UMEM Educational Pearls

The question of hyperglycemia in the critically ill and how to address it has been the topic of considerable study over the years.

There have been several attempts to try to quantify the best target glucose levels in critically ill patients.  This is still a moving target, but a recent study sheds some light on the effect of different levels of hyperglycemia and the types of patients who are particularly vulnerable.

This is a retrospective cohort study whic reviewed 259,000 ICU admissions over a three year period at 173 separate sites.  Their findings were as follows:

Compared with normoglycemic patients, the adjusted odds for mean glucose 111-145, 146-199, 200-300, and >300 was 1.31, 1.82, 2.13 and 2.85 respectively.

There is a clear association between the adjusted odds of mortality related to hyperglycemia in patients with AMI, arrhythmia, unstable angina, pulmonary embolism, pneumonia and gastrointestinal bleed.

Hyperglycemia associated with increased mortality was independent of type of ICU, length of stay and/or pre-existing diabetes.

So, even though we have not come to solid conclusions about how far down to keep the glucose levels down, it makes sense to pay particular attention and be more vigilant of the blood glucose levels, especially in the higher-risk patients  listed above. 

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Suspect your patient has an aortic dissection? Don't wait to lower the blood pressure.

A few considerations for the patient with suspected aortic dissection:

• If the patient is hypertensive AND you really think they could have the disease, start the drip then. Don't wait until the CT is done. Every second that goes by with extremely elevated BP may increase the dissection length.
• If you are really worried about a patient having a proximal aortic dissection, don't wait for the creatinine to come back...scan them without it. If you are really suspicious this is justified in many cases.
• There is very little (to no) role in performing a dry CT (because the patient's creatinine comes back elevated). Dry CT is very insensitive. Instead get a transesophageal echo or an MRI. 

Many cardiac patients take warfarin...no surprise.
Many patients use herbal supplements...no surprise.
Many herbal supplements can produce increased bleeding risk with warfarin, and some produce decreased effects of warfarin...that may be a bit of a surprise. Here's a few that are worth knowing:

Herbals that increase the bleeding risk of warfarin: alfalfa, angelica (dong quai), bilberry, fenugreek, garlic, ginger, and ginkgo

Herbals that decrease the effect of warfarin: ginseng, green tea

In addition to asking your patients about their prescription medications, specifically ask your patients if they take herbal supplements, over-the-counter products, or green tea (since many patients don't consider green tea to be either an herbal supplement)...especially if the patient takes warfarin. You just might diagnose or prevent a disastrous bleeding complication.

[Tachjian A, Maria V, Jahangir A. Use of herbal products and potential interactions in patients with cardiovascular diseases. J Am Coll Cardiol 2010;55:515-525.]

A recent study by Smith et al showed that the general abdomen/pelvic CT scan in trauma patients obtained with 5mm slices is a better screening test for spine fractures than plain films. They also showed that when compared to dedicated reconstructed thoracolumbar CT scan (2mm slices focused on the spine) it did not miss any clinically significant fractures.

The statistic for plain radiographs and the nonreconstructive CT scan are shown below.

The take home point is that dedicated Spine CT scans are probably not needed unless they are going to be used to guide surgical or non-surgical management, and plain films should probably be abandoned in patients that are undergoing CT scans of the chest/abdomen/pelvis.

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When a child is reported to be exposed to a rat poison it is commonly a long acting coumarin like brodifacoum. The rat usually eats the poison then during its traumatic little life will cause its own death by jumping and squeezing through a crack. When a human is exposed, this is the typical sequence of events:

1. Exposure (and when you usually see them in the ED)
2. 24-72 hrs later you will actually see an INR rise if actually ingested

Treatment is the same as for coumadin, vitamin K. However, do not start empirically since the patient will be committed to high doses of vitamin K for several months. Let the patient prove they have been poisoned which means they will require recheck of their INR 2-3 days later though they can be sent home with specific warning signs of anticoagulation.

• For many years the recommendations for managing new-onset seizure (NOS) in the emergency department did not include any specific instruction for such patients with HIV/AIDS.
• A study done by Pesola and colleagues found that, infact, AIDS patients with NOS require additional vigilence in terms of their management.
• This study found that over 15% of AIDS patients with NOS would have erroneously been sent home without appropriate treatment had the standard recommendation for NOS management been followed; these patients were found to have intracranial lesions related to toxoplosmosis and lymphoma, and did not necessarily have focal neurologic deficits.
• It is therefore recommended that all AIDS patients with NOS undergo neuroimaging with lumbar puncture, as indicated.

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Bleeding Dialysis Fistula?

Ever see a patient in the ED c/o "my fistula won't stop bleeding"? If you haven't, you probably will in the future.

Here are some helpful tips on getting these bad boys to stop oozing:

• Local pressure for 10 minutes will stop many of these bleeders
• Can also try locally applied gel foam/thrombin
• Pharmacologic adjuncts may be required, especially if the patient has missed dialysis-DDAVP can be given (makes platelets stickier by causing endothelial cells to release von Willibrand Factor). You can also give platelets, since platelets don't work well in a uremic state. Many dialysis patients are on coumadin because of chronic line clots, so don't forget to reverse this if present
• Probably as a last resort you can tie a superficial circular suture at the puncture site. This works quite well.

Impingement Syndrome and the Diagnostic Accuracy of 5 Common Tests

It is also reported that subacromial impingement syndrome (SAIS) is the more frequent cause of shoulder pain.

The authors of this study attempted to determine the diagnostic accuracy of the following 5 tests for SAIS:

• Hawkins-Kennedy
• Neer
• Empty Can
• Painful Arc
• External Resistance

The study demonstrated that any 3 positive tests out of the 5 has a sensitivity of 0.75 (0.54-0.96) , specificity of 0.74 (0.61-0.88), positive likelihood ratio of 2.93 (1.60-5.36) and negative likelihood ratio of 0.34 (0.14-0.80).  See the table below for the individual test characteristics.  No single test was deemed accurate enough to make the diagnosis by itself.

So in the end you should be familiar with most of these tests in order to use a combination of them to make the diagnosis of impingement syndrome.  Future pearls will review how to perform these tests.

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• Given the recent extremely cold winter weather experienced in some parts of the country, we will likely be expected to recognize and treat true frostbite and its sequelae at an increasing rate.
• Frostbite is the result of focal injury that follows the crystallization of water within subcutaneous tissue when exposed to low temperatures. 
• Sequelae such as chronic neuropathic pain syndromes can results in up to 25% of patients with frostbite due to microvascular damage.
• Hyperbaric oxygen has been shown to effectively treat this sequelae, even if administered in a delayed fashion, and should be considered as a viable therapeutic option.

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With all of the post-transplant patients we see in the ED, a refresher on the toxicities associated with the most common immunosuppressant medications is warranted.

Cyclosporine (Sandimmune^® and Neoral^®/Gengraf^®) and tacrolimus (Prograf^®) are both calcineurin inhibitors that inhibit activation and proliferation of T-lymphocytes and IL-2.

-          Major concerns: Nephrotoxicity, drug interactions (CYP3A4)

-          Adverse Effects:

o       Electrolyte abnormalities: ­K+, ¯Mg+, ­glucose

o       CNS: HA, tremor (statistically higher with tacrolimus)

o       CV: HTN, ­ lipids (increased with cyclosporine)

o       End organ: hepatotoxicity, nephrotoxicity

o       Cosmetic (cyclosporine specific): hirsutism, gingival hyperplasia, acne

Sirolimus/Rapamycin (Rapamune^®) is an M-tor inhibitor that inhibits T-lymphocyte activation and proliferation.

-          Major concerns: Drug interactions (CYP3A4)

-          Adverse Effects:

o       Delayed wound healing

o       Leucopenia, thrombocytopenia

o       Hypercholesterolemia

• Total body calcium consists of about half biologically active (ionized) and half inactive (80% bound to albumin and 20% to other ions)
• hypocalcemia caused by hypoalbuminemia is physiologically insignificant, and correction factors are not accurate or reliable
• The best way to measure true active calcium is to order an ionized calcium level

There are several conditions that alter ionized calcium levels, including:

• alkalosis (increases binding to albumin)
• gas bubbles in the sample (false lowering of calcium)
• anticoagulants (must be collected in a red top tube)
• blood transfusions (binding to citrate)
• cardiopulmonary bypass
• drugs (aminoglycosides, cimetidine, heparin, theophylline)
• fat embolism
• hypomagnesemia (correcting mg levels may preclude need for Ca repletion)
• pancreatitis (several mechanisms, poor prognosis)
• renal insufficiency (impaired phosphate retention)
• sepsis

The bottom line is to measure ionized calcium, and consider all other factors that can be contributing to hypocalcemia in addition to repleting it. 

Altered Mental Status-Does Your Patient Have Non-Convulsive Status Epilepticus?

Ever intubated a patient in status epilepticus and wondered if they were still seizing after sedation and paralysis? Ever taken care of an altered patient and wondered if you should consult neurology and attempt to get an EEG?

NCSE is defined as continuous seizure activity without obvious outward manifestations of a seizure. This is important for emergency physicians to consider because it has to be detected early to prevent morbidity and mortality.

When to consider NCSE:

• Prolonged postictal period
• Unexplained altered mental status in a patient with a history of seizures
• Altered mental status associated with "eye twitching" or blinking
• Stroke patient who clinically looks worse than expected

Scaphoid Fractures:

For suspected scaphoid fractures with negative radiographs it is common practice to put a person in a short arm thumb spica splint until followup up radiographs can be obtained in 10-14 days.

However, there is evidence that a short arm thumb spica splint is not enough for people that have a true scaphoid fracture.  Gellman et al demonstrated that long arm thumb-spica cast immobilization for six weeks followed by short arm thumb-spica cast immobilization decreased time to union by 25% when compared to short arm thumb-spica casting alone.

The theory is that the short arm splint still allows for forearm rotation that can cause shearing motion of the volar radiocarpal ligaments.  A long arm splint prevents this shearing action.  The disadvantage of a long arm splint though is potential elbow joint stiffness and muscle atrophy that can occur during the prolonged period of immobilization.

So for your next patient with a scaphoid fracture seen on radiographs place them in a long arm thumb spica splint.

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CARBAPENENEMS

• Broadest spectrum of activity of all classes
• Imipenem has slightly better gm + activity; lowers seizure threshold
• Meropenem has slightly better gm - activity
• Ertapenem does not cover Pseudomonas
• Doripenem has the most activity against Pseudomonas
• May use in PCN allergic patients (cross reactivity lower than previously thought)

TIGECYCLINE

• Has broad coverage, but does not cover Pseudomonas
• Bacteriostatic; derivative of tetracycline
• Does NOT require renal dosing
• Higher mortality in VAP than other agents; do not use for intra-abdominal infections (poss higher risk of perforation)

AMIKACIN

• Has antipseudomonal activity
• Used in combination with other agents for MDR (multi-drug resistant) bacteria
• Causes nephrotoxicity and ototoxicity

COLISTIN

• Bacteriocidal against many MDR gram - bacteria
• Not active against Proteus, Provincia, Burkholderia, Neisseria, or Serratia
• Nephrotoxicity and ototoxicity reported

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• In states without mandatory physician reporting of patients with seizures, the decision of whether to breach confidentiality and report a poorly controlled epileptic patient who continues to drive an automobile becomes an ethical dilemma.
• In making this decision, one must consider the probability and magnitude of the potential harm.
• If the probability and magnitude are both low, or the probability of harm is high but the associated magnitude is low, there is generally no moral obligation to breach confidentiality and report.
• If the probability of harm is low but the potential magnitude of the harm is high, one should strongly consider reporting the case.
• Each case should be handled on an individual basis, take into consideration the risks and benefits to the patient and society if reporting is ensued, and perhaps elicit the advice of risk management.

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The Rapid Ultrasound in Shock (RUSH) Exam

• Evaluating the ED patient with undifferentiated shock can be challenging.
• Ultrasound can be an invaluable tool in helping to differentiate between hypvolemic, cardiogenic and obstructive shock.
• The RUSH exam essentially focuses on the evaluation of the "pump", the "tank" and the "pipes".
• The pump: exclude pericardial effusion, global estimate of LV EF, and determine if RV strain is present.
• The tank: evaluate the IVC/jugular veins for volume status, look for fluid in the thorax/peritoneum, and exclude pulmonary edema or pneumothorax.
• The pipes: look for a ruptured AAA or aortic dissection and DVT.

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Pulmonary Embolism-Myths and Misconceptions

Just wanted to mention a few myths/misconceptions about acute PE that I have recently heard discussed in the ED.

1. Emergency physicians have to "get help" to give thrombolytic therapy. Sure it makes sense that we consult critical care and perhaps interventional radiology in some cases. But we do not need permission to use this drug by ourselves if indicated. Consider using lytics ESPECIALLY if the patient is unstable or if there is evidence of RV dysfunction (elevated troponin, echo criteria for dysfunction, or CT with large RV and bowing of the septum). What about the patient with RV dysfunction and a normal BP? Evidence is mounting that lytics are indicated to reduce the severity of pulmonary hypertension. 

2. "Just get a d-dimer." Be very careful. Lots of false positives. D-dimer often clouds the picture more often than not. 

3. "The mortality rate of missed PE is high." Often quoted as a 30%+ mortality rate if missed. Recent data suggests that it is < 5%. 

Missed cases of ACS account for 10% of all malpractice cases in emergency medicine, yet account for 30% of all the money emergency physicians pay out in malpractice cases. This misdiagnosis is the biggest cause of monetary payout in the specialty.

Three main themes account for the majority of missed cases of ACS:
1. Failure to recognize atypical presentations (e.g. dyspnea)
2. Failure to recognize high-risk groups (e.g. women, diabetics)
3. Over-reliance on negative tests (e.g. negative troponin or recent stress test)

Temporal Arteritis (TA) is commonly associated with the sudden onset of a unilateral headache centered around the temporal region.  The most devastating consequence of TA is blindness though this is only reported in up to 50% of cases though can be bilateral in up to 33% of patients.

According to the American College of Rheumatology criteria for classification of temporal arteritis this diagnosis can be made in the ED without a biopsy.  You just need at least 3 of the following 5 items to be present (sensitivity 93.5%, specificity 91.2%) to make the diagnosis :

1. Age of onset older than 50 years
2. New-onset headache or localized head pain
3. Temporal artery tenderness to palpation or reduced pulsation
4. Erythrocyte sedimentation rate (ESR) greater than 50 mm/h
5. Abnormal arterial biopsy (necrotizing vasculitis with granulomatous proliferation and infiltration)

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The umbilical site normally heals by 1 month of age. 

Any fluid draining after this period suggests an abnormal connection between the surface of the abdomen and the underlying structures, and requires further investigation.  Clear yellow fluid could represent a persistent connection of the bladder with the umbilicus called a patent urachus. The fluid that leaks is actually urine. The treatment is surgical closure of the connection.

Pus oozing from the umbilical stump would imply infection, especially if there is concomitant redness of the skin around the umbilicus.  An omphalitis can be life-threatening, and requires admission for invtravenous antibiotics.

Umbilical hernias are common in infants, and are usually noted with diastasis of the rectus muscles.  Most umbilical hernias resovle by school age, and do not require surgical intervention.

An umbilical granuloma is a small piece of bright red, moist flesh that remains in the umbilicus after cord separation. It is scar tissue, usually on a stalk, that did not become normally covered with skin cells. It contains no nerves and has no feeling. Most can be simply cauterised with silver nitrate.