Bites and Stings ppt

Questions and Answers

What is the preferred method for managing a mammalian bite wound?

Suture the wound immediately to ensure closure

Wrap the wound without cleaning it to prevent further contamination

Use povidone-iodine solution to clean the wound and do not close it (correct)

Apply antibiotic ointments directly on the wound without irrigation

Which of the following factors is NOT considered when evaluating a mammalian bite?

Mechanism of injury

Type of animal involved (correct)

Depth of penetration

Tetanus immunization status

What distinguishes human bites from other mammalian bites in terms of infection risk?

Human bites are less likely to penetrate deep tissues

Infection rates for human bites can reach as high as 50% (correct)

There is no significant difference in infection rates compared to animal bites

Human bites typically require immediate surgical intervention

In managing a bite wound from an avascular area, which statement is true?

Avascular areas are more likely to become infected than vascular areas Signup and view all the answers

When evaluating a bite wound, how is the status of tetanus and rabies considered?

Vaccination history must be checked to determine if boosters are necessary Signup and view all the answers

Which action is critical when performing follow-up care on a mammalian bite wound?

Wound re-evaluation should occur within 48-72 hours Signup and view all the answers

What is the primary rationale for performing debridement in bite wound management?

To remove non-viable tissue and reduce infection risk Signup and view all the answers

What specific injury is commonly associated with a 'fight bite' from a human?

Infection of the extensor tendon and joint disruption Signup and view all the answers

What is the primary antibiotic recommended for prophylaxis in human bite wounds?

Amoxicillin clavulanate (Augmentin) Signup and view all the answers

What is the infection rate associated with untreated human bites?

Up to 50% Signup and view all the answers

Which of the following pathogens is specifically associated with cat-scratch fever?

Bartonella henselae Signup and view all the answers

In the case of a human bite, which of the following steps is NOT recommended for wound management?

Immediate suturing of the wound Signup and view all the answers

What samples should be collected for diagnosis if an animal bite appears infected?

Wound culture only Signup and view all the answers

Which of the following statements is true regarding rabies vaccinations?

Vaccination status of the animal should always be confirmed after a bite. Signup and view all the answers

What type of wound is most likely to become infected following a cat bite?

Puncture wounds and deep lacerations Signup and view all the answers

Which of the following is NOT a recommended action following a human or animal bite?

Suture the wound tightly Signup and view all the answers

What is the appropriate duration for prophylaxis following a human bite?

3-5 days Signup and view all the answers

Which of the following conditions should be treated with antibiotics for a longer duration?

Tenosynovitis Signup and view all the answers

What is the primary recommendation for managing a wound after an animal bite?

Washing with soap and water for about 15 minutes Signup and view all the answers

Which infectious agent is responsible for severe complications like tenosynovitis or septic arthritis after bites?

Pasteurella multocida Signup and view all the answers

What type of rabies is most commonly seen and considered characteristic?

Encephalitic (furious) rabies Signup and view all the answers

What should be done if an individual is bitten by a person who is positive for HBsAg?

Administer hepatitis B immune globulin and start vaccination series Signup and view all the answers

What position should a patient be placed in if there is no upper airway edema present?

Recumbent position with lower extremities elevated Signup and view all the answers

What is the preferred route of administering epinephrine in cases of anaphylaxis?

Intramuscular injection Signup and view all the answers

What is the maximum dose of epinephrine that can be administered in a single IM injection?

0.5 mg Signup and view all the answers

In a patient with anaphylaxis who remains hypotensive despite IM epinephrine, what is the recommended initial fluid management?

1 to 2 liters of normal saline Signup and view all the answers

Which of the following medications is NOT effective in relieving airway obstruction during anaphylaxis?

Diphenhydramine Signup and view all the answers

What is a crucial action to take if stridor or respiratory distress occurs in a patient with anaphylaxis?

Prepare for intubation Signup and view all the answers

What is the proper dosing of epinephrine for adults using an auto-injector?

0.3 mg Signup and view all the answers

When should a cricothyroidotomy be considered for a patient in anaphylaxis?

If upper airway edema prevents intubation access Signup and view all the answers

Which of the following is true regarding the use of glucocorticoids in anaphylaxis treatment?

They are given for hours after the event Signup and view all the answers

Why is it advisable to prepare an epinephrine solution for continuous infusion in anaphylaxis treatment?

To be ready for patients not responding to repeated IM doses Signup and view all the answers

What is the recommended procedure for administering HRIG when treating a rabies exposure?

Infiltrate HRIG around and into the wound, with any remaining volume injected intramuscularly. Signup and view all the answers

Why is it critical to assess a patient's history of getting rabies vaccinations after an animal bite?

To determine the necessity and timing of HRIG and rabies vaccine administration. Signup and view all the answers

Which form of treatment is NOT recommended for localized reactions to insect stings?

Suturing the area to prevent infection. Signup and view all the answers

What is the primary reason for administering epinephrine in cases of severe allergic reactions to insect stings?

To improve airway patency and support circulation. Signup and view all the answers

What dosage of HRIG is recommended for rabies post-exposure prophylaxis?

20 IU/kg body weight. Signup and view all the answers

Which factor makes bites from bats uniquely hazardous regarding rabies exposure?

Bat saliva can contain rabies virus, and close encounters pose a risk. Signup and view all the answers

In the event of a spider bite from a black widow, what is a key distinguishing feature of its venomous bite?

Presence of an hourglass configuration on the abdomen. Signup and view all the answers

What is the recommended schedule for rabies vaccination following rabies exposure in immunocompetent patients?

Days 0, 3, 7, and 14. Signup and view all the answers

What should be done if a bite from a potentially rabid animal occurs?

Immediately begin rabies post-exposure prophylaxis. Signup and view all the answers

Which condition can lead to the most severe allergic reactions following insect stings?

Anaphylaxis. Signup and view all the answers

Why is rabies considered virtually always fatal once symptoms appear?

There is no effective treatment once clinical signs develop. Signup and view all the answers

What is a common misconception regarding spider bites in the emergency department?

Vast majority of spider bites pose little harm to humans. Signup and view all the answers

What is the primary purpose of giving parenteral antihistamines in the management of insect sting reactions?

To alleviate symptoms caused by histamine release. Signup and view all the answers

What are the challenges associated with treating rabies post-exposure prophylaxis?

The necessity of multiple expensive HRIG administrations. Signup and view all the answers

What is the first step recommended in the management of anaphylaxis?

Identify and remove the inciting cause if possible Signup and view all the answers

How many vials of antivenom are required for a moderate envenomation case?

10 vials Signup and view all the answers

Which method has a lower chance of allergic reactions when administering antivenom?

F(ab) fragments CroFab Signup and view all the answers

What constitutes a common respiratory symptom in anaphylaxis?

Stridor Signup and view all the answers

What is the definition of reduced blood pressure in adults during anaphylaxis?

Systolic BP < 90 mmHg or > 30% decrease from baseline Signup and view all the answers

What is the purpose of administering epinephrine in anaphylaxis?

To reverse bronchoconstriction and improve circulation Signup and view all the answers

In pediatric cases of envenomation treated with antivenom, what is a key consideration?

Lower dosages compared to adults Signup and view all the answers

Which symptom is least likely associated with gastrointestinal manifestations of anaphylaxis?

Flushing Signup and view all the answers

What is a significant risk factor for complicated allergic reactions during antivenom administration?

Acute allergic disposition to drugs Signup and view all the answers

How should an initial assessment of a patient with anaphylaxis prioritize evaluations?

Airway, breathing, circulation Signup and view all the answers

What is the purpose of monitoring following the administration of antivenom?

To detect allergic reactions or progression Signup and view all the answers

What is the typical dosage of CroFab for a patient with severe envenomation?

15 vials Signup and view all the answers

Which clinical sign is most indicative of severe anaphylaxis?

Stridor Signup and view all the answers

What sign is a strong criterion for diagnosing anaphylaxis?

Acute onset skin symptoms with respiratory compromise Signup and view all the answers

What is the most common systemic symptom experienced during black widow spider envenomation?

Severe abdominal pain Signup and view all the answers

Which factor primarily determines the severity of a snake bite's toxicity?

Type and quantity of venom Signup and view all the answers

In managing a brown recluse spider bite, which treatment approach is NOT typically recommended?

Antivenom administration Signup and view all the answers

What is a critical first step in snake bite management upon arrival at the emergency department?

Removal of constrictive items Signup and view all the answers

Which symptom is most characteristic of a severe reaction to a brown recluse spider bite?

Necrotic ulceration with eschar Signup and view all the answers

In the event of a rattlesnake bite, what is a common complication that can arise?

Rhabdomyolysis Signup and view all the answers

What distinguishes venomous snakes from non-venomous ones during clinical examination?

Shape of the pupils Signup and view all the answers

What is the recommended action if a snake bite shows minimal or non-progressive swelling?

Observation for 12 to 24 hours Signup and view all the answers

Which treatment is NOT typically indicated for systemic symptoms resulting from a black widow spider bite?

High-dose corticosteroids Signup and view all the answers

What form of antivenom is commonly recommended for severe snake envenomation?

CroFab Signup and view all the answers

What characteristic bite pattern is indicative of a non-venomous snake?

Multiple small punctures Signup and view all the answers

For patients with a dry snake bite, which management strategy should primarily be employed?

Monitoring for symptoms of envenomation Signup and view all the answers

What is a primary reason for consulting with poison control in cases of suspected snake envenomation?

To get recommendations on pre-hospital care Signup and view all the answers

Study Notes

Mammalian Bite Evaluation

Assess time since injury and mechanism of injury, including direct bites or injuries sustained from punches.
Evaluate the anatomic location, depth of penetration, and tetanus immunization status.
Consider medications, allergies, and risk factors for infection.
Vascular areas show lower infection rates than avascular, with dog bites having a lower infection risk compared to deeper-piercing cat bites.

Mammalian Bite Management

Follow ABCs and consider cervical spine stabilization if necessary.
Clean wounds with povidone-iodine and perform copious irrigation using normal saline.
Evaluate for foreign bodies or underlying injuries using x-rays.
Debride devitalized tissue, as flap avulsions may not heal effectively.
Prophylactic antibiotics are prescribed or are used for treating active infections.
Consider tetanus and rabies post-exposure protocols.
Avoid suturing bite wounds to reduce infection risk, except for large wounds requiring stabilization.

Human Bites

Human bites pose a high infection rate, up to 50%, especially in the hands and extremities.
Specific injuries like “fight bites” can disrupt the MCP joint leading to severe infections.
Males are more likely to sustain human bites; pathogens include Eikenella corrodens, common in human bite wounds.
Prophylactic antibiotics are crucial; standard treatment includes amoxicillin clavulanate (Augmentin).

Dog & Cat Bites

Approximately 3-6 million animal bites occur yearly in the U.S., with 85% being dog bites and 10% from cats.
Dog bites usually result in crushing/tearing wounds, while cat bites are often puncture wounds, with a higher infection rate (66%).
Cat-scratch disease includes regional lymphadenopathy developing 7-12 days after a cat bite.
Common pathogens from animal bites include Pasteurella multocida and Bartonella henselae.

Insect Bites/Stings

Hymenoptera insects (bees, wasps, hornets) can cause a range of reactions from mild to life-threatening.
Monitor for rapid onset of symptoms, including pain, edema, and potential anaphylaxis.
Management of anaphylaxis includes administering epinephrine and supportive medications.

Spider Bites

Most spider bites are non-venomous; venomous bites include those from Black Widow and Brown Recluse.
Black Widow envenomation causes neurotoxic effects like muscle cramps and systemic symptoms.
Brown Recluse bites may lead to painful necrotic lesions; management includes analgesia and sometimes surgical intervention.

Snake Bites

About 30,000 snake bites occur annually in the U.S., with 8,000 classified as venomous; most common are rattlesnakes and copperheads.
Symptoms of venomous snake bites include fang marks, swelling, and possible systemic effects.
Treatment includes removing constrictive clothing, monitoring for swelling, and administering antivenom for severe cases.
Coagulation studies are critical to managing complications like coagulopathy or compartment syndrome following envenomation.

Rabies

Rabies is nearly always fatal post-symptom onset, with domestic dogs being major carriers.
Management includes wound washing, vaccination status assessment, and initiating rabies post-exposure prophylaxis.
Rabies vaccine regimen requires doses on days 0, 3, 7, and 14, with rabies immune globulin (HRIG) for unvaccinated individuals.

Tetanus Considerations

Always inquire about tetanus vaccination status for any bite, sting, or wound.
Tetanus prophylaxis is required based on the type of wound and last immunization date.### Patient Discharge Guidelines
Normal repeat laboratory tests may allow discharge within 24 hours for children, elderly, those with significant comorbidities, or poor social support.
Asymptomatic patients with suspected Mojave rattlesnake bites may be observed for 12-24 hours due to potential delayed neurotoxicity.

Antivenoms

ANTIVENIN: High-affinity antibody that enhances elimination of venom proteins.
Wyeth Polyvalent Antivenin: Produced by immunizing horses with four pit viper venoms; effective against various snakes including rattlesnakes and South American bushmaster.
Cost-effective at approximately $40 per vial.
Dosing guidelines include:
- Dry bite: No treatment required.
- Minimal envenomation: 5 vials.
- Moderate or severe envenomation: 10 and 15 vials respectively.
CroFab: Monoclonal F(ab) fragments with a lower chance of allergic reactions, significantly more expensive (~$40,000 per dose).
Initial dosing for CroFab involves 4-6 vials, followed by additional doses if required.

Complications of Antivenom Administration

Risks include allergic reactions, anaphylaxis, and potential thrombocytopenia.
Anaphylactic Shock is most common in patients with prior allergic reactions to substances like insects, food, or medications.

Signs and Symptoms of Anaphylaxis

Skin and mucosal symptoms: Up to 90% of cases, including hives, swelling of lips/tongue/uvula.
Respiratory symptoms: Present in about 70% of cases; symptoms can include nasal discharge, stridor, shortness of breath.
Gastrointestinal symptoms: Occur in 45% of cases with nausea, vomiting, and abdominal pain.
Cardiovascular symptoms: Included are hypotension, tachycardia, dizziness, and collapse.

Diagnostic Criteria for Anaphylaxis

Criterion 1: Acute skin or mucosal symptoms with respiratory compromise or reduced blood pressure.
Criterion 2: Rapid involvement of two or more organ systems after allergen exposure, including gastrointestinal symptoms.
Criterion 3: Reduced blood pressure following exposure to a known allergen, with specific values for children.

Management Steps

Immediate identification and removal of inciting causes of anaphylaxis is essential.
Epinephrine administered via IM injection is the treatment of choice.
Supplemental oxygen and volume resuscitation with IV fluids are critical components.

Medications in Anaphylaxis Management

Steroids (e.g., solumedrol, dexamethasone) and H1 antihistamines (e.g., diphenhydramine, cetirizine) may relieve symptoms but do not replace epinephrine.
Glucocorticoids have delayed onset; typical first dose is methylprednisolone 125 mg.

Airway Management

Intubation is necessary if stridor or significant respiratory distress is noted.
Prepare for emergency airway procedures like cricothyroidotomy if severe edema occurs.

Epinephrine Administration

Route of choice is IM, with a recommended initial dose of 0.01 mg/kg (up to 0.5 mg).
Auto-injector doses are 0.3 mg for adults and 0.15 mg for children.
Repeat doses may be required every 5-15 minutes.

Fluid Management

Administer 1-2 liters of normal saline for hypotensive patients; larger volumes may be necessary.
Establish IV access for rapid fluid administration due to significant vascular permeability changes.

Additional Medications

H1 antihistamines help with itch and hives but do not address airway obstruction or hypotension.
Cetirizine is less sedating and available in both IV and oral forms.
Glucocorticoids take hours to become effective but are an essential part of management.

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Description

This quiz covers the crucial aspects of evaluating and managing mammalian bites. It includes information on injury mechanisms, bite wound characteristics, and factors influencing infection risk. Understanding how to assess and treat these injuries is essential for effective medical care.