History

•  Excessive fluid loss (V/D, sweating, polyuria, diuretic/laxatives, bowel regimen), inadequate intake (debilitated, institutionalized, NM d/o, H&N pathology), altered thirst mechanism (intoxication, systemic illness, malignancy, antipsychotic use)

Findings

•  ↑ HR w/ standing (Δ >20 beats/min lying → standing); 75% sens & spec

Evaluation

•  CBC (hemoconcentration), Chem 7 (↓ bicarb, ↑ BUN/Cr, abnl Na, K), ECG abnl

•  UA: Ketones, hyaline casts, spec grav >1.02: Uroconcentration, >1.03: Severe dehydration

Treatment

•  Initial fluid resuscitation w/ NS or LR (avoid NS if concern for hyponatremia), then tailor to electrolyte abnlty/pathology (labor: Nonglucose IVF, malnourishment: D5 NS)

•  nl LV fxn: 2–3 L NS, follow clinical sxs, VS, UOP

•  Compromised LV fxn: 500 cc/h, watch pulmonary status (O₂ sat, SOB)

•  Consider antiemetic if N/V is contributing to dehydration

Disposition

•  Home once dehydration adequately treated unless concerning electrolyte abnormalities, pt able to maintain hydration status

•  Consider care coordination/placement if pt lives alone & unable to hydrate self

Pearls

•  Up to 30% of healthy pts are orthostatic w/o dehydration (βBs, autonomic Dysfxn (DM))

•  Oral rehydration w/ glucose to facilitate intestinal absorption of Na & water if pt tolerates, “recipe” is 2 tbl sugar : 0.5 tsp salt : 1 quart water

•  Healthy adults tolerating PO rarely require IVF & PO rehydration is usually adequate

BITES AND STINGS

Approach

•  Treat anaphylaxis; give tetanus prophylaxis

•  Consider x-ray for underlying fx or FB

•  Assess for joint space violation, copious wound irrigation/wash out w/ NS; if heavily contaminated, do not close

•  24–48 h wound check for high-risk bites, esp in kids or unreliable pts

•  National Poison Control Center (PCC): (800)222-1222

HUMAN & ANIMAL BITES

Human

History

•  Laceration near MCP joint during altercation should be considered as a human bite (ie, “fight bite”); bacteria spread along tendon sheath deep into hand

Evaluation

•  Consider x-ray to assess for fracture, air in joint, tooth fragments; no serology needed

•  Extend & explore periarticular MCP joint injuries including in position that injury occurred

Treatment

•  Augmentin (ampicillin/clavulanic acid) 875/125 mg BID × 5 d OR clindamycin 300 mg BID + ciprofloxacin 500 mg BID OR clindamycin 300 mg BID + TMP–SMX; if later/infected Unasyn (ampicillin/sulbactam) 1.5 g q6h

•  Delayed primary closure if closure needed

Disposition

•  Scheduled strict f/u in 24–48 h

Pearl

•  Eikenella (most common), Staphylococcus, Streptococcus species found in mouth

Cat

Evaluation

•  Consider x-ray to assess for fracture, air in joint, tooth fragments

•  Extend & explore joint injuries including in position that injury occurred

Treatment

•  Augmentin 875/125 mg BID, cefuroxime 500 mg BID OR doxycycline 100 mg BID

•  Delayed primary closure only if cosmetically needed; 80% of cat bites become infected!

Disposition

•  Scheduled strict f/u in 24 h

Pearls

•  P. multocida most common organism

•  Consider cat-scratch dz if pt has tender LAD 1 wk after bite/scratch

•  Very high infection rate despite antibiotic use

•  Consider antirabies prophylaxis (rabies immunoglobulin + vaccine) if unknown cat (see 4i)

Dog

Evaluation

•  Consider x-ray to assess for fracture, air in joint, tooth fragments

Treatment

•  Augmentin (ampicillin/clavulanic acid) 875/125 mg BID OR clindamycin 300 QID + ciprofloxacin 500 mg BID

•  1° closure after copious irrigation possible except on hand/foot; only 5% become infected

Disposition

•  Scheduled strict f/u in 24 h

Pearls

•  Polymicrobial infections

•  Consider antirabies prophylaxis if unknown dog as above w/ cats (see 4i)

SNAKE BITES

Pit Vipers (rattlesnakes, copperheads, water moccasins, Mississauga)

History

•  Pain & swelling around fang marks, attempt identification of snake if possible

Findings

•  Local (pain, swelling, ecchymosis), systemic (↓ BP, ↑ HR, paresthesias), coagulopathy (↓ PLTs, ↑ INR, ↓ fibrinogen), pulmonary edema, acidosis, rhabdomyolysis, neuromuscular weakness if bitten by Mojave rattlesnake

Evaluation

•  Consult PCC/toxicologist; CBC, Chem 10, coags w/ fibrinogen & split products, CK, T&C, UA, CXR, x-rays to r/o retained fang; watch compartment pressures

Treatment

•  Remove rings, constrictive clothing, general wound care, tetanus

•  Antivenom (Crotalidae) if systemic effects or coagulopathy; surgical assessment if compartment syndrome; supportive care; no proven benefit w/ abx or steroids

Disposition

•  D/c if absence of any findings 8–12 h post bite envenomation in healthy adults, 12–24 h in children/elderly, 12–24 h if concerns for Mojave rattlesnake

•  ICU admission if antivenom given

Pearls

•  Avoid oral or mechanical suction of wound, tourniquets, incision, & suction

•  25% bites are “dry strikes” (no effect); pit vipers identified by 2 fangs

Elapidae or Coral Snake (Micrurus fulvius)

History

•  Bitten by brightly colored snake (black, red, & yellow bands), primarily in tx, FLA

Findings

•  Neurotoxic effects from venom: Tremor/sz, ↑ salivation, respiratory paralysis, bulbar palsy (dysarthria, diplopia, dysphagia), usually less local tissue damage than Crotalinae

Evaluation

•  Consult PCC/toxicologist; CBC, Chem 10, coags not usually indicated, UA, CXR, consider pulmonary function testing

Treatment

•  Consult PCC before giving antivenom as higher risk for allergic rxn; surgical assessment if concern for compartment syndrome; supportive care (esp respiratory support)

Disposition

•  12–24 h observation; ICU admission if antivenin given

Pearl

•  True coral snakes have red on yellow banding, nonvenomous snakes have red band on black background: “Red on yellow: Kill a fellow. Red on black: Poison lack.”

SCORPION BITES

Scorpion (Centruroides exilicauda)

History

•  Burning & stinging w/o visible injury at bite site

Findings

•  Usually no visible local injury; possible systemic effects include roving eye movements (pathognomonic), opisthotonos, ↑ HR, diaphoresis, fasciculations

•  Mydriasis, nystagmus, hypersalivation, dysphagia, restlessness

•  Severe envenomation may cause pancreatitis, respiratory failure, coagulopathy, anaphylaxis

Evaluation

•  “Tap test”: Exquisite tenderness w/ light tapping in exilicauda stings; consult PCC/toxicologist

•  CBC, Chem 10, coags, LFTs, CK, UA, CXR, ECG

Treatment

•  Most bites self-limited, supportive care

•  BZD for muscle spasm/fasciculations, pain control, tetanus, reassurance

•  If severe systemic sxs, 1–2 vials scorpion antivenom; avail from AZ PCC

Disposition

•  Admission for observation; ICU admission if antivenin given

Pearl

•  Only C. exilicauda (bark scorpion) found in Western US produces systemic tox

SPIDER BITES

Brown Recluse (Loxosceles reclusa)

History

•  Pt may not remember bite & initially have no pain, pain & pruritus develops over 2–8 h

•  Severe rxn: Immediate pain & blister formation, necrosis & eschar over next 3–4 d

•  Loxoscelism: Systemic rxn 1–3 d after envenomation; N/V, f/c, muscle/joint aches, sz, rarely renal failure, DIC, hemolytic anemia, rhabdomyolysis

Findings

•  Necrotic blister 1–30 cm w/ surrounding erythema, petechiae

Evaluation

•  Consult PCC/toxicologist, surgery/plastics consult for lesion >2 cm

•  CBC, Chem 7, coagulation profile, UA

Treatment

•  No antivenom; wound care, tetanus, supportive care (eg, hydration, abx, transfusion, HD), local débridement

•  Consider dapsone 50–100 mg BID to prevent necrosis, hyperbaric O₂ (controversial), steroids (controversial)

•  Dapsone causes hemolysis, hepatitis; monitor LFTs, check G6PD level

Disposition

•  Admission for observation

Pearl

•  Located in S. Central & SW (desert) of US; violin-shaped marking on back

Black Widow (Latrodectus mactans)

History

•  Immediate pain, then swelling, possible target-shaped lesion, can have unexplained severe abd/back pain, muscle cramps w/i 1 h

•  Pain may continue intermittently for 3 d, is often a/w muscle weakness & spasm for weeks to months

Findings

•  Severe rxns: HTN, respiratory failure, abd rigidity, fasciculations, shock, coma

Evaluation

•  CBC, Chem 10, CK, coagulation profile, UA, abd CT (r/o acute abdomen), ECG

Treatment

•  Antivenom if severe rxn: 1–2 vials over 30 min (after cutaneous test dose)

•  Wound care, tetanus, supportive care: Benzodiazepines, analgesia

Disposition

•  Admission for observation & pain control

Pearls

•  Painful abdominal muscle cramps can mimic peritonitis

•  Red hourglass-shaped marking on abdomen

HYMENOPTERA (BEE, WASP, STINGING ANT)

History

•  Immediate pain & swelling at site of bite

Findings

•  Local & systemic signs of allergic rxn can occur

Treatment

•  Treat anaphylaxis/allergic rxn; local rxn treated w/ cleansing, ice packs, & elevation

•  If present, stinger should be removed immediately by scraping it from the wound (bees)

Disposition

•  Close wound care f/u; prescribe EpiPen in case of anaphylaxis

Pearls

•  The more rapid onset of sxs, the more severe the rxn; IgE-mediated allergic rxn

•  Rapid onset: 50% death in 30 min, 75% in 4 h; usually see fatal rxn following prior mild rxn

•  Delayed rxn similar to serum sickness can present 10–14 d after a sting/bite

JELLYFISH STINGS

History

•  Swimming in seawater w/ jellyfish

Findings

•  Painful papular lesions & urticarial eruptions last minutes to hours

•  Systemic rxns rare; vomiting, muscle spasm, paresthesias, weakness, fever, respiratory distress, Irukandji syndrome: Rare, severe chest/abd/back pain, HTN, GI sx

Evaluation

•  CBC, Chem 10, CK, coagulation profile, UA, ECG

Treatment

•  Analgesia, supportive care

•  Tentacles should be removed w/ forceps, nematocysts should be scraped off w/ a knife/blade after dusting w/ talcum powder & covering w/ shaving cream

•  Analgesia & after nematocyst removal wash w/ hot (40°C) water (helps w/ pain)

•  Antivenom available for serious systemic effects (cardiopulmonary arrest, severe pain) from the Commonwealth Serum Laboratory in Melbourne, Australia

Disposition

•  D/c if mild & pain controlled, Admission for observation o/w

Pearls

•  Box jellyfish are severely toxic, can induce respiratory & myocardial arrest in minutes

•  Use seawater/acid/vinegar (not urine) to wash; freshwater causes nematocysts to fire

OCCUPATIONAL EXPOSURE

Approach

•  Institutional guidelines vary regarding occupational exposures of HC workers to bodily fluids

•  Refer to CDC/local experts for recs on postexposure prophylaxis

•  National Clinicians’ Postexposure Prophylaxis Hotline (PEPline): (888) 448-4911

History

•  Any percutaneous injury, mucous membrane exposure, or exposure of nonintact skin to any blood & other bodily fluids considered potentially infectious

•  RFs: High-risk procedures, use of equipment w/o newer safety designs, failure to follow universal precautions

Findings

•  Physical examination nl; should be documented for future reference

Evaluation

•  Consent & test source pt for HIV, HBsAg, Hep C Ab (direct viral assays not rec)

•  Test HC worker for HIV & Hep C Ab, draw HBsAb titers if unknown immune status

•  Check serum hCG, CBC, Chem 7, LFTs, & UA before starting prophylaxis

•  If source pt is HIV+, ID consult for appropriate regimen based on source pt’s regimen

Treatment

•  HIV: 2 drug regimen (Combivir) × 4 wk; 3 drug regimen (Nelfinavir) for high-risk exposures

•  Hep B: Start vaccination series if unvaccinated, Hep B immune globulin (HBIG) if HBeAg+

•  Multiple doses HBIG w/i 1 wk of exposure provides 75% protection from infection

•  Hep C: CDC does not recommend use of interferon or ribavirin for HCV exposure

•  Consider interferon & ribavirin tx as soon as HCV seroconversion is documented

Disposition

•  F/u w/ ID specialist; fully inform risks & benefits of tx & nontx

Pearls

•  ∼80% ↓ rate of transmission w/ immediate initiation (w/i 2 h) of HIV PEP

•  Rates of occupational transmission after percutaneous exposure

•  HIV + source pt: 0.3%; Hep B + source pt; 5–20%, Hep C + source pt: 1–10%

BURNS

Approach

•  Early airway assessment, determine need for intubation (soot in airway, edema, voice Δ, deep facial burns, transfer to burn center, ↓ O₂ sat)

•  100% O₂ or O₂ by NRB mask until CO (10e) & other inhalation toxins assessed

•  Evaluate for concomitant trauma (fall, blast injury); maintain c-spine precautions

•  Start IVF resuscitation early (almost universally required)

•  Keep room warm to ↓ insensate losses

History

•  How burn occurred (explosion? closed space?), duration of exposure, type of burn

Findings

•  Assess burn

Evaluation

•  Mental status on extrication, assess degree of burn,% total body surface area

•  Check CO level (10e), CBC, Chem 10, lactate, ABG, LFTs, coags, tox, T&S, UA, CXR

Treatment

•  Early & generous analgesia: Morphine 5 mg IV q5–10min titrated to pain

•  Airway management: Intubate early

•  Toxic inhalation (cough, dyspnea, carbonaceous sputum, soot in oropharynx): Intubate or perform fiberoptic airway exam early; delay could cause ↑ airway edema → airway compromise, difficult/impossible intubation

•  If >15% TBSA, aggressive IVF resuscitation, 2 LBIV through unburned skin

•  Parkland formula calculates IVF requirement in 1st 24 h after burn:

•  4 mL × weight (kg) × BSA (2nd- & 3rd-degree burns)

•  Give ½ over 1st 8 h, other ½ over next 16 h

•  Urinary catheter placement: Target urine output: 30–50 mL/h

•  Burn mgmt: Irrigate w/ NS, remove debris, clothing, jewelry, & ruptured blisters (prevent future infection)

•  Apply Silvadene (silver sulfadiazine, antipseudomonal) ointment to denuded areas

•  Bacitracin only on face (Silvadene may cause discoloration)

•  Immediate escharotomy for full-thickness circumferential burns that compromise distal neurovascular status or significantly ↓ chest compliance

•  Tetanus prophylaxis, no role for steroids or IV abx

Disposition

•  Admit 2nd-degree burns 10–20% BSA (or 5–10% if <10 y/o), circumferential or if meet criteria below

Pearls

•  Burns often progress in severity, watch for worsening burns

•  Remove tar (asphalt burns) w/ mineral oil

•  Consider cyanide w/ industrial/closed space fires, check lactate, treat w/ hydroxocobalamin

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VI: RENAL & GENITOURINARY VIII: DERMATOLOGY XVII: AIRWAY MANAGEMENT IV: INFECTIOUS DISEASE XVI: TOXICOLOGY XVIII: TRAUMA