Search
Two recently presented abstracts at the 2012 Society of Critical Care Medicine conference suggest that the combination of vancomycin and piperacillin-tazobactam may lead to acute kidney injury (AKI) in the critically ill. There may also be evidence to suggest that piperacillin-tazobactam alone increases the risk of AKI.
Both abstracts retrospectively compared patients who received either vancomycin alone or the combination of vancomycin and piperacillin-tazobactam. In both studies, the rates of AKI were significantly lower in patients treated with vancomycin alone as compared to patients receiving both vancomycin and piperacillin-tazobactam.
Bottom line: Although the current evidence does not support a change in our clinical practice, more prospective studies exploring this topic are necessary.
Show References
Question
79 year old male with headaches, ataxia, falls, and difficulty urinating. What's the diagnosis?
Show Answer
For patients presenting to the ED with chest pain, we've been taught that “classic” or “typical” presentations for ACS (chest pressure with radiation to the left neck/jaw/shoulder/arm, dyspnea, diaphoresis, nausea, vomiting, lightheadedness) are most worrisome. Yet, many of the patients that present with typical symptoms end up having negative workups for ACS. What are the symptoms that truly predict ACS? Three major studies have demonstrated that the best predictors of ACS in patients presenting to the ED with chest pain are (not necessarily ranked in order):
1. chest pain that radiates to the arms, especially if the pain radiates bilaterally or to the right arm
2. chest pain associated with diaphoresis
3. chest pain associated with vomiting
4. chest pain associated with exertion
The description of the chest pain (e.g. "pressure" or "squeezing," etc.), the dyspnea, nausea, lightheadedness, and pain at rest were, surprisingly, not helpful at predicting ACS.
The simple takehome point is the following: always ask your patient with chest pain if the pain radiates, if there was associated diaphoresis, if there was associated vomiting, and if the pain is associated with exertion. If the answers to any of these 4 questions is "yes," think twice before labeling the patient with a non-ACS diagnosis.
Show References
Contrast Allergy:
Many patients will report that they have a allergy to iodinated contrast by saying that they are allergic to iodine
Iodine, itself, is not an allergen and is a required element for thyroid homrone production. Plus could you imagine the hordes of people that would be having allergic reactions everyday when they add salt to their french fries. Our EDs would be completely swamped.
A recent meta-analysis by Drs. Schabelman and Witting also showed the following:
- The risk of a reaction to contrast ranges from 0.2% to 17% depending on the type used, and the severity of the reaction considered.
- The risk of a reaction in patients with a seafood allergy is similar to that in patients with other food allergies or asthma. Seafood is not unique to contrast media.
- A history of prior reaction to contrast increases the risk of mild reactions to as high as 7-17% but has not been shown to increase the rate of severe reactions.
- The risk of death due to contrast is estimated to be 0.0006 - 0.006%.
As we enter Crab eating season in Maryland, lets stop giving shellfish a bad name. A patent with any allergy is at increased risk, but shellfish is no higher a risk than those allergic to Strawberries.
Show References
Definition: Fracture of the humerus just proximal to the epicondyles.
- Extension type (majority >80%; distal fx segment displaced posteriorly)
- Flexion type (distal fx segment displaced anteriorly)
- Any diminished pulsations or capillary refill should cause concern for vascular compromise (arterial compression, tear, or compartment syndrome).
- Place a continuous pulse oximetry probe on the affected hand to monitor bloodflow.
- The radial, median, or ulnar nerves may be affected and should be assessed.
-Nondisplaced fractures may follow up with orthopedics within 1 week after posterior long arm splinting (elbow at 90 degrees & forearm in neutral position)
-Displaced fractures require prompt pediatric orthopedic consultation for closed reduction in OR vs operative repair.
-Obtain emergent orthopedic consultation for compartment syndrome, neurovascular compromise, or open fracture.
-Partial reductions in ED likely just increase soft tissue swelling and delay definitive reduction and should be reserved for rare cases of vascular compromise.
References:
Wheeless, CR. Pediatric Supracondylar Fractures of the Humerus. Wheeless’ Textbook of Orthopedics. [Accessed online 4/22/12.] http://www.wheelessonline.com/ortho/pediatric_supracondylar_fractures_of_the_humerus
Ryan, LM. Evaluation and management of supracondylar fractures in children. UpToDate. [Accessed 4/22/2012]. http://www.uptodate.com/contents/evaluation-and-management-of-supracondylar-fractures-in-children
- Several macrolide antibiotics can cause QTc prolongation and dysrhythmias (e.g., erythromycin), but azithromycin is thought to have little cardiotoxicity.
- A cohort of patients taking azithromycin was compared to those taking no antibiotics, amoxicillin, ciprofloxacin, or levofloxacin.
- When compared to no antibiotics, amoxicillin, and ciprofloxacin, azithromycin was associated with a small but significant increased risk of cardiovascular death. Azithromycin was similar to levofloxacin.
- Important points:
- Increased risk translates to 47 additional deaths per 1 million prescriptions.
- Increased risk only occurs during the 5 day course and does not carry on after discontinuation.
- Patients most likely to die were in the highest risk category based on preexisting cardiovascular diseases (245 deaths per 1 million prescriptions).
- Bottom line: Patients may start asking about this study finding when given a prescription for azithromycin. Although a small risk, it may be prudent to prescribe an alternative if patients have preexisting cardiovascular disease.
Show References
Use the Measured Sodium Concentration!
- During a recent shift, a question arose regarding whether to use the measured or corrected sodium to calculate the anion gap in a critically ill patient with DKA.
- Recall that the anion gap provides an estimation of unmeasured anions - in this case acetoacetate and beta-hydroxybutyrate.
- Glucose is electrically neutral and therefore does not affect the anion gap.
- When calculating the anion gap in a patient with DKA, use the actual (measured) serum Na, rather than the corrected value.
Show References
Question
19 year-old male presents with L ankle pain and obvious deformity after jumping out of a window and landing on his inverted foot. What's the diagnosis?
Show Answer
Show References
New studies are utilizing mild therapeutic hypothermia as a treatment option in cardiogenic shock. These studies have reported improved circulatory support, an increase in systemic vascular resistance, and reduction in vasopressor use which ultimately may result in lower cardiac oxygen consumption. The preliminary results suggest that mild therapeutic hypothermia could be a therapeutic option in hemodynamically unstable patients independent of current recommendations which support its use in cardiac arrest survivors.
Show References
• Wedge compression fractures
- Account for 50 – 70% of all thoracolumbar compression fractures
- Usually results from motor vehicle collisions and falls where an axial load is applied to the spine in flexion causing injury to the anterior column without posterior column injury
- Best seen on the lateral radiograph
- Simple wedge fractures are stable and have no associated neurologic injury
- Instability is present if
- There is severe compression (>50%)
- Kyphosis greater than 20 degrees
- Multilevel compression fractures
http://jbjs.org/data/Journals/JBJS/855/JBJA0851224560G02.jpeg
It may not be necessary to give oral vitamin K to patients that are not bleeding that have INRs between 4.5 and 10.
Patients who were supratherapeutic on warfarin were randomized to vitamin K 1.25 mg (n=355) versus placebo (n=369).
In the 90 days after enrollment, 15.8% of patients allocated to vitamin K and 16.3% allocated to placebo had a bleeding event. Major bleeding events occurred in 9 patients in the vitamin K group and 4 in the placebo.
Thromboembolic events occurred in 1.1% of patients in the vitamin K group, compared to 0.8% of patients in the placebo group. An equal number of patients died in each group (n=7).
Show References
Consider rhabdomyolyisis secondary to heat exposure as summertime approaches; have a low threshold to screen patients if they are at risk (e.g., people exercising in high-ambient temperatures).
Symptoms include muscle tenderness, cramping, and swelling with associated weakness. Patients with altered mental status (e.g., heat stroke) should be examined for limb induration, skin discoloration (i.e., ischemia), or compartment syndrome.
Complications:
- Electrolyte abnormalities (e.g., hyperkalemia and hypocalcemia) and malignant cardiac arrhythmias
- Metabolic acidosis
- Disseminated intravascular coagulation (release of tissue factor from muscle cells)
- Acute renal failure (myoglobin directly causes nephrotoxicity)
Treatment
- External cooling to cease the inciting process
- Aggressive fluid resuscitation with normal saline (avoid lactated ringers) for goal urine output of 200 to 300 ml/hour; foley catheters should be placed to monitor urine output.
- Start dialysis if potassium levels are elevated, acidosis, or oliguric renal failure. There is very limited evidence for the use of dialysis before the presence of these signs.
- There are no randomized controlled trials to support the use of mannitol (free radial scavenger and diuretic) or bicarbonate (to alkalinize the urine); their use is controversial.
Show References
Cardiac biomarkers lack specificity, but may help to confirm the diagnosis of myocarditis; higher levels of troponin T have been shown to be of prognostic value by predicting M&M.
Show References
Naltrexone and methylnaltrexone are both mu-receptor antagonists that look similar and have similar names. But, they have very different uses.
- Naltrexone (ReVia, Vivitrol)
- Used to treat opioid/alcohol dependence or to prevent relapse following opioid detoxifcation
- Dose: 25 to 100 mg PO daily or 380 IM every 4 weeks
- Crosses blood-brain-barrier and can precipitate withdrawal
- Methylnaltrexone (Relistor)
- Used to treat opioid-induced constipation
- Dose (weight-based): 8 to 12 mg (or 0.15 mg/kg) subcutaneously once daily
- Peripherally acting, does not cross blood brain barrier
Show References
Severe UGIB
- Differentiating between upper and lower GIB can be challenging.
- A recent review evaluated the accuracy of historical features, symptoms, signs, and lab values in distinguishing between UGIB and LGIB.
- Features with the highest likelihood for identifying UGIB included:
- Melenic stool on exam (LR 25)
- A prior history of UGIB (LR 6.2)
- Serum urea:creatinine ratio > 30 (LR 7.5)
- Features that increased the likelihood of severe UGIB (defined as requiring blood transfusion, need for urgent endoscopy, surgery, or interventional radiology) included:
- Heart rate > 100 bpm (LR 4.9)
- Hemoglobin < 8 g/dL (LR 6.2)
- History of cirrhosis or cancer (LR 3.7)
- For patients with an UGIB, the Blatchford Score can be used to determine the need for urgent intervention. Those with a Blatchford Score of 0 have a low likelihood for severe UGIB and may not need emergent intervention.
Show References
Ultrasound is useful during intubation; here is a video explaining how: http://ultrarounds.com/ultrarounds.com/Visual_Pearl_May_28,_2012.html
Today's Bonus Pearl:
EMRA has developed a great antibiotic guide for the iphone (http://itunes.apple.com/us/app/2011-emra-antibiotic-guide/id393020737?mt=8) or android (https://play.google.com/store/apps/developer?id=Emergency+Medicine+Residents'+Association). This app is a bit pricey ($15.99), but is easy to use and well organized. Enjoy!
Show References
[pearl provided by Dr. Semhar Tewelde]
Myocarditis is an under-diagnosed cardiac disease resulting from a broad range of infectious, immune, and toxic etiologies
Show References
Hamate Fractures
Occur in two locations: the body of the hamate and the hook (hamular process) of the hamate
Fractures are present in 2 to 4% of carpal bone fractures
Body fractures are less common and are associated with dislocation of the fourth and fifth metacarpals
Axial force transmitted down the metacarpal shaft (a fall or fist strike)
Hook fractures occur from a direct force from an object strikes the palm such as that from a bat, golf club or racket
Have increased suspicion in these athletes who present w/ ulnar sided wrist pain
Diagnosis is frequently missed; chronic fractures are associated w/ flexor tendon rupture and ulnar neuropathy
PE: Tenderness localized over the hamate (in the hypothenar eminence) and over the dorsal ulnar aspect of the wrist. Swelling may be present. Look for resisted flexion of the 5th digit when the wrist is held in ulnar deviation. May note sensory changes in ulnar nerve distribution
Imaging: PA and lateral views of the wrist will show a body fracture but will frequently MISS a fracture of the hook of the hamate. In those with a clinical suspicion for this entity, order a “carpal tunnel view.” In the proper clinical setting, CT imaging is excellent for those with high suspicion and normal plain films.
Proper Feeding of the Newborn
The emergency physician must be comfortable with providing anticipatory guidance to parents of newborn, especially with regards to proper feeds of the neonate.
Newborns will lose some weight in the first 5-7 days of life. A 5% weight loss is considered normal for a formula fed newborn. A 7%-10% loss is considered normal for the breastfed baby. Most babies regain their birth weight by days10-14 of life. During the first 3 months, infants gain about an ounce a day (30 g) or 2 pounds a month (900 g). By age 3-4 months, healthy term infants have doubled their birth weight.
Breast-fed Neonates:
- Should be fed every 2-3 hours while awake
- 5-20 minutes of sucking per breast
- May gain weight slower than formula-fed counterparts
Formula-fed Neonates:
- 0.5-1 ounces per feeding every 3-4 hours for the 1st week
- Then 1-3 ounces per feeding every 3-4 hours
- Typical formula contains 20 cal/ounce
In general, overfeeding during the neonatal period has been associated with adult obesity. The American Academy of Pediatrics recommends exclusive breastfeeding for at least the 1st 6 months of life. Earlier switches to formula has been associated with atopy, diabetes and obesity
References:
- Fleischer DM. “Introducing formula and solid foods to infants at risk for allergenic disease.” UptoDate;2012.
- Hammer LD, et al. “Development of feeding practices during the first 5 years of life.” Nutrition;1999;189-194.
- Philips SM and Jensen C. “Dietary history and recommended dietary intake in children.” UptoDate;2011.
- Prior LJ and Armitage JA. “Neonatal overfeeding leads to developmental programming of adult obesity.” J Physiol;2009:2419.
Nitrous Oxide(N2O) is a common gas utilized to assist with procedural sedation especially in the pediatric population and dental offices. It has a long track history of safety but also has been abused.
N2O is 35x more solube in blood than N2. This means any air-filled space can have pressure increase thus complications like pneumothorax, TM rupture and bowel distention can occur.
When abused chronically can cause bone marrow suppression, B12 deficiency and resulting in polyneruopathy.
On the street, "whip its" are N2O from whipped cream containers. Balloons filled with N2O are inhaled which combine nitrous oxide and hypoxia effects.