A 40 yo is brought to the emergency department with the following vitals: GCS 4 SBP 70mmHg HR 140 RR 50 T 39C There are no signs of injury. Heart sounds are dual and no extra sounds. There are reduced breath sounds and crepitations in the left base. The abdomen is soft and the patient appears to have peripheral cyanosis. The patient has a known history of IVDU and has been found in a chair, not rousable. An ECG is done. What does the ECG show? Take a few moments to consider the ECG. What is your most likely diagnosis?
Post-quiz: It could be Acute AMI
If we use the ‘ECG in 20 Seconds Approach’ to describe the ECG, we get the following:
Rate/Rhythm
106
Is it sinus?– P waves are upright in II and inverted in aVR; Yes
Is there a P for every QRS? Yes
QRS:
Is it tall/small?: It’s about right, there is no hypertrophy.
Is it wide/narrow? It’s narrow
Is it of abnormal morphology ie., delta wave? No
Is it clumped?(just incase we miss a Mobitz- but it’s not slow enough) No
ST-T
Remember the baseline is the T-P line
If we look we see that there is some ST elevation in some areas of the ECG of about 1mm, although this is difficult to gauge as the T wave goes straight into the p wave.
The most visible abnormality is the inverted T waves.
What causes inverted T waves?As this is an adult patient we can overlook the T wave inversion of childhood. Other prominent causes are:
Acute Myocardial Infarction
Ventricular Hypertrophy( not present on this ECG)
Pulmonary Embolism
Raised Intracranial Pressure( I would usually expect them to be deeper)
PR and QT Intervals
The PR is normal and the QT is very prolonged.
PACING Spikes:
None.
Post-quiz: It is probably Raised Intracranial Pressure.
If we use the ‘ECG in 20 Seconds Approach’ to describe the ECG, we get the following:
Rate/Rhythm
106
Is it sinus?– P waves are upright in II and inverted in aVR; Yes
Is there a P for every QRS? Yes
QRS:
Is it tall/small?: It’s about right, there is no hypertrophy.
Is it wide/narrow? It’s narrow
Is it of abnormal morphology ie., delta wave? No
Is it clumped?(just incase we miss a Mobitz- but it’s not slow enough) No
ST-T
Remember the baseline is the T-P line
If we look we see that there is some ST elevation in some areas of the ECG of about 1mm, although this is difficult to gauge as the T wave goes straight into the p wave.
The most visible abnormality is the inverted T waves.
What causes inverted T waves?As this is an adult patient we can overlook the T wave inversion of childhood. Other prominent causes are:
Acute Myocardial Infarction
Ventricular Hypertrophy( not present on this ECG)
Pulmonary Embolism
Raised Intracranial Pressure( I would usually expect them to be deeper)
PR and QT Intervals
The PR is normal and the QT is very prolonged.
PACING Spikes:
None.
Post-quiz: The patient is also febrile. Why? Remember this patient has a history of IVDU, so infective endocarditis is a consideration. The patient may also have meningitis. The fever may also be secondary to stroke as we know that about 50% of stroke develop a fever, which in itself is a marker of severity and marker of mortality.
What other investigation/s could assist with this patient's definitive diagnosis?
Post-quiz: The Echo may show the heart motion, but the CT will show if this is a neurological cause.
Here is what happened:
Is this overdose related? There are no signs of classic QRS widening of Na channel blockade, or a terminal R wave in aVR.
It might be an AMI, there may have raised intracranial pressure given the decreased conscious state, but that may be due to low blood pressure.
The patient is also febrile. Why? Remember this patient has a history of IVDU, so infective endocarditis is a consideration. The patient may also have meningitis. The fever may also be secondary to stroke as we know that about 50% of stroke develop a fever, which in itself is a marker of severity and marker of mortality.
Let’s narrow it down to 2 causes:
AMI and
Raised intracranial pressure.
Raised intracranial pressure ECG’s have deep T wave inversion and a prolonged QT.
Echo showed a myocardium, not contraction properly. The CT brain gave the diagnosis of a large subarachnoid haemorrhage.
This is a neurocardiogenic phenomenon when the heart is affected by deranged autonomic supply coming from a damage to the brain.
MCQs in Emergency Medicine
A 28 year old woman presents with a suspected overdose. Your registrar suspects Neuroleptic Malignant Syndrome. The patient's vitals are as follows: T 38.2, BP 88/50mmHg, RR 22, O2 sats 98% on room air. Which of these do not fit with that diagnosis?
It occurs in the first few days of commencing neuroleptic Agents
Neuroleptic malignant syndrome (NMS) is a rare, but life-threatening, idiosyncratic reaction to neuroleptic medications that is characterized by fever, muscular rigidity, altered mental status, and autonomic dysfunction. NMS often occurs shortly after the initiation of neuroleptic treatment, or after dose increases. The key to diagnosis is that NMS occurs only after exposure to an neuroleptic drug. On average, onset is 4-14 days after the start of therapy; 90% of cases occur within 10 days. However, NMS can occur years into therapy. Once the syndrome starts, it usually evolves over 24-72 hours.
Charcoal is of least use in which of the following?
- Salicylates
- Paracetamol
- Organophosphates
- Methanol
- Diazepam
Methanol
Activated charcoal is an inert, non toxic adsorbent with a surface area up to 2000 m2/gram. It is made from a controlled pyrolysis of coconut shells, bone, sucrose, peat, lignite (coal), wood or petroleum that ultimately, produces charcoal. It is activated by heating it in steam, air or carbon dioxide at high temperatures (600-900º C). Drugs and chemicals known to have little effect from the administration of activated charcoal include common electrolytes, iron, mineral acids or bases, alcohols, cyanide, most solvents, water insoluble compounds such as hydrocarbons, lithium and other heavy metals.
In a febrile limping child, septic arthritis is MORE likely than transient synovitis if:
CRP > 12
Post-quiz: Significant overlap in clinical appearance and investigation results of febrile limping child.
Transient synovitis most common 72% in 3-8 years olds
Clinical appearance of temp < 38.5, limited weight bearing, moderate limitation range of motion, no
obvious local source of infection, non-tender joints/adjacent bones is also consistent with septic
arthritis.
Controversy about diagnosis of septic arthritis with regard to investigation results:
WCC > 20 000 more likely septic arthritis/osteomyelitis (SA/OM) – classically
WCC > 12 000 common with left shift up to 70% SA and up to 20% SA
ESR >20 could be either; ESR >50-70 more likely septic arthritis
CRP > 12 strongly suggestive of septic arthritis
Synovial fluid cultures negative 40%/positive 60% due to bacteriostatic properties of synovial fluid.
Synovial fluid WCC < 100 000 and Neut < 75% may not be septic arthritis. Threshold WCC in synovial
fluid for definite septic arthritis is controversial.
USS good modality looking for effusions and also USS guided aspiration of hip joints
Xray recommended with trauma, bony destruction of OM late sign >10 -14 days, also detects AVN
(CHD (0-4 years old) and Perthe’s (4-8 years old), SUFE (12-16 years old) and bone tumours
Bone scan 2-3 days delay positive result for OM, DDx, Perthe’s, stress fractures
MRI especially for AVN
RF/Anti-CCP Aby, ANA, Complement levels, Uric acid useful for other causes of limping child
A 65 -year-old man presents to the emergency department complaining of severe right-sided abdominal pain. The pain radiates from his right flank towards his right groin, and is occurring in paroxysms which leave the patient extremely distressed. There is no relevant medical history. The patient's vital signs are: Heart rate 98 BP 162/ 98 mmHg Temperature 37.1°C Respiratory rate 22 /min Oxygen saturations 99% on room air. The nurses report that the patient's urine dipstick is negative for blood, leucocytes, and nitrates. Which of the following best applies?
Although 90% of urinary stones are radiopaque the sensitivity of plain radiographs for renal calculi is between 50 and 60%
The negative predictive value of haematuria for renal colic is 65% (Luchs et al, Urology 2002). A contrast scan will obscure the ureter, and make diagnosis of a stone impossible. Ultrasound does not give any information about whether an aneurysm has ruptured or not. The figures quoted for plain radiographs are correct.