Table 6 Systemic analgesics, adapted from [180]. LOE denotes level of evidence in parentheses, provided if available. COX cyclooxygenase, mcg micrograms, mg milligrams, g grams, kg kilograms, mL milliliters, IV intravenous, IM intramuscular IN intranasal, NSAIDS nonsteroidal anti-inflammatory drugs, OTFC: oral transmucosal fentanyl citrate, po: by mouth, q: ‘every,’ qd: daily, bid: twice daily, tid: three times daily

Ice

1B

Simple, noninvasive; reduces inflammation/oedema; avoid freezing injury [180].

NSAIDS/paracetamol

1A

All NSAIDS: if po, potential dyspepsia lessened with food. Avoid with GI bleed/ulcer history, dehydration. Possible kidney injury or increased bleeding

 Diclofenac topical

2.3% topical; 2-4 g bid; unknown

 Ibuprofen PO

2400 mg/d divided tid (10 mg/kg/d); 1A

 Naproxen PO

660 mg/d divided tid; unknown

 Meloxicam PO

15 mg qd; unknown

Cardiovascular events may increase. COX-2 selective inhibitor meloxicam minimises bleed/platelet disfunction.

 Ketorolac IM

60 mg q 6 h (0.5 mg/kg q6h); 2C

 IV

15-30 mg (0.5 mg/kg, max 15 mg); 1B

 Paracetamol PO

Max 1300 mg (10 mg/kg) TID; 1B

Renal and GI sparing. Avoid in severe hepatic disease. Overdose can result in hepatic failure [179, 180, 182].. NSAIDS + paracetamol result in pain diminution better than either alone.

 IV

> 50 kg:1 g < 50 kg:15 mg/kg IV/15 min; 1B

OPIOIDS

All opioids tend to cause respiratory depression/desaturation and arterial hypotension; monitor. Avoid opioids if patient needs full cognition (i.e. self-evacuation). Naloxone reverses opioids [178,179,180].

 Fentanyl IV

25-100 mcg (1-3 mcg/kg); 1A

Slow fentanyl push mitigates risk of ‘frozen chest.’

 IN

180 mcg (1.5 mcg/kg); 1B

 Buccal/transmucosal

OTFC: 800 mcg (10-15 mcg/kg); 1B

Oral transmucosal fentanyl citrate self-administered, ideal for austere situation. Transdermal route good for sustained dosing.

 Transdermal

Transdermal route good for sustained dosing.

 Morphine IV

5-10 mg (0.1 mg/kg-max 10 mg); 1A

Avoid morphine in renal failure. May cause histamine release.

 IM

10-20 mg (0.2 mg/kg, ma× 10 mg); 2B

Poor blood flow may limit absorption.

 Oxycodone PO

5-10 mg q8 h; 2B

PO opioids easy to carry on smaller expeditions.

 Ketamine

1B

Use half dose for S-ketamine. Slower administration lessens emesis and psychosis. Can cause hypertension and tachycardia; preserves respiration; many prefer for multiple trauma. Vocal calming measures and adding midazolam minimise psychosis [178,179,180,181,182,183,184,185].

 IV

10-30 mg (0.1-0.3 mg/kg); 1B

 IM

1 mg/kg; 2C

 IN

0.5 mg/kg (0.5 mg/kg); 2B

 Methoxyflurane Inhaled

3 mL given to self; max 6 mL/day; 2A

Altitude use. No renal effects; avoided by some; anxiolysis [186,187,188].

 Nitrous Oxide nhaled

60-70% N₂O/40-30% O₂; 2B

Less effective at altitude, complex; potentiates barotrauma!