Flashcards in Misc Deck (180)
Management of paracetamol overdose?
IV acetylecysteine in 5% dextrose as a glutathione precursor and reduce the adverse affects (stop if anaphylactic reactions occur), methionine is alternative, gstric lavage, transplant, liver unit
if longer after overdose, toxbase
When should you discontinue treatment for paracetamol overdose?
bass on nomogram
When should you have a liver transplant for paracetamol induced acute liver failure?
arterial pH 3 after adequate fluid resuscitations
OR if all 3 occur in 24hrs
grade III/IV encephalopathy
Prognosis of paracetamol overdose?
What dose causes aspirin poisoning?
125mg/kg is mild toxitty, 250mg/kg is moderate toxicity and 500mg/kg is severe and potentially fatal
How does aspirin cause poisoning?
uncoupling of oxidative phosphorylation leading to anaerobic metabolism and lactate and heat production
Symptoms of aspirin poisoning?
mild - nausea, vomiting, tinitus
moderate - hyperventilation and confusion
severe - hallucinations, seizures, coma, cerebral oedema, pulmonary oedema
nausea, vomiting, tinnitus, lethargy, dizziness, dehydration, hyperthermia, hyperventilation, respiratory alkalosis, metabolic acidosis, seizures, fever, confusion, hallucinations, sweating, rapid pulse
Investigations for salicylate/aspirin poisoning?
plasma salicylate concentrations 2-4 hours post ingestion as it takes this long for concentration to peak, then another 2 hours post measurement and repeated every 3 hours until concentrations are falling
renal function and electrolyes, FBC, coagulation studies, urinary pH, blood glucose, plasma potassium every 3 hours, respiratory alkalosis, metabolic acidosis, high pH, CXR
Acid base staging of salicylate poisoning?
1 = pH>7.4, urine pH>6, resp alk, increased urine HCO3
2 = pH>7.4, urine pH7.4, urine pH
Management of salicylate poisoning?
oral activated charcoal if >125mg/kg 500mg/kg
What are organophosphate pesticides and how to they poison?
odourless liquids in sprays that inhibits ACh esterase so ACh accumulated at nerve synapses and neuro muscular junctions, stimulating muscuranic and nicotinic receptors and the CNS
Symptoms of pesticide poisoning?
pinpoint pupils, conjunctival injection, pain and blurred vision, headache, nausea, mild muscle weakness, localised muscle twitching, dizziness, disorientation, agitation, SOB, sweating, flushing, seizures, drooling, bronchospasm, twitching, coma
Investigations of pesticide poisoning?
decontaminate patient, obtain samples, plasma cholinesterase level to screen for exposure
RBC cholinesterase correlate with severity and prognosis
mixed cholinesterase determines if sufficient pralidoxime has been given
Management of pesticide poisoning?
wear gloves, removed soiled clothes, wash skin, take blood
atroping IV 2mg/10minutes until full atropinisation
pralidoxime 30mg/kg IVI, diazepam IV
ABC, control haemorrhage , ABGs, UandEs, glucose, monitor ECG, EEG
What is atropinisation?
skin dry, pulse >70, pupils dilated
Complications of pesticide poisoning?
resp failure, poor conc and memory and PTSD
What is HIV?
human immunodeficiency virus, an RNA retrovirus of the lentiviruses genus which causes AIDS
How is HIV transmitted?
heterosexual sex in africa, homosexual sex in uk, shared contaminated needles, contaminated blood transfusions, vertical transmission through placenta and breast milk
Risk factors for HIV?
increase in sexual partners, sexual contact with those from a high prevalence, occupation due to needles, having other STIs
Epidemiology of HIV?
falling deaths but increased infection and prevalence, high cost from treatment, social care, lost working days, benefits claimed, associated costs, 25% are undiagnosed, and 1/6 are >55
What is the HIV point of care test?
a fingerprick blood test
Advantages and disadvantages of the HIV point of care test?
D - lower sensitivity and specificity and gives false positives and negatives, missed window periods
A -convenient, increased access, reduces transmission, early diagnosis, non specialist clinics
The law on HIV?
illegal to transmit the infection if you know you are at risk
Prevention of HIV?
circumcision, screen blood products, reduce needle excnahge, post exposure prophylaxis, sex education, reduce partner exchange, use condom, highly active antiretroviral therapy, PEP, screening, avoid ulcers, remove Langerhan cells
What is involved in HIV screening?
>99% detectable post 12 weeks
4th gen with IgM and P24 antigen is
Symptoms of HIV?
fever, arthralgia, myalgia, lethargy, lymphadenopathy, sore throat, mucosal ulcer, maculopapular rash, head ache, photophobia, myelopathy, neuropathy
What are the two types of HIV-1?
type M (main) - more prevalent in Europe, America and sub sahara afric
type 0 (outlying) - mainly in cameroon
Where does HIV-2 mainly occur?
confined to west africa
Pathophysiology of HIV?
infects CD4+T cells binding to its receptor and co receptor sites which interact with protein complexes gp120 and gp41 in the viral envelope
the gp120 receptor complex promotes binding to the coreceptor, inducing a change in gp120 so gp41 can unfold and insert its hydrophobic end into the cell membrane
gp41 folds back on its self to bring the virus towards CD4 to fuse membranes
viral nucelocapsid enters the host cell and releases 2 viral RNA strands and 3 replication strands (reverse transcriptase, integrase and protease)
reverse transcriptase causes revers transcription on viral RNA then transcribed into a double helix which is integrated into the host DNA using integrase to now be manufactured into new virons
protease cleaves longer proteins into smaller ones to create an infectious viral
the 2 viral RNA strands and the replication enzyme comes together and surrounded by core proteins forming the capsid and leave the cell to mature and infect other cells
leads to a gradual CD4 decline