosis
What is the management of anaphylaxis?
ABCDE assessment
IM ADRENALINE
Airway support and supplemental O2
IV fluids
Antihistamine
Corticosteroids to reduce chance of biphasic reaction
Allergy testing to prevent further reactions
What are the possible complications of anaphylaxis?
MI Loss of consciousness Respiratory arrest Death Recurrence
What is the prognosis of anaphylaxis?
Individuals with previous reactions puts them at increase risk of recurrence
Define acute kidney injury
An acute decrease in kidney function, leading to an increase in creatinine and a decrease in urine outflow. This results in the retention of urea and other nitrogenous waste products and the dysregulation of extracellular volume and electrolytes.
Rise in serum creatinine of > 26micromol/L within 48 hours
Rise in serum creatinine of > 1.5 times the baseline over 7 days
Urine output <0.5ml/kg/hr for > 6 hours
Summarise the aetiology of acute kidney injury
Pre-renal:
Decreased renal perfusion - dehydration, third spacing due to sepsis or acute appendicitis, renal artery stenosis, heart failure
Hypovolaemia - acute haemorrhage, severe vomiting or diarrhoea)
Cirrhosis
Nephrotic syndrome
Hypotension - shock, sepsis, anaphylaxis
Medications - NSAIDs, ACE inhibitors, ARBs
Hepatorenal syndrome (hypoalbuminaemia due to decompensated liver failure)
Intrinsic renal:
Glomerulonephritis - nephritic or nephrotic syndrome
Nephrotoxin exposure - antibiotics, methotrexate, heavy metals
Acute interstitial nephritis (autoimmune, NSAIDs)
Glomerular: glomerulonephritis, haemolytic uremic syndrome
Tubular: acute tubular necrosis (secondary to ischaemia)
Vasculitides (e.g. Wegener’s granulomatosis)
Eclampsia
Post-renal (due to obstruction): Urinary calculi Prostatic cancer BPH Abdominal tumour eg bladder Urethral stricture
Summarise the epidemiology of acute kidney injury
Pre-renal acute kidney injury is the most common
It is most commonly seen in adults
15% of adults admitted to hospital will develop an AKI
