UMEM Educational Pearls - By Robert Brown

Category: Critical Care

Title: ARDS basic management in COVID19 cases

Keywords: ARDS COVID19 (PubMed Search)

Posted: 3/17/2020 by Robert Brown, MD (Updated: 3/31/2020)
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Takeaways

This week we anticipate treating more COVID19 cases as they progress to ARDS. The World Health Organization issued guidelines on 3/13/20 for treating Severe Acute Respiratory Infection (SARI) due to COVID19. 

How to identify ARDS?

No different than before COVID. Order a CXR, ABG, and perform bedside ultrasound evaluation of cardiac function and volume status. If there are bilateral opacifications you cannot explain entirely with volume overload, nodules, or lobar collapse, AND if the ratio of PaO2/FiO2 is < 300 (mild), < 200 (moderate), or < 100 (severe), then treat for ARDS.

***While you are waiting for your blood gas, SpO2/FiO2 <315 suggests ARDS.

What is the oxygen goal?

During resuscitation: > 93%

Once stabilized: > 89%

What is the expected clinical course?

Patients experience RAPID deterioration to respiratory failure. You should expect to intubate. This should be performed with N95 protection and should be done by the person with greatest first pass success.

Be CONSERVATIVE with fluids. Do not give a 30mL/kg bolus. Give 250-500mL bolus and re-evaluate. Excess fluid results in prolonged hypoxia and mechanical ventilation.

Should empiric treatments change?

No. Co-infection with influenza, bacterial pneumonia, and all other pathogens is possible, so you should continue to cover all suspected pathogens and de-escalate as microbiology labs result.

Should ventilator settings change?

No. Use lung protective volumes and permissive hypercapnia. The volume is based on the patient's height, not weight. A quick way to do this? Measure the height in cm. Subtract 100 for a man and subtract 110 for a woman and this is the ideal body weight. Provide 6mL/kg of tidal volume with a goal plateau pressure < 30. Use the high PEEP strategy from the ARDSnet trial and even consider clamping the ET tube when transitioning from machine to bag for transport in order to preserve PEEP.

Do patients benefit from proning?

Yes. 12-16 hours/day for severe ARDS. Not true in pregnancy as a whole, though early pregnancy may still benefit.

 Is ECMO beneficial in refractory cases?

Unknown. In the case of MERS-CoV, ECMO reduced mortality.

Are corrticosteroids useful?

No. Do not administer steroids routinely to these patients. You may give steroids where indicated, including cases of refractory shock following pressors.

 

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Category: Critical Care

Title: 2020 Hindsight - looking back at autoimmune encephalitis we may have misdiagnosed for decades

Keywords: Encephalitis, autoimmune, psychosis, movement disorders (PubMed Search)

Posted: 1/24/2020 by Robert Brown, MD (Emailed: 1/28/2020) (Updated: 3/31/2020)
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Takeaways

Dr. Bryan Hayes wrote a Pearl 10/4/2013 to remind us autoimmune encephalitis can present like neuroleptic malignant syndrome.

Dr. Danya Khouja wrote a Pearl 6/28/2017 to inform us autoimmune encephalitis is associated with tumors and can be investigated with serum and CSF antibody panels.

Since those publications, the number of validated autoimmune biomarkers in these panels has increased dramatically. In 2020 we now know, autoimmune encephalitis is at least as common as infectious encephalitis.

Here is how to diagnose it

1. Suspect the diagnosis in patients with subacute/rapidly progressive altered mental status, memory loss, or psychiatric symptoms. It can be mistaken for a new diagnosis of schizophrenia or bipolar disorder. 

2. Look for one or more additional findings: new seizures, focal CNS findings, CSF pleocytosis, MRI findings

3. Exclude other likely etiologies (but try not to get hung up on a positive drug test, especially if drug use was not recent).

Why is this important?

Early treatment with steroids and plasmapheresis can prevent progression of disease (prevent seizures, prevent months-long hospitalizations).

Young girls are especially likely to have teratomas as a cause for the disease. Finding and resecting those tumors is life-saving.

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Category: Critical Care

Title: DDAVP for intracranial hemorrhage

Keywords: DDAVP, desmopressin, ICH, intracranial hemorrhage, stroke, CVA, hyponatremia (PubMed Search)

Posted: 12/8/2019 by Robert Brown, MD (Emailed: 12/10/2019) (Updated: 12/10/2019)
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Takeaways

Pearl: consider desmopressin (DDAVP) for patients with an intracranial hemorrhage who are taking an antiplatelet. Caution, this is not for patients with an ischemic stroke with hemorrhagic conversion and it was not specifically evaluated for patients on anticoagulation or going to the OR with neurosurgery.

How strong is this evidence? International guidelines already give cautious approval for this practice, and now there is a retrospective review to support it. Though there were only 124 patients in the trial, the rate of hemorrhage expansion was much lower in the DDAVP group (10.9% vs 36.2%, P = .002) and there was no increased risk of hyponatremia (no events reported).

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Category: Airway Management

Title: Can I admit this normotensive patient with PE to the general med/surg tele wards?

Keywords: PE, tachypnea, Critical Care, ED Disposition (PubMed Search)

Posted: 10/21/2019 by Robert Brown, MD (Emailed: 10/22/2019)
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Takeaways

ICU admission rates for all acute PEs vary wildly across the country (<5% to ~80%).

To predict which hemodynamically stable, normotensive PE patients should be admitted to the ICU, a single-center retrospective analysis of 7 years’ data sought to describe the reasons why normotensive patients with PE required vasopressors within 48 hours of admission to the ICU. The authors studied 293 patients admitted to the ICU at Beth Israel Deaconess in Boston and found only 8 patients (2.7%) who decompensated within the first 2 days.  Of MANY variables studied, only respiratory rate was significantly different between those who decompensated and those who did not (mean RR 29 with range 26-32 in the decompensated group vs mean 21 with range 17-24).

Bottom Line: cost control experts may lean on you to admit fewer PE patients to the ICU. There is no perfectly reliable way to predict which normotensive patient with a PE will decompensate. The PESI score has been validated but even the low risk cohort had 1.6% mortality at 3 days. The BOVA score has been validated but its endpoint of mortality at 30 days is less useful for planning admission. Tachypnea should concern you.

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Category: Critical Care

Title: Atrial Fibrillation in Critically Ill Patients

Keywords: Atrial Fibrillation, sepsis, critical care, cardioversion, beta blockers, calcium channel blockers, rate control, rhythm control (PubMed Search)

Posted: 9/3/2019 by Robert Brown, MD (Updated: 3/31/2020)
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Takeaways

One third of your critically ill patients will have atrial fibrillation. 

More than one third of those patients will develop immediate hypotension because of it.

More than one in ten will develop ischemia or heart failure because of it.

This is what you should know for your next shift:

#1 Don't wait to use electricity. If your patient is hypotensive or ischemic because of atrial fibrillation, you do not need to wait for anticoagulation before you cardiovert.

#2 Electricity buys you time to load meds. Fewer than half of patients you cardiovert will be in sinus rhythm an hour later and fewer than a quarter at the end of a day.

#3 There is no perfect rate control agent. Beta blockers have a lower mortality in A-fib from sepsis. Esmolol has the benefit of being short-acting if you cause hypotension. Diltiazem has better sustained control than amiodarone or digoxin. 

#4 There is no perfect rhythm control agent. Magnesium is first-line in guidelines. Amiodarone can be used even when there is coronary artery or structural heart disease.

#5 Anticoagulation is controversial. In sepsis, anticoagulation does not reduce the rate of in-hospital stroke, but does increase the risk of bleeding. Use with caution if cardioversion isn't planned.

 

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Takeaways

The incidence of empyema as a complication of pneumonia has been increasing since the 1990's and source control requires removing the pus from the chest as soon as possible, but how large should the drain be? The American Association for Thoracic Surgery (AATS) released the most recent guidelines for identifying and managing empyema in June 2017 and at the time had no certain evidence to guide the choice of large-bore vs small-bore catheters. Most studies to guide us are flawed (not randomized), but no recently published randomized studies exist to provide a definitive answer. 

Bottom line: a small-bore pigtail catheter is a reasonable choice to drain empyema and flushing it every 6 hours has been shown to prevent clogging.

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Category: Critical Care

Title: Don't miss the injecting drug users with botulism!

Keywords: IVDA, AMS, botulism, Tox, ID (PubMed Search)

Posted: 7/2/2019 by Robert Brown, MD (Updated: 3/31/2020)
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Takeaways

Wound botulism presents as descending paralysis when Clostridium botulinum spores germinate in anaerobic necrotic tissue. There have been hundreds of cases in the last decade, but it is poorly reported outside of California.

Black tar heroin and subcutaneous injection (“skin popping”) carry the highest risk, but other injected drugs and other types of drug use suffice. C botulinum spores are viable unless cooked at or above 85°C for 5 minutes or longer and this is not achieved when cooking drugs. 

Early administration of botulism anti-toxin (BAT) not only saves lives but can prevent paralysis and mechanical ventilation. An outbreak of 9 cases between September 2017 and April 2018 cost roughly $2.3 million, in part because patients didn’t present on average until 48 hours after symptom onset and it took an additional 2-4 days before the true cause of their respiratory depression and lethargy were understood. One patient died.

PEARL: talk to your injecting drug users about the symptoms of botulism: muscle weakness, difficulty swallowing, blurred vision, drooping eyelids, slurred speech, loss of facial expression, descending paralysis, and difficulty breathing. Consider botulism early in your patients who inject drugs but who do not respond to naloxone or who exhibit prolonged symptoms. Testing at the health department is performed with mouse antibodies to Botulism Neurotoxin (BoNT) combined with the patient’s serum.

 

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Category: Critical Care

Title: Do Little People Have Little Lungs?

Keywords: Achondroplasia, vertebral arteries, mechanical ventilation (PubMed Search)

Posted: 6/11/2019 by Robert Brown, MD (Updated: 3/31/2020)
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Takeaways

Little people (patients with achondroplasia or "dwarfism") have little lungs. Even though the trunk may appear to be a normal size with small limbs, the vital capacity is actually about 75% the predicted value based on the patient's sitting height. Macrocephaly and a decreased anterior-posterior depth are the cause for this. When you want to mechanically ventilate a little person, you can estimate their height based on a typical person with the same sitting height, but their actual volume will be about 3/4 the tidal volume predicted.

When intubating, remember these patients also have a high risk of basicranial hypoplasia (the foramen magnum may be small and key-hole shaped). These patients will be predisposed to compress the vertebral arteries when you tilt the head back and this itself can cause ischemia of the medulla and pons leading to central apnea.

Stokes DC, Wohl ME, Wise RA, et al. The lungs and airways in Achondroplasia. Do little people have little lungs? CHEST. 1990; 98(1):145-52

Pauli RM. Achondroplasia: A comprehensive review. Orphanet Journal of Rare Diseases. 2019; 14(1): 

 

 

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Category: Critical Care

Title: Alarms responsible for alarm fatigue

Keywords: Alarm fatigue (PubMed Search)

Posted: 5/21/2019 by Robert Brown, MD (Updated: 3/31/2020)
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Takeaways

In a study of alarms from 77 monitored ICU beds over the course of a month at the University of California, San Francisco, false alarms were common. Accellerated Ventircular Rhythms (AVRs) made up roughly one third of the alarms, and of the more than 4,361 AVRs, 94.9% were false while the remaining 5.1% did not result in a clinical action.

While this study had a majority of patients in the Med/Surg ICUs, a minority were from the cardiac and neurologic ICUs giving it some broad applicability. This study adds to the literature indicating there are subsets of alarms which may not be necessary or which may require adjustment to increase specificity.

Suba S, Sandoval CS, Zegre-Hemsey J, et al. Contribution of Electrocardiographic Accelerated Ventricular Rhythm Alarms to Alarm Fatigue. American Journal of Critical Care. 2019; 28(3):222-229

 

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Takeaways

Gallstones account for 35-40% of cases of pancreatitis and the risk increases with diminishing stone size. Bile reflux into the pancreatic duct can form stones there, beyond where they can be visualized by ultrasound. Biliary colic may precede the pancreatitis, but not necessarily. The pain typically reaches maximum intensity quickly but can remain for days.

Alanine aminotransferase (ALT) > 3x normal is highly suggestive of biliary pancreatitis.

Abdominal ultrasound is not sensitive to common bile duct stones but may find dilation.

In the absence of cholangitis, endoscopic ultrasound or MRCP are sensitive tests and permit intervention. Patients who recover are much more likely to develop cholangitis, therefore cholecystectomy is indicated in patients after they recover from gallstone pancreatitis.

Bottom Line: a patient presenting with days of abdominal pain but an absence of gallstones or cholangitis may still suffer from gallstone pancreatitis which requires further intervention, including cholecystectomy.

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Category: Critical Care

Title:

Keywords: Alarm Fatigue (PubMed Search)

Posted: 5/20/2019 by Robert Brown, MD (Emailed: 3/31/2020) (Updated: 3/31/2020)
Click here to contact Robert Brown, MD

Takeaways

In a study of alarms from 77 monitored ICU beds over the course of a month at the University of California, San Francisco, false alarms were common. Accellerated Ventircular Rhythms (AVRs) made up roughly one third of the alarms, and of the more than 4,361 AVRs, 94.9% were false while the remaining 5.1% did not result in a clinical action.

While this study had a majority of patients in the Med/Surg ICUs, a minority were from the cardiac and neurologic ICUs giving it some broad applicability. This study adds to the literature indicating there are subsets of alarms which may not be necessary or which may require adjustment to increase specificity.

Suba S, Sandoval CS, Zegre-Hemsey J, et al. Contribution of Electrocardiographic Accelerated Ventricular Rhythm Alarms to Alarm Fatigue. American Journal of Critical Care. 2019; 28(3):222-229

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Category: Critical Care

Title:

Keywords: Botulism, IVDA (PubMed Search)

Posted: 7/2/2019 by Robert Brown, MD (Emailed: 3/31/2020)
Click here to contact Robert Brown, MD

Takeaways

Don’t miss the injecting drug users with botulism!

Wound botulism presents as descending paralysis when Clostridium botulinum spores germinate in anaerobic necrotic tissue. There have been hundreds of cases in the last decade, but it is poorly reported outside of California.

Black tar heroin and subcutaneous injection (“skin popping”) carry the highest risk, but other injected drugs and other types of drug use suffice. C botulinum spores are viable unless cooked at or above 85°C for 5 minutes or longer and this is not achieved when cooking drugs. 

Early administration of botulism anti-toxin (BAT) not only saves lives but can prevent paralysis and mechanical ventilation. An outbreak of 9 cases between September 2017 and April 2018 cost roughly $2.3 million, in part because patients didn’t present on average until 48 hours after symptom onset and it took an additional 2-4 days before the true cause of their respiratory depression and lethargy were understood. One patient died.

PEARL: talk to your injecting drug users about the symptoms of botulism: muscle weakness, difficulty swallowing, blurred vision, drooping eyelids, slurred speech, loss of facial expression, descending paralysis, and difficulty breathing. Consider botulism early in your patients who inject drugs but who do not respond to naloxone or who exhibit prolonged symptoms. Testing at the health department is performed with mouse antibodies to Botulism Neurotoxin (BoNT) combined with the patient’s serum.

 

 

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