Environmental Emergencies Flashcards
High altitude illnesses
- acute mountain sickness
- high altitude pulmonary edema
- high altitude cerebral edema
Factors contributing to high altitude illness
- Rate of ascent
- Altitude reached
- Baseline health
- Home altitude ( < 900 m)
- Prior Hx of AMS
- Latitude
- Age, gender
- ? Baseline physical fitness
- ? Genetics
signs and sx of acute mountain sickness
- Headache* ( migraine- like)
- Loss of appetite
- Nausea and vomiting
- Disruptive sleep*
- Fatigue
- Dizziness
- Possible peripheral and facial edema
What tool is used to asses AMS
Lake Louise Self Assessment
-Headache with recent gain in altitude
Mild AMS : 3-8
Moderate AMS: 9 – 18
Severe AMS: + 19
Prophylaxis for AMS
- Gradual ascent - spend first night at 1500 m prior to ascending to 2500 m
- Acetazolamide( Diamox) 125 mg BID started one day prior to travel and continued for 2 days after reaching maximum altitude.
- Respiratory stimulant that makes your blood a little more acidic - Avoidance of alcohol use or dehydration
- Suggest eating high carb diet and use of NSAIDS.
affect of changes in barometric pressure on inspired PO2 from sea level to 9,000m
-at higher altitudes there is lower barometric pressure and lower inspired PO2
- Concentration of Oxygen present in air is 21% both at sea level and high altitude.
- with each breath, you get in less O2 molecules in (same amount of molecules just spread out bc no “net” holding it down- lower barometric pressure)
Don’t prescribe acetazolamide (Diamox) to who
sulfa allergy
Ventilatory Response to High Altitude induced hypoxia
reduction in partial pressure of oxygen (PO 2) leads to:
- increase rate and depth of ventilation or HVR ( hypoxic ventilator response)
- increased CO2 elimination
Resulting in:
resp. alkalosis and decreased ventilation
Renal Adaptation Response to High Altitude induced hypoxia
in response to alkalosis:
1. increase excretion of bicarb to eventually correct pH over a couple of days
- secretion of erythropoietin (EPO)
- increased red cell mass/ Hgb
- increase O2 carrying capacity in blood (takes weeks to month)
Management of AMS
- Descent and supplemental oxygen are cornerstone in treatment.
- Acetazolamide (Diamox)
- Dexamethasone?
- hyperbaric portable chambers in remote environment
- Re-acclimatization (< 600 m increase in sleeping altitude Q 24 hours)
descent of ____ results in resolution of most mild/moderate AMS
500 to 1000 m
cause of most deaths related to Acute Mountain Sickness
HAPE: High Altitude Pulmonary Edema
Symptoms of HAPE
- AMS criteria (Lake Louise Survey)
- Fever up to 38.5C
- Plus 2 or more sx below
- dyspnea at rest
- cough (dry or productive) late stage pink and frothy
- weakness or decrease in exercise performance
- chest tightness or congestion
PE findings of HAPE
- crackles, wheezes in at least 1 lung field
- central cyanosis
- tachypnea or tachycardia
*2 or more signs
Clinical findings of HAPE
- Hypoxia ( < 89% RA)
- CXR: normal heart, prominent pulmonary arteries, patchy infiltrates (RML and RLL) (don’t always get CXR– get to r/o other causes)
- EKG: Sinus tach with possible R ventricle strain pattern, RAD ,RBBB or p waves abnormalities.
- ABG: Respiratory Alkalosis
- PE: crackles, wheezes, central cyanosis, tachycardia/pnea
*Usually occurs on 2nd night at altitude and rarely after 4 days at same altitude.
DDX for HAPE
pneumonia, CHF, asthma, sinusitis, PE, bronchitis
RV strain pattern EKG ddx
pneumothorax
PE
lung things
HAPE
*ST depression and T wave inversion in V1-4
Treatment for HAPE
- High flow oxygen, watch for @ 4 hours and taper to Nasal cannula–> no improvement, transport down
Rarely used:
- Nifedipine (Procardia)/CCB for both RX and prevention
- phodiesterase Inhibitors– Sildenafil (viagra)
- ?Beta-agonist– albuterol or salmeterol (Serevet)
- ?Dexamethasone (better for HACE)
Pathophysiological process of HACE
- Hypobaric hypoxia leads to increase cerebral blood flow and capillary hydrostatic pressure
- Causing fluid shifts and cerebral edema
- Increase SNS (sympathetic nervous system) response
Increase SNS with HACE leads to
- decreased urine output
- increased renin-angiotensin
- increased aldosterone
- increased ADH
Signs and sx of HACE
- Presence of mental status changes and/or ataxia with AMS
OR - Presence of both mental status changes and ataxia without AMS
- Papilledema,
- retinal hemorrhage and
- cranial nerve palsy may be present
DDX for HACE
stroke, alcohol, drugs, TBI, brain mass, psychosis, AVM (arteriovenous malformation), CNS infection, dehydration, DKA, electrolyte imbalance, hypothermia, complex migraine, CO poisoning
Treatment of HACE
- Decent
- supplemental O2
- Dexamethasone
- Treat HAPE if also present
**may need imaging to r/o other ddx
Mild, moderate, and severe hypothermia occurs at what temps
What is normal body temp
Mild: 32-35C (89.6-95F)
Moderate: 30-32C (86-89.6F)
Severe: less than 30C (<86F)*
Normal body temp at 37C (98.6F)
Skin cooling provokes thermogenesis ( shivering) resulting in:
- increased metabolism, ventilation and CO (37-32C)
2. thermogenesis less effective at temps less than 30C
hypothermia causes a decrease in __ and ____
resting metabolism and inhibition of central and peripheral neurologic function
Signs and sx of mild hypothermia (32- 35 C or 89.6 – 95 F)
- Shivering* (worry when they stop shivering!!)
- skin cool to touch
- loss of manual dexterity
- mildly confused/disoriented and irritable or unusually quiet
- poor insight and refusal to acknowledge or help
tx of mild hypothermia
- Remove from cold environment.
- Remove wet clothing
- Apply blankets, hats
- Give warm fluids and food ( high carbs)
- Monitor for changes.
signs and sx of moderate hypothermia (30 – 32 C or 86 – 89.6 F)
- No Shivering
- Slurred speech
- Apathetic, confused, irrational
- Clumsy
- Blue lips
- Decrease levels of consciousness
- Possible dysrhythmias ( A fib)
- Osborn wave
*can occur in homeless ppl in denver
tx of moderate hypothermia
- Apply heat to torso
- Keep patient HORIZONTAL and avoid unnecessary movement or activity
- Peripheral IV , IO for volume replacements warm fluids to 40-42C - boluses preferred. ( saline lock b/w boluses)
- Check glucose level , if unsure and pt has poor mentation, give 1amp D50.
- ABC’s and frequent monitoring.
signs and sx of severe hypothermia (less than 30C or 86F)
- Unconscious
- Osborn wave
- Faint or undetectable pulse
- Lack of respirations
- High risk of V- fib with any movement of body
DDX of Osborn Wave
- hypothermia,
- normal variant,
- hypercalcemia,
- medications,
- Closed head injuries
- ICP
What is an Osborn wave?
J wave
-positive deflection at the J point (negative in aVR and V1. J-point is the point at which the QRS complex meets the ST wave.
Tx of severe hypothermia
- Intubate with normal ventilation. Avoid hyperventilation
- Consider NG tube placement
- CPR or load and go ?
- Defibrillation less effective <30 C core temp.
- Lidocaine, Epi not recommended for ACLS in hypothermic patients.
- *ECMO : extracorporeal membrane oxygenation
- *CPB : cardiopulmonary bypass.
Serum potassium level ___ indicates hypoxia preceded hypothermia resulting in cell lysis and irreversible death. TERMINATE CPR .
over 12 (VERY HIGH)
Considerations during rescue efforts with hypothermia
1) AFTER DROP: continuing core cooling after removal from exposure and re- warming. Resulting in abrupt heat redistribution. Predisposing risk of cardiovascular collapse
2) CIRCUM- RESCUE COLLAPSE: occurs in pt with stable vital signs during or shortly after rescue , experience massive drop in blood pressure and VF. ( water rescues)
3. Avoid starting CPR in pt with organized rhythm. Risk VF.
Describe the different degress of frostbite
1st degree : Frostnip – partial skin freezing
2nd degree : Full thickness skin freezing
3rd degree: Deeper with sub dermal involvement
4th degree : Extension beyond subcutaneous tissue with muscle, tendon and bone involvement.
Sx of first degree frostbite (frost nip)
- Erythema
- Mild Edema
- NO blisters
- Pain
Sx of 2nd degree frostbite
- Substantial Edema
- Blisters with possible desquamate
- Eschar
- Pain
Sx of 3rd degree frostbite
- Hemorrhagic Blisters
- Necrosis
- Blue-gray discoloration
- “ Block of wood “
Sx of 4th degree frostbite
- Little Edema
- Mottled Skin
- Nonblanching cyanosis
4/ Mummified Eschar
- involvement of muslces tendon and bones.
Describe the 3 zones of frostbite injury
- Coagulation (most distal, most severe, damage irreversible)
- Stasis (middle zone, severe w/ potential to reverse damage w/ RX)
- hyperemia (most proximal, least severe, resolves w/o RX in 10 days)
Treatment of frostbite
- Avoid multiple freeze – thaw cycles.
- Avoid excessive movement or use of affected extremity
- Keep clean and covered.
- Place is circulating warm water 40- 42 C for 20 to 30 minutes
- Adequate pain control
- Check tetanus status bc skin is compromised
- Penicillin G IV
- tPA
*Avoid dry air warming which can cause more damage.
tPA contraindications for frostbite
- Associated trauma or recent trauma, CVA or Active bleeding
2 Recent surgery or hemorrhage - Multiple freeze- thaw cycles
- > 48 hours of cold exposure
- Severe Hypertension systolic >185 and/or diastolic >110
- Pregnancy
- Current anticoagulant therapy ( INR >3)
- Thrombocytopenia ( platelets < 100x 10(9)/L )
- History of GI bleeding
What is the great imitator
CO poisoning
*Gas produced by the combustion of carbon type fuels or exposure to natural gas in poorly ventilated spaces
DDX of CO poisoning
AMS, flu, gastroenteritis, drug use, migraine, ICB
Leading cause of death by poisoning in industrial countries
CO poisoning
*Often misdiagnosed and found after return ED visit
In blood stream C0 prevents oxygen from __
reaching tissues
What other poisoning should you consider w/ CO poisoning
cyanide poisoning
how can you get cyanide poisoning
smoke inhalation involving rubber, plastic or silk (cigarettes)
tx of cyanide poisoning
- get off clothing
2. hydroxocobalamin (cynokit)
Signs and sx of of mild C0 poisoning and corresponding COHb levels
HA
N/V
dizziness
Blurred vision
COHb: less than 15-20%
Signs and sx of of moderate C0 poisoning and corresponding COHb levels
confusion, CP, dyspnea, weakness, tachycardia, tachypnea, rhabdomyolyis
21-40%
Signs and sx of of severe C0 poisoning and corresponding COHb levels
palps, dysthymias, hypotension, MI, cardiac and resp. arrest, pulm edema, SZ, coma
41-59%
What test do you get if you suspect CO poisoning
Carboxyhemoglobin (COHb) %
Challenges of diagnosing CO poisoning
- Normal pulse ox reading.
- Half- life is 4 – 6 hrs in room air( RA ) and 40 – 60 minutes with 100% O2 .
- Mismatch of C0Hb levels to presenting SXS.
- Identifying low-level chronic CO exposure in smokers and COPD pts.
- Identifying pt who SXS are intermittent and resolve when leave environment .
Red flags in hx taking for CO poisoning
NEED HIGH INDEX OF SUSPICION !!!!!
- “ Only have HA at home which improve at work”.
- “Everyone at home has HA and flu-like SXS”.
- New persistent HA in winter or fall.
- Always ask about Employment /activities
Treatment of C0 Poisoning
- 100% Oxygen by nonrebreather mask.
- Treat associated conditions.
- Consider Hyperbaric Oxygen Therapy ( HBO)
- HBO can decrease the half-life of CO to 22 minutes.
- HBO can induce vasoconstriction which reduces ICP and cerebral edema.
Potential Sequelae of CO poisoning
- Delayed Neurological Syndrome ( DNS) in 11- 30 % patients
- Those who suffered myocardia ischemia at risk for future MI or Cardiac arrest.
- Chronic kidney damage or renal failure
Confusion, SZ, Hallucinations, short- term memory loss, psychosis, parkinsonism, behavioral changes. Can occur 3- 240 days after exposure
Delayed Neurological Syndrome ( DNS)
Describe 1st, 2nd, and 3rd degree burns
First Degree (Partial Thickness, epidermis) -Superficial, red, sometimes painful.
Second Degree (Partial Thickness)
- Skin may be red, blistered , swollen.
- Very painful.
Third Degree (Full Thickness) -Whitish, charred or translucent, no pin prick sensation in burned area
What is the rules of nines
helps you describe the burn on how much of the body is involved (only for 2-3rd degree burns)
- arms: 9%
- legs 18%
- Front 18%
- back 18%
- face 9%
- neck 1%
- hands 1%
*can use palm of hand (1%) to estimate patch of burn
Complications from under and over resuscitation for burns
Under: MOF, extension of depth of burn wound death
Over: flash pulm. edmea, ARDS, extension of depth of burn wound, compartment sydnrome
Parkland Resuscitation Formula for Adults for burns
2-4 cc x wgt Kg x % TBSA
- Give first half of fluid over 8 hours***
- LR is prepared over NS to avoid hypernatremia
Ex. 38 y/o female 70 kg with 50% TBSA
- 4 x 70 x 50 = 14,000
- 14,000 / 2 = 7,000 in first 8hr)–> 7,000 /8 = 875 cc/hr
Burn reuscitation Initial managment
- ABCDEF
- Cover burns
- Remove all jewelry
- Avoidance of hypothermia
- Foley
- NG tube to start tube feeds to avoid ileus
- pain management and fluid resusciation!!!!
Labs/Work up for burns
- ABG,CBC,Chem 8, INR and Lactate Q 4 hours.
- Replace K+,Mg, Phos and CA+ as needed
- Keep Albumin level >2.0
- If INR > 1.5 transfuse FFP
- Monitor Urine output but guide treatment by acidosis clearance.
- CXR, LFT, UTOX, COHb . Remember Tetanus status
Signs and sx of compartment syndrome
- cyanosis distal of burn
- unrelenting deep tissue pain
- progressive numbness
- decreased or absence of pulse
- pain out of proportion
**common in chest and abdomen – w/ burns
compartmental pressure in compartment sydrome is ___ mmHg
over 30 mmHg
tx of compartment syndrome
Eschartomy
ABA Referral Criteria for TX to Burn Center
- Second Degree Partial –thickness burn > 10 % TBSA
- Burn to face, hands, feet, perineum, or major joints**
- Full-thickness
- Electrical, inhalation or chemical burn
- Pediatric burn in hospital without Ped burn staff
- Associated trauma or major pre-existing medical conditions
- Associated emotional or mental health condition. Cognitive impairment
acid burns can cause __
basic burns can cause __
coagulation necrosis (eschar) liquefaction (necrosis)
What is the Lund-Browder Chart
tells you percentage of burns more specifically than rule of nines
-commonly used in peds
Hydroflouric ( HF) Acid : produces a ____ penetration
liquefaction necrosis , deep
Factors to consider in chemical burns
- Agent
- Concentration
- Volume
- Duration of exposure.
- Dry chemicals should be brushed off
- Eye exposure requires copious irrigation and recheck with PH paper.
- Elemental metal burns should not be distinguished with water instead consider using Mineral oil. ( K+.NA+,MG, Aluminum, Sodium, Lithium)
- Airway or GI involvement. (don’t induce vomiting right away)
- Tetanus status
Lightning injuries are classified as
- Direct strike- uninterrupted
- Contact injury- pt is touching objec that is truck
- Side splash- lightning jumps from object to person
- Ground current- strikes group and tx to person (1/3rd of all)
Elemental metal burns should not be distinguished with _____ ( K+.NA+,MG, Aluminum, Sodium, Lithium)
water instead consider using Mineral oil.
Lightning injuires have potential for what
Potential for sudden cardiac and respiratory arrest
Tx of lightning injuries
- ROSC precedes return of respiratory system as medullary can remain paralyzed . * Must continue to support ventilations *****
- Reverse triage with multiple patients, attending to those who are pulseless first
Cardiac findings w/ lightning injuries
- Cardiac arrest
- ST elevation, prolong QT, A-fib, Vtach
- Elevated cardiac markers
Neurological findings w/ lightning injuries
- Transient: LOC , SZ, HA, Paresthesias, memory loss
- Keraunoparalysis: lower limbs pulselessness ,pallor,cyanosis, motor and sensory loss .
- Permanent : Hypoxic encephalopathy , intracranial hemorrhage
Dermatologic findings w/ lightning injuries
- Lichtenberg figure ferning or feathering pattern.
2. Burns
Ocular and audiovestibular system findings w/ lightning injuries
- Anterior and posterior chamber damage
- Cataracts make up majority of injuries
- Ruptured Tympanic Membranes
Lightning position
squat down low
Low voltage AC electrical injuries can cause
causes muscle tetany ( grasps source increase contact time
high voltage AC electrical injuries can cause
single violent muscle contraction – throwing patient
- blast and blunt trauma injuries
Sequelae of Electrical injuries
- Damage to nerves, vascular system and muscles. Leading to coagulation necrosis and neuron death.
- Secondary trauma
- Sudden cardiac arrest
- Burns
- Rhabdomyolysis– get CPK or urine mirco
- damage to surrounding muscles - Bones have high resistance allowing current to travel easily along bone Which generates heat and causes significant heat- related damage to surrounding muscles
** Beware there can be significant deep tissue injury with minimal superficial tissue injury
How to dx and tx electrical injuries
- ABC
- EKG
- CPK
- Chem 8 and CBC
- Radiographs based on injuries and HX.
- Urine Myoglobin
- Consider need for CT scan of head
- Burn care
- IV fluid resuscitation