UMEM Educational Pearls

Category: Critical Care

Title: Accidental Hypothermia

Posted: 11/3/2017 by Ashley Menne, MD (Updated: 7/22/2024)
Click here to contact Ashley Menne, MD

Core Temp <32 degrees leads to impaired shivering and confers increased risk for malignant ventricular dysrhythmias. Core Temp <28 degrees substantially increases risk of cardiac arrest. 

 

If in cardiac arrest:

  • VA ECMO. Rewarming rate ~6 degrees per hour.
  • Cardio Pulmonary Bypass. Rewarming Rate ~9 degrees per hour.
  • Consider transfer to center with ECMO or CPB capabilities
  • Consider up to 3 defibrillation attempts for shockable rhythm
  • Consider with holding epi until core temp >30 degrees and doubling interval between doses (q6-10 minutes) until core temp >35 (European Resuscitation Council recs – note this differs from AHA guidelines/recommendations)

 

If perfusing rhythm:

  • Institute active external rewarming (warm environment, forced-air heating blankets, arctic sun, warm parenteral fluids). Rewarming Rate ~ 0.1-3.4 degrees per hour.
  • Consider minimally invasive rewarming with TTM cooling/rewarming catheter (Alsius/Zoll) via femoral vessel. Rewarming Rate ~3.5 degrees per hour.
  • Hemodialysis or CRRT can be considered if intravascular rewarming device unavailable. Rewarming rate 2-4 degrees per hour.
  • Avoid IJ or SC central lines, rewarming catheters, and HD catheters -- myocardial irritation with wire/catheter may precipitate ventricular dysrhythmia.

 

Consider addition of more invasive rewarming techniques in those with hemodynamic/cadiac instability or without access to VA ECMO/CPB:

  • Thoracic lavage. Rewarming rate ~ 3 degrees per hour
  • Peritoneal lavage. Rewarming rate ~ 1-3 degrees per hour  
  •  

Consider stopping resuscitation efforts if/when:

  • K >12- suggests hypoxia before cooling, no reported survivors. Some recommend K of 10 as cutoff in adults.
  • Rewarmed to 32 degrees and no signs of life.

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The cornerstone treatment of poisoning is removal of the toxin from the patient. This can be accomplished before absorption into the body by decontamination methods (dermal or gastrointestinal) or after absorption by blocking metabolism of parent compound, displacing drugs from receptors, binding toxins with neutralizing agents (chelators, Fab fragments), or enhancing elimination by dialysis. Toxins that are ideal candidates for dialysis include substances that are low molecular weight, have low volume of distribution (stay in the blood stream), or low protein binding. Toxins most commonly treated with dialysis are:

  • Lithium
  • Salicyclates
  • Ethylene glycol
  • Methanol
  • Acetaminophen

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Category: Orthopedics

Title: Quadriceps Contusion

Keywords: Muscle injury, splinting (PubMed Search)

Posted: 10/28/2017 by Brian Corwell, MD (Updated: 7/22/2024)
Click here to contact Brian Corwell, MD

Question

Quadriceps Contusion

Mechanism: Blunt trauma to the anterior thigh (frequently football helmet or opponents knee)

Usually involves the anterior quadriceps (rectus femoris and vastus intermedius)

Pain on passive stretch and active contraction

Can develop large hematomas

Loss of knee flexion is a poor prognosticator

Complication: Myositis Ossificans (MO) (5-17%)

               Increased risk with delay in treatment > 3 days

               Radiographs can lag. Ultrasound in more sensitive

               Painful firm area in region of contusion occurring 2 to 3 weeks post injury

http://fifamedicinediploma.com/wp-content/uploads/2015/12/myositis_ossificans_lateral-1.jpg

Prompt treatment….key to good outcome and earlier return to sports

Large hematoma can be aspirated. NSAIDs may reduce edema and risk of MO. Splinting

Place quadriceps in 120 degrees of flexion for 24 hours following injury (keep muscle lengthened)

https://upload.orthobullets.com/topic/3103/images/quad%20contusion_moved.jpg

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Category: Pediatrics

Title: Pediatric ARDS continued...

Keywords: ARDS, oxygenation index, OI, PALICC, acute lung injury, respiratory distress, PARDS (PubMed Search)

Posted: 10/27/2017 by Mimi Lu, MD
Click here to contact Mimi Lu, MD

Some pediatric practitioners have adopted the oxygenation index (OI) ([FiO2 × mean airway pressure (Paw) × 100]/ PaO2) or oxygen saturation index (OSI) ([FiO2 × Paw × 100]/ SpO2) to assess hypoxemia in children instead of P/F ratios because of the less standardized approach to positive pressure ventilation in children relative to adults. 

OI can be used in pediatric patients to define severity of Acute Respiratory Distress Syndrome (ARDS) in patients receiving invasive mechanical ventilation and assess for potential ECMO treatment. 

In contrast, the P/F ratio should be used to diagnose Pediatric ARDS for patients receiving noninvasive continuous positive airway pressure [CPAP] or bilevel positive airway pressure [BiPAP]) with a minimum CPAP of 5 cm H2O.

Oxygen Index (OI) = FiO2 x MAP x 100
                                 ---------------------
                                         PaO2

  • Mild ARDS: 4 ≤ OI ≤ 8
  • Moderate ARDS: 8 ≤ OI < 16
  • Severe ARDS: OI ≥ 16
  • OI < 25: good outcome
  • OI 25-40: >40% mortality
  • OI > 40: Consider ECMO

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Category: Toxicology

Title: Agatha Christie 2.0 Strychnine

Keywords: strychnine (PubMed Search)

Posted: 10/26/2017 by Hong Kim, MD (Emailed: 10/27/2017) (Updated: 10/27/2017)
Click here to contact Hong Kim, MD

Her first book “The mysterious affair at Styles,” Agatha Christie introduced her lead detective in her novels, Hercule Poirot - the Belgian detective.  She also described the death of Mrs. Emily Inglethorp by strychnine.

Strychnine is found in a disc-like seed of strychnos nux-vomica, a tree native to tropical Asia and North Australia.

It is currently used as rodenticide (moles and gophers), in Chinese herbal medicine and a traditional remedy in Cambodia.

Strychnine inhibits binding of glycine (a major inhibitory neurotransmitter in spinal cord) to Cl-channel resulting in identical clinical syndrome – seizure-like generalized muscle contraction with normal mental status – as tetanus toxin. Tetanus toxin inhibits the release of presynaptic glycine in the spinal cord. 

 

Management

Goal: decrease muscle hyperactivity

  • 1st line: benzodiazepine
  • 2nd line: barbiturates or propofol
  • 3rd line: paralysis by non-depolarizing agents


Category: Neurology

Title: Guillain- Barr Syndrome

Keywords: weakness, infection, paralysis, intubation, influenza, vaccine (PubMed Search)

Posted: 10/25/2017 by Danya Khoujah, MBBS
Click here to contact Danya Khoujah, MBBS

It's respiratory infection and flu vaccine season! Time to brush up on Guillain-Barré Syndrome..

- It is the most common cause of acute or subacute flaccid weakness worldwide

- 70% of cases are preceded by an infection in the past 10-14 days, but most are minimized or forgotten by the patient. 40% of these infections are by Campylobacter jejuni.

- 30% develop respiratory failure requiring intubation and ventilation

- Half of the patients will develop their maximum weakness by 2 weeks, most will develop it by 4 weeks.

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Infectious Diarrhea:

Have your wondered what you should do with patients that you suspect have infectious diarrhea. Well the IDSA has updated their 2001 guidelines for the management of infectious diarrhea. The TAKE HOME Points are:

  • Most patients with diarrhea do not need to be tested for an infectious cause. Stop ordering those cultures.
  • Testing IS recommended in the folllowing populations:
    • Patients younger than 5 years
    • Elderly
    • Patients that are immunocompromised
    • Patients with bloody diarrhea
    • Patients with severe abdominal pain or tenderness, or have signs of sepsis.
    • Testing may be considered for C. difficile in people >2 years of age who have a history of diarrhea following antimicrobial use and in people with healthcare-associated diarrhea
  • Some additional recommendations that are noteworthy:
    • Fecal leukocyte examination and stool lactoferrin detection should NOT be used to establish the cause of acute infectious diarrhea
    • A peripheral white blood cell count and differential and serologic assays should NOT be performed to establish an etiology of diarrhea
    • Reduced osmolarity oral rehydration solution (ORS) is recommended as the first-line therapy of mild to moderate dehydration in infants, children, and adults with acute diarrhea from any cause

 

You can find all the recommendations at https://academic.oup.com/cid/article/doi/10.1093/cid/cix669/4557073/2017-Infectious-Diseases-Society-of-America

 

 

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Question

Within the first hour after administration, ondosterone, metoclopramide and bromopride were equally efficacious.  At the 6 hour and 24 hour period after receiving the initial dose of medication, ondansetron was statistically superior to bromopride (not available in the US) and metoclopramide.  There were no reported side effects in the ondansetron group (including diarrhea or sedation).

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Category: Toxicology

Title: Arsenic and Agatha Christie

Keywords: Arsenic poisoning (PubMed Search)

Posted: 10/19/2017 by Hong Kim, MD
Click here to contact Hong Kim, MD

Agatha Christie is an English crime novelist who frequently used poisons in her books to murder the victims. In her book, Murder is Easy, Ms. Christie uses arsenic/arsenic trioxide to kill several characters.

 

Primary source of arsenic in general population is contaminated food, water and soil. Arsenic exists in several forms: elemental, gaseous (arsine), organic and inorganic (trivalent or pentavalent).

 

Arsenic trioxide has also been used to treat acute promyelocytic leukemia in China; it’s use in other leukemia, lymphoma, and other solid tumors are currently being investigated.

 

Arsenic primarily inhibits the pyruvate dehydrogenase complex and multiple other enzymes involved in the citric cycle/oxidative phosphorylation, resulting in mitochondrial dysfunction.

 

Acute toxicity of arsenic after ingestion

  1. GI symptoms (minutes to several hours) – nausea, vomiting, abdominal pain and cholera like diarrhea.
  2. Cardiovascular: QT prolongation/torsade de pointes, orthostatic hypotension, ventricular dysrhythmias, myocardial dysfunction and shock.
  3. CNS (days): encephalopathy, delirium, coma, and seizure due to cerebral edema and microhemorrhages.
  4. Respiratory: ARDS, respiratory failure,
  5. Others: AKI, leukemoid reaction, hemolytic anemia, and hepatitis.

 

 Management

  1. Chelation: dimercaptrol (BAL) or succimer
  2. Whole bowel irrigation if radiopaque material is present (abdominal XR)
  3. Electrolyte and fluid management
  4. Cardiac monitoring and pressor support in hypotension


Improving CPR Performance

  • High-quality CPR is the cornerstone of successfull resuscitation from cardiac arrest.
  • In fact, high-quality CPR is considered the most important intervention for achieving ROSC and good neurologic recovery.
  • Pearls for optimizing CPR performance include:
    • Use a team-focused approach
    • Avoid leaning and ensure complete recoil of the chest
    • Target a chest compression fraction of at least 60%
    • Use POCUS, but pay attention to the duration of hands-off time
    • Target ETCO2 of > 20 mm Hg

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Category: Orthopedics

Title: Osteochondritis Dissecans

Keywords: Knee pain (PubMed Search)

Posted: 10/14/2017 by Brian Corwell, MD (Updated: 7/22/2024)
Click here to contact Brian Corwell, MD

Complete or incomplete separation of the articular cartilage and subchondral bone

               -70% occur at the lateral aspect of the medial femoral condyle

               -Also seen in the talar dome and capitellum

Repetitive overloading leads to fragmentation and separation from surrounding bone

Prognosis better in kids than in adults

http://www.eorif.com/KneeLeg/Images/OCD4w.jpg

CC: Vague difficult to localize activity related pain and swelling. Mechanical symptoms only if loose body is present

PE: Wilson’s test

Internal tibial rotation and knee extension impinges the tibia on the OCD lesion causing pain. Pain abates with external rotation and flexion.

https://www.youtube.com/watch?v=e7zrKo41Pos

Plan of care: Limit activity and trial period of non-weight bearing for 6 weeks.

50% resolve in 10 to 18 months with conservative care.

Detached, loose or unstable fragments or failure of non-operative care will need surgery



Pediatric patients are at a higher risk of blunt renal injury due to multiple anatomic features, include relatively less protective perinephric fat and surrounding musculature, and larger size of the kidneys in relation to the abdomen compared to their adult counterparts (1). For this reason, it is important to keep a high clinical suspicion for renal injury in the pediatric patient with blunt abdominal trauma, particularly in those with lower rib fractures, direct injury, flank ecchymosis and/or tenderness, rapid deceleration injury, or other significant traumatic mechanism (2). Despite the risk of radiation exposure, the preferred imaging modality for the diagnosis of renal injury in pediatric patients is computed tomography (similar to adults). Studies evaluating the utility of renal ultrasound have demonstrated poor sensitivity with a decreased likelihood of diagnosing low-grade injuries. While ultrasound may be a useful screening tool to evaluate for severe injury, it should not be used to rule out traumatic injury (1). Take home point: Keep a high suspicion for renal injury in pediatric patients with blunt abdominal trauma and confirm the diagnosis with computed tomography of the abdomen and pelvis with contrast.

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Category: Toxicology

Title: Cannabinoid Hyperemesis Syndrome

Keywords: Cannabinoid, cyclic vomiting, Capsaicin (PubMed Search)

Posted: 10/12/2017 by Kathy Prybys, MD
Click here to contact Kathy Prybys, MD

Cannabinoid hyperemesis is a syndrome (CHS) characterized by severe intractable nausea, cyclical vomiting, and abdominal pain associated with chronic marijuana abuse. It is often a underrecognized cause of cyclic vomiting syndrome. Despite well established anti-emetic properties of marijuana, paradoxical effects on the GI tract exist through cannabinoid receptors which exert their neuromodulatory properties in the central nervous system and the enteric plexus. Multiple theories of mechanism of CHS are in the literature. Diagnosis is based on the following clinical criteria:

  • History of regular cannabis for any duration of time
  • Refractory nausea and vomiting
  • Gastrointestinal evaluations fail to identify other clear causes
  • Compulsive bathing in hot water temporarily alleviates symptoms often done several times a day. A red flag symptom.
  • Resolution of symptoms after cannabis is discontinued

Acute care goals are to treat dehydration and terminate nausea and vomiting. Administration of intravenous fluids, dopamine antagonists, topical capsaicin cream, and avoidance of narcotic medications are recommened treatment measures. Benzodiazepines followed by haloperidol and topical capsaicin are reported to be most effective. Capsaicin  activates the transient receptor potential vanilloid 1 receptors (TRPV1) which impairs substance P signalling in the area postrema and nucleus tract solitarius similar to noxious stimuli, such as heat. 

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Category: Neurology

Title: Traumatic Brain Injury in Older Adults - The Silver Tsunami?

Keywords: traumatic brain injury, TBI, fall, subdural hematoma, SDH, elderly (PubMed Search)

Posted: 10/11/2017 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

Traumatic brain injury (TBI) is associated with close to half of major trauma admissions in adults over age 65 in the U.K.

Falls accounted for 85% of all TBIs, while 45% of patients had subdural hematomas (SDH).

More than 3/4 of patients were treated conservatively, though outcomes were not significantly better than those who underwent neurosurgical intervention.

Higher age is associated with higher mortality and greater disability.

Bottom Line: Trauma in older adults is increasing and fall prevention is important in reducing significant injuries.

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Category: Critical Care

Title: Liver Dialysis on MARS (Molecular Adsorbent Recirculating System)

Keywords: liver failure, dialysis, MARS, Molecular Adsorbent Recirculating System (PubMed Search)

Posted: 10/10/2017 by Kami Windsor, MD
Click here to contact Kami Windsor, MD

Question

Molecular Adsorbent Recirculating System (MARS) is an artificial liver support system colloquially known in the medical field as "dialysis for the liver."  

  • Limited data, small studies
  • Consistently shown to improve hemodynamics, toxin clearance, and hepatic homeostasis
  • No consistent proven mortality benefit
  • Only performed by limited number of US hospitals (including the University of Maryland)
  • May depend on the acute liver failure subpopulation, but best use currently seems to be for severe acute liver failure due to a potentially reversible/recoverable cause (toxin ingestion, trauma, acute alcoholic hepatitis, etc) or as a bridge to transplant

Take-Home:

1. Consider MARS in your patient with severe acute liver failure due to potentially reversible/recoverable etiology

2. Know if and where MARS is offered near you

 

(http://findbesttreatment.com/images/healthnet_dialyse_schema.gif)

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Category: Pharmacology & Therapeutics

Title: Fever Treatment in Sepsis

Keywords: antipyretic, sepsis, fever (PubMed Search)

Posted: 10/7/2017 by Ashley Martinelli (Emailed: 10/10/2017) (Updated: 7/22/2024)
Click here to contact Ashley Martinelli

Fever occurs in 40% of patients with sepsis.  Historically, there has been conflicting evidence of whether patient outcomes improve with antipyretic therapy.

A recent large meta-analysis assessed the effect of antipyretic therapy on mortality of critically ill septic patients.  The analysis included 8 randomized studies (1,531 patients) and 8 observational studies (17,432 patients) that assessed mortality of septic patients with and without antipyretic therapy.

The authors found no difference in mortality at 28 days or during hospital admission.  There was also no difference in shock reversal, heart rate, or minute ventilation.

As expected, they found a statistically significant reduction in posttreatment body temperature (-0.38°C, 95% IC -0.63 to -0.13) in patients who received antipyretic therapy.  NSAIDs and cooling therapies were more effective than acetaminophen, however no agent or dosing information was provided and only one study included physical cooling therapies.

Bottom Line: Antipyretic therapies do not reduce mortality in patients with sepsis, but they may improve patient comfort by reducing body temperature.

 

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Category: Pediatrics

Title: Risky Business in Bronchiolitis

Keywords: Pediatrics, Bronchiolitis, Respiratory Decompensation, Risk factors (PubMed Search)

Posted: 10/6/2017 by Megan Cobb, MD
Click here to contact Megan Cobb, MD

Question

Bronchiolitis season will soon be upon us. Here are some risk factors for children under 2 y/o with bronchiolitis, who may be more likely to suffer respiratory decompensation:

1. Age under 9 months

2. Black race

3. Hypoxia documented in the ED

4. Persisent accessory muscle use. 

Bottom Line: Consider providing respiratory support sooner than later in bronchiolitic infants with risk factors for decompensation. For HFNC, start at 1.5 - 2.0 L/kg/min, and titrate to work of breathing and  0saturations. 

_______________________________________________________________________________

Pathophysiology: Bronchiolitis is a disease process that leads to inflammation of lower airways, causing bronchiolar edema, epithelial hyperplasia, mucus plugging, and air trapping or atelectasis. Common viral causes include RSV, Human Metapneumovirus, Rhinovirus, Influenza, and Parainfluenza. 

Clinical Course: For most strains, the disease course is often 5-7 days with the worst days being 3-5. The disease process can last longer, especially in neonates. The predominant presenting symptoms are often rhinorrhea, low grade fevers, and cough, but apnea can be the primary symptom in younger infants. As a result of increased work of breathing, PO feeding tolerance decreases and leads to dehydration. 

Treatment: Primarily supportive care with suctioning, hydration, supplemental oxygen via standard NC, HFNC, and in severe cases BiPAP, CPAP or intubation. Trial of bronchodilator is often used, but there is no role for repeated bronchodilator use if no benefit is seen in pre and posttreatment respiratory effort. Hypertonic saline is not recommended for routine use in the ED. Corticosteroids have no role for routine use in viral bronchiolitis, either.

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Category: Toxicology

Title: Hunan Hand

Keywords: Capsaicin, hunan hand, chili peppers (PubMed Search)

Posted: 10/6/2017 by Kathy Prybys, MD
Click here to contact Kathy Prybys, MD

Hunan hand syndrome is a painful contact dermatitis that frequently presents in cooks and chili pepper workers after preparing or handling chili peppers. Contact with other body parts gives rise to the terms: "Hunan nose" ''Hunan eye",and "Chili Willie". Capsaicin, found in the fruit of plants from the genus Capsicum such as red chili peppers, jalapeños, and habaneros, is a hydrophobic, colorless, odorless compound that binds with pain receptors causing the sensation of intense heat or burning. The "heat" or pungency of a peppers is measured in Scoville heat units (SHU), the number of times a chili extract must be diluted with water to lose heat. Habanero peppers generate 30,000 SHU. Even at low concentrations capsaicin is a skin irritant. It is the primary ingredient in pepper spray used in law enforcement and in personal defense sprays.   

Treatment consists of decontamination with water irrigation for opthalmic exposure and milk or antacids for dermal or gastrointestinal exposure. Burning can be recurrent and of of long duration depending on tissue penetration. Topical anesthetic especially for the eye and cool compresses for the skin can relieve pain.  Parodoxically capsaicin is used as a topical analgesic medication for local pain relief from muscle pain, itching,  and painful neuropathies (diabetic, postherpetic). Capsaicin initially causes neuronal excitation followed by a long-lasting refractory period due to depletion of substance P, during which neurons are no longer responsive to a large range of stimuli and thus are desensitized.

 

 

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Risk of Pneumocystis pneumonia  (PCP) increases with degree of immunosuppression. If clinical suspicion exists (CD4 <200 with cough, pulmonary infiltrates, hypoxic respiratory failure), it is reasonable to initiate empiric therapy. 

First line treatment is trimethoprim-sulfamethoxazole (TMP-SMX) orally or IV for 21 days.  IV pentamidine has equivalent efficacy to IV TMP-SMX but greater toxicity and is generally reserved for patients with severe PCP who cannot tolerate or are unresponsive to TMP-SMX.

Importantly, adjunctive corticosteroids have been shown to significantly improve outcomes (mortality, need for ICU admission, need for mechanical ventilation) in HIV-infected patients with moderate to severe PCP (defined by pO2 <70 mmHg on Room Air).

·      Ideally steroids should be started BEFORE (or at the same time as) Pneumocystis-specific treatment to prevent/mitigate the sharp deterioration in lung function that occurs in most patients after initiation of PCP treatment. This is thought to be secondary to the intense inflammatory response to lysis of Pneumocystis organisms, which can cause an ARDS-like picture.

·      Recommended dosing schedule: 40mg prednisone twice daily for 5 days,  then 40mg once daily for 5 days, followed by 20mg once daily for the remaining 11 days of treatment.

 

Bottom Line: In patients with moderate to severe PCP (pO2 <70 mmHg on RA), don’t forget to initiate adjunctive corticosteroids early (at the same time you initiate empiric therapy for PCP). 

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The current number of influenza cases in the Southern Hemisphere is substantially higher than normal.  For example, in Australia the number of influenza cases this year are twice the next highest year. 

Have you gotten your flu shot yet?

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