In the US, approximately 200,000 people are diagnosed with a new or recurrent pulmonary embolism each year. More than twice this many are diagnosed with a DVT without PE, and 1 in 300 ER patients are diagnosed with a DVT. The lifetime risk of a DVT is 2-5%, and the incidence of DVT increases with age. DVTs can lead to a pulmonary embolism, which is one of the leading causes of sudden, nontraumatic death in the US. 

Most DVTs are unprovoked, with an increased risk for reoccurrence, requiring a longer treatment period than those with provoked DVTs from drugs, trauma, or surgery.

Typically, DVTs begin at the valves of the veins. Proximal DVT include Femoropopliteal (FP) ilieofemoral (IF) DVTs, and account for 80% of symptomatic DVTs. Distal DVTs of the calf account for only 20% of symptomatic DVTs. 

Dizziness can be difficult to assess in the ED given the vast range of etiologies and varying ways patients interpret their symptoms. Additionally, not all patients with emergency conditions will present with obvious focal deficits. A clinical decision making rule (HINTS) can help to more rapidly identify stroke patients to initiate acute therapies faster. The HINTS rule outperforms ABCD2  for stroke diagnosis in the ED when performed by qualified practitioners in patients with Acute Vestibular Syndrome. 

Typically, patients with peripheral vertigo appear to have an acute change and may be very ill appearing, with nausea and vomiting and severe vertigo symptoms. Those with central vertigo typically have a more insidious onset, constant symptoms, and typically less severe symptoms. 

Symptoms of a central vertigo may be difficult to identify. Typically, there are some of the "5 D's"

• Dizziness
• Dysarthria
• Diplopia
• Dysphagia
• Dysmetria
• Ataxia

Otitis externa is frequently caused both by swimmer and water exposure as well as the use of household items to 'clean out' the ear. This should be treated with cipro otic drops, and patients should not be placed on oral antibiotics as this will only increase the risk for fungal infection and not assist in treating the bacterial infection. Consider placing an ear wick to help increase the amount of antibiotic which reaches the infected area. 

An infection of the ear drum that causes severe pain and loss of hearing. On examination a red or clear blister will be present on the ear drum. Treatment is antibiotics and rupturing the blister. 

Typically due to blunt trauma or direct penetrating trauma from Q-tips or other objects. Ciprodex antibiotic drops, and water precautions should be given, as well as ENT followup. Those with severe symptoms such as hearing loss, vertigo, or nystagmus should have urgent ENT followup. 

Over 70% of OM is viral,  but it is difficult to determine viral vs bacterial. Most bacterial infections are strep pneumo (50%). On exam the patient will have bulging of the TM or an air-fluid level. To accurately diagnose OM, you should be unable to move the TM with suction. Treatment is to either wait and watch or provide high-dose amoxicillin. 

Acute loss of hearing without an external or conductive cause. It is sudden (<72 hours) and unilateral, caused by viral, ischemic, or auto-immune causes. Syphilis and idiopathic intracranial hypertension can both cause acute unilateral hearing loss. Many cases are idiopathic.  Treatment is either PO steroids or direct steroids to the middle ear, and urgent ENT followup. Antivirals should only be given if there are signs of a vesicular lesion. 

Patients presenting with symptoms of Bells Palsy should have a full history and physical examination to identify facial paralysis and possible causes, including evaluated for lesions of the TM concerning for Ramsay Hunt Syndrome. The AAO do not recommend routine lab testing or imaging in patients with Bell's Palsy, unless the patient lives in an area with endemic Lyme Disease. Patients should be treated with both oral antiviral AND oral steroid treatment together within 72 hours of symptom onset. Antiviral treatment alone is not recommended, however steroids alone may still have benefit. Patients should be sent home with eye protection and eye drops to prevent trauma and corneal abrasions or ulcers. AAO Guidelines. 

CPR induced consciousness is characterized by a patient waking up, moving their limbs, or even fighting responders during compressions. Typically, when the providers stop compressions, either for a pulse check or because of assumed ROSC, the patient stops moving and again goes unresponsive. This has been described in both pre-hospital and hospital settings, and with improvement of CPR quality, will occur more frequently. ​

For treating Candida Vaginitis in early pregnancy, ACOG recommends local treatment instead of oral diflucan.  This is based on studies that show higher doses (400-800 mg) of oral diflucan has been linked to birth defects.  Although a 2013 NEJM cohort study found no association between diflucan and birth defects. 

When treating pregnancy women for a UTI in early pregnancy, Nitrofurantoin or Bactrim are both not recommended as a first line agent.  A Case-Control study published in 2009 showed an association between treatment with these medications in first trimester and  malformations. While there are several limitations to this study, ACOG recommends avoiding these two medications in the first trimester.  During the 2nd and 3rd trimester, sulfonamides and nitrofurantoin may be used as first-line therapy. Prescribing these in the first trimester is still considered appropriate when no other alternative is available. 

Penicillins, erythromycin, and cephalosporins have not been found to have any associations with birth defects. 

Inhaled toxins frequently cause asphyxiation and can be classified further as chemical asphyxiants, simple asphyxiants, and pulmonary irritants.  

Chemical Asphyxiants include Hydrogen Sulfide and cyanide. Hydrogen sulfide typically presents with a sulfur-like smell, while cyanide is typically presented in the burning of plastics. 

Simple Asphyxiants are anything which replaces oxygen in the atmosphere, including carbon monoxide or dioxide, methane, helium, or nitrogen. These may be present in a mine or other industrial setting, and may classically present as an unconscious worker who was attempting to rescue another unconscious worker. 

Irritant gases cause pulmonary irritation from coughing to diffuse lung injury. Irritants are categorized by their solubility; highly soluble irritants typically have strong scents because they are easily mixed into the upper airway, while less soluble irritants are typically less rapid in onset and will result in lower airway complaints. 

• High Solubility: Rapid onset of symptoms and upper airway symptoms due to increased solubility. Will have strong scent. These include ammonia, formaldehyde, sulfuric acid, and chloramines.
• Intermediate Solubility: Chlorines & hydrogen sulfides. Slight delay in presentation
• Poorly Soluble: Perfluororisobutylene (PFIB) from burning plastics, phosgene. Delayed presentation and severe lower airway irritation. 

Utilization of blood cultures can assist the treatment of many patients, however not every patient requires blood cultures. Whenever drawn, you should obtain two sets of cultures (or 3 for endocarditis). A recent article found a number needed to treat was 250 for a change in treatment, however other studies have found blood cultures more useful.

Major Criteria:

• temperature > 39.5°C (103.0°F)
  
• indwelling vascular catheter
  
• clinical suspicion of endocarditis
  

Minor criteria

• temperature 38.3–39.4°C (101– 102.9°F)
  
• age > 65 years
  
• chills
  
• vomiting
  
• hypotension (systolic blood pressure < 90 mm Hg)
  
• neutrophil% > 80
  
• white blood cell count > 18 k
  
• bands > 5%
  
• platelets < 150 k
  
• creatinine > 2.0.
  

​www.sciencedirect.com/science/article/pii/S0736467908004447?via%3DihubA blood culture is indicated by the rule if at least one major criterion or two minor criteria are present.

Patients with CURB 65 scores 0-1 can potentially be discharged, however consider the patient's physical exam, oxygen saturation, and immunosupressed status, as the CURB 65 score does not take these into account. Those with a CURB 65 score greater than 3 should be considered for an ICU admission. 

The PSI/PORT score can also be used but is more thorough, including nursing home status, liver and heart disease status, as well as ABG data. While the CURB 65 has better specificity for identifying severe disease, the PSI/PORT score is more sensitive at identifying low-risk patients for discharge.

For CAP, guidelines recommend Azithromycin or Doxycycline as azythromycin has increasing rates of resistance. In outpatients with co-morbidities or risk for resistance, you should consider levofloxacin or moxifloxacin. Patients admitted for CAP should be treated with single agent fluoroquinolone or dual agent treatment with ceftriaxone and azithromycin. ICU admitted CAP patients require an anti-pneumococcal betalactam (Ceftriaxone) and either azithromycin or fluoroquinolone. Treatment duration is typically 5 days.