Comparison of Intubation Characteristics of McCoy Laryngoscope and LMA CTrach with Cervical Collar in Situ- A Simulation Study.

Cervical spine motion restriction is an integral component of protocol for management of trauma victims. The use of rigid cervical collar for the same, presents a hurdle in airway management in patients where intubation is mandated for successful resuscitation. Hence, techniques alternative to conventional laryngoscopy need to be explored through simulation studies, to ease the process of intubation and benefit the actual trauma victims. We wanted to assess the performance of McCoy laryngoscope and LMA CTrach assembly and compare the intubation characteristics in patients with cervical collar.METHODS80 patients of ASA status I or II, scheduled for elective surgery requiring general anaesthesia and endotracheal intubation were randomly allocated to two groups- A and B. Patients in Group A were intubated using McCoy laryngoscope and Group B using LMA CTrach, with cervical collar in situ. Airway assessment included measuring thyromental distance, observing MPC grade and measuring inter-incisor distance, before and after application of semirigid cervical collar. Glottic view was noted using modified Cormack-Lehane grading. Device insertion time, total intubation time, number of attempts, haemodynamic factors and airway complications during the procedure were noted.RESULTSThere was decrease in inter-incisor distance and worsening of MPC grade in both groups post application of cervical collar. The time taken for device insertion in Group A was 16.95 + 3 sec, and in Group B was 33 + 4 sec (P= 0.0001). The total intubation time in Group A was 40.4 + 6 sec and in Group B was 57.4 + 4.37 sec (P= 0.0001). CL grade I was more common in Group B (31) than Group A (17) (P= 0.003). The number of attempts required, mean haemodynamic parameters and airway complication were comparable between the two groups.CONCLUSIONSThe McCoy laryngoscope requires less time to obtain glottic view and subsequent intubation, but LMA CTrach provides better glottic exposure. Thus, LMA CTrach has better performance characteristics in patients with cervical collar in situ.

Cytotoxicity Test of Cervical Collar in Aids / 中国康复理论与实践

Objective To study the cytotoxicity of cervical collar in rehabilitation technical aids and to investigate the cytotoxicity of domestic marketed products. Methods According to the experimental principle of GB/T 16886.5-2003 and GB/T 16175-2008,microscopic observa-tion and Thiazole Blue Colorimetric methods were used to observe the toxicity of extract from four different cer-vical collars on the cells(L929). Results When the concentration of the extract was 0.1 g/ml,the cytotoxicity was grade three and grade two in the cervi-cal collars D and A,respectively;and it was grade one both in cervical collars B and C.When the concentration of the extract was 0.2 g/ml,the cytotoxicity was grade four in cervical collars A and D,and was grade two in cer-vical collars B and C. Conclusion The cervical collars varied in the cytotoxicity,especially in cervical collars A and D.

Cervical collar makes difficult airway: a simulation study using the LEMON criteria

OBJECTIVE: Endotracheal intubation is extremely difficult to perform in patients wearing a cervical collar for a head and neck injury. Therefore, we analyzed actual measurements using the look externally, evaluate 3-3-2, Mallampati score, obstruction, and neck mobility (LEMON) criteria before and after cervical collar application to investigate the causes of a difficult airway. METHODS: This simulation study was performed in 76 healthy volunteers. We measured the mouth opening, modified Mallampati classification, and neck extension before and after cervical collar application. RESULTS: The mean inter-incisor distance significantly decreased from 4.3 to 2.6 cm (P < 0.001). Fifty-seven participants classified as I and II were newly classified as III and IV according to the modified Mallampati classification after cervical collar application (16% to 91%). The angles of neck extension significantly decreased from 44° to 22° after cervical collar application (P < 0.001). Before cervical collar application, our simulations predicted that 14 of 76 participants (18%) would have a difficult airway, whereas after cervical collar application, 76 of 76 (100%) were predicted to have a difficult airway. CONCLUSION: All values for the LEMON criteria (mouth opening, modified Mallampati classification, and neck extension) worsened significantly after cervical collar application. Additionally, a difficult airway was predicted in all participants after cervical collar application.

The influence of cervical collar height on the compressive strength of CAD/CAM zirconia-ceramic restora-tion / 实用口腔医学杂志

Objective:To evaluate the influence of cervical collar height on the compressive strength of CAD/CAMzirconia-ceramic restoration.Methods:Zirconia cores were manufactured and divided into 5 groups (n =1 0)based on the cervical collar height(mm):0.0(A),1 .0(B),1 .5(C),2.0(D)and 2.5(E).After veneered with porcelain,all the samples were cemented on the metal tooth analog and then mounted in an universal test machine.The force was applied at a crosshead speed of 1 mm/min until catastrophic fail-ure occurred.Fracture loads and failure modes were recorded.Results:Mean of the fracture strength values(kN)in group A,B,C, D and E were 0.95 ±0.39,1 .29 ±0.50,1 .54 ±0.28,2.04 ±0.1 9 and 2.27 ±0.53 respectively(among groups,P <0.05).Two types of fracture modes were observed:chipping of the veneering porcelain and fracture of the veneering porcelain together with the framework.Conclusion:Zirconia coping design with 1 .5 mm cervical collar height may increase the compressive strength of CAD/CAMzirconia-ceramic restoration.

Efficacy of Cervical Collar on Cervical Hypertension / 中国康复理论与实践

Objective To observe the effect of cervical collar on cervical hypertension. Methods 98 patients with cervical hypertension were divided into two groups. The treatment group (n=50) wore the cervical collar, and the control group accepted massage and traction. Re-sults 52.0%of the treatment group were cured, and 92.0%improved, which were 41.7%and 75.0%in control group respectively (P<0.05). The blood pressure reduced in the treatment group after treatment, and was less than those in the control group (P<0.05). Conclusion Cervi-cal collar is effective on cervical hypertension.