This document compares the advantages and disadvantages of rocuronium versus suxamethonium for rapid sequence induction of anesthesia in remote settings. While suxamethonium has a faster onset of less than 60 seconds, studies have shown that rocuronium at doses of 1.0-1.2 mg/kg provides comparable intubation conditions. Suxamethonium also carries significant risks like malignant hyperthermia, hyperkalemia, and prolonged desaturation during apnea. Overall, rocuronium provides predictable pharmacokinetics, fewer contraindications, and is safer for conditions like burns and muscle diseases compared to suxamethonium. Though initially cheaper, the cost savings of suxame

1. Muscle relaxants
Comparison of the advantages and disadvantages of rocuronium versus suxamethonium in
the setting of rapid sequence induction of anaesthesia in a retrieval setting

2. Or
Roc rocks and Sux sucks

3. Apologies to any anaesthetists present

4. Closer to this level

5. Few weeks ago
 Flew into Quairading
 53 year old male, 130 kg with asthma
 History of NIDDM, 30 cpd smoker
 Stable airport pick up
 Patient arrived at airstrip not quite so stable

6. Things went downhill quickly
 Quickly transferred him to the aircraft on NRB, then even more quickly
transferred him back off it!
 Agitated, sats 85-90%, P120, bilateral creps, hypotensive, on iv salbutamol
 BiPaP applied in hanger, transferred back to hospital
 Noted ECG to have elevation in aVr and widespread ST depression anterlaterally
 CO2 78 HCO3 suggested mostly chronic
 Noted cpap machine in patients bag later

7. What next?
 Transfer on BiPaP versus RSI in remote location?
 Failing on BiPaP
 Not adequately preoxygenated
 Likely difficult airway
 Possibly hard to bag valve mask ventilate

8. Decision to RSI
 Which induction agent?
 Which muscle relaxant?

9. History of muscles relaxants
 First encountered by Europeans in the 16 century in the amazon basin with
the use of curare tipped darts
 Tubocurare was most active of these poisons, but was not really established
in anaesthetic practice until 1943

10. Depolarizing agents
 Acetylcholine
 Succinylcholine (suxamethonium)
 Decamethonium
 Small molecules , can enter NMJ

11. Non depolarizing agents
 Aminosteroids eg.pancuronium, vecuronium, rapacuronium, dacuronium,
maloutine, duador, dipyrandium, pipecuronium
 Tetrahydroisoquinoline derivatives atracurium, mivacurium, doxacurium,
tubocurare
 Gallamine

12. And for real bush doctors
 Death adder
 Blue ringed octopus
 Puffer fish/blow fish

13. Our choices
 Vecuronium
 Rocuronium
 suxamethonium

14. rocuronium
 Dose adult RSI 0.6 – 1.2 mg/kg
 Duration of action 30 to 90 minutes
 BMI >40 use ideal body weight x 1.2 mg / kg, provides good or excellent intubation
conditions at 60 seconds ( Gaszynski 2011)
 Tracheal intubation (not RSI) 0.3 or 0.45 – 0.6 mg /kg
 Can be used for ongoing paralysis 0.1 – 0.2 mg/ kg bolus prn or 10 – 12 mcg/kg/min
 Children same dose onset time reduces as dose increases, however not recommended by
manufacturer, however successfully used in children > 1 year (Chong 2002, Fuchs-Buder
1996, Mazurek 1998, Naguib 1997)

15. Rocuronium continues
 Geriatric dose , same
 Renal impairment, same dose , duration may vary
 Hepatic impairment, no dose change advised from manufacturer, however
ascites may result in need for dose at higher end of range and duration may
be increased
 Stable in D5NS, D5, RL, NS
 Not incompatible with anything we have (mitafungin!)

16. Adverse reactions
 Cardiovascular , increased peripheral vascular resistance, tachycardia (< 5%,
incidence greater in children), hypertension, transient hypotension
 Hypersensitivity <1%
 Contraindications hypersensitivity to rocuronium , any component thereof
or other neuromuscular blocking drugs

17. Roc, disease related concerns
 Burn injury , resistance may occur if > 20 % TBSA(Han 2009)
 CV disease, use with caution, action may be delayed and duration prolonged
 Conditions that antagonize neuromuscular blockade: resp alkalosis,
hypercalcaemia, demyelinating lesions, peripheral neuropathies may
antagonize NM blockade (Greenberg 2013, Miller 2010, Naguib 2002)
 Conditions that potentiate NM blockade, v low Ca , low K, cachexia, NM
disease, pH disturbances, myasthenia gravis
 Pulmonary hypertension, may increase PVR

18. Suxamethonium
 Depolarizing muscle relaxant
 Iv 1- 1.5 mg/kg, can be used IM
 Obesity use total body weight
 Renal imapirment no dosage adjustment
 Hepatic impairment no dosage adjustments
 Compatibility, stable in all common fluids, but incompatible with
thiopentone

19. Does have a few little problems though
 Cardiovascular: arrhythmias, bradycardia, cardiac arrest, hyper/hypotension,
tachycardia
 Dermatologic: rash
 Metabolic: hyperkalaemia (check K first and all will be well?)
 Gastrointesinal: salivation (excessive)
 Neuromuscular and skeletal, jaw rigidity, muscle fasciculation, post
operative muscle pain, rhabdomyolysis (with possible myoglobinuric renal
failure)

20. And the rest
 Ocular: increased intraoccular pressure
 Resp: sux apnoea
 Miscellaneous: anaphylaxis, malignant hyperthermia
 Case reports: acute quadriplegic myopathy syndrome, myositis ossificans
(prolonged use)

21. Case report of hyperkalaemic arrest
 Piotrowski et al. Paed critical care Med 2007: vol8 no2
 Hyperkalaemia and cardiac arrest following succinylcholine administration in
a 16 year old boy with acute non lymphoblastic leukaemia and sepsis
 Pre induction K 3.1 mmol
 30 minutes post sux cardiac arrest K 8.64 mmol
 90 minutes later (survived) K 3.8 mmol/l

22. Contraindications from up to date
 Hypersensitivity to sux, or any part thereof
 Personal or family history of malignant hyperthermia
 Myopathies associated with a raised CK
 Acute phase injury following major burns
 Multiple trauma !!!
 Extensive denervation of skeletal muscle or upper motor neurone injury

23. Sux disease related concerns (utd)
 Burns : high risk 7-10 days
 Conditions which may antagonize NMB: alkalosis, hypercalcaemia,
demyelinating lesions, peripheral neuropathies, denervation, infection,
muscle trauma and DM
 Conditions which may potentiate NMB: electrolyte abnormalities, severe
low Na, Low Ca, low K, high Mg, NM disease, acidosis, porphyria,
myaesthenia gravis, Eaton Lambert, renal failure and hepatic failure
 Plasma pseudocholinesterase disorders

24. Sux drug interactions (utd)
 abobbotulinumtoxinA, Acetylcholinesterase inhibitors, Aminoglycosides
 Analgesia, may increase the bradycardic effect of opiodes
 Bambuterol, clindamycin, cyclophosphamide, cyclosporin, echothiophate
 Lincosamide antibiotics, lithium, loop diuretics (diminish effect), magnesium
salts, phenelzine, polymyxin B, procainamide, quinidine
 Tetracycline derivative
 Vancomycin most of these will enhance effect

25. If they both new drugs which would you
choose?

26. Advantages of Rocuronium
 Few side effects
 Few/ no real contraindications
 Predictable dose dependent kinetics
 Safe in burns, hyperkalaemia, renal failure, hepatic failure, denervation
conditions
 Longer duration of action *

27. Disadvantages of rocuronium
 Unfamiliarity
 Price
 Duration of action *

28. Advantages of suxamethonium
 Rapid onset <60 seconds
 Possibly less anaphylaxis
 Can visualize onset with cessation of fasciculation
 Cheap
 Short acting, may wear off in time in can’t intubate can’t ventilate scenario
 Familiar, so why change
 Easy to spot contra-indications to sux

29. disadvantages
 Burns
 Hyperkalaemia
 Denervation conditions, MS
 Autonomic instability
 Crush injuries
 Malignant hyperthermia
 Masseter spasm

30. Sux disadvantages continued
 Bradycardia, increased with second dose or children, incidence reduced with
atropine
 Increased intraoccular pressure, use with caution in narrow angle glaucoma
or penetrating eye injury
 Vagal tone may be increased

31. So let’s look at those advantages of sux
 First rapid onset
 Sluga et al,Anaesth Analg. 2005: 101:1356-61, prospective study
 Compared 0.6 mg /kg rocuronium with 1 mg / kg suxamethonium
 They found that suxamethonium had a statistically significant improvement
on intubating conditions at 60 seconds
 So far so good?

32. McCourt et al, Anaesthesia 2006;
101:1356-61
 Compared roc 0.6 mg/kg, 1.0 mg/kg and sux 1.0 mg/kg, ? blinded
 Found 1.0 mg/kg better than 0.6 mg/kg of rocuronium at 50 seconds
 Comparison of the rocuronium 1.0 mg/kg group and the sux 1.0 mg/ kg
group revealed had similar frequency of acceptable intubating conditions at
50 seconds
 However there was a higher incidence of “excellent” intubating conditions in
the sux 1.0 mg/kg group

33. Lauren et al, Acad Emerg Med 2000;
7:1362-9
 Basically found the same
 They used the same rocuronium doses but 1.7 mg /kg suxamethonium
 so far so good?

34. however
 Patanwala et al, Comparison of succinylcholine and rocuronium for first
attempt intubation success in the emergency department. Acad Emerg Med.
2011; 18:11-14
 Retrospective analysis
 Compared a mean dose of 1.65 mg/kg of sux (n=113) and roc mean 1.19
mg/kg
 “no difference at success rate for first intubation attempt or number of
attempts regardless of the type of paralytic used or the dose administered.”

35. Then Cochrane chipped in their 2 cents
worth in 2008
 “rocuronium versus succinylcholine for rapid sequence induction”
 Combined 37 studies
 Concluded “no statistical difference in intubating condition when
[suxamethonium] was compared to 1.2 mg/kg of rocuronium”
 So let’s review the advantages of sux

36. Advantages of suxamethonium
 Rapid onset <60 seconds X
 Possibly less anaphylaxis
 Can visualize onset with cessation of fasciculation
 Cheap
 Short acting, may wear off in time in can’t intubate can’t ventilate scenario
 Familiar, so why change
 Easy to spot contra-indications to sux

37. Next risk of anaphylaxis
 Rose et al. Rocuronium: high risk for anaphylaxis? Br J Anaesth. 2001; 86(5):
678-82
 Concluded the incidence of anaphylaxis to any NMJ blocking drug is
proportional to its market share
 The authors concluded rocuronium should be considered an “intermediate
risk” for anaphylaxis, compared to suxamethonium which is “high risk”

38. Advantages of suxamethonium
 Rapid onset <60 seconds X
 Possibly less anaphylaxis X
 Can visualize onset with cessation of fasciculation
 Cheap
 Short acting, may wear off in time in can’t intubate can’t ventilate scenario
 Familiar, so why change
 Easy to spot contra-indications to sux

39. Lets knock an easy one off next
 Contra indications to sux are easy to spot
 Unless you can see the potassium level I’m going to call b******t on this
one
 As we’ve already seem a normal K doesn’t ensure your patient won’t have a
hyperkalaemic arrest shortly afer induction

40. Advantages of suxamethonium
 Rapid onset <60 seconds X
 Possibly less anaphylaxis X
 Can visualize onset with cessation of fasciculation
 Cheap
 Short acting, may wear off in time in can’t intubate can’t ventilate scenario
 Familiar, so why change
 Easy to spot contra-indications to sux X

41. However sux is still safer, right?
 Many clinicians believe that by using sux the have inserted a safety margin
into their RSI protocol
 Only lasts 5 to 10 minutes
 NMB may wear off and patient will spontaneously breath, and all will be
well, and they all lived happily ever after…….
 Whereas roc will last 30-90 minutes

42. Heier et al. Desaturation after succinylcholine-induced apnoea.
Anaesthesiology 2001;94.754-9
 12 healthy volunteers aged 18 -45
 All pre-oxygenated to end-tidal O2 > 90%, after 3 mins FiO2 1.0
 Administration of thiopentone and sux @1mg/kg
 No assisted ventilation
 1/3 desaturated to <80 %, then BVM
 This is not our usual patient cohort

43. Neguib et al. Succinylcholine dosage and apnoea induced
haemoglobin desauration in patients. Anaesthesiology.
2005;b102(1)35-40
 Similar experiment
 Except used 0.6 mg /kg sux instead of 1.0 mg/kg
 Found SpO2 desaturation to <90% in 65 % (was 85 % in Heier study)
 Did not however shorten time to spontaneous diaphragmatic movement
 Therefore probably doesn’t support the “might be safer as will breathe
yourself” theory

44. Advantages of suxamethonium
 Rapid onset <60 seconds X
 Possibly less anaphylaxis X
 Can visualize onset with cessation of fasciculation
 Cheap
 Short acting, may wear off in time in can’t intubate can’t ventilate scenario X
 Familiar, so why change
 Easy to spot contra-indications to sux X

45. well at least its cheap
 Generic, US prices
 Rocuronium 100mg $8.51 US
 Suxamethonium 100 mg as cheap as $2 US
 Potential saving of over $6 US, it all adds up

46. Except
 You have to buy a fridge to keep the sux in
 After 10 minutes you will have to spend a further $6 dollars US ( the $6 you
saved on the last slide) on a 10 mg vial of vecuronium
 So only cheaper if you already own a fridge and you are sure your patient
will not be requiring NMB in 15 minutes, so either fully recovered or dead.

47. Advantages of suxamethonium
 Rapid onset <60 seconds X
 Possibly less anaphylaxis X
 Can visualize onset with cessation of fasciculation
 Cheap X
 Short acting, may wear off in time in can’t intubate can’t ventilate scenario X
 Familiar, so why change
 Easy to spot contra-indications to sux X

48. Disadvantages of rocuronium
 Unfamiliarity
 Price X
 Duration of action * X

49. So that leaves 3 good reasons to use sux
 You like watching fasciculations
 You are familiar with sux and don’t want to change
 Your patient has no contraindications to sux, will not require NMB in 15
minutes time and you desperately need to save $6, and you already own a
fridge.

50. For those of you that love fasciculations
 Rate of desaturation is an issue
 Fasciculations use oxygen and this may increase rate of desaturation
 This was explored by Taha et al.Effect of suxamethonium vs rocuronium on
onset of oxygen saturation during apnoea following rapid sequence
induction. Anaesthesia 2010,65:358-361

51. methods
 3 groups
 Lidocaine/fentanyl/rocuronium, lidocaine/fentanyl/suxamethonium,
propofol/suxamethonium
 Measured time to reach sats of 95%
 Both sux groups desaturated significantly quicker than roc group
 Lidocaine/ fentanyl took longer than propfol group

52. Another study backs this up
 Tang et al. Desaturation following rapid sequence induction using
succinylcholine vs rocuronium in overweight patients. Act Anaesthesiology
scand. 2011; 55:203-6
 BMI of 25-30 undergoing elective surgery
 Either 1.5 mg /kg sux or 0.9 mg/kg rocuronium
 No assisted ventilation until sats <92%
 Measured time to get to 92%, then measured the time to sats >97% with
assisted ventilation
 Results desaturated faster with sux, and took longer to recover sats to 97%

53. Scared of a little commitment?

54. Sugammadex, (for those without the
courage of their convictions)
 Effective reversal for rocuronium
 Gamma cyclodextrin that enccapsulates rocuronium
 Lee et al. Reversal of profound neuromuscular block by sugammadex administered 3
minutes after rocuronium. Anaesthesiology. 2009; 110:1020-5
 1.2 mg / kg of rocuronium given
 Then at 3 minutes 16 mg /kg of sugammadex given
 Mean time to 1st twitch on To4 4.4 minutes for roc, 7.1 minutes for sux
 Another study De Boer, Anaesthesiology.2007; 107: 239-44 found the mean recovery to
90 % at 1.9 minutes

55. Is a long duration of action a good or a bad
thing?
 Encourages definite plan to take control
 Possibly reduces incidence of “can’t ventilate” situations
 Our cohort of patients waking up is not usually an option
 Removes the need for adding a non depolarizing agent in the 10 minutes
post induction, when everything is happening

56. Going back to the Quairading patient
 Choice of muscle relaxant?

57. One good reason left to use sux
 You don’t want to change

58. They both do the job, both reasonable
options