UMEM Educational Pearls

Hemofiltration

• Renal replacement therapy (RRT) involves the use of semipermeable membranes to remove fluid and toxic substances from the bloodstream
• The basic methods of RRT are hemodialysis (HD) and hemofiltration (HF)
• There have been a few cases in our ED in which our Renal consultants have used HF
• Hemofiltration can remove large volumes of fluid (up to 3 Liters per hour)
• Major advantages to HF: less likely to produce hypotension than HD, can remove larger molecules than HD
• Disadvantages to HF: must be done continuously to provide effective dialysis, requires anticoagulation to maintain circuit patency, not well suited for hypotensive patients (requires a hydrostatic pressure gradient for solute clearance)

A neutropenic cancer patient that presents with right lower quadrant abdominal pain, fever, and bloody diarrhea should raise suspicion for typhlitis (necrotizing colitis, cecal inflammation). This most commonly occurs in patients with hematologic malignancies who have been treated with cytotoxic agents. This condition is high risk and is associated with high morbidity and mortaiity.

Treatment:

• Broad-spectrum antibiotics
• CT scan of the abdomen and pelvis
• Surgical consultation
• Usually requires ICU admission

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An increasing amount of attention in the literature is now being paid to ways of optimizing care of patients that are post-cardiac arrest. Simple things to focus on for us in the ED are the following:
1. induction of therapeutic hypothermia
2. aggressively manage hypotension and cardiac ischemia
3. treat hyperglycemia aggressively
4. avoid hyperventilation, though maintain adequate oxygenation

 

Critical Care Billing Pearls:

 

Level	RVU	Medicare	Commerical
99285    ED E/M, Level 5	4.71	$170	$304
99291    Critical Care, first hour	5.84	$211	$363

As the table shows Critical Care billing will earn you approximately 25% more with no additional overhead.  Critical care time must be at least 30 minutes, and the following procedures are included in the critical care code:   

• Interpretation of ABG and labs
• Interpretation of CXR
• IV insertation
• Transcutaneous pacing
• Blood Draws
• NG Tube placement

The following procedures are not bundled into critical care time, so they can be billed separately, therefore the time you spend doing these procedures can not be included in your total critical care time:

• Central Line Placement
• Lumbar Puncture
• Intubation
• Transvenious pacemaker placement
• Arterial Line Placement
• Chest Tube Placement
• CPR

Remember critical care time does not need to be continuous but you need to be immediately available to the patient for the time to count.  You can not count time going off the floor to review an xray or CT, but this time can be counted if you do it in the immediate vacinity of the patient.

FINAL CAVEAT  To help your coders bill appropriately it helps to include a statement such as "Critical Care time XX minutes where I was directly involved in the care of this patient exclusive of all other separately billable procedures."

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• Bronchiolitis is the most common lower respiratory tract disease in infants, and RSV (Respiratory syncytial virus) bronchiolitis is the leading cause of hospitalization in infants.  It will infect 90% of children by 2 years of life.
• Bronchiolitis "season" in the US is typically December to March but it does occur year round. 
• Pathology is caused by respiratory epithelial cell death that results in inflammation, edema, smooth muscle contraction, bronchoconstriction and mechanical obstruction by cellular debris and mucus plugging.
• History that suggest Bronchiolitis is cough, rhinorrhea, fever
• Most common PE findings are runny nose, tachypnea, wheezing, cough, crackles, use of accessory muscles,  and/or nasal flaring.
• Respiratory distress, dehydration, sepsis, and RSV associated apnea are feared severe complications.
• RSV associated apnea may be the presenting symptom in some infants. 
  • Infants at greatest risk for this are younger (usually < 3 months), hx of prematurity, hx of apnea of prematurity, and those who are early on in the illness.

 

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The FDA has ruled that Long-Acting Beta Agonists (LABAs) are not worth the risk with increased hospitalization and increased mortality. Serevent has largely been replaced by Advair now. Unfortunately, for the children, it took 3 years to look at the data and finally come to this conclusion. Advair (LABA + fluticasone) has escaped the ruling with lack of evidence.

• Despite guidelines that recommend against opioid use as first-line treatment for migraine headaches,  meperidine (Demerol) is still administered in 36% of all migraine headache ED visits in the U.S.

• Meperidine's lack of efficacy, adverse effects such of seizure, and toxic metabolic accumulation all contribute to its use for migraine headaches being discouraged.

• A recent meta-analysis out of New York again supports the avoidance of using meperidine for migraine headaches, and instead, encourages clinicians to use anti-emetic and dihydroergotamine regimens.

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Catheter Positioning

• Central venous catheters (CVC) inserted from the left side must make an acute angle downward when the enter the SVC from the innominate vein
• CVCs that do no make this turn can end up with the tip pointing directly at the lateral wall of the SVC
• CVCs in this position can cause perforation of the SVC
• If the catheter tip is pointing at the SVC, then advance the catheter further down

There is clearly no way you can document everything on a chest pain chart. However, there are some pretty important things that should be on the chart.

Some key things to consider documenting:

• Why you did not work up someone's chest pain, i.e. what would you want your chart to look like if the patient went home to have an MI and an attorney looked at your chart? You don't think a ECG is warranted? Fine. Just document why. The chart tells all.
• Documentation of risk factors for the three deadly causes of chest pain: ACS/MI, aortic dissection, and PE. Documenting these is proof you were thinking about a differential diagnosis.
• Documenting key chest pain physical exam findings and pertinent negatives-Documenting "legs normal, no DVT" is proof you were thinking about PE the whole time, even if it isn't in your medical decision making section. Writing "no diastolic murmur" is proof you thought about aortic dissection. These kinds of documentation pearls will serve to make the chart defensible. Obviously, you should perform this part of the exam and not just write it on the chart.
• Documentation of why you didn't go after ACS, aortic dissection, or PE. We will all make mistakes in our careers. And remember, we can't diagnose every MI, dissection, and PE. But, remember that you want your chart to show that you thought about these bad boys and WHY you didn't go after them. What is frequently missing on charts of missed MI, AD, and PE is exactly this!

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Exchange resins (sodium polystyrene sulfonate, Kayexalate) are useful for elimination of potassium from the body in the setting of hyperkalemia, though they work slowly. When given orally, the onset of action is at least 2 hours and peak effect may take > 6 hours. SPS normally produces constipation so it is almost always given with sorbitol. Patients that cannot tolerate oral SPS can receive the therapy as a retention enema, though the magnitude of effect is lower. There is controversy regarding exactly how much SPS will decrease the potassium level, so it seems best to recheck levels to be certain that it's achieving the desired results. Don't rely on this as the sole therapy in moderate to severe cases of hyperkalemia. There are rare case reports of patients receiving SPS + sorbitol that developed intestinal necrosis. The reports seem to indicate that is is a bit more common in post-operative patients and perhaps renal transplant patients. I'm not certain of the mechanism or if there's another way of predicting which patients are at high risk. [Weisberg LS. Management of severe hyperkalemia. Crit Care Med 2008;36:3246-3251.]

It seems to come up about once or twice a month about the safety of metronidazole in pregnancy.  This has been very controversial over the years, but the current stance is that it is safe in pregnancy.  In fact, untreated vaginal infections, bacterial vaginosis and trichomonas, have been associated with miscarriages and preterm labor, so the benefits outweigh the risks.

Below are two good references to add to your file in case you get into a debate with somebody quoting old data.

Organization of Teratology Information Specialists Information on Flagyl and Pregnancy

Safety of metronidazole during pregnancy: a cohort study of risk of congenital abnormalities, preterm delivery and low birth weight in 124 women. J Antimicrob Chemother 1999; 44: 854-855 http://jac.oxfordjournals.org/cgi/content/full/44/6/854

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My math may appear incorrect, however, I mistakenly left out that the protocol may be repeated once thereby giving up to a total of 4 mg of tPA.

Central Venous Catheter Occlusion

• Many of us care for patients that present with pre-existing CVCs
• Catheter occlusion is the most common complication associated with CVC
• Thrombosis is the most common cause of obstruction of CVCs
• Thrombosis is often be due to insoluble precipitates; meds such as diazepam, digoxin, phenytoin, and TMP-SMX can cause these precipitates
• Local instillation of a thrombolytic agent (tPA) can be effective in restoring CVC patency
• One protocol for use of tPA in CVC occlusion is to:
  • reconstitute a 50 mg vial with 50 mL sterile water (1 mg/mL)
  • draw up 2 mL in a 5 cc syringe and inject into the CVC - total tPA dose 2 mg
  • leave in place for approximately 2 hours
  • attempt to flush the CVC with a saline solution
• If the catheter remains obstructed, a new CVC should be placed at a new site
• The total drug dose in this regimen (4 mg) is too small to cause systemic thrombolysis

A search of the toxicology literature will reveal that naloxone has been tried in many different overdose situations.  It is thought that the endogenous opioid system mediates several physiologic and pharmacologic pathways.

• Captopril – naloxone reverses hypotension (Ann Emerg Med 1991;20(10):1125-7)
  • Evidence: One case report.
• Valproic Acid – naloxone reverses CNS depression possibly through GABA attenuation
  • Evidence: Two case reports demonstrated effectiveness in patients with minimally elevated VPA levels.  Other reports showed no effect in patients with much higher concentrations.
• Clonidine – naloxone reverses coma, bradycardia, and hypotension
  • Evidence: Several case reports suggest positive response while others demonstrate no benefit.  Anecdotal experience estimates a response in about 50% of cases.

Bottom line: In none of these instances was improvement as dramatic or consistent as in the reversal of the toxic effects of an opioid.  Naloxone can certainly be tried in non-opioid overdoses but should not be considered a first-line antidote.  The most benefit appears to be with clonidine.

Important things to document in acute ischemic stroke cases from a medicolegal aspect:

-- time of onset
-- time of diagnosis
-- why tPA given or not given (the longer note for NOT giving it; 90% of related litigation cases based on NOT giving tPA.)
-- date and time on each side of note of every page
-- make it legible
 

 

Hypertension and Epistaxis

We commonly encounter patients with epistaxis who are found to be hypertensive. Some have taught over the years that hypertension causes nosebleeds and that some nose bleeds won't stop until the BP is lowered...

Some pearls about HTN/Epistaxis:

• Most patients we see with hypertension are not experiencing epistaxis, casting serious doubt on a causal relationship
• Studies show that the degree of blood pressure elevation does not correlate with risk of nose bleed
• No studies have ever shown that acute BP reduction in the ED for a nose bleed is beneficial or reduces bleeding
• Much of the debate is sparked by our ENT colleagues who swear that hypertension leads to nose bleeds and that bleeding will not stop until the BP is "treated." Much of this is based on experience with patients in the OR or IR suite. These blood pressures tend to be treated with IV antihypertensives by the ENT folks, and they feel pretty strongly about this relationship.

Beta adrenoreceptor agonists administered by nebulization (e.g. albuterol nebulizers) are thought to be rapidly effective for lowering serum potassium levels in hyperkalemic patients. The mechanism is via a transient shift of the potassium intracellularly. It makes sense. But don't count on it. At least not much. The truth is that the beta-agonist nebs work much slower than you might think. Though they are quickly effective for bronchospasm, the potassium-shifting effect takes at least 30 minutes, and there's not much peak effect for perhaps as many as 60 minutes. Also, the "peak effect" is only approximately a 1.0 mmol/L reduction...and that's with a 20 mg dose. That's 8-times the normal dose than a typical albuterol neb (one of those albuterol "bullets" has 2.5 mg in 3 cc of solution, so a 20 mg dose would be 24 cc of the albuterol solution). The bottom line is that albuterol nebs are not really effective treatment, even transient, for patients with severe hyperkalemia. If you want do something while people are trying to gain IV access on a "tough stick," then it's certainly better than nothing. Ask the nurses or respiratory techs to start continuous nebs...but the IV calcium and insulin are still the key early temporizing measures to focus on until you've got elimination measures underway (kaexylate, hemodialysis, etc.). [Weisberg LS. Management of severe hyperkalemia. Crit Care Med 2008;36:3246-3251.]

Just a quick remainder that Thrombotic thrombocytopenia Purpura, TTP, is typically described as a pentad of symptoms:

1. Neurological symptoms such as altered mental status, stroke, or headache
2. Renal failure
3. Fever
4. Thrombocytopenia (low platelets) associated with purpura
5. Microangiopathic hemolytic anemia

Not all symptoms need to be present and it would be rare for you to see the full pentad.  Consider the diagnosis and request that the lab due a manual differentiation or blood smear.  It is there that they will notice schistocytes, fragmented RBCs, that will help clinch the diagnosis.

Most cases of TTP are idiopathic (~60%) but secondary TTP is known to occur with cancer, pregnancy, HIV, bone marrow transplantation, immunospressive drugs like cyclosporin and tacrolimus, and platelet aggregation inhibitors such as cloperidol.

Treatment consists of plasmapheresis, plasma exchange, immunospression with steroids, Rituximab, and other chemotherapies.

CO is formed from the incomplete combustion of carbon materials, eg. fires, stoves, portable heaters CO reversibly binds hemoglobin, producing carboxyhemoglobin (HbCO). This causes oxygen to bind more tightly to hemoglobin, releasing less in the tissues. Because of this, it affects the organs with the highest oxygen requirements most profoundly (eg. brain and heart).

Symptoms are mainly neurological and cardiovascular, but may include a wide variety of non-specific symptoms. The initial symptoms of CO poisoning may include headache and flu-like illness progressing to confusion, agitation, lethargy, seizures and coma.

Place patients on 100% oxygen to decrease the half-life of HbCO. Though controversial, HBO therapy is thought to decrease the incidence of neurologic sequelae. HBO therapy should be considered for patients with a HbCO level above 20%, severely symptomatic patients with lower levels, and pregnant patients. Remember that pulse oximetry will not be accurate.

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** Fosphenytoin (Cerebyx) is a pro-drug of Phenytoin (Dilantin).

** Differences between fosphenytoin and phenytoin are primarily due to fosphenytoin being more water soluble.
 

Fosphenytoin versus Phenytoin:
•     Fosphenytoin  >  less risk for cardiac-related adverse effects (propylene glycol not required for solubilization)
•     Fosphenytoin >  lower risk of local skin and subcutaneous irritation during infusion 
•     Fosphenytoin > can be given intramuscularly
•     Fosphenytoin >  can be infused at a faster rate (20 mg/kg phenytoin equivalents (PE’s) load at a rate of 100 to 150   mg of PE’s/minute) due to its safer side/adverse effects profile.

Hemodialysis Catheters

Two weeks ago, we had a PEA arrest of a patient receiving HD.  A significant delay occurred in administering fluids and medications as a result of "no iv access".  Don't forget that in these situations you can use the hemodialysis catheter.

• Typically these are double-lumen catheters in the IJ or femoral vein; one lumen carries blood to the HD machine and the other returns it to the patient
• Importantly, each lumen is equivalent in diameter to an introducer catheter (8 French) - permitting rapid flow
• Fluids and medications can be rapidly given through these catheters in code situations