Monday, January 8, 2018

Croup - Laryngotracheobronchitis

Viral Laryngotracheobronchitis (Croup) is the most common cause of stridor commonly affecting children between 6 months to 6 years old, with a peak in the fall and early winter months. Croup is acquired through inhalation of the virus. 

Possible agents could be parainfluenza virus (most common), rhinovirus. enterovirus, respiratory syncytial virus, influenza virus and human metapneumovirus.


Clinical Presentation 
Typically, symptoms begin after 1 to 3 days of URTI symptoms (nasal congestion, rhinorrhea, cough, and low-grade fever). Classic symptoms include a harsh barking cough, hoarse voice, and stridor. Symptoms often tend to be worse at night and the severity of symptoms is related to the amount of edema and inflammation of the airway. 


Diagnosis and Assessment of Severity 
Look for tachypnea, stridor at rest, nasal flaring, retractions, lethargy or agitation, and oxygen desaturation. Symptoms are most severe on 3rd or 4th day of illness. Agitation and crying increase oxygen demand and may worsen airway compromise. Bloods and imaging are only required in children who fail to respond to conventional therapy. X Rays may demonstrate “steeple sign” (subglottic narrowing). 


Steeple Sign
Croup is a clinical diagnosis
Steeple sign may be present in normal children and can be absent in up to half of those with croup






















Management 
Treatment is directed at decreasing airway obstruction and keeping the child comfortable 
  • Corticosteroids: All patients with croup get steroids as a one- time dose (PO/IM/IV). Steroids reduce the severity and duration of symptoms and result in a decrease in return visits and hospital length of stay. The long half-life of dexamethasone (36-54 h) often allows for a single injection. Studies have shown that dexamethasone dosed at 0.15 mg/kg is as effective as 0.3 mg/kg or 0.6 mg/kg (with a maximum daily dose of 10 mg). Effects can be seen within 1 hour of oral administration. Nebulized budesonide 2 mg as a single dose and IM dexamethasone (0.6mg/kg) are alternatives to PO dexamethasone in children who are vomiting.
Treatment of croup: Nebulized epinephrine for moderate to severe croup and corticosteroids for all



  • Epinephrine: Epinephrine comes as two different forms: racemic, which is composed of equal parts of L- and D-isomers, and L-epinephrine, which is the drug routinely used in acute situations in concentrations of 1:1000 and 1:10,000. 
  • L-Epinephrine (1:1000): 0.5 ml/kg neb or 5ml maximum  
  • Racemic Epinephrine (2.25%): 0.05ml/kg neb or max 0.5ml
Mild croup generally does not require epinephrine. For those with moderate or severe croup who receive nebulized epinephrine, observe in the ED for at least 3 hours before considering discharge. Epinephrine decreases airway edema through vasoconstrictive alpha effects and acts wishing 10-min lasting up to 2 hours. The use of Adrenaline decreases the number of children with croup requiring intubation, ITU admissions, and admission to the hospital. 

Observation for about 3 hours is recommended because an increase in croup scores can occur between doses of epinephrine nebulisation

  • Intubation is reserved for cases of severe croup not responding to medical treatment. When intubation is necessary, use endotracheal tubes smaller than recommended for patient size and age to avoid traumatizing the inflamed mucosa. 

Treatment options with limited evidence: 
  • Cool Mist: Humidified air was used to treat croup, but they are no longer recommended as studies have consistently failed to show clinical improvement with these interventions.
  • Heliox (70% helium/30% oxygen): Despite its theoretical benefits, studies show no definitive advantage of heliox over conventional treatment.24-28
  • Beta 2 Agonists: Insufficient data. Concerns about risk of worsening upper airway obstruction as β-receptors on the vasculature cause vasodilation (as compared to the vasoconstrictive α effects of epinephrine), which might worsen upper airway edema in croup, and there is no smooth muscle in the upper airway. Therefore, β-agonists are not recommended for treatment of croup.
  • Antibiotics have no role in uncomplicated croup 
  • Antitussives have no proven effect on the course or severity of croup and may increase sedation


Differential Diagnosis (Consider if no relief with Rx)
  • Bacterial tracheitis
  • Laryngomalacia
  • Tracheomalacia
  • Vascular rings
  • Epiglottitis (unlikely if vaccinated)
  • Foreign body aspiration
  • Peritonsillar abscess
  • Retropharyngeal abscess
  • Tracheo-esophageal fistula

Admit 
  • Moderate to Severe Croup
  • Looking toxic and not tolerating oral fluids
  • Comorbidities 
  • Social Issues
  • Persistent stridor at rest, tachypnea, retractions, and hypoxia

Discharge Advice 

  • Advise the parents/carers to use either paracetamol or ibuprofen to treat a child who is distressed due to fever. 
  • Encourage the child to take fluids regularly.
  • To check on the child regularly, including through the night.

References and Further Reading :
  1. https://cks.nice.org.uk/croup#!scenario
  2. http://www.ebmedicine.net/topics.php?paction=showTopic&topic_id=334
  3. Russell KF, Liang Y, O’Gorman K, Johnson DW, Klassen TP. Glucocorticoids for croup. Cochrane Database of Systematic Reviews 2011, Issue 1. Art. No.: CD001955.
  4. Johnson DW. Croup. BMJ Clin Evid. 2009; 2009: 0321.
  5. Bjornson, C.L. and and Johnson, D.W. (2013)  Croup in children. CMAJ. 185(15), 1317-1323

    Posted by:

                  
         Lakshay Chanana
         
         Speciality Doctor
         Northwick Park Hospital
         Department of Emergency Medicine
         England

         @EMDidactic


      

      

Monday, January 1, 2018

Benzodiazepine Overdose

Benzodiazepines work through GABAa receptors and this class of medications are commonly used in Emergency Department to aid sedation, anxiolysis and amnesia. IV administration may result in significant complications, particularly respiratory depression and hypotension, especially when combined with opioids or other sedatives.


Alternatively, BZDs are also used as first line anticonvulsants. Patients with mental health issues are often given this set of medications to treat concomitant anxiety and thus overdose is frequently a problem. Fortunately, isolated benzodiazepine overdose has low mortality and fatalities are rare. In cases of mixed overdose i.e combination with TCAs and opioids, complication rates are higher. Out-patients use of BZDs is limited to short-term treatment of anxiety and insomnia.




Clinical Presentation (think EtOH intoxication)
  • Typical - Slurred speech, Drowsiness, Stuporous, Confusion, Ataxia, Incoordination and Coma
  • Paradoxical reactions - Excitement, Anxiety, Aggression and delirium are more commonly seen in hyperactive children and psychiatric patients


Treatment
  • Maintain ABCs
  • Use Flumazenil if no contra-indications 
  • Wait for the drug to wear off

Consider activated charcoal in case of early presentations and have a secured airway prior to that. It is debatable to intubate someone with a BZD overdose coming with a low GCS (say E1M5V1) with isolated BZD overdose. Make a decision in liaison with ITU team as there is a clear and reversible cause of low GCS. However, this needs to weighed against risk of aspiration if the patient vomits. 

Flumazenil is a selective antagonist of the central effects of benzodiazepines. It should be used only in two scenarios:
  • Definite isolated BZD overdose in naive BZD user
  • Reversal of iatrogenic benzodiazepine induced sedation (see contra-indications below)
Recurrent benzodiazepine toxicity may result once the effects of flumazenil have worn off.  Flumazenil Dose: 0.2 milligram IV q1min up to a total dose of 3 milligrams

Contraindications to Flumazenil:
  • Chronic BZD users
  • Mixed Overdoses (esp TCA)
  • Seizure Disorder
  • Suspected raised ICP
Flumazenil induced seizures should be treated with other GABAA receptor agonists (propofol and phenobarbitone) because the benzodiazepine site on the receptor is antagonised. 


Admit if:
  • Persistent drowsiness
  • Respiratory depression
  • Hypotension

Take Home:
  • Definite indication of Flumazenil is iatrogenic overdose of BZD
  • Mortality is low with isolated BZd overdose --> Maintains ABCs and wait for the drug to wear off
  • Reduce dose to half when sedation elderly 

References:


  1. Ngo AS, Anthony CR, Samuel M, Wong E, Ponampalan R: Should a benzodiazepine antagonist be used in unconscious patients presenting to the emergency department? Resuscitation 74: 27, 2007. 
  2. Charlson F, Degenhardt L, McLaren J, et al: A systematic review of research examining benzodiazepine-related mortality. Pharmacoepidemiol Drug Saf 18: 93, 2009

Posted by:

              
     Lakshay Chanana
     
     Speciality Doctor
     Northwick Park Hospital
     Department of Emergency Medicine
     England

     @EMDidactic


  
  

Monday, December 25, 2017

Post-Partum Haemorrhage

Postpartum hemorrhage that occurs within the first 24 hours of delivery is called as primary postpartum hemorrhage. The main causes of primary postpartum haemorrhage are:
  • Uterine atony (TONE)
  • Retained placental fragments (TISSUE)
  • Lower genital tract lacerations (TRAUMA)
  • Uterine rupture (Click here to read more)
  • Uterine inversion (requires repair under general anesthesia)
  • Hereditary coagulopathy (THROMBIN)

Secondary postpartum hemorrhage occurs after the first 24 hours and up to 6 weeks postpartum. Common causes of secondary postpartum haemorrhage are:
  • Failure of the uterine lining to sub-involute at the former placental site
  • Retained placental tissue
  • Genital tract wounds
  • Uterogenital infection
Causes can be remembered as TONE, TISSUE, TRAUMA, THROMBIN


Risk Factors fro PPH
  • Primipara or Grandmultipara 
  • Previous PPH
  • Pre-eclampsia
  • Prior CS
  • Placenta Previa
  • Cervical or Uterine trauma
  • Fetal Wt >4.5Kgs
  • Prolonged 3rd stage
Excessive blood loss in the postpartum period is defined as a 10% drop in the hematocrit, a need for transfusion of packed red blood cells, or volume loss that causes symptoms of hypovolemia. The hematologic changes of pregnancy can mask the typical symptoms of hemorrhage, and the first sign may be only a mild increase in pulse rate.



Resuscitation
  • ABC
  • IV Access x 2
  • Fluid Resuscitation 
  • Involve OBGYN ASAP
  • Keep them warm (Prevent the deadly triad of hypothermia, coagulopathy and acidosis)
  • Bimanual uterine massage - place a fist in the anterior fornix and compress the uterine fundus against the hand in a suprapubic location 
  • Uterotonics 
Oxytocin: 10U IM or 20-40 units in NS over 1 hour 
Carboprost: 250mcg IM q30min (up to 2mg if needed), Avoid in HTN, Asthma
Misoprostol: 1000mcg PR
Methylergonovine: 0.2mg IM (up to 5 doses q2-4h), Contraindicated in HTN/Pre-eclampsia
  • Consider Tranexamic Acid for critically ill 
  • Look for evidence of trauma, uterine inversion and uterine rupture
  • Inspect for missing placenta fragments 
  • Arrange blood products (Packed Cells, FFP and Cryo if in DIC)
  • Intrauterine balloon tamponade using Bakri balloon or Rusch catheter if uterine atony is the only or main cause of haemorrhage
  • Move to OR for hysterectomy or Uterine Artery Ligation


Other advanced care methods:
  • Interventional Radiology for Uterine Artery Embolisation
  • REBOA as a temporary measure 
Take Home:

  • Keep them warm (prevent Hypothermia, Coagulopathy and Acidosis)
  • Remember the 4 causes - TONE, TISSUE, TRAUMA, THROMBIN
  • Involve OBGYN ASAP


References and Further Reading:
  1. Tintinai EM 8th edition
  2. Shakur H, Elbourne D, Gülmezoglu M, Alfirevic Z, Ronsmans C, Allen E, Roberts I. The WOMAN Trial (World Maternal Antifibrinolytic Trial): tranexamic acid for the treatment of postpartum haemorrhage: an international randomised, double blind placebo controlled trial. Trials. 2010 Apr 16;11(1):40.
  3. https://www.rcog.org.uk/en/guidelines-research-services/guidelines/gtg52/

Posted by:

              
     Lakshay Chanana
     
     Speciality Doctor
     Northwick Park Hospital
     Department of Emergency Medicine
     England

     @EMDidactic



Monday, December 18, 2017

Renal Colic

Acute Pain is one of the key reasons why patients present to Emergency Department and we should be experts at managing any sort of acute pain. Renal Colic is one such pathology that presents with sudden onset intermittent severe crampy flank pain a/w nausea and vomiting. NSAIDs are the drugs of choice as they inhibit prostaglandin synthesis and result in relaxation of ureteral spasm and decrease of renal capsular distension and associated pain. Here is a quick review of Renal Colic:




Risk Factors for Renal Stones
  • Obesity
  • Diabetes
  • Metabolic Abnormalities
  • Hyperparathyroidism
  • Immobilisation
  • Excess intake of meat and Na
  • Gout
  • Inflammatory Bowel Disease
  • Family History


Up to 15-30% patients with Nephrolithiasis may not show blood in urine. Do not exclude tis diagnosis based on the absence of hematuria. 


Things that you should not miss (Mimics):
  • Dissection/Aneurysm (most common misdiagnosis given to patients with a rupturing or expanding abdominal aortic aneurysm)
  • Renal Infarct
  • Pyelonephritis
  • Biliary Colic
  • Pancreatitis
  • Diverticulitis
  • Ovarian Torsion
  • Ectopic Pregnancy
  • Lower Lobe Pneumonia
  • Testicular Torsion
  • Herpes Zoster

Investigations:
  • Urine Dip (look for infection)
  • Full Blood Count (WCC is elevated due to stress demargination)
  • Uric Acid, CA (Helps in further evaluation as an out-patient)
  • Renal Function (Normal creatinine does not rule out obstruction)
  • Imaging (CT KUB, Bedside USG, Formal USG) - read more on imaging at aliem
  • Beta hCG
Consider adding amylase, LFT, CXR if history or examination findings are atypical. 


Management
  • Pain Relief (IM/IV/PR NSAIDs, Opioids, Antispasmodics are of uncertain benefit)
  • Anti-emetics (Metocloperamide)
  • Medical Expulsion Therapy (No proven benefit. Prescribe only for >5mm distal ureteric stones)
  • Antibiotics if febrile, systemically unwell (WCC is elevated due to stress demargination)
IV Fluids do not expedite stone expulsion


Consult Urology in cases of:
  • Refractory Pain
  • Obstruction and Acute Renal Failure
  • Urosepsis
  • Advanced age and co-morbidities
  • Solitary/Transplanted Kidney
  • Pregnancy

Take Home
  • Look for risk factors and potential mimics (aortic dissection and renal infarct)
  • Do not rule out kidney stones based on the absence of hematuria
  • Provide pain relief and arrange follow up 

Further Reading
  1. Core EM - Renal Colic
  2. REBEL EM - Does Use of Tamsulosin in Renal Colic Facilitate Stone Passage?
  3. Golzari, S. E., Soleimanpour, H., Rahmani, F., Zamani Mehr, N., Safari, S., Heshmat, Y., & Ebrahimi Bakhtavar, H. (2014). Therapeutic Approaches for Renal Colic in the Emergency Department: A Review Article. Anesthesiology and Pain Medicine, 4(1), e16222. http://doi.org/10.5812/aapm.16222
  4. Stewart A, Joyce A. Modern management of renal colic. Trends in Urology & Men's Health. 2008 May 1;13(3):14-7.

Posted by:

              
     Lakshay Chanana
     
     Speciality Doctor
     Northwick Park Hospital
     Department of Emergency Medicine
     England

     @EMDidactic