Monday, September 24, 2018

Non-specific back pain

Back pain is a common ED presentation. Usually, the non-specific pain is mild to moderate and is aggravated by movement and relieved with rest. There are no risk factors for a serious disease on the history and physical examination. 


Pain lasting >6 weeks is an indicator of more serious disease, since most episodes of nonspecific back pain (80% to 90%) resolve within 6 weeks. 

Red Flags

  • Trauma (Fracture)
  • Unexplained Weight Loss (Malignancy, Metastasis)
  • Neurologic Symptoms (Coed COmpression)
  • Age <18 years old and >50 years old (BOny abnormalities, Spinal Stenosis, AAA)
  • Fever (Infection - Systemic, Osteomyelitis, Epidural Abscess)
  • IVDU (Spinal Infection)
  • Steroid Use, Immunocompromised (Infection)
  • H/O Cancer (Metastasis)
Injection drug user + Back Pain = Spinal infection (Osteomyelitis, Epidural Abscess)
Elderly + Back Pain - Think Aortic Pathology
Bowel or bladder incontinence + Back Pain = Cauda equina syndrome



Back Pain - Critical documentation components
  • Fever
  • Localised warmth/tenderness
  • Abdominal Masses
  • Renal Angle Tenderness
  • Sensory-Motor Exam (Perianal/Saddle Anesthesia)
  • Reflexes
  • Rectal Exam (Tone, Masses) - Must be performed in those with neurologic complaints or findings or other red flags for back pain
  • SLRT (screening examination for a herniated disk) - With the patient lying supine, lift each leg separately to approximately 70 degrees in an attempt to produce radicular pain. A positive straight leg raise test causes a radicular pain radiating below the knee of the affected leg. This pain is worsened by ankle dorsiflexion and improved with ankle plantar flexion or decreasing leg elevation. 

Hip Flexion – L2 
Knee Extension – L3
Ankle Dorsiflexion – L4 
Great toe flexor – L5 
Ankle Plantarflexion – S1 




ED Management
  • FBC, ESR/CRP, Urine Analysis, ALP, Ca (Only if clinically indicated)
  • LS Spine X-Ray (with h/o trauma)
  • For most patients, no testing is required
  • MRI/CT Myelogram in suspected Epidural Abscess
Patients who resume their normal activities to the furthest extent tolerable recover more rapidly than those bed rest. Management options include:

  • Analgesics (Paracetamol + NSAIDs with PPI cover if concerned about GI bleed). 
  • Muscle relaxants (Diazepam, 5 to 10 milligrams) 
  • Local application of heat 
  • Manipulative therapy - Controversial treatment 
  • Physical modalities (traction, diathermy, exercise, US treatment, TENS) - Questionable benefit


Take Home
  • Watchful waiting (6-8 weeks) ensures appropriate utilisation of resorces and reduces unnecessary radiation exposure. 
  • Set expectations and arrange follow up - Patient may expect some sort of imaging. Clarify this and let them know what symptoms concern you.



Further Reading
https://www.rcemlearning.co.uk/foamed/back-pain-advice-know-say/
https://www.rcemlearning.co.uk/references/lower-back-pain/



Posted by:

              
     Lakshay Chanana
     
     ST4 Trainee
     Royal Infirmary of Edinburgh
     Department of Emergency Medicine
     Edinburgh
     Scotland

     @EMDidactic



Monday, September 17, 2018

Ankle Block (Landmark Technique) - Procedures

Ankle block covers the five nerves around the ankle joint. Three nerves are located anteriorly and supply the dorsal aspect of the foot. Two nerves are located posteriorly and supply the volar aspect. A complete nerve block of the foot requires blocking three subcutaneous nerves and two deeper nerves. Overlap of the sensory distribution frequently necessitates blocking multiple nerves for adequate anesthesia. 
  1. Deep peroneal - Deep - Supplies Anteriorly 
  2. Posterior tibial - Deep - Supplies Posteriorly 
  3. Saphenous - Superficial - Supplies Anteriorly 
  4. Superficial peroneal - Superficial - Supplies Anteriorly 
  5. Sural nerves - Superficial - Supplies Posteriorly 

Depending on the desired area of anesthesia, one or more of the five nerves are blocked. Nerve block of the sural and posterior tibial nerves together anesthetizes the bottom of the foot and is the most useful combination.



Indications
Procedures on the foot (lac repair, I&D, FB removal, wound irrigation). The rationale for using Ankle block over infiltration anesthesia on the sole is that skin of the sole is thicker and more tightly bound to the underlying fascia making skin puncturing quite difficult and painful. Large amounts of anesthetic on sole may lead to painful distention of the tissue and circulatory compromise of the microvasculature.


Relevant Anatomy and Sensory supply of 5 nerves around Ankle Joint
Image from Roberts & Hedges - Clinical Procedures in Emergency Medicine
Site of Injections (2 deep injections and 3 bands)
1. Posterior Tibial NervePosterosuperior to the posterior tibial artery between medial malleulus and Achilles. At a depth of 1 cm, inject 3 to 5mls of anesthetic.
2. Deep Peroneal NervePalpate the EHL and anterior tibial tendons (Ask the patient to dorsiflex the foot and big toe) and inject 3-5mls LA 1 cm superior to the medial malleolus under the EHL tendon until it strikes the tibia. 

3. Superficial Peroneal - Inject 4 to 10 mL of anesthetic subcutaneously in a band between the EHL tendon and the lateral malleolus. 
4. Saphenous - Inject 3-5ml of LA subcutaneously in a band between the medial malleolus and the anterior tibial tendon. 
5. Sural NerveBlock at the lateral aspect of the ankle between Achilles and the lateral malleolus. Inject 3 to 5 mls of anesthetic subcutaneously in a band like fashion at about 1 cm above the lateral malleolus. 


All five nerves can be blocked by placing subcutaneous band blocks around 75% of the ankle circumference and two deep injections: one next to the palpable posterior tibial artery (Post Tibial Nerve) and the other under the extensor tendon of the big toe (Deep Peroneal Nerve).


Posted by:

              
     Lakshay Chanana
     
     ST4 Trainee
     Royal Infirmary of Edinburgh
     Department of Emergency Medicine
     Edinburgh
     Scotland

     @EMDidactic



Monday, September 10, 2018

Febrile Neutropenia

Neutropenia in oncology patients often results due to chemotherapy. The lowest neutrophil count is generally seen 5 -10 days after the last chemotherapeutic dose and the risk of developing an infection primarily depends on the severity and duration of neutropenia, comorbidities, use of in-dwelling catheters. 

The absolute neutrophil count (ANC) normal range is 1500 to 8000/mm(1.5 to 8.0 × 109/L).  Fever is defined as a temperature of 38.3°C on one occasion or 38.0°C persisting >1 hour.


Definitions
Neutropenia is defined as an absolute neutrophil count <1000/mm3(<1.0 × 109/L)
Severe neutropenia is defined as an absolute neutrophil count <500/mm(<0.5 × 109/L) Profound neutropenia is defined as an absolute neutrophil count <100/mm(<0.1 × 109/L).

Fever is the most common finding seen with bacterial infections in the neutropenic patient. Common symptoms and signs are often absent in the neutropenic patient because impaired inflammatory response. 



Examination (Head to toe to look of any signs of infection)

Lungs
Skin
Urine
Abdomen
CNS

Oral cavity
Perianal area
Intravascular catheters (Thrombophlebitis, Infective Endocarditis)


Avoid doing a Digital Rectal Examination in neutropenic patients. Id necessary, do only after antibiotic administration. 


Work up
  • Blood cultures
  • Urinalysis, Urine culture,
  • CXR
  • Sputum, stool, and wound drainage Gram stains and culture 
  • FBC, Renal and Liver function  


Treatment 

Known source - Guided Antibiotics
Unknown source and ill patient - Empiric Broad Spectrum Antibiotics

Gram-positive bacteria currently account for more than half of microbiologically confirmed infections in febrile neutropenic patients. Monotherapy with an appropriate broad-spectrum agent is as effective as dual-agent treatment in most circumstances. Consider adding vancomycin if:

  • Hemodynamic instability
  • Radiographic pneumonia
  • Catheter-related infection
  • Skin or soft tissue infection
  • Known colonization with a resistant gram-positive organism
  • Severe mucositis (recent use of fluoroquinolone prophylaxis)

Discussion with patient's treating oncologist should happen simultaneously about the choice of Antibiotics (unless there are agreed existing protocols) and plan for admission v/s discharge since hospitalization may lead to drug-resistant infections. 

A subgroup of patients with febrile neutropenia may appear well with no signs of infection. They are expected to settle their neutropenia within a week have a low risk of severe infection and can be considered for outpatient care in liaison with the Oncologist.        Ensure early follow up for them prior to discharge. 

Decision Rules to risk stratify Neutropenic Patients

Clinical Index of Stable Febrile Neutropenia 

MASCC Risk Index for Febrile Neutropenia 


Clinical evidence supports the benefits of empiric antibiotics only with ANC 500/mm. There is little evidence for empiric antibiotics when the ANC >1000/mm. Abx are continued until the infection has clinically resolved and/or the ANC is >500/mm(>0.5 × 109/L).



Posted by:

              
     Lakshay Chanana
     
     ST4 Trainee
     Royal Infirmary of Edinburgh
     Department of Emergency Medicine
     Edinburgh
     Scotland

     @EMDidactic






Monday, September 3, 2018

Corneal Abrasions - Eye emergencies

Cornea
The cornea is a transparent layer over the anterior part of the eye that serves as a  protective coat, aids refraction, and filtration of some UV light. Cornea has no blood vessels and receives nutrients through tears as well as from the aqueous humor. It is innervated primarily by the ophthalmic division of the trigeminal nerve and the oculomotor nerve.

https://www.allaboutvision.com/resources/cornea.htm

Corneal Abrasion
Corneal abrasion is the most common form of eye trauma presenting to the emergency department. Abrasions may result from contact lens wear, foreign objects blown into eyes or other trivial trauma. Patients present with a feeling of foreign body sensation, photophobia, and tearing. It is important to enquire about the work circumstances and the mechanism of injury because injuries with the use of high-speed machine are associated with corneal laceration and globe perforation. 



Examination (Evert the eyelids to look for a foreign body)
  • Exam reveals conjunctival injection, tearing, and lid swelling. 
  • Blepharospasm may accompany due to severe pain (may require a topical anesthetic to do the examination). Relief of pain with topical anesthesia is virtually diagnostic of corneal abrasion
  • Photophobia 
  • Decreased visual acuity (if the abrasion is in the central visual axis or if there is an associated iritis)
  • Use Seidel's test to check for open globe injury 

The corneal abrasion is often visible to the naked eye as an irregular area of light reflection off the cornea

  • Slit lamp examination: Shows a flare and cells from iritis if the abrasion is large and >24 hours old. It is crucial to check the entire thickness of the cornea for a full-thickness laceration, and the Seidel test should be negative. The abrasion usually appears as a superficial, irregular corneal defect appearing bright green under the cobalt blue light after instillation of fluorescein.
A series of small, fine-lined vertical/linear corneal abrasions seen with fluorescein staining suggests the presence of a foreign body embedded in the tarsal conjunctiva of the upper lid


Treatment
Majority of corneal abrasions heal spontaneously and thus treatment is aimed at relieving pain and preventing infection. 

Cycloplegics - Believed to relax the ciliary body and relieve pain from spasm (However, no good evidence exists in the literature to support the common practice of using cycloplegics/mydriatics for the treatment of routine corneal abrasions)

Pain Relief: Traditionally, these agents have never been prescribed for home use, because they may cause a secondary keratitis, compromise epithelial wound healing, and block effective corneal protective reflexes and sensation. Topical NSAIDs provide pain relief and do not impair healing in patients with corneal abrasions. 

Antibiotics
Topical antibiotics ointment are usually prescribed

  • Non-contact lens wearers: erythromycin ointment.
  • Contact lens wearers: cover for Pseudomonas species (ophthalmic ciprofloxacin, ofloxacin, etc.)
Antibiotic drops are more comfortable than ointments but must be administered every 2-3 hours. Ointments that retain their antibacterial effect longer can be used less often (every 4-6 h) but are more uncomfortable due to visual blurring.

Patching no longer recommended for abrasions involving < 50% of the cornea. A meta-analysis of 7 trials in patients with corneal abrasion showed similar healing rates between patching and no patching. Patching the eye does not promote healing. Abrasions from fingernails, vegetable matter, or a contact lens should not be patched, as they are at higher risk of infection.

Tetanus prophylaxis


Consult Ophthalmology in ED for:
  • Large abrasions (involving > 50% of the cornea)
  • Findings suggestive of corneal ulceration.
  • Inability to remove retained FB.
  • Hypopion
Smaller abrasions should be checked in 48 to 72 hours. 


Further Reading:
  • Flynn CA, D'Amico F, Smith G. Should we patch corneal abrasions? A meta-analysis. J Fam Pract. 1998 Oct. 47(4):264-70.
  • http://rebelem.com/topical-pain-control-for-corneal-abrasions/
  • https://anatomyforemergencymedicine.wordpress.com/2015/05/03/031-eye-anatomy-part-2/



Posted by:

              
     Lakshay Chanana
     
     ST4 Trainee
     Royal Infirmary of Edinburgh
     Department of Emergency Medicine
     Edinburgh
     Scotland

     @EMDidactic