Educational Objective:

Recall the importance of a normal pCO2 in patients following cardiac arrest and resuscitation.

Key Point:

pCO2 values above 35-45 mm Hg results in cerebral vasoconstriction due to compensatory hyperventilation.

Explanation:

A number of studies have shown that hospital survival after cardiac arrest is increased if normocarbia is maintained. After cardiac arrest and resuscitation, a pCO2 value should be between 35 to 45 mm Hg to avoid cerebral vasoconstriction due to hypercarbia and resultant hyperventilation.  

References:

American Heart Association. Advanced Cardiovascular Life Support Provider Manual. 2016.

Manole MD, Fink EL., Arterial CO₂ Tension after Cardiac Arrest: Too little; Too much.  Resuscitation 2013; 84: 863-864

McKenzie N, Williams TA, et al. A systematic review and meta-analysis of the association between arterial carbon dioxide tension and outcomes after cardiac arrest. Resuscitation. 2017; 111: 116-126

Educational Objective:

Describe the manifestations of pericardial friction rub.

Key Point:

Patients with pericarditis may have a high-pitched, scratchy, cardiac sound in systole and diastole at the left sternal border called a pericardial friction rub.

Explanation:

The classic chest sound with acute pericarditis is a friction rub, which is a high-pitched, scratchy sound that begins in systole and goes through diastole, sometimes obscuring the first and second heart sounds. It is loudest at the left sternal border and is caused by the visceral pericardium rubbing against the parietal pericardium. It is present in 85% of patients with pericarditis.

PE rarely has a pleural friction rub (3% of patients). It is present on inspiration and expiration. A pericardial friction rub is present even when a person holds his or her breath.

Dressler syndrome occurs when a person develops pericarditis weeks to months following myocardial infarction, which was not part of the above patient’s history. This woman has clear lungs and is afebrile, so pneumonia is unlikely.

References:

Little WC, Freeman GL. Pericardial disease. Circulation. 2006;113(12):1622-1632.

Longo D, et al. Harrison’s Principles of Internal Medicine. 18th ed., 2012.

Educational Objective:

Discuss who should be screened for hepatitis B.

Key Point:

Pregnant women and people at high risk of infection should be screened for HBV.

Explanation:

The US Preventive Services Task Force recommends screening for HBV infection in pregnant women at their first prenatal visit and in persons at high risk for the infection. Persons at high risk for HBV infection include those born in countries and regions with a high prevalence of hepatitis B, US-born persons not vaccinated as infants whose parents were born in regions with a very high prevalence of hepatitis B (≥ 8%), such as Sub-Saharan Africa and southeast and central Asia, HIV-infected individuals, users of intravenous illicit drugs, men who have sex with men, and household contacts or sexual partners of persons with known HBV infection. The patient in this case, who was born in South Africa, is at risk for HBV and therefore should be screened.

Evidence suggests that universal prenatal screening for HBV infection significantly reduces perinatal transmission of the disease. Screening consists of a hepatitis B surface antigen (HBsAg) test followed by a licensed, neutralizing confirmatory test for initially reactive results. Testing for antibodies to HBsAg and hepatitis B core antigen is also performed as part of a screening panel to help distinguish between infection and immunity.

Reference:

LeFevre ML; U.S. Preventive Services Task Force. Screening for chlamydia and gonorrhea: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2014;161(12):902-910.

Educational Objective:

Review electrocardiographic criteria for conditions mimicking acute myocardial infarction.

Key Point:

Chest pain can indicate other conditions than acute cardiac syndrome. PE, aortic dissection, cardiac tamponade, tension pneumothorax, and esophageal rupture are all other emergent causes of chest pain.

Explanation:

The formerly "classic" pattern of S1, QIII, and TIII changes has been closely studied and is neither sensitive nor specific. Several studies have shown that a right ventricular strain pattern, as seen on this patient's ECG findings, is present in 34% of cases of PE. Right ventricular strain is noted by T-wave inversions in the right precordial leads V1 to V4, and it is often associated with inferior T wave inversions.

References:

ECG Courtesy of Mike Cadogan

Brown J.Chest pain. In: Marx J, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 8th ed., 2014:215.

Life in the Fastlane. The ECG in pulmonary embolism. Accessed May 15, 2017.

Educational Objective:

Identify the various traits of warfarin-reversing agents.

Explanation:

PCC has a rapid rate of temporary reversal. It is contraindicated in patients with an allergy to heparin or in those with heparin-induced thrombocytopenia.

FFP restores all clotting factors and has a very slow onset of action (range, 0.5-2 days). rFVIIa is a useful supplement to 3-factor PPC, although 10% of patients given it experience a significant thrombotic event. Vitamin K allows for permanent reversal, but its long-acting reversal makes it potentially undesirable.

References:

Frumkin K. Rapid reversal of warfarin-associated hemorrhage in the emergency department by prothrombin complex concentrates. Ann Emerg Med. 2013;62(6):616-626.

This story is a reminder that a single serum drug concentration represents a single point in time. In addition, the time of ingestion was not mentioned in the scenario. Although the patient's valproic acid level is therapeutic at this point, one does not know if the level is on its way up or down. Therefore, clearance at this point is not recommended; her level may dramatically increase over the next several hours; this is particularly true if her presentation is soon after ingestion. The patient is not yet manifesting any signs of toxicity; therefore, hospital admission is not indicated. Activated charcoal may assist with preventing absorption of any valproic acid that remains in the stomach and small intestine, and she currently has no contraindications (vomiting or a depressed level of consciousness) to this treatment option. In addition, a repeat serum level in a few hours is appropriate to determine the trend. This patient attempted to harm herself, so discharge to home is ill advised at this point.

Reference:
Doyon S. Anticonvulsants. In: Nelson LS, et al, eds. Goldfrank's Toxicologic Emergencies. 9th ed., 2011.

Using limited societal financial resources on programs that will positively affect the largest number of people with the lowest possible negative outcomes

Generally, the utilitarian principle refers to societal programs that will affect or benefit the largest number of people in a positive manner. It is not used to refer to an individual or to one person.

Widespread use of DNAR orders are limited more by lack of physician-patient communication regarding their implementation than by availability of process or forms. Prehospital providers and their medical directors should discuss cases involving DNAR to address potential conflicts, such as the relationship between patients with DNAR orders who have attempted suicide and patients with potentially reversible problems (e.g., choking on meat, anaphylaxis). Although specific comments on the DNAR order would assist in this decision, these are often not available. Wider utilization of DNAR orders with specific discussion and counseling of family members would help to clarify decisions regarding prehospital resuscitations in most circumstances.

When DNAR forms are not immediately available, maximal resuscitation should occur, including transport, regardless of the circumstances.

13-year-old being treated for a sexually transmitted disease

As soon as an individual turns 18, she or he legally becomes an adult and is automatically emancipated from parental custody and control. Likewise, when a minor marries or joins the armed forces (with parental consent and permission from the court), she or he becomes emancipated from her or his parents. In many states, a pregnant minor is considered an emancipated minor for the purposes of providing informed consent for her own treatment and the treatment of the fetus during the pregnancy and childbirth. For this principle to apply, however, the minor pregnant mother cannot have a cognitive disability that prevents her from giving informed consent for or refusing treatment.