Tehran University Medical Journal

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Background: Failed endotracheal intubation is one of the principal causes of morbidity and mortality in anesthetized patients. If the anesthetist can anticipate which patients may be more difficult to intubate, can reduce the risks of anesthesia greatly and be more prepared for any difficulties that may occur. The aim of this study was to investigate the inability of patients to protrude the lower jaw in predicting difficult intubation.
Methods: In this prospective study, we enrolled 300 patients, above 16 years of age or older, who were scheduled for elective surgery. For all of the patients, before each operation, a single anesthesiologist measured the temporomandibular mobility, which was defined as the difference between the distances, from the lower incisors to the upper incisors in a neutral position and at maximum mandibular protrusion. At the time of intubation, another anesthesiologist, blinded to the preoperative airway assessment test, performed a laryngoscopy in which the laryngoscopic view of the larynx was determined according to the Cormack and Lehane scoring system. Difficult intubation was defined as laryngoscopic views of grade III and IV.
Results: Twenty-one patients were identified as having difficult intubation. Only one patient could not be intubated. The forward movement of the mandible was significantly greater in patients with easy intubation compared to those with difficult intubation (6.42±1.95 mm vs. 3.58±1.26 mm respectively, P<0.001). The use of a cut-off point of less than 5 mm for prediction of difficult intubation showed a sensitivity of 92.86% and a specificity of 70.43%.
Conclusion: The forward movement of the mandible is significantly greater in patients with easy intubation compared those with difficult intubation Although infrequent difficulties may arise, most patients that do not have indicators of difficult intubation will be easy to intubate under anesthesia.

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Background: Rheumatoid arthritis (RA) is a chronic inflammatory disease with several factors that contribute to its manifestation and continuation. One of the factors that initiate RA is emotional stress, which is in direct relationship with the sufficiency or insufficiency of the neuro-endocrine axis. Therefore, any stress that is not resolved in the neuro-endocrine axis might lead to RA and, as the stress continues, it causes the continuation of the disease. The aim of this study is to determine the effect of stress on continuation of RA and to find curative methods and, ultimately, the best method for treatment.

Methods: One hundred rheumatoid arthritic patients (80 females and 20 males), having a final diagnosis of RA based on the guidelines of the American College of Rheumatology and onset of disease within the last 12-36 months, were studied as case and control subjects. Data was collected using interviews and questionnaires that reflected their life events with stress as a serious factor in their disease. The patients were divided into two groups: group A with stable stress and group B with unstable stress. The same treatment method was given to both groups. The results of the treatment were evaluated and compared after two years of follow up. Results: There was significant improvement in the patients in group B with unstable stress over that of the patients in group A with stable stress (P<0.0001). Conclusion: The present study shows that a considerable number of RA patients suffer from serious stress that affects their clinical path and improvement, and is quite visible in the health indexes and continuity of the disease. The results further showed that stress can play an important role in the initiation and continuation of RA. Therefore, by identifying and making efforts to remove the stress factors using anti-anxiety drugs, the disease can be better controlled.

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Background: The major responsibility of an anesthesiologist is to provide adequate respiration for the patient. The most vital element in providing functional respiration is the airway. No anesthetic is safe unless diligent efforts are devoted to maintaining an intact functional airway. Difficult intubation had been classified into four grades, according to the view obtainable at laryngoscopy by Cormack and Lehane in 1984. This grading system has been in use to evaluate and manage those patients with difficult airway by anesthesiologists. In clinical state, grades III and IV are quite rare, so the need for a modified Cormack and Lehane grading system was felt. The use of a modified Cormack-Lehane scoring system of laryngoscopic views during direct laryngoscopy, was previously examined in the Western population. Koh and his co-workers had examined this modified Cormack and Lehane grading system in Asian population in a study in Singapore General Hospital. The aim of this study was to investigate this scoring system in Iranian patients.

Methods: In a cross sectional study, a modified version of the Cormack and Lehane grading system was evaluated in 300 patients requiring tracheal intubation. In the modified system, grade II (only part of the glottis is visible) was divided into IIa (part of the cords is visible) and IIb (only the arytenoids or the very posterior origin of the cords are visible). Difficult intubation was defined as requiring more than one laryngoscopy or the use of special equipments.

Results: Sixty eight patients (22.7%) were scored as grade IIa and 32 (7.7%) as grade IIb. The prevalence of difficult intubation in grade IIb was significantly higher than patients in group IIa (47.8% vs. 2.9% respectively, Fisher's exact test, p= 0.001)

Conclusion: The modified grading system provides more information than the original Cormack and Lehane system.