Knowledge
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Possibly... but with some important caveats.
“Sugammadex is likely the most exciting drug in clinical neuromuscular pharmacology since the introduction of atracurium and vecuronium in the middle 1980s.” – RD Miller (2007).
Sugammadex (Bridion®) is a remarkable drug – and the anaesthesia community has moved very quickly to embrace the potential of this first ‘selective relaxant binding agent’ (SRBA), despite it’s considerable cost.
Sugammadex offers a new and improved way of reversing aminosteroid muscle relaxation, in particular from rocuronium. The speed at which it reverses even profound neuromuscular blockade is incredible and potentially life saving. Sugammadex’s onset is 10 times faster than neostigmine and three times faster than edrophonium.
Though beyond the parlour-trick of speedy action, or the possibility of rescuing a cannot-intubate-cannot-ventilate crisis – the biggest benefit of sugammadex for our patients may be in the dramatic reduction of post-operative residual paralysis. A common problem with serious consequences that the anaesthetic community has ignored for far too long.
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First described in 1909, and then used for treatment of various types of headache and facial pain, the sphenopalatine ganglion block may offer a novel, simple and less-invasive treatment for post-dural puncture headache.
Very little has been published, primarily case studies, case series and retrospective audits. This limited data does however suggest that the technique may be as effective as the traditional epidural blood patch, though with significantly fewer risks.
Larger studies are however needed to properly define the block's role in treating PDPH.
Publications describe a trans-nasal approach, either sitting or supine. First topicalising with co-phenylcaine spray, then placing 2%-4% viscous lignocaine-soaked cotton-tipped applicators for 10 minutes, and finally repeated for a further 20 minutes. Success appears to range from 30-70%.
The mechanism of action may result from parasympathetic blockade at the SPG, resulting in reversal of the cerebral vasodilation thought to be associated with post dural puncture headache.
Several videos showing how simple SPG techniques:
- Roger Browning demonstrating one method for performing a topical SPG block.
- SPG Block for chronic migraine.
- SPG demonstration in the ED setting.
- SPG demonstration for family member to perform later at home.
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Oxycodone is a semi-synthetic opioid commonly used as an oral, rectal or intravenous analgesic (subcutaneous, intramuscular & intranasal also possible). Trade names include Endone™, OxyContin™ and OxyNorm™.
A. Physiochemistry
- Semi-synthetic opioid; thebaine derivative. First synthesised in 1916.
B. Pharmacokinetics
- Dose
- Oxycodone po conversion from morphine IV 2:1 (oxycodone:morph).
- (NB: oral to IV morphine 3:1)
- 10 mg of oral oxycodone is equivalent to 20 mg of oral morphine.
- 10 mg of oral oxycodone is equivalent to 5 mg of IV/IM morphine.
- 10-15 mg of parenteral oxycodone (IV/IM) is equivalent to 10-15 mg parenteral morphine (ie. morphine up to 50% more potent)
- Absorption - orally up to 87%
- Distribution - 2.6 L/kg
- Protein binding
- Onset - within 10-15 min orally, peak 45-60 minutes; Offset ~2-3h.
- Metabolism - ß1/2 ~3-4hrs, metabolised principally to noroxycodone, noroxymorphone and oxymorphone (p450 system). Oxymorphone has some activity
- Clearance - 0.8 L/min; predominately renally excreted.
C. Pharmacodynamics
- Oxycodone is a full opioid agonist with no antagonist properties whose principal therapeutic action is analgesia.
- It has affinity for kappa, mu and delta opiate receptors in the brain and spinal cord.
- Oxycodone is similar to morphine in its action. Other pharmacological actions of oxycodone are in the central nervous system (respiratory depression, antitussive, anxiolytic, sedative and miosis), smooth muscle (constipation, reduction in gastric, biliary and pancreatic secretions, spasm of sphincter of Oddi and transient elevations in serum amylase) and cardiovascular system (release of histamine and/or peripheral vasodilation, possibly causing pruritus, flushing, red eyes, sweating and/or orthostatic hypotension).
- Strong potentially for tolerance, dependence and abuse.
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