Diarrhea: Approach (Harrison)

Diarrhea: Approach (Harrison)

The decision to evalute acute diarrhea depends on its severity and duration and on various host factors Most episodes of acute diarrhea are mild and self-limited, and they do not justify the cost and potential morbidity of diagnostic or pharmacologic interventions. Indications for evaluation include profuse diarrhea with dehydration, grossly bloody stools, fever 38.5 C, duration >48 h without improvement, new community outbreaks, associated severe abdominal pain in patients older than 50 years of age, and elderly (70 years) or immunocompromised patients. In some patients with moderately severe febrile diarrhea with fecal leukocytes (or increased fecal levels of the leukocyte proteins lactoferrin or calprotectin) present or with dysentery, a diagnostic evaluation might be eschewed in favor of an empiric antibiotic trial.

The cornerstone of diagnosis in those suspected of severe acute infectious diarrhea is microbiologic analysis of the stool. Workup includes cultures for bacterial and viral pathogens, direct inspection for ova and parasites, and immunoassays for certain bacterial toxins (C. difficile), viral antigens (rotavirus), and protozoal antigens (Giardia, E. histolytica). The aforementioned clinical and epidemiologic associations may assist in focusing the evaluation. If a particular pathogen or set of possible pathogens is so implicated, then either the whole panel of routine studies may not be necessary or, in some instances, special cultures may be appropriate as for enterohemorrhagic and other types of E. coli, Vibrio species, and Yersinia. Molecular diagnosis of pathogens in stool can be made by identification of unique DNA sequences; and evolving microarray technologies could lead to a more rapid, sensitive, specific, and cost-effective diagnostic approach in the future.

Persistent diarrhea is commonly due to Giardia, but additional causative organisms that should be considered include C. difficile (especially if antibiotics had been administered), E. histolytica, Cryptosporidium, Campylobacter, and others. If stool studies are unrevealing, then flexible sigmoidoscopy with biopsies and upper endoscopy with duodenal aspirates and biopsies may be indicated.

Structural examination by sigmoidoscopy, colonoscopy, or abdominal CT scanning (or other imaging approaches) may be appropriate in patients with uncharacterized persistent diarrhea to exclude inflammatory bowel disease, or as an initial approach in patients with suspected noninfectious acute diarrhea such as might be caused by ischemic colitis, diverticulitis, or partial bowel obstruction

A 75-year-old white female comes to your office with symptoms suggestive of vertigo. You maneuver the patient from a sitting position to a lying position, with her shoulders and head slightly off the edge of the table. Upon rotating the head to one side, you observe horizontal nystagmus. Upon repetition of this maneuver, the nystagmus becomes less prominent.

Which one of the following is the most likely diagnosis?


a.Vestibular neuronitis
b.Acoustic neuroma
c.Viral labyrinthitis
d.Benign paroxysmal positional vertigo
e.Meniere's disease

D

This patient has a positive response to the Dix-Hallpike maneuver, which confirms the diagnosis of benign paroxysmal positional vertigo. The other conditions listed do not have a positional component.

A 48-year-old white female comes to see you because of abnormal vaginal bleeding. Her periods are lasting 3 to 5 days longer than usual, bleeding is heavier, and she has experienced some intermenstrual bleeding. Her physical examination is unremarkable, except for a parous cervix with dark blood at the os and in the vagina. She has no orthostatic hypotension, and her hemoglobin level is 11.5 g/dL. A pregnancy test is negative.

Which one of the following is the most important next step in management?


a.Laboratory tests to rule out thyroid dysfunction
b.An endometrial biopsy
c.Oral contraceptives, 4 times a day for 5 to 7 days
d.Cyclic combination therapy with conjugated estrogens (Premarin) and medroxyprogesterone acetate (Provera) each month
e.Administration of a gonadotropin-releasing hormone analog such as leuprolide acetate (Lupron)

B

A patient over the age of 40 who experiences abnormal vaginal bleeding must have an endometrial assessment to exclude endometrial hyperplasia or cancer. An endometrial biopsy is currently the preferred method of identifying endometrial disease. A laboratory evaluation for thyroid dysfunction or hemorrhagic diathesis is appropriate if no cancer is present on endometrial biopsy and medical therapy fails to halt the bleeding. The other options listed can be used as medical therapy to control the bleeding once the histopathologic diagnosis has been obtained.

Which one of the following has proven most useful for breast cancer screening in women who have had silicone breast implants?


a.Thermography
b.Ultrasonography
c.Mammography
d.Magnetic resonance imaging

C

Screening by conventional film-screen mammography, supplemented by the displaced or Eklund view, is the recommended method for breast cancer screening in women with breast implants. The displaced view draws the breast forward while placing the implant posteriorly, increasing the amount of breast tissue visualized. None of the other modalities has proven useful for screening asymptomatic women for breast cancer.

A 68-year-old Asian male complains of a 2-hour history of pain in the right leg. He first noted paresthesia of the foot and lower leg, then increasingly severe pain which he describes as excruciating. He had a myocardial infarction (MI) 6 years ago. He is diabetic and tries, with moderate success, to control his blood sugar. He quit smoking when he had the MI.

On examination, his right leg is cool compared to the left. The distal leg is pale. The foot and toes are very weak and sensation is diminished. No pedal pulse can be palpated on either side.

What is the most likely diagnosis?


a.Diabetic neuropathy
b.Acute arterial embolism to the femoral artery
c.Ruptured abdominal aneurysm
d.Sciatica
e.Left hemisphere cerebrovascular accident

B

Acute lower extremity arterial occlusion is an urgent medical emergency which occurs more often in the elderly. Almost all patients with acute embolism have preexisting heart disease. The diagnosis must be suspected immediately from the clinical presentation, if the limb is to be saved. The predominant symptoms are paresthesia and severe pain, and signs include pallor, pulselessness, paralysis, and coolness. Diabetic neuropathy would not, by itself, be expected to cause the sudden onset of symptoms. A ruptured abdominal aneurysm would cause some symptoms related to the back or abdomen. Sciatica is usually not associated with the sudden onset of a cool, pallid extremity. A cerebral vascular accident also does not lead to the combination of pain, pallor, and coolness. The absence of pulses in the other leg is easily explained by coexisting peripheral atherosclerosis caused by age and diabetes.

A 5-year-old white male is brought to your office for treatment 24 hours after being stung on the right hand by a bee. He has marked swelling of the right hand and forearm, redness, itching, and mild pain at the sting site. His mother says that the swelling began about 2 hours after the sting and is continuing to worsen. She is quite concerned and requests a referral to an allergist to have the child evaluated.

Which one of the following would be appropriate advice?



a.The child is unlikely to have anaphylaxis with subsequent stings, and he should be treated with antihistamines and antibiotics now
b.The child is unlikely to have anaphylaxis with subsequent stings, and he should be treated with antihistamines only now
c.The child's parents should carry an anaphylaxis emergency treatment kit with them at all times to treat future reactions
d.The child is at risk for anaphylaxis from subsequent insect stings, and immunotherapy may be appropriate
e.This type of reaction is not likely to occur with subsequent insect stings

B

This patient is experiencing a large local reaction to an insect sting. Symptoms usually worsen for 48 hours and may last up to 7 days. People who have had large local reactions to stings tend to have similar reactions after subsequent stings. The risk of anaphylaxis is less than 5% per episode. Immunotherapy will not prevent large local reactions, thus venom skin tests serve no purpose. An anaphylaxis emergency kit (Ana-Kit) is designed to treat anaphylactic reactions and would not be appropriate for this patient. Antihistamines and aspirin, with or without short-term steroid therapy, constitute appropriate treatment. Cellulitis rarely develops after an insect sting, and antibiotics are not indicated in most cases.

63 year-old wm presents with six-day hx of unstable angina at night between 1 and 3 am. He has a 10-year history of mild type II diabetes, high cholesterol, an inferior wall AMI 20 years ago and a stroke 16 years ago that has left him with right hemiparesis, and moderate aphasia and a 100% occlusion of his left carotid artery and 40-50% stenosis of his right carotid artery. Family hx is significant for heart disease in his father and severe diabetes in his mother.
At the time of admission seven days ago he had a BP 190/110 and a pulse 100. Cardiac enzymes were negative. Since his admission he has been symptom-free.
Prior to discharge a stress test revealed significant ST segment depression in V4-5. Cardiac echo shows mild concentric left ventricular hypertrophy, good systolic function and baseline hypomotility of inferior wall (unchanged). Medications include a nitroglycerin-patch, aspirin, a statin, a benzodiazepine, enalapril and a beta blocker.
What is your next step in management?
Is coronary angiography indicated?
Given his carotid status is CABG or PTCA absolute or relative contraindicated? Prognosis?
Thanks

Do not forget: he has 25% of his original carotid diameter left. With CABG they clamp the aorta, this may lead to significant hypoperfusion (especially in his right-left collaterals) in his left hemisphere causing ischemic rarefaction/strokes in the watershed areas. Not to mention the possibilty of dislodging plaques.
I feel Cabg is absolute/relative contraindicated. Maybe PTCA.

DM with multivessel CAD- CABG
ref- Ann Intern Med 128:216, 98
Please correct me if I am wrong.

This patient is at high risk candidate for CABG. He already has neurological deficits. His LCA is already 100% occluded. The question is whether he has developed collaterals on that side. If the patient has had 70%-99% occlusion on that side, I would have said do a L. CEA then CABG. Your point of cross clamping of aeorta and further neurological compromise is well taken.I would consider PTCA only here

A 76 year old male patient is brought to the ED by his wife with complaints of neurological deficits. After a quick assessment, you suspect a stroke. Which of the following statements is true about thrombolysis with tPA?
a. a contrast CT would be appropriate prior to tPA administration.
b. a recent lumbar puncture is not a contraindication.
c. tPA may be given with heparin.
d. evidence suggests that tPA should be given within 3 hours for benefits to outweigh risks.

Answer is D.
Stroke is the third most common cause of death in the United States today and it is also a leading cause of long term disability. The National Institute of Neurological Disorders and Stroke (NINDS) trial in 1995 was the first large investigation to show that a thrombolytic agent, in this case, tissue plasminogen activator (tPA) could benefit victims of ischemic stroke.

The study showed that tPA therapy improved morbidity only if given to select patients within three hours of stroke onset. Beyond three hours, the risks of tPA significantly outweigh the benefits.

Contraindications to tPA therapy include: History or evidence of intracranial hemorrhage on non-contrast CT
(a contrast CT will not be helpful)
Active internal bleeding or bleeding diathesis
Major surgery or trauma within the previous two weeks (except head trauma)
GI bleed within the previous three weeks
Recent arterial puncture at a non-compressible site
Recent spinal tap
Glucose levels less than 50 or greater than 400
Seizure
Documented AVM or aneurysm
Improving symptoms
Systolic bp > 185mm Hg or diastolic bp > 110mm Hg.

Since the potential complications of tPA include intracerebral hemorrhage, close neurological monitoring of patients is vital and administration of anticoagulant or antiplatelet medications such as aspirin, warfarin, coumadin, or ticlid are not advised.