Difficult and failed tracheal cannulation remains a taking cause of anaesthetic morbidity and mortality despite progresss in schemes both to predict and to pull off [ 5 ] the hard air passage. Many hard cannulations are non recognized until after initiation of anaesthesia [ 3 ] . Despite the handiness of options, the Macintosh Laryngoscope remains the most widely used.
Endotracheal cannulation, considered to be the gilded criterion in procuring the air passage, is normally performed utilizing a direct Laryngoscope. In add-on to hapless light, troubles in executing conventional direct laryngoscopy normally arise from the limited position angle of about 10-15 [ 5 ] . Standard direct laryngoscopy requires alliance of the unwritten, pharyngeal, and laryngeal axes in order to see the vocal cords. In contrast, indirect Laryngoscopes merely requires alliance of the guttural and laryngeal axes, which lie along similar angles as compared with the unwritten axis [ 6 ] . Insufficient laryngoscopic position constitutes the chief ground for hard cannulations. Without equal visual image, cannulation remains insecure and associated with elevated hazard for injury [ 7 ] . Therefore, different blade designs such as the McCoy purchase blade,
DoA? rges cosmopolitan blade and so on were developed to better cannulation success. [ 8, 9 ] Owing to staying cannulation troubles in some patients, instruments leting indirect glottic position such as flexible and stiff fiberscope, cannulations endoscopes and optical stylets were introduced [ 10-12 ] . However, extended costs and the demand for particular preparation basically contributed to a limited spread of many of these devices [ 13 ] . Therefore, anesthesiologists are still seeking for cannulation devices uniting first-class glottic visual image with simple and efficient usage. Over the last few old ages, video-assisted endoscopic techniques have successfully been introduced into assorted surgical subjects. In contrast, anesthesiologists have been loath to take up the advantages of the picture technique for their intents. The first efforts were undertaken with jury-rigged instruments uniting Laryngoscopes and flexible fiberscopes [ 14 ] . Today, several luxuriant picture Laryngoscopes are commercially available [ 15-18 ] . Whereas some devices feature a conventional Macintosh blade signifier, others show a distinguishable blade design. A marked curvature resembling oropharyngeal and hypopharyngeal anatomy enables a widened position.
As a affair of fact, airway direction in injury patients has turned out to be exceptionally critical [ 19 ] . In instance of hurt and instability, motion of the cervical spinal column can do irreversible harm to the spinal cord [ 20 ] . Attachment of stiff or semi-rigid cervical neckbands are a compulsory measure in exigency medical attention but makes ETI by standard laryngoscopy much more hard or even non possible [ 21 ] . Video Laryngoscopes ( VLs ) , which allow an indirect position of the glottis, may therefore ease ETI even when the direct glottic position can non be obtained and better visibleness of the vocal cords [ 22 ] . The broad handiness of VLs poses the inquiry whether their usage can ease ETI safe and speedy even without remotion of the cervical neckband.
AIM OF THE WORK
To measure the safety and utility of glidescope, Airtraq and UE video-Laryngoscope use in anesthetized patients with fake ( with an immobilized cervical spinal column ) and expected hard cannulation conditions in comparing to the Macintosh Laryngoscope.
Patients and methods
Ethical blessing was obtained from the Ethical commission in HUST, and written informed consent was obtained from all participants before registration in the survey.
. Target population
Patients which showing for elected surgery necessitating orotracheal cannulation, were recruited and indiscriminately assigned into two chief groups, each chief group include four subgroups of 20 patients.
Type of the survey:
Comparative, prospective, random clinical test survey
An helper who was non involved in the survey obtained numbered opaque pre-sealed envelopes incorporating the randomized group allocations after each patient was enrolled into the survey. Anesthetists non involved in the aggregation or analysis of the informations performed all cannulation.
GROUPE ( 1 ) : { expected hard cannulation }
macintosh laryngoscope-
– glidescope
– Airtraq
– UE video-laryngoscope
GROUPE ( 2 ) : { fake hard cannulation }
macintosh laryngoscope-
– glidescope
– Airtraq
– UE video-laryngoscope
Inclusion standards & A ; Exclusion standards: –
GROUP ( 1 ) :
Inclusion standards:
Both sexi?›
Patients are ASA I or ASA IIi?›
Age 20-60 yearsi?›
Consent from patients about the nature of the survey and techniquei?›
Expected hard airway upon appraisal.
Exclusion standards:
Patient refused to inscribe in the research survey
Ear, nose or throat surgery
A demand for rapid sequence initiation or exigency surgery
Any upset of the cardiovascular, pneumonic, hepatic, nephritic, or GI systems known from history or general scrutiny
Patients with unstable cervical spinal column
If the patient at hazard of pneumonic aspiration.
GROUP ( 2 ) :
Inclusion standards:
Both sex
Patients are ASA I or ASAIIi?›
Age 20-60 old ages.
Consent from patients about the nature of the survey and technique.
Exclusion standards:
Patient refused to inscribe in the research survey
Ear, nose or throat surgery
A demand for rapid sequence initiation or exigency surgery.
Any upset of the cardiovascular, pneumonic, hepatic, nephritic, or GI systems known from history or general scrutiny.
Patients with unstable cervical spinal column
If the patient at hazard of pneumonic aspiration.
Expected hard airway upon appraisal.
MorbidObesity( organic structure mass index & gt ; 35 ) .
Study results: will be in the signifier of cannulation clip, laryngoscope clip, success rates, figure of tests, failurerate, air manner injury, hemodynamic response and glottic visual image grads with all picture assisted devices.
A-Preoperative appraisal
Medical history:
History of chronic medical unwellness.
Drug history.
Anaesthetic history: including old anaesthesia, air passage troubles, and household jobs related to anaesthesias.
Physical scrutiny:
General scrutiny:
Pulse, arterial blood force per unit area, respiratory rate and temperature.
Heart, thorax and abdominal scrutiny.
Local scrutiny
Air manner appraisal for any troubles or any oropharyngeal hurt was noted before surgery
Laboratory probes:
Complete blood count.
Prothrombin clip ( PT ) , INR, partial thrombokinase clip ( PTT ) , shed blooding clip.
Electrocardiogram: for patients above 40years old.
Anaesthetic appraisal:
To except marks of hard cannulation
1 ) Airway Physical Examination ( Signs of expected hard cannulation )
A ) Interincisor distance: Less than 3 centimeter.
B ) Visibility of uvula: Not seeable when lingua is protruded with patient in sitting place ( Mallampati category greater than II )
C ) Thyromental distance: Less than three ordinary fingers.
D ) Length of cervix: Short.
Tocopherol ) Thickness of cervix: Midst.
F ) Range of gesture of caput and cervix: Patient can non touch tip of mentum to chest or can non widen cervix. [ 23 ]
Demographic informations:
The patient ‘s age, sex, ASA position and BMI was recorded
B-Methods:
Patients were prepared by fasting for at least 6 – 8 hours.
Airway devices and anesthesia machine, ventilator, flowmeters and equipments checked were checked preoperatively. After canulation monitoring equipments will be attached to the patient including 5 leads ECG, non-invasive blood force per unit area, pulse oximetry and anaesthetic gas proctor.
Initiation of anaesthesia & A ; cannulation:
Patients were preoxygenated with 100 % Oxygen for 3 proceedingss, No sedation was given to the patients. Then all patients receivedi? s
propofol 2-3 mg. kg i. v
fentanyl 1. 5 Aµg. kg i. v
cis- atracurium 0. 5 mg. kg i. v
Devicess:
One of the helpers will help the anesthesiologist who will execute the cannulations. A Magill tracheal tubing with 7. 5 millimeters internal diameter ( ID ) was used for all efforts. Lubricant was already applied to the tracheal tubing, and a 10 milliliter syringe to barricade the tubing ‘s turnup. The devices used for the survey were:
( 1 ) Standard Macintosh laryngoscope, blade 3 ( gold-standard ; HEINE Optotechnik, Munich, Germany ) .
( 2 ) Glidescope Ranger, Cobalt blade # 3 ( Verathon Inc, Bothell, WA, USA ) .
( 3 ) Airtraq, Size 3 ( Prodol, Madrid, Spain ) .
( 4 ) UE Video Laryngoscope, medium size blade ( China )
A semi-rigid stylet was inserted in the tracheal tubing when intu-bation was performed with Macintosh and UE laryngeaoscope. The GlideRite stiff stylet was used for efforts with GlideScope. As the Airtraq have integrated counsel channels for the tracheal tubing, they were non designed to be used with a stylet and were accordingly used without any extra counsel.
IN Group ( 2 )
The patients ‘ lungs will so manually air out for 3 min before a stiff cervical neckband will be applied maintaining the cervix in a impersonal place. This is an established technique for imitating a hard air passage.
Tracheal cannulation will so execute with one of the three picture laryngoscopes or mackintoshs laryngoscope, in conformity to the randomized allocation.
IN Group ( 1 ) , the same thing as group ( 2 ) without apply the stiff cervical neckband.
Parameter will mensurate
1-Laryngoscope clip:
Timess from the first contact with the device until accomplishment of a successful position of the glottis.
2-Time to intubation
Will be recorded as the clip from interpolation of one of the videolaryngoscope to visual aspect of an end-tidal C dioxide hint on the capnograph.
3, 4-Number of tests & A ; failure rate:
If cannulation is unsuccessful at the first effort, or took longer than 180 s, or if desaturation is note on the pulsation oximeter ( defined as SpO2 & lt ; 93 % ) , the cannulation effort will halt and the lungs ventilate with an oxygen-volatile anesthetic mixture for 3 min. A 2nd effort will be allowed with the randomly allocated airway device. If cannulation is unsuccessful after two efforts, the protocol allow for the cervical neckband to be take and the patient ‘s windpipe to be intubated with the anesthesiologist ‘s instrument of pick.
5-Hemodynamics response: ( bosom rate, systolic and diastolic blood force per unit areas ) Will be recorded during the cannulation procedure with readings taken pre-induction, pre-intubation and at 3 and 5 min after cannulation
6-Glottic visual image mark: ( categorization of Cormack and Lehane, as modified by Yentis and Lee )
class I – full position of the glottis ;
class IIa – partial position of the glottis ;
class IIb – arytaenoids or posterior part of the cords seeable ;
class III -only the epiglottis seeable ;
class IV – neither epiglottis nor glottis visible.
7- Airway injury:
A careful scrutiny of the oropharynx, will be performed after cannulation to find any lip or mucosal injury. The presence of any of the followers will taken to be grounds of mucosal hurt: blood discolorations on the tracheal tubing upon extubation ; seeable lacerations in the oropharynx ; or any hemorrhage noted on the lips or oropharyngeal mucous membrane.
8-Number of optimisation manoeuvres before tracheal cannulation.
Each option technique add 1 point: repositioning of the patient, alteration of stuffs ( blade, Endo-tracheal tubing, alteration in stylette form ) , need for ( raising force, laryngeal force per unit area, jaw push )
Statistical Analysis
The IBM SPSS Statistics ( version 20 ) will be used for statistical analysis. The sample size of n = 20 participants was calculated to be sufficient to observe a standardised mean difference of ( 1. 4 ) in the cannulation clip with a power of 80 % and reversible significance degree of 5 % .
All consequences are shown as agencies A± standard divergence ( SD ) or figure ( % ) . The normal distribution of informations will be tested utilizing the Kolmogorov-Smirnov trial. Student ‘s t-test will be used for statistical significance of the difference in the average cannulation and laryngeal clip between the MAC group and each of the other groups ; Mann-Whitney trial will be used for non-parametric informations. One-way ANOVA will be used for statistical significance of difference in quantitative variables ( e. g. age, BMI, laryngeal & A ; cannulation clip and hemodynamic parametric quantities ) between the 4-devices groups. Paired t-test will be used for statistical significance of the average difference in hemodynamic parametric quantities ( in each group ) at pre-induction/pre-intubation clip and each of the other clip points ( 1-min, 3-min & amp ; 5-min ) . Categorical variables will be tested for statistical significance utilizing Chi-square trial ; Fischer ‘s exact trial will be used when any expected frequence is less than 1 or 20 % of expected frequences are less than or equal to 5. A
