Article Type : Research Article
Authors : Manjunath Kandiraju, Avinash Basvapattana Maheshwarappa, Chethan Manohara Koteswara, Prajnyananda Das and Sanjiv S Bais
Keywords : Complications; Endotracheal intubation; Sore throat; Cough; Larynx; Damage; Pharmacology; Betamethasone gel; Lidocaine; Patient comfort
Background: Steroids like Betamethasone gel usually
restricted for application and treatment of skin disorders, but it can also be
helpful in preventing postoperative complications of intubation such as cough,
sore throat, and hoarseness of voice.
Methods and Results: Multiple case studies including
prospective, randomized controlled studies are taken into consideration,
various studies, analysed and concluded that Betamethasone gel is superior when
compared to other jellies like lignocaine jelly, K Y jelly application on the
endotracheal tube optimizes the intubating conditions with ease and prevents
post-operative complications.
Conclusion: The maximum benefits of Betamethasone gel
outweighs the benefit -risk ratio and superior as compared to other jellies in
the market.
Airway management with endotracheal intubation is an integral part of an anesthesiologist’s responsibilities towards patient care. Cuffed endotracheal intubation offers additional safety to the patient by preventing aspiration syndromes. In addition, the wastage of anaesthetic gases and the pollution of the operation theatres are also reduced substantially. However, amongst the sequelae inherent to the usage of the cuffed endotracheal tube, the local irritation and the inflammation of the airway caused by prolonged inflation of the cuff is the prominent one which results in post-intubation morbidities like sore throat, hoarseness of voice, and cough. Many studies have been performed and published exploring the measures to minimize/eliminate post-intubation morbidities, viz,
The use of water-soluble jellies for lubrication of
the endotracheal tube is to facilitate smooth insertion of the endotracheal
tube and also to reduce trauma to airway mucosa thereby decreasing the overall
morbidity. Local anesthetic (2% Lignocaine) jellies along with lubricating
properties also limit the potential damage to tracheal mucosa by suppressing
the airway reflexes, but the incidence of postoperative morbidities continues
to be high (90%) probably due to lack of anti-inflammatory action [4]. Steroids
like Betamethasone gel are well known for their anti-inflammatory action and
have been claimed to reduce (up to 60%) the incidence of post-intubation
morbidities [6]. Other factors were
known to correlate with occurrence of these complication, including sex [4,5],
age, season, anesthetic drugs and gases, numbers of trials for intubation [4],
duration of intubation [4,6], size of endotracheal tube its type and cuff type
and size [1], site of the surgery [4,8] and application of lidocaine [2-9] or
steroids [3-11].
Betamethasone
Betamethasone [12] (9a-16ß-methyl prednisolone) is a synthetic glucocorticoid agent which has been most popular in the treatment of corticosteroid-responsive dermatologic disorders. It is also used systemically for treating inflammatory conditions (Figure 1).
Figure 1: Pharmacology of Betamethasone.
Mechanism of action
For the most part, glucocorticoid effects involve
interactions between the steroids and intracellular receptors that belong to
the superfamily of receptors that control gene transcription. This superfamily
includes the receptors for mineralocorticoids, the sex steroids, thyroid
hormones, Vitamin D; and retinoic acid. There are believed to be 10-100
steroid-responsive genes in each cell. The glucocorticoids, after entering the
cell, bind to specific receptors (glucocorticoid receptor a {GRa} and
glucocorticoid receptor ß {GRB}) in the cytoplasm. These receptors, which have
high affinity for glucocorticoids, found in virtually all tissues - about 3000
to 10000 per cell, number varying in different tissues., GRa has been cloned and
contains 777 amino acid residues. Becomes 'activated', i.e. it after
interaction with the steroid, the receptor becomes ‘activated’, i.e. it
undergoes a conformational change that exposes a DNA-binding domain. The
steroid-receptor complexes form dimers, then move to the nucleus and bind to
steroid-response elements in the DNA. The effect is either to repress (prevent
transcription of) or induce (initiate transcription of) particular genes.
Repression is brought about by inhibition of the action of various
transcription factors such as AP-1 and NF-KB. These transcription factors
normally switch on the genes for cyclooxygenase-2, various cytokines and
adhesion factors, as well as the inducible isoform of nitric oxide synthase.
Basal and induced transcription of the genes for collagenase is modified and
vitamin D; induction of the osteocalcin gene in osteoblasts is inhibited.
Induction involves the formation of specific mRNAs, which direct the synthesis
of specific proteins. In addition to the enzymes involved in their metabolic
actions [cAMP-dependent kinase]; glucocorticoids induce the formation of
annexin-1 (previously called lipocortin-I). Annexin-1 is important in the
negative feedback action of glucocorticoids on the hypothalamus and anterior
pituitary and has anti-inflammatory actions (possibly by inhibiting
phospholipase A). As might be predicted, the anti-inflammatory effect of
glucocorticoids takes hours to become evident since the formation of annexin-1
and other active proteins is relatively slow. Glucocorticoids can, however,
produce effects over a very much shorter time frame. These rapid effects of
glucocorticoids do not involve interaction with the genes but are mediated
instead by interacting with specific membrane receptors to Cause changes within
the cell (e.g. on intracellular calcium) that are similar to those triggered by
neurotransmitters (Table 1).
Table 1: Betamethasone.
Compound
|
Relative affinity for glucocorticoid receptors |
Approximate relative potency in clinical use
|
Duration of action
|
|
Anti-inflammatory |
Sodium- retaining |
|||
Hydrocortisone (cortisol) |
1 |
1 |
1 |
S |
Betamethasone |
5.4 |
30 |
Negligible
|
L |
S:- 8-12 hours L:-36-72
hours |
General metabolic and
systemic effects
The main metabolic effects are on carbohydrate and
protein metabolism. It causes both a decrease in the uptake and utilization of
glucose and an increase in gluconeogenesis, resulting in the tendency to
hyperglycemia. There is a concomitant increase in glycogen storage, which may
be a result of insulin secretion in response to the increase in blood sugar.
There is decreased protein Synthesis and increased protein breakdown,
particularly in the muscle. Glucocorticoids have a permissive effect on the
lipolytic response to catecholamines and other hormones, which act by
increasing intracellular cAMP concentration. Such hormones cause lipase
activation through a cAMP-dependent kinase, the synthesis of which requires the
presence of glucocorticoids. The glucocorticoids, in non-physiological
concentrations, have some mineralocorticoid actions, causing sodium retention
and potassium loss-possibly by occupying mineralocorticoid receptors. They also
tend to produce a negative calcium balance by decreasing calcium absorption in
the gastrointestinal tract and increasing its excretion by the kidney.
Administration of exogenous glucocorticoids depresses the
corticotrophin-releasing factor and adrenocorticotrophic hormone, thus
inhibiting the secretion of endogenous glucocorticoids and causing atrophy of
the adrenal Cortex.
Anti-inflammatory and
immunosuppressive effects
When given therapeutically, glucocorticoids have
powerful anti-inflammatory and immunosuppressive effects. They affect all types
of inflammatory reactions whether caused by invading pathogens, by chemical or
physical stimuli, or by inappropriately deployed immune responses such as are
seen in hypersensitivity or autoimmune diseases.
Actions on inflammatory cells include
Action on the mediators of inflammatory and immune responses include
Absorption
Betamethasone may be given by a variety of routes. It
can be given oral, intramuscular, intravenous, intraarticular, and topical.
There is much less likelihood of systemic toxic effects after topical
administration unless large quantities are used. Betamethasone 0.6 milligram is
equivalent to Triamcinolone 4 milligrams, Methylprednisolone 4 milligrams,
Dexamethasone 0.75 milligram, and Hydrocortisone 20 milligrams.
Distribution
The endogenous glucocorticoids are carried in plasma,
bound to corticosteroid-binding globulin and to albumin. Corticosteroid-binding
globulin does not bind to synthetic steroids but albumin binds both natural and
synthetic steroids. Peak serum concentrations of betamethasone occur within 10
to 36 minutes with intravenous doses; systemic absorption from topical therapy
is 12% to 14% of a dose; protein binding is 64%; volume of distribution is 75
to 90 L; elimination half-life is 56 hours.
Metabolism and excretion
Betamethasone has a double bond in the 4, 5 positions
and a ketone group Metabolism involves sequential additions of oxygen or
hydrogen atoms, Followed by conjugation to form water-soluble derivatives.
Reduction of the 4,5 double bond occurs at hepatic sites yielding inactive
compounds. Subsequent reduction of the 3-ketone substituent to the 3-hydroxyl
derivative, forming tetrahydrocortisol. Most of these are conjugated through
the 3-hydroxyl group with sulfate or glucuronide by enzymatic reactions that
take place in the liver and, to a lesser extent, in the kidney. The resultant
sulfate esters and glucuronides are water-soluble and are the predominant forms
excreted in the urine.
Interactions
The concomitant use of corticosteroids with neuromuscular blocking agents has been reported to antagonize neuromuscular blockade. In addition, prolonged coadministration of these agents may increase the risk and/or severity of myopathy resulting in prolonged flaccid paralysis following discontinuation of the neuromuscular blocking agent. Concomitant corticosteroid and phenobarbital therapy has been reported to result in enhancement of the metabolism of corticosteroids due to hepatic microsomal enzyme induction. It may be necessary to increase the dosage of corticosteroids if barbiturates or other enzyme inducers are used concomitantly.
Contraindications
Dosage
need of steroid may be increased before, during, and after stressful
situations.
Topical betamethasone dipropionate is only available
in a vehicle that augments the penetration of this product. BETAMETHASONE
DIPROPIONATE cream, ointment, and lotion should be stored at 36 to 86 degrees F
(2 to 30 degrees C), the gel should be stored at 36 to 77 degrees F (2 to 25
degrees C).
Adverse effects
In the year 2003, Levy B [1] conducted a study on 60
patients, divided into 2 groups, one group received topical lidocaine 5% (15
puffs) and the other group aerosolized methylprednisolone (80mg) before
endotracheal intubation and showed that the incidence of sore throat and cough
were less in the methylprednisolone group compared to lidocaine group. EI Hakim
[10] showed that beclomethasone reduced the incidence of postoperative sore
throat by 45% in comparison to 10% with lignocaine but its cost precludes its
use.
Though Stride P C [3] (1990) concluded that 1%
hydrocortisone water soluble cream applied to the tip and cuff of the
endotracheal tube was ineffective in
reducing the incidence of postoperative sore throat, Ayoub M Cand Selvaraj [11]
Showed that wide spread application of betamethasone accounted for decrease in
incidence of post-operative Sore throat, hoarseness of voice and cough. Asif
Kazemi and Afshin Amini15 concluded that betamethasone gel, when used for
lubrication of endotracheal tubes reduced the incidence of postoperative sore
throat, cough and hoarseness of voice.
P A Sumathi,T Shenoy, M Ambareesha, H M Krishna
[14,15] {2008 } randomized controlled trial study has found that widespread (15
cm) application of steroid gel markedly reduced the incidence of sore throat,
hoarseness of voice and cough. The scores for sore throat, hoarseness of voice
and cough were significantly very low in steroid group at 1hr, 6hrs, 12hrs and
24hrs, though the duration of endotracheal intubation is significantly more in
betamethasone group. It also shows that betamethasone gel is superior to
lignocaine jelly and normal saline in reducing post intubation morbidities.
This study confirms that pharyngotracheal sequelae
after endotracheal intubation are due to local inflammation and not irritation,
as steroid gel proved far superior to local anesthetic jelly in decreasing
their incidence. The beneficial effect was observed because of the application
of steroid gel to all portions of the tube that come in contact with the
posterior pharyngeal wall, vocal cords, and tracheal mucosa and not just
confined to the tip and cuff of the endotracheal tube as observed by Stride P
C's [3] study (1990) where the percentage and the total quantity of the gel
applied was high.
Considering the pros and cons of Betamethasone gel
application on endotracheal tube is an added advantage for effective airway
management. Since betamethasone gel is cost-effective and easily available, it
can be used routinely as an applicant on the endotracheal tubes in the
preemptive methods to mitigate the postoperative sore throat, hoarseness of
voice and cough.