Background: Laryngoscopes are one of the potential mediators of infection transmission due to their blades contact with oral mucous membranes. Using single-use plastic blades is a method of preventing infection transmission. The aim of this study is to compare the efficiency of single-use plastic and reusable metal laryngoscope blades in orotracheal intubation during the rapid- sequence induction of anesthesia Materials and Methods: In this clinical-trial, 310 patients, more than 10 years of age, who were candidates for elective surgery, were selected. After anesthesia induction, orotracheal intubation was done by either single-use plastic or reusable metal blades for patients. Duration of intubation and arterial oxygen saturation were recorded before and after intubation. Data analysis was done using SPSS software. Results: Orotracheal intubation was done successfully in all patients. Mean differences of intubation time from the standard upper limit were 1.42±8.19 and 13.1±4.22 seconds in the plastic and metal blades groups, respectively. Also, the mean of difference in oxygen saturation of the low 90% after intubation were 6.07±2.71 and 7.16±1.21 in plastic and metal blades groups, respectively. Both parameters indicated statistically significant differences. Conclusion: In rapid-sequence induction of anesthesia, by using single-use blades, both intubation time and arterial oxygen saturation drop will increase in comparison with metal blades. This will cause complications such as aspiration in the patients.

Comparison of the efficiency of single-use plastic and reusable metal laryngoscope blades in orotracheal intubation during rapid-sequence induction of anesthesia

Dear Editor 

 Endotracheal intubation may be required for every patient  under  general anesthesia (GA). Direct laryngoscopy is a routine method for endotracheal intubation  in patients. Various blades are used for intubation  depending on the choice of anesthetist and patient's  conditions  [1].  These  laryngoscope blades  can  trigger  infection  among patients  [1]. Nowadays it is believed that the standard method for sterilization of laryngoscope blades does not destroy all existing pathogens [2]. Using cheap disposable blades can eliminate the infection risk [2]. The main reason for using the disposable laryngoscope blades is to  minimize  the  risk of infection  transmission between the patients. Several cases of prion transfer between  patients  have been reported  after  blood transfusion, and it is well known that laryngoscopes can become contaminated with blood during use [3]. Therefore, single-use devices are an obvious solution to the problem. However, plastic blades do not have the same physical characteristics as metallic ones. Shape, size, light sources, and stiffness are different between  blade  types  [4].  Most  of  the  operators involved in this study believed that stiffness of the plastic blades was less than that of metallic ones and might be the main factor influencing the quality of laryngoscopy. 

Modir  and  his colleagues [5] evaluated duration and success of intubation in a clinical trial involving 320 patients aged over 10 years. After induction  of general  anesthesia, endotracheal  intubation was done using disposable plastic or metal reusable blades. Average time for reusable metal laryngoscope blades was 13.1±4.29 minutes and it was 16.4±8.1 minutes   for  disposable  plastic  blades  (p<0.001) [5].  Using  plastic  disposable  blades, outside  the hospital emergency, reduced the success rates of first attempt intubation  [6]. Amour et al. compared the disposable blades and metal reusable blades in rapid sequence induction (RSI). The findings showed that the disposable metal blades were more useful than reusable metal blades in RSI [7]. In another clinical study conducted in operation room (OR) the failure rate for RSI was 17% for disposable plastic blades and 3% for disposable metal blades [7]. In emergency department and out-of-hospital care, single use  disposable  plastic  laryngoscope blades are now available and may be used in daily practice because of the strong suggestion that single-use devices should be used when mucosal contact occurs. However, the effectiveness of the 2 types of blade has not been compared in the emergency setting. If the plastic blades lead to a lower intubation success rate and make intubation  more difficult, any theoretical benefits of avoiding rare infectious diseases are to be negated.

In short, the metal disposable blades facilitated the intubation,  whereas the plastic blades increase the time of intubation.  Further studies on this subject provide more definitive information.

http://eprints.ajaums.ac.ir/3393/2/f6a6ea4b-d127-45eb-a6dd-9fc91d7a6829.pdf

Amenable Intubation by Disposable Laryngoscope Blades.

Background:
Laryngoscopes are the potential cause of cross-contamination between patients. A considerable way to prevent this problem is to use of disposable laryngoscopeâ€™s blades. This study was designed to evaluate laryngoscopic conditions in pediatrics with disposable and metalic Macintosh blades.
Methods:
152 children scheduled for elective surgery aged 3-12 years were enrolled in this randomized clinical trial. After induction of anesthesia, anesthesiologist intubated the patients with one of two kinds of laryngoscopeâ€™s blades (disposable or metalic Macintosh). During laryngoscopy and tracheal intubation, glottic view, brightness of laryngoscopic field, time of intubation and satisfaction degree of anesthesiologist was recorded.
Findings:
All patients were successfully intubated. There was significant difference between disposable and metalic Macintosh blades with respect to time of intubation and brightness of laryngoscopic field. Grade I of laryngoscopy was more frequent in metalic group compared to disposable group (83% vs. 49%) Anesthesiologist satisfaction was significantly improved during laryngoscopy with metalic Macintosh blade.
Conclusion:
With respect to successful tracheal intubation of all patients in this trial and the usefulness of disposable laryngoscopes to prevent cross-contamination between patients and regardless of significant difference in laryngoscopic conditions between disposable and metalic blades, disposable laryngoscopes can be used under normal intubating conditions in pediatrics.
Key words: Pediatric, Disposable laryngoscope, Anesthesia, Children.

Rahimi Iman

Papers

Comparison of Laryngoscopic Conditions by Means of Disposable and Metalic Macintosh Blades in Pediatric Patients