UMEM Educational Pearls

• Ingestion of concentrated hydrogen peroxide (H2O2) has been associated with venous and arterial gas embolic events, hemorrhagic gastritis, gastrointestinal bleeding, shock, and death.
• Although H2O2 is generally considered a benign ingestion in low concentrations (OTC is 3%), case reports have described serious toxicity following high concentration exposures.
• Hyperbaric oxygen (HBO) has been used with success in managing patients suffering from gas embolism with and without manifestations of ischemia.
• A recent poison center case record review confirmed previous findings.
  • It identified 11 cases of portal gas embolism. In 10 cases 35% H2O2 was ingested and in 1 case 12% H2O2 was ingested. All abdominal CT scans demonstrated portal venous gas embolism in all cases. Hyperbaric treatment was successful in completely resolving all portal venous gas bubbles in nine patients (80%) and nearly resolving them in two others. Ten patients were able to be discharged home within 1 day, and one patient had a 3.5-day length of stay.
• Bottom Line: In a patient with a history of hydrogen peroxide ingestion, have a low threshold for CT scan.  HBO therapy is an effective treatment modality.

French LK, et al. Hydrogen peroxide ingestion associated with portal venous gas and treatment with hyperbaric oxygen: a case series and review of the literature. Clinical Toxicology 2010;48:533–38.

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• Many neurologic conditions present with motor dysfunction.  It is often helpful to distinguish these movement abnormalities in order to properly recognize and manage the disorder.
• Chorea >>> Sudden, ballistic movements.
• Athetosis >>> Writhing, repetitive movements.
• Fasiculations >>> Fine twitching of individual muscle bundles, most easily noted on the tongue.
• Dystonia >>> Sudden, tonic contractions of muscles of the tongue, neck (torticollis), back (opisthotonos), mouth, or eyes (oculogyric crisis).
• Tardive dyskinesia >>> lip smacking, chewing, and teeth grinding (early signs).

Ocular sonography is a fast, simple, and non-invasive tool to detect elevated intracranial pressure (ICP) by measuring the optic nerve sheath diameter (ONSD). Several studies have shown a positive correlation between increased ONSD (>5.7mm) and elevated ICP (>20mmHg).  Although ultrasound may not replace CT or MRI to diagnose the cause of the increased ICP, its use as a triage tool can expedite these tests.

The technique:

1. Use linear probe on closed eyelid.
2. Identify the optic nerve sheath.
3. Measure the optic nerve sheath, 3mm behind globe.
4. Rotate probe 90 degrees and measure again.
5. Average both diameters.

Please see the references below for more information and, as with any new technique please consult local experts prior to making clinical decisions. 

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The new 2010 AHA guidelines have provided greater focus on airway issues in patients suffering from cardiac arrest. Amongst the important areas of new emphasis are: (1) Cricoid pressure is no longer routinely recommended during intubation, and in fact it has been given a Class III rating ("harmful"); and (2) there is now a very strong push to use quantitative end-tidal CO2 monitoring (rather than just qualitative confirmation) of the airway after endotracheal intubation.

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Dabigatran

• the first new ORAL anticoagulant in over 50 years
• is a direct thrombin inhibitor
• Indicated for reducing strokes and systemic embolism in patients with a fib
• DOES NOT need monitoring and frequent dose adjustments
• Has fewer drug and food interactions than warfarin
• Costs about $8/day (more than the cost of warfarin PLUS monitoring)
• Both warfarin and dabigatran have a similar OVERALL bleeding risk, but warfarin causes more intracranial bleeding and dabigatran more GI bleeding

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Optimal management of subarachnoid hemorrhage requires prognostic understanding and effective communication with neurology and neurosurgical consultants, as well as the patient and their family members.

It is therefore often helpful to utilize and reference the widely recognized Hunt and Hess Scale in grading symptoms of ruptured cerebral aneurysm and subarachnoid hemorrhage severity:

• Grade 1:  Asymptomatic; or minimal headache with slight nuchal rigidity.  Approximate survival rate (ASR) 70%.
• Grade 2:  Moderate to severe headache; nuchal rigidity; no neurologic deficit except cranial nerve palsy.  ASR 60%.
• Grade 3:  Drowsy; minimal neurologic deficit.  ASR 50%.
• Grade 4:  Stuporous; moderate to severe hemiparesis; possible early decerebrate rigidity and vegetative abnormality.  ASR 20%.
• Grade 5:  Deep coma; decerebrate rigidity; moribund. ASR 10%.
• Grade 6:  Death; brain dead.

For your convenience, an online Hunt and Hess Scale calculating tool can be found at:

http://www.mdcalc.com/hunt-and-hess-classification-of-subarachnoid-hemorrhage-sah

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Ventilation Pearls in the Post-Cardiac Arrest Patient

• Some ventilation pearls from the recently released 2010 AHA guidelines include:
  • Set the tidal volume to 6-8 ml/kg ideal body weight
  • Titrate minute ventilation to achieve a P_aCO₂ between 40-45 mm Hg or P_ETCO₂ between 35-40 mm Hg
  • Reduce the F_iO₂ to maintain S_pO₂ > 94%

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In honor of Halloween and candy....

Hyperglycemia (> 140 mg/dl) at the time of admission is an independent risk factor for adverse outcomes and mortality both during the hospital stay and long-term in patients with acute MI. Hyperglycemia is associated with adverse platelet function, thrombolysis, and coagulation. Tight glucose control is recommended to begin as soon as possible after admission in patients with acute MI in order to optimize outcomes.

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Risk Factors for Spinal Epidural Abscesses

Building on Dr. Corwell's pearl from last week concerning Spinal Epidural Abscess, risk factors for Spinal Epidural Abscesses other than IV drug abuse are:

1. Diabetes
2. ESRD
3. Septicemia
4. HIV infection
5. Malignancy
6. Morbid obesity
7. Long-term corticosteroid use
8. Alcoholism
9. Infection at a distal site
10. Indwelling catheters
11. Spinal surgery

The infection can occur via three routes 1) hematogenous spread 2) Direct Extension from a local infection such as osteoomyelitis, and 3) iatrogenic introduction which is thought to be responsible for 14-22% of the cases.  A catheter in the epidural space for more than 2 days has a infection rate of 4.3%.

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Necrotizing Enterocolitis

• NEC is an inflammatory lesion of bowel which can progress to intestinal gangrene, with perforation, and /or peritonitis
• characterized by abdominal distension, feeding difficulties, and GI bleeding
• mainly affects pre-term infants, and most commonly affects distal ileum and proximal colon
• usually presents during the first 2 weeks of life, but may occur up to 3 months of age in infants who who born weighing <1000grams
• classic finding on abdominal XR is pneumatosis intestinalis or air in the bowel wall (pathognomonic) and is present 50-75% of the time
• treat emergently with nasogastric decompression, IVF recussitation, NPO, and IV antibiotics

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When a patient presents to the ED with a recent ingestion of a wild mushroom there are three very specific questions you must ask:

1) Exactly what time did you eat the mushroom?

2) Exactly what time did you begin vomiting/diarrhea/GI Sx in general?

3) Are there are more mushrooms that can be brought to ED for identification?

The reason the first two questions are critically important is it determines the total time of onset of toxicity. As a very general rule of thumb, delayed GI symptoms >6hrs is predictive of a possible lethal ingestion of a cyclopeptide containing mushroom like Amanita Phalloides. Immediate symptoms < 6hrs and even more so if within 2 hrs usually indicates ingestion of a nonlethal mushroom that causes GI distress (many mushrooms like Clitocybe nebularis)

Website with pics of the most poisonous mushrooms: 

http://scienceray.com/biology/botany/13-deadliest-mushrooms-on-the-planet/

There is a saying:

"There are old mushroom pickers and wise mushroom pickers but no old and wise mushroom pickers"

Classic Cerebrospinal Fluid Characteristics

• Bacterial Meningitis >> Milky CSF with increased protein, decreased glucose, high WBC's, few RBC's, mildly increased opening pressure, normal % gamma globulin.

• Viral Meningitis >> Cloudy CSF with increased protein, normal glucose, increased WBC's (lymphocyte predominant), no RBC's, normal opening pressure, normal % gamma globulin.

• Herpes Simplex Encephalitis >>  Cloudy CSF with increased protein, normal glucose, increased WBC's (lymphocyte predominant), few RBC's, increased opening pressure, normal % gamma globulin.

• Subarachnoid Hemorrhage >> Yellow CSF with increased protein, normal glucose, few WBC's, inumerable RBC's, mildly increased opening pressure, normal % gamma globulin.

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Increasing literature demonstrates ICU delirium is bad. Delirium in mechanically ventilated patients is an independent predictor for long-term cognitive defects (e.g., managing money, following detailed instructions, reading maps, and developing dementia). The cited study found 80% of patients with ICU delirium had cognitive dysfunction at three months, and 70% had residual dysfunction at one year (33% had severe dysfunction).

You must be aggressive to prevent delirium:

-         Implement daily assessment tools (e.g., CAM-ICU)

-         Daily awakening and spontaneous breathing trials

-         Early patient mobilization

-         Aggressive pharmacological treatment of delirium

-         For more information: www.icudelirium.org

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Magnesium is considered a mainstay of treatment of prolonged QT syndrome leading to torsade de pointe, including those cases caused by drugs. The exact mechanism of action is unknown, though it is thought to stabilize the myocardium. Interestingly, magnesium infusions will not necessarily change the heart rate or QT interval on ECG.

The dose is 2 g IV followed by an infusion (similar to treatment of eclampsia/preeclampsia). The bolus should be given slowly if the patient is relatively stable, but can be pushed over 1 minute in a patient with ongoing torsade that is not responding to electricity.
 

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Epidural compression syndrome encompasses spinal cord compression, cauda equina syndrome, & conus medullaris syndrome.

Causes include:

1. massive midline disc herniation (most commonly), usually at the L4 to L5 level.
2. tumor
3. epidural abscess
4. spinal canal hematoma.

Measurement of a post-void bladder residual volume tests for the presence of urinary retention with overflow incontinence (a common, though late finding) (sensitivity of 90%, specificity of 95%).  Large post-void residual volumes (>100 mL) indicate a denervated bladder with resultant overflow incontinence and suggest significant neurologic compromise. The probability of cauda equina syndrome in patients without urinary retention is approximately 1 in 10,000.

Use this in your daily practice!!

The administration of glucocorticoids can minimize ongoing neurologic damage from compression & edema until definitive therapy can be initiated. The optimal initial dose and duration of therapy is controversial, with a recommended dose range of dexamethasone anywhere from 10 to 100 mg intravenously. Consider traditional dosing (dexamethasone 10 mg)  for those with minimal neurologic dysfunction, & reserve the higher dose  (dexamethasone 100 mg) for patients with profound or rapidly progressive symptoms, such as paraparesis or paraplegia.

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Colic

• excessive, unexplained paroxysms of crying in an otherwise well-nourished normal infant
• lasts >3 hours/day, and occurs >3 days/week...ughh!
• usually occurs at the same time of the day or evening
• usually resistant to most attempts to quell it
• infant may have excess flatus and draw legs up during episodes (but don't change formulas)
• beings in first week of life and ends by 4 months of age

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• A broadly-accepted, standard definition of concussion, also known as mild traumatic brain injury (MTBI), does not exist and is still a work in progress. 

• Historically, the diagnosis of concussion has been based upon the presence of three findings:  (1) Loss of consciousness (usually for less than 30 seconds), (2) post-traumatic amnesia (usually for less than 24 hours), and (3) a Glascow Coma Scale score of 13 to 15.                  

• Today, many experts question whether loss of consciousness is inherently associated with concussion, but rather that any change in consciousness, such as that related to amnesia, suffices.  

• Patients with the following symptoms should be screened, typically with head CT, for more serious injury:  loss of/deteriorating consciousness, persistent headache, dizziness, vomiting, disorientation/confusion, seizure, and unequal pupil size.

• Treatment of concussion consists of monitoring and rest.  Symptoms usually spontaneously resolve within 3 weeks, but may persist for up to around 3 months.

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Ketamine for RSI in Hemodynamically Unstable ED Patients

• Recall that ketamine acts as a sympathomimetic resulting in increases in heart rate, blood pressure, and ultimately cardiac output.
• Because of its rapid transport across the blood-brain barrier, its sympathomimetic effects, and lack of significant adverse effects, ketamine is recommended by many organizations as a first line agent for RSI in unstable patients.
• Important contraindications to ketamine include an acute coronary syndrome, aortic dissection, and acute heart failure.
• Take Home Point: Consider using ketamine the next time you need to intubate a hypotensive, critically ill ED patient.

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ECG early repolarization (or sometimes referred to as "benign early repolarization" or BER) is a common finding on ECGs, especially in young patients. It is a common "confounding" pattern when trying to identify STEMI. Here are some pearls that help in distinguishing BER vs. true STEMI. Remember at the outset, though, nothing in medicine is 100%....and that getting old ECGs or getting serial ECGs can be incredibly helpful.

1. BER is ONLY allowed to have STE that is concave upwards. If you ever see STE that is convex upwards (like a tombstone) or horizontal, it MUST be a STEMI.
2. BER should not have ST-segment depression, except maybe in aVR and V1. If there is ST depression in any of the other 10 leads, it is almost definitely a STEMI.
3. If you see STE in the inferior leads, compare the STE in lead II vs. lead III. If the STE in lead III is greater than the STE in lead II, it rules out BER....gotta be STEMI.
4. STE from BER is usually maximal in the mid precordial leads. You CAN have STE in the inferior leads with BER also, but you really shouldn't have STE isolated to the inferior leads. In other words, BER can have (1) STE in the precordial leads alone, or (2) STE in the precordial + inferior leads, but it should never have STE isolated to the inferior leads, and also the STE in the precordial leads should be more prominent than the STE in the inferior leads.
5. BER should usually not have STE > 5 mm. However, I've seen some occasional exceptions when the patient has large voltage QRS complexes.

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