Critical Care Flashcards
What are some causes of chronic kidney disease?
Diabetic nephropathy
HTN
Glomerulonephritis
PCKD
Pyelonephritis
Obstructive nephropathy
What are the features of chronic kidney disease?
Fatigue
Anorexia
N+V
Anaemia
Plt dysfcuntion
Bony disease
Encephalitis/pericarditis (due to the high urea).
What are the stages of CKD?
1 = GFR >90 (required RF management).
2= GFR 60-90
3 = GFR 30-60 (needs to manage any complications e.g. K+ restriction, protein restriction and consider EPO)
4= 15-30
5= <15 (needs dialysis/transplant
What are the advantages and disadvantages or dialysis?
Haemodialysis:
Advantages - shorter treatment, efficient K+ removal.
Disadvantages - required heparin, needs a fistula, large fluid shift, BP control is harder, requires hospital.
Peritoneal dialysis:
Adv - lower biochemical changes, higher Hct, self care
Disadv - peritonitis, hernia
What are the types of AV fistula?
Autologous - direct joins of veins to arteries.
Autologous bridge - uses a vein graft
Synthetic
What are the complications of an AV fistula?
Nerve Injury
Thrombosis
Steal phenomenon
Venous HTN
What is the difference between haemofiltration and haemodialysis?
Haemodialysis: requires dialysis fluid. The blood and the dialysis fluid flow in counter current on either side of a permeable membrane to allow osmotic pressure gradient to filter blood.
Haemofiltration: filters blood via hydrostatic pressure.
What is an embolus?
This is an abnormal mass of material that travels in the flowing circulation from one part of the body to another.
What causes necrotising fasciitis?
- Necrotising fasciitis may be caused by a solitary organism or a combination.
- Group A haemolytic streptococci and Staphylococcus aureus frequently initiate infection, followed by anaerobes, such as Bacteroides spp. and clostridium spp., and coliforms, Proteus
spp., Pseudomonas spp. and Klebsiella spp.
What is the role of hyperbaric oxygen therapy in necrotising fasciitis?
It improves the oxygenation to infected wounds, it has a bactericidal effect and improves healing.
What is gas gangrene?
This is a particularly severe form of necrotising fasciitis which is caused by Clostridium perfringens. The necrosis can destroy subcutaneous tissue and muscle rapidly, with copious gas production.
What conditions may you need to measure ICP?
Traumatic brain injury
Intracerebral/subarachnoid haemorrhage
Hydrocephalus
Malignant Infarction
Cerebral oedema
CNS infection
Hepatic encephalopathy
What is the normal ICP?
7-15mmHg
What are the ways to measure ICP?
- Intraventricular catheter (GOLD STANDARD but most invasive).
- Intraparenchymal probe
- Subarachnoid probe
- Epidural probe
- Lumbar puncture
- Tympanic membrane displacement
- Transcranial doppler
What is the Cushing reflex?
This is a physiological nervous system response (with mixed vagal and sympathetic stimulation) to an elevated ICP that results in Cushing’s triad. It leads to hypertension, which ensures an adequate CPP.
What are the symptoms of raised ICP?
Headache
Nausea
Vomiting
Papilledema
Fall in GCS (pressure symptoms and ischaemia)
Dilated pupil due to oculomotor nerve palsy
Defect in lateral gaze
Cushing’s triad
How would you manage a raised ICP?
- Improve venous drainage from the brain: elevate the head of the bed to 30, ensure ties holding the endotracheal tube do not compress the neck veins
- Reduce cerebral oedema with mannitol +/- furosemide. Maintain sodium levels at a range of 140-145mmol/l
- Reduce the cerebral metabolic rate: avoid hyperthermia, sedation, anticonvulsants, thiopentine infusion reduces the cerebral metabolic rate.
- Reduce intracranial blood volume: hyperventilation can be used to reduce PaCO2 as a temporary measure.
- Reduce CSF volume: drains
- Surgical decompression.
What does loss of grey-white mater suggest?
This is the areas of the brain that contain nerve cell bodies, this can cause long-lasting cognitive dysfunction.
What is the management of an acute subdural haematoma?
Urgent surgical evacuation of haematoma for:
- acute SDH +/- coma, with neurological deterioration.
- clot thickness 10mm or midline shift >5mm on initial brain CT
- Signs of neurological deterioration or persistently increased ICP (>20mmHg)
What are the advantages of a tracheostomy tube?
Easier to clean mouth and face
Better tolerated in the long term
Less likely to aspirate
May help weaning off ventilator
Allows swallowing
Less dead space
What is the management of a liver laceration?
Conservative: Blood transfusion and monitoring.
Surgical: damage control: perihepatic packing, repair or resection.
What four areas are typically examined in a FAST scan?
Peri-hepatic space, peri-splenic space, pericardium and pelvis.
What are the grades of liver tear?
Grade 1:
Haematoma: subscapular <10%
Laceration: capsular tear: <1cm depth
Grade 2:
Haematoma: subscapular 10-50%
Intraparenchymal haematoma: <10cm diameter
Laceration: 1-3cm depth and <10cm length
Grade 3:
Haematoma subscapular: >50% of SA
Intraparenchymal haematoma: >10cm or expanding
Laceration: capsular tear >3cm depth.
Grade 4:
Laceration involving 25-75% of hepatic lobe or 1-3 segments.
Grade 5:
Laceration involving >75% of hepatic lobe or >3 segments
Vascular injury
Grade 6: Hepatic avulsion
What are the types of shock?
Distributive: septic, SIRS, neurogenic, anaphylactic, endocrine
Cardiogenic
Hypovolaemia (haemorrhagic and non-haemorrhagic)
Obstructive