Emergency intubation is becoming very common in anaesthesia,
emergency medicine and critical care practice. Intubation is performed faster
in order to avoid complications like hypoxia and aspiration. Administration of
neuromuscular blockade is essential for most of the cases. Succinylcholine
which is a depolarising muscle relaxant is the gold standard neuromuscular
blocking agent in rapid sequence intubation. Due to its side effects,other non
depolarizing muscle relaxants such as atracurium and vecuronium when used with
recommended dosage for intubation has developed rapid sequence intubation 2-3
minutes later than that of succinylcholine. Non depolarising muscle relaxant
with low potency has rapid onset of action. Many studies has shown that in
spite of rapid onset, mivacurium didn’t produce satisfactory results. Studies
on Rocuronium showed that as the intubating dose increased, the duration of
action also increased proportionately. Rocuronium dose of 0.6 mg/kg has
obtained intubation conditions within 60-90 seconds and has a duration of
action of 30-40 minutes. A priming dose of 0.06mg/kg (10% of intubating dose)
& priming interval of 3 minute has been used in order to achieve an onset
of action closer to succinylcholine. Magnesium has found to potentiate the
effect of non-depolarising muscle relaxants and could shorten the onset of
time. This study is to evaluate the effect of magnesium pretreatment on
rocuronium priming in achieving rapid onset of intubation conditions and
evaluation of conditions during the same.
Study Objectives
Primary objective To compare the efficacy of magnesium
pretreatment on rocuronium priming to reduce the onset time of
intubation.
Secondary objective To assess the intubating conditions
using Cooper’s scoring system. To observe the duration of rocuronium induced
neuromuscular block after pretreatment with magnesium sulfate.
To evaluate the adverse
effects Study design A randomised, prospective, double blinded case study.
Number of subjects/sample size The calculated sample
size is 30 in each group. Group A-30 and Group B-30. Total of 60 samples.
Study Methodology or procedure
Inclusion criteria
ASA grade 1 and 2 patients.
Age 18-70 years.
Mallampatti class 1 and 2.
Exclusion criteria
Refusal of consent.
Known or anticipated difficult airway.
Pregnant patients
Patients with BMI of 30 or more.
Patients with significant hepatic,renal,metabolic and
neuro muscular disorders.
Patient receiving drugs like aminoglycosides,
polymyxin A and B, colistin, clindamycin, lincomycin that influence
neuromuscular functions.
Methodology
A routine preoperative examination is done prior to
the day of surgery.
On night prior and at 6am on the day of surgery
premedications- Tablet Alprazolam 0.5mg and Tablet Ranitidine 150mg is given to
the patient.
Prior to shifting the patient inside the operation
theatre,the anaesthesia machine, laryngoscope with Macintosh blade of
appropriate size,working suction apparatus and drug tray are checked.
Once the patient is shifted inside the Ot,standard
monitoring such as,ECG, non invasive blood pressure,SPO2 and end tidal carbon
dioxide( ETCO2) are attached. A 18G cannula is secured and an infusion of 100ml
NS placebo(group A)/with Magnesium sulfate(50mg/kg)(Group B)is infused over 10
minutes.Hemodynamic parameters like heart rate, systolic and diastolic blood
pressure are recorded at baseline. Inj.Fentanyl 2mcg/kg IV given. After 10
minutes both the groups will receive 0.05mg/kg of rocuronium(priming dose)
while the patient is being pre-oxygenated. After 2 minutes Inj.propofol 2mg/kg
IV is given before a further dose of rocuronium 0.45mg/kg(intubating dose).
In both the groups train of four (TOF) response to
stimuli of ulnar nerve at Adductor pollicis in the forearm is monitored.
Patient is Intubated using suitable endotracheal tube when the TOF ratio
becomes 0 and then the anaesthesia will be maintained using isoflurane or
sevoflurane Perioperative monitoring of the patient is done and when TOF >1
muscle relaxant is supplemented.
Study outcome or end points This study will be used to
investigate whether onset of neuromuscular blockade was shortened by
combination of Magnesium pretreatment with rocuronium priming,compared with
rocuronium priming alone.
References
1. The Effect of Magnesium Sulphate Pre-Treatment on
Rocuronium Priming in Achieving Rapid Onset of Intubating Conditions Nirmal
Sheshagiri*, Khalid Zahir, Lokesh Reddy, Salman Mohammad Kutty, Surjya Kanta
Mohanty and https://juniperpublishers.com/jaicm/pdf/JAICM.MS.ID.555693.pdf
Supriya Preman
2. Comparison of intubating conditions between rocuronium
with priming and without priming: Randomized and double-blind study M
Hanumantha Rao, Andal Venkatraman, and R Mallleswari DOI :
https://pubmed.ncbi.nlm.nih.gov/22174467/
3. M. H. Kim, A. Y. Oh, Y. T. Jeon, J. W. Hwang, S. H.
Do.A randomised controlled trial comparing rocuronium priming, magnesium
pre-treatment and a combination of the two methods. DOI:
https://pubmed.ncbi.nlm.nih.gov/22420830/
4. Comparison of Magnesium Pre-treatment
With Two Different Doses of Rocuronium in Rapid Sequence Intubation: A
Randomized 2024Cureus 16(3):e56794DOI:10.7759/cureus.56794 Controlled
Trial.March