Corrosive Poisoning

Corrosive poisoning is a common emergency as corrosive agents are easily available for household use. Corrosives can injure the GI tract by causing tissue necrosis, perforation, fibrosis, stricture formation and malignancy years after the exposure. These compounds include acids, bases, salts, heavy metals, iodine tincture etc. 

Acids

• Car battery fluid (sulfuric acid)
• Descalers (hydrochloric acid)
• Metal cleaners (nitric acid)
• Rust removers (hydrogen fluoride) 

Alkalis

• Bleach (hypochlorite)
• Sodium hydroxide (liquid lye) 

Pathophysiology

Alkali ingestion: Causes liquefaction necrosis. This process includes protein dissolution, collagen destruction, fat saponification, cell membrane emulsification, submucosal vascular thrombosis and cell death.

Acid ingestion: Causes coagulation necrosis. In this process, hydrogen (H+) ions desiccate epithelial cells producing an eschar. This process leads to edema, erythema, mucosal sloughing, ulceration and necrosis of tissues.

Both acids and alkalis cause fibrosis and stricture formation 

Signs and Symptoms

Clinical presentation varies and depends on the type/quantity of the agent ingested, timing of ingestion, presence of food in the stomach. Burns to the lips, mouth, and oropharyx may be seen but this does not necessarily correlate to the degree of injury tothe esophagus or stomach. Patients with airway deem may present with stridor, aphonia, hoarseness, or dyspnea. Other presenting symptoms include abdominal or chest pain, nausea/vomiting, GI bleed, dysphagia, odynophagia, drooling. 

If there is GI perforation, it may result in fluid loss causing renal failure, altered mental status, lethargy, arrythmias, respiratory distress and seizures.

Investigations

CBP

Basic Metabolic Profile

ABG

CXR (look for free air)

Type and Cross Match 

CT Scan (for suspected perforation despite negative X-Rays and to assess oesophageal wall thickness)

Endoscopy (for direct evaluation and management of strictures)

Esophagogastroduodenoscopy should be performed in the first 12 to 24 hours post-ingestion with great care, to avoid iatrogenic perforation. The grade and extent of the lesions of the upper gastrointestinal tract can be determined and classified according to the Zargar’s modified endoscopic classification of burns due to corrosive ingestion. 

Grade Description

0. 0  Normal mucosa
   
1. 1  Erythema/Hyperemia
   

1. 2a  Superficial ulcer/erosion/friability/hemorrhage/ exudates
   
2. 2b  Findings in 2a + deep discrete/circumferential ulcers
   

1. 3a  Scattered necrosis (black/grey discoloration)
   
2. 3b  Extensive/circumferential necrosis of mucosa 
   

Severe hypopharyngeal burns are an absolute contraindication for esophagogastroduodenoscopy.

Management 

1. If only a small amount is ingested: Observe and discharge from the ED if tolerating orallly, asymptomatic and normal intra oral examination. 

2. Major Ingestion

• Pay special attention to the Airway/Oxygenation
• IV Fluids
• Add PPIs (reduce exposure of injured esophagus to gastric acid, which may result in decreased stricture formation.)
• Antibiotics if there is evidence of perforation
• Don't forget to add pain relief 
• Keep Nil by Mouth 

Activated charcoal is relatively contraindicated in caustic ingestions because of poor adsorption and endoscopic interference. Emergency surgical intervention is indicated in case of perforation or peritonitis, or if uncontrolled massive hematemesis occurs. 

DO NOT

• Induce Emesis (risk of mucosal injury and perforation)
• Insert NG Tube (may cause esophageal perforation and increase the risk of aspiration)
• Do Lavage (risk of damage to oesophagus and aspiration)
• Try to neutralise the substance (risk of heat production resulting from this exothermic reaction
• Administer systemic steroids

Nutrition: Endoscopic grade of lesions needs to be assessed for planning nutritional support in patients with caustic ingestion. Patients with Grade 1/2a lesions on endoscopy can tolerate oral feeds, while those with Grade 2b/3a lesions will need nasoenteral feeding. Patients with Grade 3b lesions require gastrostomy for enteral feeding and rarely need total parenteral nutrition (TPN). 

Acute presentation 
Within 48-72 hours of corrosive ingestion: Upper GI endoscopy should be performed on Day 1-2. (ideally between 12-24 hours of ingestion). If endoscopy reveals only mild lesions, then the patient can be discharged and clinical follow-up should be done at one month. If severe lesions are found on endoscopy, then surgical gastrostomy is indicated, which should be followed by repeat endoscopy and dilatation after three weeks.

Delayed Admission
Within 72 hours to three weeks of corrosive ingestion: No endoscopy is indicated here. Gastrostomy should be done if there is severe dysphagia. Endoscopy and dilatation of stricture (if present) should be done three weeks after ingestion.

Late Admission

More than three weeks of ingestion: Requires endoscopy and dilatation of stricture. If the procedure is successful, then follow-up endoscopy should be done at one month. If the procedure is unsuccessful, then surgical gastrostomy is performed, which is followed by retrograde dilatation of stricture after 10 days of operation.

Complications of the Disease and/or Management

Aspiration of corrosive substances into the respiratory tree may cause endotracheal or bronchial necrosis with mediastinitis. Acute kidney injury, disseminated intravascular coagulation, acid-base disturbances and pneumonia. Oesophageal stricture formation is the most feared long-term complication; stenosis gastric antrum or pylorus may also occur, as may fistula formation.

Stricture formation begins weeks to months after injury and is the most important consequence of corrosive poisoning. Procedures used for prevention and treatment of strictures are:

1. Dilatation therapy: This is done 3-6 weeks after injury, progressively larger bougies are passed over endoscopically placed guide wires for dilatation. 
2. Surgery: Esophageal strictures resistant to dilatation therapy may require surgery that includes resection of stricture surgically and esophageal bypass surgery. 

Key Points:

1. Both acids and Alkalis can cause strictures.

2. Endoscopy performed in the first 12 to 24 hours following ingestion is the gold standard  to assess the GI tract.

3. Pay attention to Airway, Hydration, Nutrition.

4. Say no to NG tube, gastric lavage, emetics, dilution and neutralisation, systemic steroids and activated charcoal.

For further reading:

1. In: Critical Care Toxicology: Diagnosis and Management of the Critically Poisoned Patient. 1st edition, Brent, Wallace, Burkhart, Phillips, Donovan (Eds.) 2005:p. 1035-44.
2. Caustics. In: Goldfrank’s Toxicologic Emergencies. 8th edition.
3. Zargar SA, Kochhar R, Mehta S, Mehta SK. The role of fiberoptic endoscopy in the management of corrosive ingestion and modified endoscopic classification of burns. Gastrointest Endosc 1991;37(2):165-9.
4. Anderson KD, Rouse TM, Randolph JG. A controlled trial of corticosteroids in children with corrosive injury of the esophagus. N Engl J Med 1990;323(10):637-40.
5. Acids and alkalis. The Poisoning and Toxicology Handbook. 4th edition, Jerrold B. Leikin, Frank P. Paloucek Informa Healthcare, USA 2007:p.713-9.
6. Alkali injury. In: Clinical Management of Poisoning and Drug Overdose. 3rd edition, Lester M. Haddad, Michael W. Shannon, and James F. Winchester (Eds.) 1998: p.817-20. 
7. http://medind.nic.in/iaa/t12/i8/iaat12i8p131.pdf 

Necrotizing Fasciitis - A diagnostic challenge

Necrotizing Fascitis is characterized by fulminant, extensive soft tissue necrosis, systemic toxicity, and high mortality. Early in the course, the disease can appear deceptively benign and may look like cellulitis. 

Prompt diagnosis of necrotising fasciitis (NF) and early intervention reduces mortality and amputation rates. Unfortunately NF is misdiagnosed in the initial stages of the disease in almost 75% of the patients. Because thrombosis of large numbers of capillary beds must occur before skin findings develop, early infection has little overlying skin changes to indicate the extent of infection. 

Patients classically present with the triad of pain, swelling and erythema. The most consistent feature of early NF is that the pain is out of proportion to the swelling or erythema. Other important features that make NF likely are:

• Tenderness extending beyond the apparent involved area 
• Indistinct margins of involvement 
• Absence of lymphangitis  (because the infection is in the deep fascia and not in the skin)
• Rapidly progressive despite the use of antibiotics 
• If the patients looks too sick for cellulitis
• Bleb/Bullae, Crepitus (Though you cannot not rule out NF in their absence)

Usually fever or pain develops first followed by the cellulitic changes. The classic textbook picture of hemorrhagic bullae, crepitus, and skin necrosis often does not occur until day 5. 

Risk factors: 

Advanced age

Diabetes mellitus

Alcoholism

Peripheral vascular disease, Heart disease

Cenal failure

HIV, Cancer (Immunocompromised state)

NSAID use

Decubitus ulcers, chronic skin infections

IV drug abuse

Note: Although risk factors are frequently present, the disease can occur in healthy young patients. 

POCUS (Point of care ultrasound)
This is a great tool that can aid to diagnose cellulitis, NF or underlying collection/abscess. 

1. Cellulitis: 
   1. Diffuse thickening of subcutaneous layer, Echogenecity +
   2. Hypoechoic septae between the fat and connective tissue : “cobble-stone” appearance - See the image below
      
      
      
      
      
      
      
      
      
      
      
2. Abscess:
   1. Variable appearance from anechoic to irregularly hyperechoic, internal echoes; may find hyper echoic sediment, septae or even gas!
   2. Posterior acoustic enhancement
   3. “Squish sign” with compression: ability to induce motion in the material with
      palpation/pressure
3. Necrotizing fasciitis: 
   1. Marked thickening of the subcutaneous layer (i.e. cellulitis) 
   2. Layer of anechoic fluid measuring >4mm, adjacent to the deep fascia 
   3. Subcutaneous gas (acoustic shadowing and reverberation artifact) may be present 

Click on the link below to learn Soft tissue ultrasound in 17 minutes.

http://www.emergencyultrasoundteaching.com/narrated_lectures.html 

Treatment for NF:

1. Treat Sepsis (Fluids/Antibiotics)
2. Remove the focus (Debridement/Amputation) - ASAP

Key Points:

• Always think NF whenever you call it cellulitis.
• Early NF may not show classical textbook skin changes.
• If you see bullae, feel crepitus - you are dealing with NF.
• Use POCUS (Point of Care USG) for soft tissue infections.

For Further reading:

1. Yen ZS, Wang HP, Ma HM, Chen SC, Chen WJ. Ultrasonographic screening of clinically-suspected necrotizing fasciitis. Acad Emerg Med 2002;9(12):1448-51.
2. Chao HC, Lin SJ, Huang YC, Lin TY. Sonographic evaluation of cellulitis in children. J Ultrasound Med 2000;19(11):743-9. 
3. www.emergencyultrasoundteaching.com
4. Tayal VS, Hasan N, Norton HJ, Tomaszewski CA. The effect of soft-tissueultrasound on the management of cellulitis in the emergency department. Acad Emerg Med 2006;13(4):384-8.
5. Vincent LM. Ultrasound of soft tissue abnormalities of the extremities. Radiol Clin North Am 1988;26(1):131-44.
6. Squire BT, Fox JC, Anderson C. ABSCESS: applied bedside sonography for convenient evaluation of superficial soft tissue infections. Acad Emerg Med 2005;12(7):601-6.

Demystifying ED Consultations!!

One of the most crucial things that we do everyday at work is “asking for a consult/referral”. ED Consultations can be really difficult at times revolving around self-respect – diverse values – bonding - interests and interpersonal relationships. But “How to ask for a consult” is something that is rarely taught to EM residents, at least I was never taught this as a junior trainee in EM. Lets find out what’s the best way to get a consultation:

As Emergency Physicians deal with multiple other subspecialists, 24X7. It is our responsibility to take care of the sickest and simultaneously pass on the information and arrange for definitive care. To do this, we must have a thorough subject knowledge about General Emergency Medicine and also the competency to pass the information appropriately. There is not much of literature out there on this particular topic. Trainees screw up time and again; learning this skill gradually with their own goof ups gauging them as per the requirements of various consultants.

Whether this info is passed on to the specialty consultants/Attendings or Specialty Registrars/Residents depends on the institutional protocols. Here we are going to set some general rules that should probably work for everyone.

1)    Why/ When do you need a consult – Lead with a headline

You must have a succinct idea about this – Clarify the purpose and urgency of your consult. Do not start your medical school kind of presentation with a detailed history. They are too busy for that. Cut it short and come to the point ASAP, have your thoughts organized and the data that supports your thinking. Don’t ask for a consult just because the consultant is available; ask for it only if it is required.

2)    Gather your ingredients

Get all the data with you before you call them – history – old blood reports – meds – previous procedures - imaging etc. Another way of doing this is, by thinking, if you were in their shoes, then “what would you want”? When you do your rotations with them, understand their perspective to smoothen your consultations when you get back to the ED.

For instance - Few important specialty-specific questions that they love to know are:

(Note: This by no means is a complete list)

·      Neurosurgery: GCS, Na, Pupillary Response

·      Cardiology: ECG, Troponin, Previous Stress tests

·      Nephrology: Urine Output, K, Urea/Creat

·      OGYN: GPLA, LMP

And if you don't have an answer to something – never cook up a story or numbers – Be blunt and let them know that you DON’T KNOW.

3)    Negotiate

Whenever there is a difference of opinion, try to negotiate and settle down the differences. For instance, if the neuro consultant is too busy for a suspected epidural abscess and wants ED to get some sort of imaging first, ask him to send at least someone from neurology services (may be a resident/registrar) to evaluate the patient as you arrange for the imaging.

4)    Be Nice

Don't have a prejudice and avoid judging them if you have had a bad experience with them. Anyone will get upset if you call and tell them to come to the ED right away – This is human nature. Be nice and soft, but never compromise patient care.

All this can be summarized in the “5C” model of consultation:

5C Model

ü  Contact - Introduction of consulting and consultant physicians. Building of relationship.

ü  Communicate - Give a concise story (30-60seconds) and ask focused questions. DON’T START MEDICAL SCHOOL CASE PRESENTATION – They don't have the time for that.

ü  Core Question - Have a specific question or request of the consultant. Decide on reasonable timeframe for consultation. Come to the point ASAP.

ü  Collaboration - A result of the discussion between the emergency physician and the consultant, including any alteration of management – BARGAIN/ NEGOTIATE.

ü  Closing the Loop- Tell them what is the plan and whatever you understood

Document your conversation (better to record all telephonic conversations)

+ Don't forget the kindergarten basics

Ø  Greet & Introduce yourself

Ø  Confirm their name (Occasionally, some of them might get upset if you ask their name!)

Ø  Permission: Do you have a moment to discuss a case?

Ø  Be confident and pleasant

Ø  Listen to them and show respect for their opinion

Ø  Thank them

Ø  Also, practice a few times with your supervisor before you actually call them

Difficult Consults:
We all have seen nasty consultants who come to the ED and start throwing things around. 
Consultants are like "guests in your house". Treat them the way you treat your guests. This is going to turn things in your favour often getting them to do stuff you wanted to be done (procedure, admission etc.)

Use Key phrases: Often required to make people feel valued:

Ø  We need your expertise/help….

Ø  Your opinion is really going to make a difference….

Ø  I am concerned because….

Ø  I think this is best for the patient….

Ø  I would really appreciate if you could come down and see him once.…

Ø  I know you guys are really busy abut I cannot miss this diagnosis….

Ø  I don't want to waste your time but no one else can do it….

Ø  I know, It was a really busy day for you – but I need your help..

If nothing is working to get them down to the ED, Remember:

• Not to raise your Voice or Swear – Bad for you and for the patient as well
• Don’t threaten them

Occasionally, despite doing your best, things are not going to turn out well. Then, just be polite and tell them you are going to speak to your consultant/supervisor/attending and get back

OR

Tell them respectfully : “This discussion is not going anywhere, I think we both need to think over it and I shall get back in sometime”.

These methods may not always work but definitely provide us with a good framework for asking a consultation from the ED. Factors like your rapport, previous interactions with them also play an important role when you ask for a consultation.

Take Home Points

1)   5 Cs:  Contact, Communicate, Core Question, Collaborate & Close the loop

2)    Never raise your voice or swear at them

3)    Don't forget the Kindergarten Basics

4)    Know the key statements to get them down!

Thanks!

For further reading:

1. Salerno, Stephen M., et al. "Principles of effective consultation: an update for the 21st-century consultant." Archives of internal medicine 167.3 (2007): 271-275.
2. Kessler, Chad S., et al. "A prospective, randomized, controlled study demonstrating a novel, effective model of transfer of care between physicians: the 5 Cs of consultation." Academic Emergency Medicine 19.8 (2012): 968-974.
3. EMRAP - Feb 2011 Episode Summary
4. EMRAP - Sep 2013 Episode Summary
5. http://shortcoatsinem.blogspot.com.au/2012/10/sweating-bullets-and-killing-em-with.html?spref=tw
6. http://lifeinthefastlane.com/referring-patients-from-the-emergency-department/