Unit 3: Snakebites Flashcards
1
Q
Envenomation
A
when a venomous snake bites and injects venom through its fangs
2
Q
Venom
A
- differs from species to species
- complex mixture of enzymes and proteins designed to immobilize and digest prey
- immobilization occurs b/c of the neurotoxic properties of venom, causing weakness and paralysis
- can be hemotoxic (destruction of RBCs)
3
Q
Clinical Manifestations
A
- local swelling and ecchymosis (bruising)
- fang marks, teeth marks, and/or scratches visible
- with envenomation, edema and erythema at site and surrounding tissues; occurs within 30 to 60 minutes
- ecchymosis (bruising) appears around the site within 3 to 6 hours in moderate or severe envenomation
- within 8 hours, serous and/or hemorrhagic bullae appear at site
- with rattlesnake bites, necrosis around site is common
4
Q
Systemic Effects of Venom
A
- damage at the cellular level, weakening vascular walls, causing muscle breakdown, and initiating the coagulation cascade; results in excessive clotting abnormalities similar to DIC
- the toxic systemic effects can be seen in the lungs, kidneys, myocardium, peritoneum, and CNS
- thrombocytopenia (low platelets) in rattlesnake bites
5
Q
Coagulopathies that may occur
A
- cause more bleeding
- patients can hemorrhage from the bite site, mucous membranes, and venipuncture sites
- epistaxis (bloody nose)
- hematemesis (bloody emesis/vomit)
- hematuria (blood in urine)
- gingival bleeding (gums)
- hematochezia (blood in stool)
- later, hypovolemia occurs while blood loss continues, and fluid pools into the microcirculation as a result of increased capillary permeability
6
Q
Connection Check: The nurse is caring for a patient bitten by a rattlesnake 3 hours before admission to the ED. The nurse correlates which of the following clinical manifestations with a venomous snakebite? A. Edema at the site B. Bleeding at the site C. Excessive diuresis D. Dysrhythmias E. Numbness at the site
A
A. Edema at the site
B. Bleeding at the site
7
Q
Laboratory Tests for Snake Bites
A
- CBC: to evaluate hemoglobin, hematocrit, and platelet values
- Urinalysis: testing for blood, myoglobin, and protein in urine
- Coagulation studies: evaluate presence of clotting abnormalities and DIC
- Renal studies: elevated BUN, and creatinine = renal failure
- Electrolytes: potassium may be elevated in renal failure
- Serum creatinine kinase (CK-MB): increases because of muscle breakdown; will be elevated in rhabdomyolysis
8
Q
Treatment
A
- patient’s who do not show immediate signs of envenomation should be observed for 12 hours; if does not show local or systemic signs after 12 hours, discharge home
- for severe envenomation, antivenin
- prior to administration, consultation with a medical toxicologist through the poison control center should be performed
- wound should be cleansed
- receive tetanus prophylaxis if immunization outdated or unknown
- no need for antibiotics unless wound is heavily contaminated
- do not apply a tourniquet, ice, or alcohol to the affected extremity
9
Q
Antivenin
A
- most effective when given 4 to 6 hours after envenomation
- the tissue swelling and ecchymosis around the bite site should be evaluated to determine the appropriate dose
- the adequacy of the dose is based on improvement of vital signs; decrease in tachycardia and tachypnea and a increase in BP
- partial or complete reversal of the coagulopathies
- improvement of systemic findings; diarrhea, vomiting, pain, altered mental status, or oral paresthesias
10
Q
Complications of Antivenin: Hypersensitivity
A
- reactions can occur; acute hypersensitivity
- infusions should be stopped immediately
- Epinephrine (0.3 to 0.5 mg intramuscularly), diphenhydramine, inhaled albuterol, and IV corticosteroids should be available to treat anaphylactic reaction
- antivenin may be restarted at a lower infusion rate after reaction treated
- continually monitored in ICU for 24 hours after administration of antivenin to observe for signs of immediate or recurrent toxicity
11
Q
Nursing Management: Assessment and Analysis
A
- a Crotalinae bite w/ envenomation produces swelling, pain, blistering, and ecchymosis d/t proteins in venom breaking down muscle and blood vessels and triggering the clotting cascade
- later manifestations: signs of ventilatory decompensation, rhabdomyolysis, compartment syndrome, and signs of coagulopathies (bleeding from wound, IV sites, and mucous membranes)
- muscular weakness, ptosis (drooping eye), and dysphagia
12
Q
Nursing Assessments for Sake bites
A
- Vital Signs
- Pulse oximetry
- Skin assessment
- Lab assessment: renal studies, coagulation studies, urinalysis, electrolytes (potassium)
13
Q
Assessment: Vital Signs
A
- tachycardia, hypotension, and tachypnea may be present w/ fluid volume loss d/t bleeding and increased capillary permeability causing leakage into the tissues
- worsening vital signs indicate either worsening of systemic reaction, anaphylaxis to antivenin, or needing a higher dose of antivenin
- adequacy of the antivenin dose is based on improvement of vital signs
14
Q
Assessment: Pulse Oximetry
A
-decreased O2 saturation and increases in respiratory distress may indicate a venomous coral snake bite
15
Q
Assessment: Skin Assessment
A
-venomous bite produces edema, bleeding, ecchymosis, and pain at the site
