Acute Care & Trauma Flashcards
What is acute respiratory distress syndrome?
Condition occurring in critically ill patients, characterised by widespread inflammation of the lungs
- Clinical phenotype which may be triggered by various pathologies such as trauma, pneumonia and sepsis
What is the aetiology of acute respiratory distress syndrome?
- Diffuse compromise of pulmonary system resulting in ARDS often occurs in setting of critical illness
- May be seen in pulmonary (pneumonia) or systemic infection (sepsis), following trauma, multiple blood transfusions, severe burns, severe pancreatitis, near-drowning, drug reactions or inhalation injuries
What is the epidemiology of acute respiratory distress syndrome?
- Incidence is higher in mechanically ventilated population
- Worldwide, severe sepsis is common trigger
What are the signs and symptoms of acute respiratory distress syndrome?
- Often begin within 2 hours of inciting event but can occur after 1-3 days
- Shortness of breath
- Fast breathing
- Low oxygen level in the blood due to abnormal ventilation
What are the investigations for acute respiratory distress syndrome?
- CXR, CT thorax: bilateral opacities not explained by other lung pathology
- ABG: Pa02/Fi02 ratio: decreased
What is alcohol withdrawal?
Condition that occurs in alcohol abusers as a result of decrease or cessation of alcohol drinking, resulting in blood alcohol levels below the level to which the drinker has become habituated
- Commonly referred to as ‘the shakes’ and begins about 4-12 hours after last drink and may progress to delirium, seizures, hallucinations, coma and death
What are the risk factors for alcohol withdrawal?
- FHx
- Cultural, parental, peer influences
- Availability of alcohol
- Occupation: lawyers, publican, doctors
- Depression
- Anxiety
What is the aetiology of alcohol withdrawal?
- Alcohol enhances inhibitory GABA activity and inhibits glutamate transmission
- Glutamate receptors upregulated and downregulated GABA receptors
- Abrupt cessation= overactive glutamate activity
What is the epidemiology of alcohol withdrawal?
1.8 million deaths per year
What are the presenting symptoms of alcohol withdrawal?
- Mild: Can’t sleep, nausea, anxiety, irritable
- Sweating and tremor
- Restlessness
- Agitation
- Sleep disturbance
- Visual hallucination: liliputian hallucinations, seeing little people
- Confusion
- Seizures
What are the signs of alcohol withdrawal on examination?
- Mild: Hypertension, tachycardia, hyperreflexia
- Derlium tremens (usually after 3rd day: 48-47h after cessation, agitation, fever, tachycardia, confusion, delusions, hallucinations (visual or tactile), dilated pupils
What are the investigations for alcohol withdrawal?
- FBC: hypoglycaemia
- Serum urea & creatinine: dehydration may occur if pt delirious -> impaired renal function. Uraemic encephalopathy may mimic alcohol withdrawal
- LFTs: Addition to Dx
- Toxicology screen: To determine other causes, serum and urine testing
- Electrolytes; lactic acidosis may be related to alcoholic seizures, ketoacidosis, ingestion of other alcohols
- CT head: exclude other causes of presentation in bran
- CXR: Exclude infection
How is alcohol withdrawal managed?
1) IV vitamin p complex (Pabrinex), folic acid, Mg (Mg sulphate infusion)
2) Thiamine in Wernicke’s encephalopathy suspected
3) Reducing doses of chlodiazepoxide
4) Nutritional support as often malnourished
5) Lactulose and phosphate enemas if encephalopathy
What is the criteria for admission for alcohol withdrawal?
- Alcohol withdrawal and at high risk of developing seizures
- Under 16s
- Vulnerable people; frail, cognitive impairment, many comorbidities, lack social supports
- If not admitted, advise against sudden reduction in alcohol
What are the chronic complications of alcohol withdrawal?
- Cerebral atrophy and dementia
- Cerebellar degeneration
- Optic atrophy
- Peripheral neuropathy
- Myopathy
- Hepatic encephalopathy
- Thiamine deficiency
- Wernicke’s encephalopathy
- Korsakoff’s psychosis
- Alcohol withdrawal seizures
- Sedation form benzodiazepine treatment
- Delirium tremens
- Mortality
What is the prognosis for alcohol withdrawal?
- Insomnia and autonomic symptoms last for a few months- at least 6
- 50% relapse after starting treatment
- To present relapse: Counselling, encourage alcohol support group attendance, Acamprosate for anxiety, insomnia, craving for 1y, Disulfiram causes acetaldehyde built up with unpleasant side effects for alcohol ingestion- flushing, throbbing, headache, palpitations
What is anaphylaxis
Acute life-threatening multisystem syndrome caused by sudden release of mast cell and basophil derived mediators into the circulation
What is the aetiology of anaphylaxis?
Can be classified as
- Immunological: IgE-mediated or immune complex/complement-mediated
- Non-immunological: Mast cell or basophil degranulation without the involvement of antibodies (e.g. reactions caused by vancomycin, codeine, ACE inhibitors
- Can be induced by exercise
- Common allergens (e.g. drugs, radiological contrast agents, latex, insect stings, egg, peanuts, shellfish, fish
- Repeated administration of blood products in pts with selective IgA deficiency (due to formation of anti-IgA antibodies)
What causes tissue oedema in anaphylaxis?
Inflammatory mediators such as histamine, tryptase, chimase, histamine-releasing factor, PAF, prostaglandins and leucotrienes cause bronchospasm, increased apillary ermeability and reduced vascular tone
What is the epdidemiology of anaphylaxis?
- Relatively common
- Occurs in 1/5000 exposures to parenteral penicillin or cephalosporins
What are the presenting symptoms of anaphylaxis?
Acute onset of symptoms on exposure to allergen
- Wheeze, shortness of breath or sensation of choking
- Swelling of lips and face
- Pruritis, rash
Severity of previous reactions does not predict the severity of future reactions. Pts may have history of other allergic hypersensitivity reactions e.g. asthma, allergic rhinitis. Biphasic reactions occur 1-72h after the first reaction in 20% of pts
What are the signs of anaphylaxis on examination?
- Tachypnoea. wheeze, cyanosis
- Swollen upper airways and eyes, rhinitis, conjunctival injection
- Urticarial rash (erythematous wheals)
- Hypotension, tachycardia
What are the investigations for anaphylaxis?
- Dx made clinically
- Serum tryptase, or histamine levels and urinary metabolites of histamine can support clinical Dx. normal levels of these do not exclude dx
What are the investigations for anaphylaxis after the attack?
- Allergen skin testing: Identifies allergen. Should be performed by allergy specialist because risk of anaphylaxis
- IgE immunoassays: E.g. radioallergosorbent tests (RASTs) to identify food-specific IgE in the serum
How is anaphylaxis managed?
Stop any suspected drugs
- Resuscitation: according to principles of airway, breathing and circulation
- Secure airway: and give 100% 02. Intubation and transfer to ITU may be necessary so anaesthetist must be informed early
- Adrenaline IM: Can be repeated ever 10m according to response of pulse and BP
- Antihistamine IV
- Steroids IV
- IV crystalloid or colloid: to maintain blood pressure. If hypotensive, lie pt flat with head tilted down
- Treat bromchospasm: with salbutamol +/- ipratropium inhaler. Aminophyllin IV infusion may be required
- Advice: Educate on use of adrenaline pen for IV administration. Provide Medicalert bracelet. make not in pts notes and drug charts. Referral to an allergy specialist for identification of culprit allergen and education in allergen avoidance
What are the possible complications of anaphylaxis?
- Respiratory failure
- Shock
- Death
What is the prognosis of anaphylaxis?
Good if prompt treatment given
What is an arterial blood gas?
- Blood gas test of blood from an artery
- Measures amounts of certain gases e.g. oxygen and carbon dioxide - dissolved in arterial blood
What are the indications for an arterial blood gas?
- Determine pH of blood
- Partial pressure of C02 and 02
- Determine bicarbonate level
- Mainly used in pulmonology and critical care medicine to determine gas exchange which reflects gas exchange across the alveolar- capillary membrane
What are the possible complications of arterial blood gas?
- Pts with severe coagulopathy at higher risk of bleeding complications
What is an aspirin overdose?
Excessive ingestion of aspirin causing toxicity
What is the aetiology of aspirin overdose?
Overdose can occur as result of deliberate self-harm, suicidal intent of by accident (e.g. in children). Ingestion of 10-20g can cause moderate-to-severe toxicity in adults
How does aspirin overdose cause toxicity?
- Aspirin (acetylsalicylate) increases resp rate and depth by stimulating the CNS respiratory centre
- This hyperventilation produces respiratory alkalosis in the early phase.
- The body compensates by increasing urinary bicarbonate and K+ excretion, causing dehydration and hypokalaemia - Loss of bicarbonate together with the uncoupling of mitochondrial oxidative phosphorylation by slicyclic acid and build up of lactic acid can lead to metabolic acidosis
- In severe overdoses, CNS depression and respiratory failure can occur
What is the epidemiology of aspirin overdose?
One of the most common drug overdoses
What are the presenting symptoms of aspirin overdose?
- Ascertain key facts: How much? When? Any other drugs? Have you had any alcohol?
- Pt may initially be asymptomatic
- Early symptoms: Flushes appearance, fever, sweating, hyperventilation, dizziness, tinnitus, deafness
- Late symptoms; Lethargy, confusion convulsions, drowsiness, respiratory depression, coma
What are signs of aspirin overdose on examination?
- Fever
- Tachycardia
- Hyperventilation
- Epigastric tenderness
What are the investigations for aspirin overdose?
- Blood: Salicylate levels, FBC, U&E, LFT, clotting screen, glucose and other drug levels. ABG: may show mixed metabolic acidosis and respiratory alkalosis
- ECG: May show signs of hypokalaemia- small T waves, U waves
What is a burns injury?
Injuries predominantly to the skin and superficial tissues, caused by heat from hot liquids, flame or contact with heated objects, electrical current or chemicals
What is the aetiology of a burns injury?
- Thermal burns; heat, hot liquids, flame, heated objects
- Electrical burns
- Chemical burns
- Non-accidental burns
What is the epidemiology of burns injuries?
In the UK, burn injuries are experienced by about 250,000 people each year. Approximately 175,000 people visit A&E departments with burn injuries each year, and some 13,000 of them are admitted to hospital for treatment
What are the presenting symptoms of a burns injury?
- Presence of risk factors: young children, age over 60, male
- Painful and dry burns
- Wet and painful burns
- Dry and insensate burns
What are the signs of a burns injury on examination?
- Erythema
- Burns affecting subcutaneous tissue, tendon or bone
- Cellulitis
- Clouded cornea
What are the investigations for burns injuries?
- FBC: May show low haematocrit, hypovalaemia, neutropenia, thrombocytopenia
- Metabolic panel: May show high levels of urea, creatinine, glucose, hyponatraemia, hypokalaemia
- Carbocyhaemoglobin: high levels in inhalation injury
- ABG: metabolic acidosis in inhalation injury
- Fluorescein staining: damaged corneal epithelial cells in corneal burns
- CT scan of head and spine: May show brain injury or fracture in cases of head or spine trauma
- Wound biopsy culture
- Wound histology: may show infection
What is an epidural?
Medical route of administration in which a drug or contrast agent is injected into epidural space of the spinal cord
What are the indications for an epidural?
- Analgesia
- Adjunct to general anaesthesia
- Sole technique for surgical anaesthesia
- Post-operative analgesia
- Treatment of back pain
- Treatment of chronic pain or palliation of symptoms in terminal care: usually in short or midterm
What are the possible complications of an epidural?
- Failure to achieve analgesia or anaesthesia resulting in: obesity, multiparity etc
- Accidental dural puncture with headache
- Delayed onset of breastfeeding and shorter duration of breastfeeding
- Catheter misplaced into subarachnoid space
- Epidural abscess formation
- Epidural haematoma
- Paraplegia
- Arachnoiditis
- Death is extremely rare
What is an extradural haemorrhage?
Bleeding and accumulation of blood into the extradural space
What is the aetiology of an extradural haemorrhage?
- Trauma
- Most commonly fractures of the temporal or parietal bones causing rupture of the middle meningeal artery
What are the risk factors for an extradural haemorrhage?
- Haemorrhagic diathesis (e.g. haemophilia, anticoagulation therapy
- Dural vascular anomalies (e.g. dural AVMs)
What is the epidemiology of extradural haemorrhages?
- 10% of severe head injuries
- Most commonly seen in young adults
- Uncommon in elderly (subdural haemorrhages more common in that age group)
What are the presenting symptoms of an extradural haemorrhage?
- Head injury with a temporary loss of consciousness
- Followed by a lucid interval
- Then development of progressive deterioration in conscious level
What are the signs of an extradural haemorrhage on examination?
- Signs of scalp trauma or fracture
- Headache
- Deteriorating GCS, signs of raised ICT (e.g. dilated unresponsive pupil on the side on the injury)
- Rising BP and bradycardia (Cushing’s reflex) is a late sign
What are the investigations for an extradural haemorrhage?
Urgent CT can
- Diagnostic and identifies location of haematoma
- An arterial bleed produces a convex or lens-shaped haematoma
- Associated signs of raised ICP include midline shift, compression of ventricles, obliteration of basal cisterns sulcal effacement
What is a head injury?
Any injury that results in trauma to the skull or brain
- This broad classification includes neuronal injuries, hemorrhages, vascular injuries, cranial nerve injuries, and subdural hygromas, among many others.
What is the aetiology of head injury?
- Motor vehicle traffic collisions
- Home and occupational accidents. falls and assaults
- Wilson’s disease
What is the epidemiology of head injuries?
Leading cause of death in many countries
What are the signs and symptoms of head injury?
Varies according to injury
- Some pts with head trauma stabilise and other pts deteriorate
- May present with or without neurological deficit
- Coma, confusion, drowsiness, personality change, seizures, nausea and vomiting, headache, lucid interval
What are the investigation for head injuries?
- Non contrast CT head
- MRI
What is multi-organ dysfunction syndrome?
Altered organ function in an acutely ill patient requiring medical intervention to achieve homeostasis
- Involves 2 or more organ systems
What is the aetiology of multi-organ dysfunction system?
- Usually results from infection, injury (accident, surgery), hypoperfusion and hypermetabolism
- Primary cause triggers an uncontrolled inflammatory response
- Sepsis is most common cause
- Sepsis may result in septic shock
- In absence of infection -> SIRS
- SIRS + infection -> sepsis -> Severe sepsi -> Multi-organ dysfunction syndrome
What are the presenting symptoms of multi-system organ failure?
- Head and neck infections: Ear age, sore throat, sinus pain, swollen lymph nodes
- Cough, pleuritic chest pain, dyspnoea
- Abdo pain, nausea, vomiting, diarrhoea
- Pelvic or flank pain, vaginal or urethral discharge, urea, frequency, urgency
- Focal pain or tenderness, focal erythema, oedema
What are the signs of multi-system organ failure on examination?
- Profound depression in mental status and meningismus
- Inflamed or swollen tympanic membranes, sinus tenderness, pharyngeal exudates, stridor, cervical, lymphadenopathy
- Localised or evidence of consolidation
- Regurgitant valvular murmur
- Focal tenderness, guarding or rebound, rectal tenderness or swelling
- Costovertebral angle tenderness, pelvic tenderness or cervical motion pain
- Focal erythema
- Petechiae and pupura
What are the investigations for multi-organ dysfunction syndrome?
Four clinical phases have been suggested:
Stage 1 the patient has increased volume requirements and mild respiratory alkalosis which is accompanied by oliguria, hyperglycemia and increased insulin requirements.
Stage 2 the patient is tachypneic, hypocapnic and hypoxemic; develops moderate liver dysfunction and possible hematologic abnormalities.
Stage 3 the patient develops shock with azotemia and acid-base disturbances; has significant coagulation abnormalities.
Stage 4 the patient is vasopressor dependent and oliguric or anuric; subsequently develops ischemic colitis and lactic acidosis.
What is an opiate overdose?
When larger quantities than physically tolerated are taken, resulting in CNS and respiratory depression, miosis and apnoea, which can be fatal if not treated rapidly
What is the aetiology of an opiate overdose?
- Complications of substance abuse in regular users/abusers of illict or prescription opioids
- Unintentional overdose in pts prescribed opioids for pain by taking larger amounts than tolerated
- Intentional overdose and intent of self-harm (suicidality)
- Therapeutic drug error: iatrogenic overdose by a practitioner unfamiliar with opioid prescribing, or an adverse drug reaction
What is the epidemiology of opiate overdoses?
- Growing problem worldwide
- Heroin overdose comprises the majority of opiate-related mortality
- Most deaths from overdoses occur in male IV heroin abusers in their 20s and 30s using heroin for 5 to 10 years
What are the presenting symptoms of opiate overdoses?
- Presence of risk factors: opioid abuse and dependence, recent abstinence in chronic users
- Altered mental status
- Fresh needle marks
- Drug paraphernalia nearby
- Old track marks on arms and legs
What are the signs of opiate overdose on examination?
- Miosis
- Bradypnoea
- Dramatic response to naloxone
- Decreased GI motility
What are the investigations for opiate overdoses?
- Therapeutic trial of naloxene: reversal of overdose signs
- ECG: prolonged QRS or signs of MI
What is a paracetamol overdose?
Excessive ingestion of paracetamol causing toxicity
What is the aetiology of a paracetamol overdose?
Maximum recommended dose: 2 500mg tablets 4 times in 24h. Intake of more than 12g or over 150mg/kg can cause hepatic necrosis
What are the risk factors for a paracetamol overdose?
- Chronic alcohol abusers or those on enzyme inducing drugs (which increase cytochrome P450 activity e.g. anticonvulsants or anti-TB drugs), malnourished, anorexia nervosa, HIV more susceptible to toxic effects of paracetamol
- Overdose commonly associated with other substances such as alcohol
What is the epidemiology of paracetamol overdoses?
Most common intentional drug overdose in UK
- Females more than Males
- Deaths have been reduced by legislation in restricting pack sizes
What are the presenting symptoms of paracetamol overdoses?
Very important to ascertain timing and quantity of overdose, and presence of risk factors
- 0-24h: Asymptomatic or mild nausea, vomiting, lethargy, malaise
- 24-72h: RUQ abdo pain, vomiting
- Over 72h: Increasing confusion (encephalopathy), jaundice
What are the signs of a paracetamol overdose on examination?
- 0-24h: No relevant signs
- 24-72h: Liver enlargement and tenderness
- Over 72h: Jaundice, coagulopathy, hypoglycaemia and renal angle pain
What are the investigations for a paracetamol overdose?
- Paracetamol levels, 4h post ingestion (absorbed rapidly, hence these are peak plasma levels)
- Assess need to treat based on normogram
- FBC, U&Es, glucose, LFTs, clotting screen, lactate, ABG
