EmergencyMed Flashcards
Causes of cardiac arrest, briefly?
Hs and Ts
Hs: hypovolemia, hydrogen ions, hyper/hypoglycemia, hypo/hyperkalemia, hypoxia, hypothermia
Ts: tablets/toxins, tamponade, tension pneumothorax, thrombosis (MI), thromboembolism (PE), trauma
How can you tx hyperkalemia?
- Ca++ administration to stabilize cardiomyocyte electrochem potentials and thus prevent fatal arrythmias
- Nebulized salbutamol
- IV insulin (usually with glucose and bicarb) to drive K+ into cells
- loop diuretics like furosemide to spill potassium in urine
- sodium polustyrene sulfonate to bind K+ to excrete in stool
- emergent hemodyalisis
How do you treat HYPOkalemia?
Give IV K+
How do you treat hypoxia?
- Give OXYGEN
- Proper ventilation
- Good CPR technique
If cyanide or CO poisoning —> HYPERBARIC OXYGEN
How do you treat hypothermia (core temp < 35ºC)?
- Cadiac bypass
- Irrigation of body cavities with warm fluids
- Warmed IV fluids
How do you treat hypovolemia?
- IV fluid resuscitation (if in hypovolemic shock, use 2 16 gage (large bore) IVs)
- Blood transfusion
- CONTROL BLEEDING
In hyperglycemia that causes DKA and cardiac arrest, how should you treat the patient?
Correct the metabolic acidosis.
How do you treat hypoglycemia (ex. in the scenario of syncope/cardiac arrest)?
Give IV glucose.
Which tablets or toxins can cause cardiac arrest?
- Tricyclic antidepressants
- Phenothiazides
- Beta blockers (antihypertensive, antiarrhytmic)
- CCBs (antiarrhythmic, antihypertensive)
- Digoxin (ionotrope)
- COCAINE
- Aspirin
- Paracetamol/acetaminophen
- Acetaminophen
How do you treat cardiac arrest due to tablets or toxins?
Give fluids for volume expansion
Use specific antidotes
- Give NaHCO3 if TCAs
- Use benzos if cocaine
- Use glucagon or Ca++ for CCBs
As a last resource, cardiopulmonary bypass
How do you treat cardiac tamponade?
Pericardiocentesis
Pericardial window
How do you treat a tension pneumothorax?
Needle decompression thoracotomy, with the largest needle you can get.
LATER: chest tube decompression to definitively drain the (hemo)pneumothorax.
Where should you insert the needle for a needle decompression thoracotomy?
Insert needle in the 2nd intercostal space in the mid-clavicular line.
In obese patients, go through the axilla.
Where do you insert a chest tube to drain a (hemo)pneumothorax?
5th intercostal space, in the mid-axillary line.
Dissect ABOVE the rib, because the neurovascular bundle is just BELOW the rib.
How do you treat a myocardial infarction in the ED (i.e. “thrombosis” in the Hs and Ts mnemonic)?
- Rescucitation (ABC)
- OMI (oxygen, monitors/EKG, and IVF)
- MONA (morphine, oxygen, nitrates, aspirin)
- Antiplatelet therapy (plavix = clopidogrel)
- Thrombolytic therapy
- Percutaneous coronary intervention
How do you treat thromboembolic causes of cardiac arrest (i.e. a hemodynamically significant pulmonary embolism)?
Thrombolytics or thrombolectomy.
Prognosis is POOR.
What is commotio cordis?
A form of CARDIAC ARREST.
An often lethal disruption of heart rhythm that occurs as a result of a blow to the area directly over the heart (the precordial region), at a critical time during the cycle of a heart beat causing CARDIAC ARREST. It is a form of ventricular fibrillation (V-Fib), not mechanical damage to the heart muscle or surrounding organs, and not the result of heart disease.
What are risk factors for acute coronary syndrome?
Smoking HTN DM Hypercholesterolemia Age Family history of CAD in < 55 yo in 1st degree relative Prior personal history of CAD or PVD
How often is ST segment elevation seen on ECG in acute MIs?
50%
Which cardiac markers can you order to aid in the diagnosis of acute coronary syndromes (ACS)?
Is there another type of lab test you would also want to order?
The cardiac markers are:
- CK-MB (creatine kinase)
- Troponin- The most sensitive and specific test for myocardial damage. Because it has increased specificity compared with CK-MB, troponin is a superior marker for myocardial injury.
Troponin isoforms T and I are specific to the myocardium: Tn-I is similar to CK-MB but duration of elevation is 5-10 days; Tn-R is less sensitive, but is an independent marker for CV risk.
ALSO, would want to order a BMP to assess electrolytes and renal function because if the patient is going to the cath lab, they are going to get IV contrast.
What are the drawbacks of CK-MB as a diagnostic marker for acute coronary syndromes?
- It takes a while to elevate. Elevation @3-12 hours, peak @18-24h, and duration is 2 days. Therefore, while it is > 90% sensitive for MI for 5-6h after symptom onset, it is only 50% sensitive shortly after presentation.
- Becomes less specific when skeletal muscle damage is present.
What is the differential diagnosis for cardiac troponin elevation?
- Acute infarction
- Severe pulmonary embolism causing acute right heart overload
- Heart failure
- Myocarditis
Why is aspirin an important medication for preventing and treating acute coronary syndromes?
Aspirin inhibits thromboxane A2.
This inhibition leads to decreasing platelet aggregation.
How do nitrates help in treating acute coronary syndromes?
Nitrates (or nitrovasodilators), are prodrug pharmaceutical agent that cause VASODILATION by donation of nitric oxide (NO) via various mechanisms (many of which are enzymatically mediated).
The most important effect in angina is the widening of veins, which increases their capacity to hold blood and reduces the pressure of the blood returning to the heart (the preload). Widening of the large arteries also reduces the pressure against which the heart has to pump, the afterload. Lower preload and afterload result in the heart needing less energy and thus less oxygen. Besides, NO donated by nitrovasodilators can reduce coronary spasms, thus increasing coronary perfusion.
