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Title: Passive Leg Raise

Category: Critical Care

Keywords: passive leg raise, arterial pressure, pulse pressure variation, volume responsiveness, fluid resuscitation (PubMed Search)

Posted: 9/20/2016 by Mike Winters, MBA, MD

Pitfalls with PLR

  • The passive leg raise (PLR) test has become a popular method to assess volume responsiveness in critically ill patients.
  • PLR mobilizes a volume of approximately 150-300 mL and can be used in spontaneously breathing patients, those receiving positive pressure ventilation, or those with various arrhythmias. 
  • In order to properly perform the PLR, you must have a method to monitor cardiac output. (See previously pearl on 7/26/16).
  • Pitfall: Simply monitoring arterial blood pressure alone is not a sufficient method to assess a positive PLR.
  • Pitfalls:Risks of performing a PLR include increased intracranial pressure, reduced cerebral blood flow, and decreased pulmonary compliance.

Show References

Aneman A, Sondergaard S. Understanding the passive leg raising test. Intensive Care Med. 2016; 42:1493-5.



Title: What is the diagnosis ? (Case submitted by Dr. Kevin Campos and Dr. Adeleke Oni)

Category: Visual Diagnosis

Posted: 9/19/2016 by Hussain Alhashem, MBBS

Question

A 67 year old female with history of CVA, presented from a nursing home with RUQ abdominal pain and inablitiy to tolerate PO for 3 days. A CT scan of her abdomen was obtained. What is the diagnosis ?

Show Answer

1- Cholecystitis

Ultrasound remains the best modality to test for cholecystitis. However, CT scans can still be obtained for non-classic presentations. The negative predictive value of CT is still relatively high. CT has a negative predictive value of 89%, compared to 97% to that of ultrasound. The absence of cholecysitis on CT will help the argument against the diagnosis, but if the suspicion is high an ultrasound study should still be obtained.

Things to look for on an abdominal CT that are suggestive of cholecysitis:

  1. Gallbladder distension ( >5 cm width, >8 cm length).

  2. Wall thickening ( >4mm thickness).

  3. Pericholecystic fat stranding.

  4. Presence of gallstones.

2- An inflated foley catheter in the ureter!

Ureteric insertion of foley catheters is a very rare complication of foley catheterization. There are no clear predisposing factors to this complication. However, it is thought that the presence of an underlying anatomical deformity (e.g. abnormal ureteric insertion site) might put the patient at a higher risk for it. Inflating a balloon in the ureter might result in severe ureteric injury. A suggested method to prevent this kind of injury is to perform bladder aspiration to insure balloon positioning prior to inflation.

Show References

References

1- Shakespear, Jonathan S., Akram M. Shaaban, and Maryam Rezvani. "CT findings of acute cholecystitis and its complications." American Journal of Roentgenology 194.6 (2010): 1523-1529.

2- Kim, Myung Ki, and Kwangsung Park. "Unusual complication of urethral catheterization: a case report." Journal of Korean medical science 23.1 (2008): 161.



Title: PatelloFemoral Syndrome Treatment

Category: Orthopedics

Keywords: Patellofemoral Syndrome (PubMed Search)

Posted: 9/17/2016 by Michael Bond, MD (Updated: 9/17/2016)

Patellofemoral Syndrome Treatment options

Patients do best with a combined intervention (ie, exercise therapy, education, manual therapy and taping)  plan or patellofemoral bracing may improve outcomes for people with patellofemoral syndrome and the subtype of patellofemoral osteoarthritis.

For for the ED, we can start NSAIDs, and then have them follow up with Physical Therapy, A sports trainer if in organized sports, or with a sports medicine physician/PCP.  Physical therapy is targeted at strengthening the quadricep muscle particularly vastus medialis, which improves the patella’s tracking with knee flexion.



Title: Utility of End tidal CO2 for bronchiolitis

Category: Pediatrics

Keywords: Bronchiolitis, ETCO2 (PubMed Search)

Posted: 9/16/2016 by Jenny Guyther, MD

114 children with bronchiolitis had end tidal carbon dioxide (ETCO2) measured on presentation to the ED. The ETCO2 levels did not differ significantly between admitted and discharged patients. In the subset of admitted patients, there was no correlation with ETCO2 on admission and days of oxygen requirement or length of stay.

Bottom line: Initial ETCO2 does not predict outcome for patients with bronchiolitis.

Show References

Jacob R, Bentur L, Brik R, Shavit I and Hakim F. Is capnometry helpful in children with bronchiolitis? Respir Med 2016; 113:37-41.



Title: Variation in naloxone dose recommendation for opioid intoxication among medical specialties: Is there a "right" dose?

Category: Toxicology

Keywords: naloxone, opioid intoxication (PubMed Search)

Posted: 9/15/2016 by Hong Kim, MD

Naloxone has been used to reverse opioid-induced respiratory depression for decades. The “standard” dose of opioid intoxication has been 0.4 mg.  However, over the past decade, initial naloxone dose for opioid intoxication has evolved to recommend a lower initial dose (0.04 – 0.05 mg).

 

A recent article by Connors et al. reviewed 25 medical resources (internet, medical texts and study guides) of different medical specialties (internal medicine, medical toxicology, emergency medicine, pediatrics, anesthesiology, pain medicine and general medicine)

 

Findings:

  • 12 medical resources (48%) recommend using 0.05 mg or less IV as an initial dose.
  • 9 medical resources (36%) recommend using 0.4 – 0.5 mg or higher as an initial dose.
  • Maximum dose also ranged widely from 2 to 20 mg.

 

Recent editions of emergency medicine text (Rosen’s and Tinitinalli) recommend using 0.04 – 0.05 mg IV in ED patients with history of opioid dependence. Higher doses of naloxone are recommended for non-opioid dependent/apneic patients.

 

However, history of opioid dependence is difficult to obtain in patients with opioid induced CNS/respiratory depression.

 

Administering 0.4 mg or higher dose may/can acute agitation or opioid withdrawal symptoms that can utilize more ED resources to calm agitated patient/management of withdrawal. Thus it may be prudent to use low-dose strategy (0.04 mg IV with titration) to minimize the risk of precipitating naloxone-induced opioid withdrawal/agitation.

 

Bottom line:

In opioid-induced respiratory depression/apneic patients:

  1. Ventilate with bag-valve mask for apnea/hypoxia
  2. Administer naloxone: 0.04 mg IV every 2 – 3 min until reversal of respiratory depression/hypoxia is achieved.

To make 0.04 mg naloxone solution:

  • Dilute 1 mL of 0.4 mg naloxone with 9 mL normal saline in 10 mL syringe. 

 

Show References

Connors NJ, Nelson LS. The evolution of recommneded naloxone dosing for opioid overdose by medical specialty. J Med Toxicol 2016;12:276-281.



Title: My Patient Won't Open His/Her Eyes!

Category: Neurology

Keywords: eyelid apraxia, eye opening apraxia (PubMed Search)

Posted: 9/14/2016 by WanTsu Wendy Chang, MD

 
My patient won't open his/her eyes!
 
  • Beware of the patient who can't open his/her eyes but is otherwise awake!
  • This coma mimic is the result of eyelid apraxia, which is the inability to voluntarily open eyes despite intact frontalis muscle contraction and absent oculomotor dysfunction.
  • This can be seen in injuries of the nondominant hemisphere (e.g. R MCA stroke), medial frontal lobe, bilateral thalami (e.g. bilateral thalami stroke), and brainstem (e.g. progressive supranuclear palsy).
  • When asking these patients to open their eyes, they may use their forehead muscles to try and raise their eyelids.


Title: Flush-Rate O2 for Preoxygenation prior to RSI

Category: Airway Management

Keywords: RSI, Preoxygenation (PubMed Search)

Posted: 9/13/2016 by Rory Spiegel, MD

During rapid sequence intubation (RSI) we endeavor to avoid positive pressure ventilation, prior to securing a definitive airway. As such, an adequate buffer of oxygen is necessary to ensure a safe apneic period. This process involves replacing the residual nitrogen in the lung with oxygen. It has been demonstrated that a standard nonrebreather (NRB) mask alone does not provide a high enough fractional concentration of oxygen (FiO2) to optimally denitrogenate the lungs (1). Even when a nasal cannula at 15L/min is utilized in addition to the NRB, the resulting FiO2 is not ideal. A bag-valve mask (BVM) with a one-way valve or PEEP valve has been demonstrated to provide oxygen concentrations close to that of an anesthesia circuit. But its effectiveness is drastically reduced if a proper mask seal is not maintained during the entire pre-oxygenation period (1). This is not always logistically possible in the chaos of an Emergency Department intubation.

A standard NRB with the addition of flush-rate oxygen appears to be a viable alternative. Recently published in Annals of Emergency Medicine, Driver et al demonstrated that a NRB with wall oxygen flow rates increased to maximum levels, rather than the standard 15L/min, provided end-tidal O2 (ET-O2) levels similar to an anesthesia circuit (2).

Show References

1. Hayes-bradley C, Lewis A, Burns B, Miller M. Efficacy of Nasal Cannula Oxygen as a Preoxygenation Adjunct in Emergency Airway Management. Ann Emerg Med. 2016;68(2):174-80.

2. Driver BE, Prekker ME, Kornas RL, Cales EK, Reardon RF. Flush Rate Oxygen for Emergency Airway Preoxygenation. Ann Emerg Med. 2016;



Title: Flush-Rate O2 for Preoxygenation prior to RSI

Category: Airway Management

Keywords: RSI, Preoxygenation (PubMed Search)

Posted: 9/13/2016 by Rory Spiegel, MD

During rapid sequence intubation (RSI) we endeavor to avoid positive pressure ventilation, prior to securing a definitive airway. As such, an adequate buffer of oxygen is necessary to ensure a safe apneic period. This process involves replacing the residual nitrogen in the lung with oxygen. It has been demonstrated that a standard nonrebreather (NRB) mask alone does not provide a high enough fractional concentration of oxygen (FiO2) to optimally denitrogenate the lungs (1). Even when a nasal cannula at 15L/min is utilized in addition to the NRB, the resulting FiO2 is not ideal. A bag-valve mask (BVM) with a one-way-valve or PEEP valve has been demonstrated to provide oxygen concentrations close to that of an anesthesia circuit. But its effectiveness is drastically reduced if a proper mask seal is not maintained during the entire pre-oxygenation period (1). This is not always logistically possible in the chaos of an Emergency Department intubation.

A standard NRB with the addition of flush-rate oxygen appears to be a viable alternative. Recently published in Annals of Emergency Medicine, Driver et al demonstrated that a NRB with wall oxygen flow rates increased to maximum levels, rather than the standard 15L/min, provided end-tidal O2 (ET-O2) levels similar to an anesthesia circuit (2). 

Show References

1. Hayes-bradley C, Lewis A, Burns B, Miller M. Efficacy of Nasal Cannula Oxygen as a Preoxygenation Adjunct in Emergency Airway Management. Ann Emerg Med. 2016;68(2):174-80.

2. Driver BE, Prekker ME, Kornas RL, Cales EK, Reardon RF. Flush Rate Oxygen for Emergency Airway Preoxygenation. Ann Emerg Med. 2016;



Title: What's the Diagnosis? Case by Dr. Tejusve Rao

Category: Visual Diagnosis

Posted: 9/12/2016 by Tu Carol Nguyen, DO (Updated: 9/12/2016)

Question

 

A 25-year-old male was brought in by EMS with a stab wound to the chest. What's the diagnosis?

 

 

 

Show Answer

Pneumopericardium
 
 
 
 
 
CT Chest was done with the image below:

 
 
 
Penetrating Cardiac Trauma
  • Initial Assessment of ABC, ATLS primary survey guidelines.
  • Evaluate for tension pneumothorax or cardiac tamponade in all patients presenting with chest trauma and shock.
  • Cardiac Box: Surrounded by sternal notch, xiphoid process and nipples.
  • Order of injury: Right Ventricle --> Left Ventricle --> Right Atrium --> Left Atrium
  • Beck’s Triad: Hypotension, JVD, muffled heart sounds may not be present initially.
  • Conduct FAST exam to examine for cardiac tamponade, hemothorax, pneumothorax.
  • Cardiac Tamponade more common from stab wounds than from gun shot wounds.
  • Hemodynamically unstable patients require immediate operative therapy after quick bedside assessment (physical exam, ultrasound, chest tube as needed)

Differential Diagnosis: Bronchial injury, Diaphragm injury, Hemothorax, Tension Pneumothorax, Aortic Transection, Esophageal injury, Pneumomediastinum

Evaluation: Ultrasound (FAST Exam), CXR, CTA in stable patients, ECG, troponin.

Management: Penetrating cardiac trauma require emergent thoracotomy, pericardial window.

 

Show References

Clancy K, Velopulos C, Bilaniuk JW, et al. Screening for blunt cardiac injury: an Eastern Association for the Surgery of Trauma practice management guideline. J Trauma Acute Care Surg. 2012;73(5 Suppl 4):S301-6.

El-menyar A, Al thani H, Zarour A, Latifi R. Understanding traumatic blunt cardiac injury. Ann Card Anaesth. 2012;15(4):287-95.

Tintinalli's 7th Edition. Emergency Medicine Manual. Chapter 164: Cardiothoracic Trauma.



Title: Pelvic avulsion fractures

Category: Orthopedics

Posted: 9/10/2016 by Brian Corwell, MD

Young athletes, especially around the age of puberty, are at higher risk for pelvic avulsion fractures

Often seen in sports that require sprinting, rapid changes in movement or jumping

Caused by sudden, forceful contraction of the muscles of the abdominal, the hip and thigh or the hamstring

Avulsion fractures can occur at many areas of the pelvis.

A mnemonic is: Alabama’s stoned rappers got ill hunting armadillos

·  Iliac crest: Abdominal muscles

·  Anterior superior iliac crest: Sartorius

·  Anterior inferior iliac crest: Rectus femoris

·  Greater trochanter: Gluteal muscles

·  Lesser trochanter: Iliopsoas **(rare in adults)

·  Ischial tuberosity: Hamstrings

·  Pubic symphysis: Adductor group

http://roentgenrayreader.blogspot.com/2010/07/pelvic-avulsion-fractures.html

** Isolated nontraumatic avulsion fractures of the lesser trochanter in adults is a pathognomonic sign of metastatic disease

This site has some good images of common injury patterns

http://radiopaedia.org/articles/apophyseal-avulsion-fractures-of-the-pelvis-and-hip

Show References

http://roentgenrayreader.blogspot.com/2010/07/pelvic-avulsion-fractures.html



Title: Atypical antipsychotics: are they truly safer than typical antipsychotics?

Category: Toxicology

Keywords: atypical antipsychotic toxicity (PubMed Search)

Posted: 9/8/2016 by Hong Kim, MD (Updated: 7/21/2026)

Antipsychotic as a class has diverse range of toxicity. The atypical (2nd generation) antipsychotics are considered to possess less toxicologic manifestation compared to the typical (1st generation) antipsychotics - lower K channel blockade and minimum Na channel blockade properties. However, select atypical antipsychotics overdose can results in significant morbidity in addition to sedation.

 

Alpha-1 blockade (hypotension)

  • Clozapine
  • Olanzapine
  • Quetiapine
  • Risperidone
  • Ziprasidone

 

Antimuscarinic effect (anticholinergic toxicity)

  • Clozapine
  • Olanzapine
  • Quetiapine

 

Delayed rectifier K channel blockade (QT prolongation)

  • Ertindole
  • Ziprasidone

 

Bottom line:  Although lethal overdose from atypical antipsychotics are rare, they can result in significant clinical toxicity when ingested alone or in combintation with other classes of medications.

 

 



Title: Cancer Deaths Globally

Category: International EM

Keywords: Cancer, mortality, burden of disease (PubMed Search)

Posted: 9/7/2016 by Jon Mark Hirshon, MPH, MD, PhD (Updated: 9/8/2016)

Bottom Line:

  • Cancers figure among the leading causes of morbidity and mortality worldwide, with approximately 14 million new cases and 8.2 million cancer related deaths in 2012.
  • The number of new cases is expected to rise by about 70% over the next 2 decades.
  • More than 30% of cancer deaths could be prevented by modifying or avoiding key risk factors

Show Additional Information

Cancer is a leading cause of death worldwide, accounting for 8.2 million deaths in 2012 (1). The most common causes of cancer death are cancers of:

  • lung (1.59 million deaths)
  • liver (745 000 deaths)
  • stomach (723 000 deaths)
  • colorectal (694 000 deaths)
  • breast (521 000 deaths)
  • oesophageal cancer (400 000 deaths) (1).

More than 30% of cancer deaths could be prevented by modifying or avoiding key risk factors, including:

  • tobacco use
  • being overweight or obese
  • unhealthy diet with low fruit and vegetable intake
  • lack of physical activity
  • alcohol use
  • sexually transmitted HPV-infection
  • infection by HBV
  • ionizing and non-ionizing radiation
  • urban air pollution
  • indoor smoke from household use of solid fuels.

Show References

http://www.who.int/mediacentre/factsheets/fs297/en/



Title: Blood Pressure Management in Intracerebral Hemorrhage (ICH)

Category: Critical Care

Keywords: Intracerebral hemorrhage, intraparenchymal hemorrhage, ICH, IPH, hypertensive emergency, blood pressure, neurocritical care, nicardipine (PubMed Search)

Posted: 9/6/2016 by Daniel Haase, MD (Updated: 9/6/2016)

Question

--Aggressive BP management (SBP <140) in atraumatic intracerebral hemorrhage (ICH) does NOT signifcantly improve mortality or disability compared with traditional goal (SBP <180) [1]

--However, a lower goal (SBP <140) has been shown to decrease hematoma size and be safe compared to a higher goal (SBP <180) [2]

Show Answer

The recently published ATACH-2 study investigated aggressive BP control in hypertensive acute atraumatic ICH/IPH (intraparenchymal hemorrhage). [1]

--Control group SBP 140-179 mmHg vs. intervention group SBP 110-139 mmHg with nicardipine infusion (control group actually had SBP 140-150 vs. intervention group SBP 120-130 most of the time).

--Study stopped early for futility. No difference in mortality or modified Rankin.

Previously, INTERACT2 demonstrated that aggressive SBP management (<140) was safe, decreasing hematoma expansion leading to a change in some individuals' practice. [2]

Show References

1. Qureshi AI, Palesch YY, et al; ATACH-2 Trial Investigators and the Neurological Emergency Treatment Trials Network. Intensive Blood-Pressure Lowering in Patients with Acute Cerebral Hemorrhage. N Engl J Med. 2016 Jun 8. [Epub ahead of print] PubMed PMID: 27276234.

2. Anderson CS, Heeley E, et al; INTERACT2 Investigators. Rapid blood-pressure lowering in patients with acute intracerebral hemorrhage. N Engl J Med. 2013 Jun 20;368(25):2355-65. doi: 10.1056/NEJMoa1214609. Epub 2013 May 29. PubMed PMID: 23713578.



Title: The INCH Trial: FFP versus PCC

Category: Pharmacology & Therapeutics

Keywords: FFP,PCC,ICH,warfarin (PubMed Search)

Posted: 9/3/2016 by Michelle Hines, PharmD

Prothrombin complex concentrate (PCC) and fresh frozen plasma (FFP) are used for INR reversal in patients on vitamin K antagonists (VKA) (e.g., warfarin) with life-threatening bleeding. Guidelines from the Neurocritical Care Society and Society of Critical Care Medicine recommend using PCC over FFP for patients with VKA-associated hemorrhage and an INR >=1.4.

New study-INCH trial:

  • Multi-center, prospective, randomized, open-label trial comparing FFP IV 20 ml/kg + phytonadione IV 10 mg versus 4-factor PCC IV 30 IU/kg + phytonadione IV 10 mg
  • Adult patients on VKA with intracerebral or subdural hemorrhage with INR >=2.0 were included. Patients with traumatic intracranial hemorrhage were excluded.

What they found:

  • Analysis included 50 (23 FFP and 27 PCC) patients (trial was stopped early after a safety analysis)
  • 2 (9%) patients in the FFP group and 18 (67%) patients in the PCC group achieved an INR <=1.2 within 3 hours (adjusted OR 30.6, 95% CI 4.7-197.9; p=0.0003)
  • Hematoma expansion at 3 hours was higher in those treated with FFP than PCC (adjusted difference 16.9 ml, 95% CI 2.5-31.3; p=0.023)
  • Time until INR <=1.2 was longer in the FFP group than the PCC group (1482 vs 40 minutes; p=0.050)

Application to clinical practice:

  • Of note, FFP 30 ml/kg has been suggested to provide more complete coagulation factor correction (this trial used 20 ml/kg), and package inserts for PCCs recommend doses based on INR and weight (this trial used 30 IU/kg for all patients)
  • Although the sample size was small, this study suggests that in patients with VKA-associated non-traumatic intracranial hemorrhage and an elevated INR, PCC may provide faster INR correction than FFP, and may additionally be associated with a smaller degree of hematoma expansion.

Show References

  1. Frontera JA, Lewin JJ, Rabinstein AA, et al. Guideline for reversal of antithrombotics in intracranial hemorrhage. Neurocrit Care 2016; 24:6-46. (PMID 26714677)

  2. Steiner T, Poli S, Griebe M, et al. Fresh frozen plasma versus prothrombin complex concentrate in patients with intracranial haemorrhage related to vitamin K antagonists (INCH): a randomised trial. Lancet Neurol 2016; 15:566-73. (PMID 27302126)

Follow me on Twitter @mEDPharmD



Title: Zika Update: Signs and Symptoms

Category: Infectious Disease

Keywords: Zika, arbovirus, infectious disease, mosquitos (PubMed Search)

Posted: 8/31/2016 by Jon Mark Hirshon, MPH, MD, PhD

Zika virus and its transmission is currently an important infectious disease topic in the United States and the Western Hemisphere.  With domestic spread in the Continental United States, and the likely further spread to other parts of the southern United States, continued vigilance by healthcare providers remains important.

 

What are the signs and symptoms of Zika?

 

Most common signs and symptoms are:

  • Fever
  • Rash
  • Arthralgias
  • Conjunctivitis (generally nonpurulent)

 

Other symptoms can include

  • Myalgias
  • Headaches
  • Retro-orbital pain
  • Gastrointestinal upset

 

Symptoms can generally last 2 to 7 days.  Most individuals will have minimal or no significant symptoms and may not seek medical care. These symptoms are similar to other arboviruses, such as dengue or chikungunya. Potential serious complications include Guillian Barre syndrome.

 

Of course, the main concern remains infection of pregnant women and the impact that Zika has on the developing fetus, especially for the brain.

Show References

https://www.cdc.gov/zika/symptoms/symptoms.html

 

Shastry S, Koenig KL, Hirshon JM. Zika Virus: Critical Information for Emergency Providers. Emerg Med Clin North Am. 2016 Aug;34(3):e25-37.



Title: Refractory Status Epilepticus

Category: Critical Care

Keywords: refractory status epilepticus, ketamine, propofol, siezure, midazolam (PubMed Search)

Posted: 8/30/2016 by Mike Winters, MBA, MD

Ketamine for RSE?

  • Up to 43% of patients with status epilepticus may progress to refractory status epilepticus (RSE).
  • Propofol, midazolam, and barbituates are often recommended for patients with RSE.
  • Importantly, all of these medications may be limited by hypotension and respiratory depression.
  • Ketamine is emerging as adjuvant therapy for patients with RSE.
  • The loading dose of ketamine ranges from 0.5 to 3 mg/kg, followed by a maintenance infusion of 0.3 to 4 mg/kg/h.

Show References

Legriel S, et al. What's new in refractory status epilepticus? Intensive Care Med 2016. [Epub ahead of print]



Title: Nitrous Oxide (submitted by Dan Gingold, MD)

Category: Pediatrics

Keywords: procedural sedation (PubMed Search)

Posted: 8/26/2016 by Mimi Lu, MD

Inhaled nitrous oxide gas (N2O) or laughing gas, has a long history of use as anesthetics in dental and medical procedures, and can be used as a single agent for brief pediatric procedures. It has a short half-life of 5 minutes and is eliminated essentially non-metabolized through respirations.
Inhaled N2O has analgesic, anxiolytic, and amnestic properties. The mechanism of analgesia is hypothesized to be similar to that of opioids. Anxiolytic and sedative effect is similar to benzodiazepines and may involve GABA receptors.
The N2O is typically given as a mixture of 30% N2O with 70% O2, although 50:50 mixture is also safe. In the ED, it is usually given as monotherapy, as this meets criteria for minimal sedation. Nitrous oxide concentrations > 50% meet criteria for moderate sedation.
Complications are rare (most commonly, nausea/vomiting). Persistent use or abuse can be habit forming and has been associated with anemia and B12 deficiency. Rare side effects include asthma exacerbation, coughing, laryngospasm, cardiac events, and seizures. High nitrous concentrations can cause hypoxia and asphyxiation if sufficient oxygen isn’t supplied (FiO2 < 25%).

Show References

Alai, A. Nitrous Oxide Administration. Medscape/emedicine. http://emedicine.medscape.com/article/1413427-overview#a1


Guideline for Monitoring and Management of Pediatric Patients During and After Sedation Diagnostic and Therapeutic Procedures. American Academy of Pediatrics. 2011


Clinical Policy: Critical Issues in the Sedation of Pediatric Patients in the Emergency Department. Annals of Emergency Medicine, 51(4):378-399 (2008)



Title: What is Ataxia?

Category: Neurology

Keywords: cerebellar disease, tremor, nystagmus (PubMed Search)

Posted: 8/24/2016 by Danya Khoujah, MBBS

Ataxia is an important clinical sign of cerebellar pathology, but how is it actually described?

Stance ataxia: inability to stand with feet together for more than 30 seconds

Gait ataxia

Sensory ataxia: the first 2 elements, in addition to a positive Romberg sign

Truncal ataxia: oscillation of body while sitting or standing

Limb ataxia: functional impairment in performing actions such as writing or buttoning and improves with slowing down the movement

Dysdiadokinesia: impairment of rapidly alternating movement

Intention tremor: tested by finger-to-nose and heel-to-shin.

Dysmetria: pastpointing or undershooting on finger-chasing or shin-tap.

Dysarthria: irregular and slow speech with unnecessary hesitation

Nystagmus and other ocular disturbances, such as ocular flutter and opsoclonus.

The first 3 are present in both cerebellar pathology and loss of proprioceptive input, the rest are usually due to cerebellar pathology or ataxic syndrome.

Show References

Ashizawa T and Xia G. Ataxia. Continuum 2016;22(4):1208-1226



Title: Ketone Negative DKA

Category: Critical Care

Keywords: DKA (PubMed Search)

Posted: 8/23/2016 by Rory Spiegel, MD

Is it possible to have a patient present in diabetic ketoacidosis (DKA) with both negative serum and urinary ketone levels?

A case report published in American Journal of Emergency Medicine by Jehle et al provides a helpful reminder of this phenomenon (1). The degree of acidosis is directly related to the ratio of the various ketones/ketone metabolites: acetone, acetoacetate and beta-hydroxybutyrate present in the serum. The proportion of each respective substance is determined by the existing redox state in the blood. At any given time, acetoacetate and beta-hydroxybutyrate exist in an equilibrium dependent upon the ratio of NAD+ and NADH(fig.1). These substances freely convert with the assistance of the enzyme beta-hydroxybutyrate dehydrogenase (2). This conversion requires the donation of a hydrogen atom from NADH. The balance between beta-hydroxybutyrate and acetoacetate, is determined by the ratio of NADH to NAD+. Acetoacetate will freely degrade into acetone through non-enzymatic decarboxylation. Early in DKA, acetoacetate is the most prevalent substance. As the disease progresses and the serum ratio of NADH to NAD+ increases, the proportion of beta-hydroxybutyrate rises, decreasing the quantity of acetoacetate and acetone.

Traditional serum and urinary ketone assays react strongly to acetoacetate but neither reliably react with beta-hydroxybutyrate. Patients in whom the majority of their anion gap is filled by beta-hydroxybutyrate, urinary or serum ketone levels may be negative. In such cases, serum beta-hydroxybutyrate assays would be positive but are not universally available.

It is important to note, with resuscitation and insulin therapy, the ratio of NADH/NAD+ will start to normalize causing an increase in the quantity of acetoacetate. As the patient improves and the anion gap clears, the degree of ketones detected in the serum and urine will paradoxically increase.

Show References

1. Jehle D, et al, Severe diabetic ketoacidosis presenting with negative serum ketones: First case report and a review of the mechanism, Am J Emerg Med (2016)

2. Konijn, Abraham M., Naama Carmel, and Nathan A. Kaufmann. The redox state and the concentration of ketone bodies in tissues of rats fed carbohydrate free diets. The Journal of nutrition 10 (1976): 1507.



Title: PatelloFemoral Syndrome

Category: Orthopedics

Keywords: Patellofermoral Syndrome (PubMed Search)

Posted: 8/20/2016 by Michael Bond, MD (Updated: 7/21/2026)

According to the 4th International Patellofemoral Pain Research Retreat recently published in British Journal of Sports Medicine, the core criterion required to define Patelofemoral Pain (PFP) syndrome is pain around or behind the patella, which is aggravated by at least one activity that loads the patellofemoral joint during weight bearing on a flexed knee (eg, squatting, stair ambulation, jogging/running, hopping/jumping).

Additional criteria (not essential):

  1. Crepitus or grinding sensation emanating from the patellofemoral joint during knee flexion movement
  2. Tenderness on patellar facet palpation
  3. Small effusion
  4. Pain on sitting, rising on sitting, or straightening the knee following sitting

PFP is common in young adolescents, with a prevalence of 7–28%, and incidence of 9.2%.

Stay tuned for recommendations on treatment and diagnosis.

Show References

Br J Sports Med 2016;50:839-843 doi:10.1136/bjsports-2016-096384


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