Case Studies

Question 1

You are called for the SOB 56M. On arrival, you find a severely dyspneic pt with signs of impending respiratory and cardiovascular collapse (shock index >1). PMHx of asthma, currently refractory to MDI salbutamol. Mass=80kg. PCP crew have given 4x100mcg salbutamol MDI and 0.5mg IM epinephrine 2 minutes prior to your arrival with no relief. They have obtained vascular access by 20Ga IV in left ACF. Currently assisting ventilations with BVM and 5cm H20 PEEP. Discuss pharmacology for:

• Bronchodilation
• Sedation facilitated intubation

Answer 1

Bronchodilation:

• Salbutamol
  
  • 4x100mcg MDI
    
    • May be given through BVM med-port
• Ipratropium
  
  • 8x20mcg MDI
    
    • May be given through BVM med-port
• Magnesium Sulfate
  
  • 2g over 20 minutes IV infusion
    
    • Only after transport initiated
• Epinephrine
  
  • 50-100mcg IV push
  • Repeat as needed
    
    • patient is PRE-ARREST and IV push Epi is preferred to IM

Induction for sedation-facilitated intubation

• Lidocaine
  
  • Applied by spray to pharyngeal structures for pre-intubation topicalization
• Fentanyl
  
  • 40-80mcg (0.5-1.0mcg/kg) loading dose
  • Repeat q5mins to effect
    
    • max total dose = 300mcg
• Ketamine
  
  • 80mg IV (1mg/kg since shock index >1)
  • Repeat 1/2 dose at 10-15 minutes
• Phenylephrine
  
  • 100mcg IV slow push q2-5mins. PRN
  • 500mcg MAX total dose

Question 2

You are called for the 23M (~70kg), entrapped in vehicle following MVI. On arrival you find the Pt. (driver, lone occupant) with open femur fracture, external bleeding controlled, 10/10 pain, SBP=135mmHg, HR=120reg. Pt. is entrapped under dash and fire states extrication will be complex and difficult. PCP crew state that they are unable to obtain IV access depsite multiple attempts. Discuss relevant pharmacology for:

• IO insertion
• Trauma management
• Analgesia
• Procedural sedation for extrication

IV access is not available

Answer 2

IO Insertion

• Lidocaine
  
  • 40-50mg (max 100mg total) for pain of infusion
• N/S
  
  • 10CC flush post-insertion
• Consider pre-IO IM analgesia with fentanyl/ketamine
  
  • Fentanyl
    
    • 35-70mcg IM
  • ketamine
    
    • 35mg (0.5mg/kg) IM

Trauma Management

• TXA
  
  • 1g over 10 minutes IO
• N/S
  
  • 250-500mL IO repeat boluses to correct severe hypotension, target SBP =70-90 mmHg OR return of peripheral pulses (MAX 2000mL)

Analgesia

• Entonox
  
  • inhaled PRN to effect
  • Sub-optimal choice in suspicion of facial/thoracic trauma plus numerous other practical factors
• Fentanyl
  
  • 35-70mcg IO (0.5-1.0mcg/kg), repeat q.5minutes to effect
    
    • MAX total dose = 300mcg
• Ketamine
  
  • 21mg (0.3mg/kg) IO
  • Note that Ketamine is also the drug of choice for procedural sedation. Analgesic dosage should be taken into account when sedating, if used.

Procedural sedation

• Ketamine
  
  • 35mg IO, with repeat 17.5mg IO doses q60sec to effect
    
    • Other dosing regimens are possible, but initial 0.5mg/kg IO followed by repeat 0.25mg/kg IO doses recommended by BCEHS guidelines
• Midazolam
  
  • May be used to treat emergence phenomenon, if required
  • 1-2mg IO/IM q 2 to 3 minutes

Question 3

You are called for the SOB 36F (~55kg). On arrival, PCP crew states she was stung by a wasp (known anaphylactic) 15 minutes prior to your arrival. She has audible stridor, with clinical signs of shock and dyspnea. Bystanders gave 0.3mg Epinephrine IM by auto-injector, PCP crew has given a further 0.5mg IM with only moderate relief of symptoms. Lungs have pan-exiratory wheezes and squeeks. SBP = 80 mm Hg, HR = 135, RR = 42, GCS = 13, SpO2 = 88% with 15LPM by NRM. At your request, the PCP crew begins assisting ventilations with BVM and obtains IV access; 18Ga L. forearm. Discuss pharmacology for:

• Management of anaphylaxis
• Sedation-facilitated intubation

Answer 3

Anaphylaxis

• Salbutamol
  
  • For bronchoconstriction
  • 4x100mcg MDI
    
    • Through med-port on BVM
• Epinephrine
  
  • 0.5mg IM repeat doses
    
    • q5-20 minutes, MAX 3 doses (consider doses already given)
  • 50-100mcg IV push
    
    • repeat as necessary
    • Consider if Pt is refractory to treatment and Pre-arrest
  • 5mg 1:1000 nebulized for angioedema if anticipated difficulty with airway management
• N/S
  
  • 250-500mL IV repeat boluses to correct hypotension, target SBP = 90mmHg

Sedation-facilitated intubation

• Epinephrine
  
  • nebulized (see above)
• Lidocaine
  
  • for topicalization of pharynx
• Fentanyl
  
  • 27.5-55mcg (0.5-1.0mcg/kg) IV, repeat q5 mins to a max of 300mcg
• Ketamine
  
  • 55mg IV (1mg/kg as shock index >1)
  • 27.5mg IV q.10-15 mins for maintenance
• Phenylephrine
  
  • 100mcg IV slow push q.2 to 5 mins
  • MAX 500 mcg total

Question 4

You are called for the agitated ~36M (~110kg). On arrival you are met by police who state the pt. has been exremely restless and threatened violence against their members. The Pt. is shouting incoherently, is profusely flushed and diaphoretic, and is pacing and gesticulating wildly. Discuss pharmacology for:

• Excited delirium
• Cocaine induced ACS

Answer 4

Excited delirium

• Ketamine
  
  • 500mg IM (4-5mg/kg)
  • Consult clinicall if appropriate sedation is not achieved
  • Note maximum volumes of administration by site:
    
    • Deltoid: 2mL
    • Thigh: 4-5mL
    • Gluteal: 5mL

Cocaine-induced ACS

• Midazolam
  
  • 2-5mg IV or 5-10mg IM
  • CAUTION: respiratory depression is no bueno for ExDS

Question 5

You are called for the ~80M (~60kg) “man down”. On arrival, PCP crew states pt. was found down IFO a local business this morning, responsive only to pain stimuli, with noisy resps and cyanosis, cool to touch. SBP = 60mmHg, HR = 30irreg, RR = 36, SpO2 = 88% with BMV at 15LPM O2 with 5cm H20 PEEP, GCS = 1+2+4=7, BGl = 2.8mmol/L. Airway is badly soiled with vomitus. IV access is not available. Gags on attempted OPA insertion. Discuss pharmacology for:

• Hypoglycemia
• Pre-arrest shock
• Sedation facilitated intubation

No IV access!

Answer 5

Hypoglycemia

• D10W
  
  • 10-25g (100-250mL) IO bolus
• Glucagon
  
  • 0.5-1.0mg IM
  • Consider effects of hemodynamics on dosing

Pre-arrest shock

• N/S
  
  • 500mL boluses up to 2000mL total to correct hypotension
  • Target SBP = 90mmHg
• Epinephrine
  
  • 2-10mcg per minute IO infusion
  • OR
  • 10mcg IO aliquots q2-3 mins

SFI

• Lidocaine
  
  • for topicalization of pharynx
• Fentanyl
  
  • 30-60mcg (0.5-1.0mcg/kg) IO/IM
  • Repeat q5mins to a MAX 300mcg total
    
    • Consider 1/2 dose (15-30mcg) due to geriatric Pt.
• Ketamine
  
  • 60 or 120mg (1 or 2 mg/kg) IO
    
    • Shock index is technically <1, but cinical signs of shock are clearly present
  • Maintenance with 1/2 induction dose every 10-15 mins
• Phenylephrine
  
  • 100mcg IO slow push q2 to 5 mins.
  • MAX 500mcg total