This week's monday pearl is from our very own Azher Merchant....who recently gave an excellent talk on the risks of radiation.
Be afraid....be very afraid....
Risk is based on acute exposure and is extrapolated largely from atomic bomb survivors.
Effective radiation dose = Sievert (Sv)
Lifetime Attributable Risk of Cancer 1:1000 at 10mSv
Lifetime Attributable Risk of Cancer Mortality 1:2000 at 10mSv
Risk estimates follow a linear rate of change such that:
Lifetime Attributable Risk of Cancer in Adults = Radiation Dose (mSv) x 0.0001
Risk is Cumulative
Lifetime Attributable Risk of Cancer is greater than for adults and is age-dependent
Lifetime Attributable Risk of Cancer Mortality 1:1000 at 10mSv
Common Effective Dose Estimates (mSv)
Background radiation 3.5/year (chronic exposure)
Head, Face 2
Neck, Cervical Spine 2
Chest, Thoracic Spine 8
Abdomen/Pelvis, Lumbar Spine 15
Note that it doesn't take very much radiation to reach the 10 mSv level!
Bottom line: CT if you need to, but carefully consider whether it is worth it or not
One last pearl, carefully consider whether or not you want that d-dimer and don't order one unless you are prepared to order a CT scan.
Keywords: UTI, infection, delirium (PubMed Search)
The most common cause of delirium in the elderly is infection, and the most common type of infection is just a simple UTI. The second most common cause of delirium is medication effects. ALWAYS look carefully for signs of infection and look carefully at medication lists whenever evaluating an elderly patient with a change in mental status.
Keywords: Hypercalcemia, Hyperparathyroidism (PubMed Search)
Medical Treatment of Hyperparathyroidism
Keywords: infant, neonate, spasm (PubMed Search)
Infantile Spasms (West Syndrome):
Nelson's Essentials of Pediatrics, 5th Edition.
Keywords: Iron; Poisoning; Deferoxamine (PubMed Search)
|Checking TIBC to determine if treatment is necessary||Checking iron levels...If peak is > 500 mcg/dl, or the patient shows signs of systemic toxicity, treat with deferoxamine|
|Deferoxamine challenge... no longer recommended!||Using WBI for ingestion of 20 mg/kg iron, if visible iron pills on x-ray, or symptoms of mild toxicity (for treatment of severe toxicity see above)|
|Platform shoes||Strappy sandals|
WBI: whole bowel irrigation
Reminder from Poisondex:
OVERDOSE: SEVERE: Stupor, shock, acidosis, GI bleed, coagulopathy, hepatotoxicity, and coma. MILD/MODERATE: Nausea, vomiting, diarrhea, lethargy, leukocytosis, and hyperglycemia. Clinical phases: (1) 0-2 hours: Nausea, vomiting, diarrhea, and abdominal pain. Lethargy, shock, GI bleeding, and acidosis if severe; (2) Apparent recovery; (3) 2-12 hours: Acidosis, hypotension; (4) 2-4 days: Hepatotoxicity; (5) days-weeks: GI strictures.
Balmadrid C, Bono M. Recognizing and Managing Iron Toxicity. Emergency Medicine May 2009;14-21.
Keywords: phenytoin, phenbarbital, dilantin (PubMed Search)
Category: Critical Care
The Supraclavicular Subclavian Central Venous Cathetherization
Patrick SP, Tijunelis MA, Johnson S, Herbert ME. Supraclavicular subclavian vein catheterization: The forgotten central line. West J Emerg Med 2009;10(2):110-4.
Keywords: aortic dissection, syncope (PubMed Search)
Painless thoracic aortic dissection (TAD) and syncope
Patients with TAD do not always present with chest pain. In the International Registry of Aortic Dissection (IRAD) study, 2.2% of TAD cases were painless and approximately 13% of TAD cases presented with isolated syncope (i.e. NO PAIN). Other studies have shown that as many as 15% of TAD cases are painless.
Patients with TAD may present after a syncopal episode. The underlying pathophysiology of syncope is related to proximal rupture into the pericardium with resultant tamponade.
Add TAD to your differential diagnosis of unexplained syncope, especially in older folks and especially if a patient "looks bad" and you don't have a reason.
Keywords: resuscitaiton, elderly, geriatric, magnesium, ventricular, dysrhythmia (PubMed Search)
When caring for elderly patients that are having dysrhythmias, especially ventricular dysrhythmias, or in cardiac arrest, give strong consideration to empiric use of magnesium. Elderly patients are more likely to be hypomagnesemic because of diuretic use, poor GI absorption, poor daily intake, and diabetes.
[Narang AT, Sikka R. Resuscitation of the elderly. Emerg Med Clin N Am 2006;24:261-272.]
Keywords: hyperparathyroidism, hypercalcemia (PubMed Search)
Hyperparathyroidism results in elevated PTH and typically results in elevated calcium levels (hypercalcemia).
Though most cases are asymptomatic, symptomatic patients can present with:
Treatment options to be discussed next week....Stay tuned.
Valproic Acid (Depakote)
Haslam RH. Seizures in childhood. In: Behrman RE, Kliegman RM, Jenson HB, eds. Nelson Textbook of Pediatrics. 16th ed. Philadelphia, Pa: WB Saunders Co, 2000;1813-1829
Sabo-Graham T, Seay AR. Managemnt of status epilepticus in children. Pediatr Rev. 1998;19:306-309
Keywords: seizure, first-time seizure, new onset seizure (PubMed Search)
Category: Critical Care
Pulse Pressure Variation and Volume Responsiveness
Marik PE, Cavallazzi R, Vasu T, Hirani A. Dynamic changes in arterial waveform derived variables and fluid responsiveness in mechanically ventilated patients: A systematic review of the literature. Crit Care Med 2009;37(9):2642-7.
Keywords: AAA (PubMed Search)
Unusual Presentations of AAA
Many unusual presentations of AAA have been reported in the literature and include:
One more note on the whole urge to deficate thing: any thing that leads to hemoperitoneum may cause this strange complaint (ruptured AAA, ruptured ectopic pregnancy).
Keywords: hyperthermia, heat stroke (PubMed Search)
Be wary of the limitations of correlating a temperature with infection in the elderly:
1. The elderly are 3-4x more likely to develop hypothermia in response to serious infections. Never rule out a serious infection simply based on a low or normal body temperature.
2. The elderly take longer to mount a fever than younger patients.
3. The elderly have a slightly lower body temperature at baseline, possibly 1 degree lower. As a result, "fever" in the elderly is sometimes defined as 99.5 degrees rather than the traditional 100 or 100.4 used in younger patients.
Keywords: Pediatrics, hypertension, encephalopathy (PubMed Search)
Hypertensive encephalopathy is generally seen in children with renal disease, e.g. acute glomerulonephritis or ESRD.
Signs and symptoms include bp >99th percentile for age and height and neurologic impairment. May present acutely with seizure or coma, or subacute with HA, vomiting, lethargy, blurry vision or change in mental status. Exam findings may also include papilledema.
MRI may show increased signal in occipital lobes of T2 weighted images, known as reversible posterior leukoencephalopathy.
Treatment is to lower BP by 20-25% for the first 8 hours and to normative levels over 24-48 hrs. IV therapy with esmolol drip, labetalol or nicardapine are the treatments of choice. Nitroprusside prudent in most hypertensive adult emergencies must be used cautiously if history of renal disease secondary to cyanide toxicity. Seizure should also be treated as you would with status epilepticus.
Belsha CW - Ann Emerg Med - 01-MAR-2008; 51(3 Suppl): S21-3
Herman, Andrea "Visaul Diagnosis: A Child Who Has a Nosebleed and High Blood Pressure." Pediatrics in Review 2001 22:104-107
Kleigman et al. Nelson Textbook of Pediatrics. 18th edition 598.3.
Category: Obstetrics & Gynecology
Keywords: Rhogam, Pregnancy (PubMed Search)
Though most textbooks recommend Micro-Rhogram (50mcg) for woman that have miscarried and are less than 12 weeks gestation, you might find it a real challenge to get that dose from your pharmacy or blood bank.
The cost difference between microRhogram and Rhogam is minimal so most hospitals have decided to only stock full dose (300 mcg) Rhogam. The full dose can be given to woman in their 1st trimester without any deleterious effects.
Just remember if you are giving it as a result of a delivery you should order a Kleihauer-Betke test to determine if additional doses of Rhogam are needed.
Keywords: priapism, yohimine, trazadone (PubMed Search)
Priapism - prolonged involuntary erection - is an adverse effect with some drugs. Here is a list of the more commonly reported:
Keywords: correction to altered level of consciousness pearl (PubMed Search)