Tehran University Medical Journal

Background: Difficult intubation (DI), often unexpected, remains a primary concern for anesthesiologists. The purpose of this study was to compare the sensitivity and specificity of ULBT with sternomental, thyromental and interincisor distances in predicting difficult intubation.

Methods: In a prospective study, 380 patients undergoing general anesthesia were included. In all patients sternomental, thyromental and inter-incisor distances and the ULBT score were evaluated preoperatively. The Cormack grade was determined after the induction of anesthesia and grade 3 or 4 was considered as difficult intubation. The best points with highest accuracy were determined by ROC curve. Sensitivity and specificity of these tests in predicting difficult intubation were calculated and evaluated.

Results: In 19 (5%) patients, intubation was difficult. ULBT class III, inter-incisor distance less than 4.5 cm, thyromental distance less than 6.5 cm, sternomental distance less than 13 cm were considered as difficult intubation and there were significant differences between them and laryngeal view (P<0.05, McNemar) but there was no difference between laryngeal view in both sex. The sensitivity and specificity of ULBT is significantly higher than thyromental and sternomental and Inter-incisor distances (the specificity were respectively 91.96% vs. 64.77%, 70% and 82.27% and accuracy were respectively 91.05% vs. 76.58%, 71.32%, 81.84% and 59.53%)

Conclusion: We conclude that the specificity and accuracy of ULBT is significantly higher than inter-incisor, thyromental and sternomental distances and is more accurate in airway assessment.

Background: Prolonged endotracheal intubation is a growing method for supporting ventilation in patients who require intensive care. Despite considerable advancement in endotracheal intubation, this method still has some complications the most important is laryngo-tracheal injuries.                   

Methods: Over a 2-year period, this retrospective study was conducted on 57 patients with history of prolonged intubation who were referred to the ENT Department of Amir Alam Hospital. For each patient, a complete evaluation including history, physical examination, and direct laryngoscopy and bronchoscopy was done under general anesthesia.

Results: Fifty-seven patients (44 male mean age, 23.014.7 years) were studied. Mean intubation period was 15.88 days. The most common presenting symptom was dyspnea (62%). Head trauma was responsible for most cases of intubation (72.4%). The most common types of tracheal and laryngeal lesions were tracheal (56.9%) and subglottic (55.2%) stenosis, respectively. Mean length of tracheal stenosis was 0.810.83 cm. There was a statistically significant relationship between length of tracheal stenosis and intubation period (P=0.0001) but no relation was observed between tracheal stenosis and age, sex, and etiology of intubation (All P=NS). Among the glottic lesions, inter- arytenoids adhesion was the most common lesion (25.9%). No statistically significant relation was found between glottic and subglottic lesions and age, sex and intubation period (all P=NS). Length of stenosis and intubation period was significantly greater in tracheal/ subglottic lesions than those in glottic/ supraglottic lesions (all P=NS).

Conclusion: After prolonged endotracheal intubation, laryngo-tracheal lesions had no relation with patient’s age, sex, and cause of intubation.There was direct relation between length of tracheal stenosis and intubation period. Glottic lesions were more commonly observed in head trauma patients. Lesion length and intubation period were greater in tracheal and subglottic lesions.

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.

Background: Nasogastric tube (NG tube) usage was first described in 1921 by Levin. Surgeons routinely use NG tube in most esophageal resections. Considering the numerous complications caused by this tube, the uncertainty about its usefulness and the scarcity of studies conducted on the subject, particularly in esophageal cancer patients, we investigated the necessity of the NG tube in these cases.

Methods: This clinical trial was performed at the Cancer Institute of Imam Khomeini Hospital. Esophageal cancer patients were randomized into groups either with or without postoperative NG tube the latter group was also prescribed metoclopramide. Postoperative obstruction was the exclusion criteria. The operation was done by a team of surgeons using the surgical techniques of McKeown or Orringer. All patients received ranitidine, heparin and antibiotics postoperatively. All patients received postoperative chest X-ray and chest physiotherapy. The NG tube was inserted or reinserted for those with abdominal distention and/or repeated vomiting. The NG tube was pulled out after return of bowel movements. The variables recorded for each patient included the first day of flatus, the first day of defecation, the first day of bowel sound (BS) upon auscultation, duration of post-operative hospitalization, nausea and vomiting, abdominal distension, pulmonary complications, wound complications, anastomotic leakage and the need for placing/replacing the NG tube. Statistical analysis was performed using SPSS, v. 11.5.

Results: After randomization, the NG tube was inserted for 22 patients, and 18 patients had no NG tube. The incidence of anastomotic leakage was significantly higher in the NG-tube group. No significant differences between the two groups were found for other complications. The mean times until first passage of flatus, defecation and BS upon auscultation and the duration of post-operative hospitalization were not significantly different. The need for placing/replacing the NG tube was the same for both groups. There was no difference in the perioperative death rates between the two groups.

Conclusions: We conclude that the routine use of NG tubes after surgery is not recommended for all patients. NG tube should be used according to the specific needs of each patient. This protocol will protect patients from undesired complications.

Background: The risk of atherosclerosis and cancer is high in hemodialysis (HD) patients. There is evidence that HD causes oxidative stress. However, the causative factors of oxidative stress are unknown. It has been suggested that HD imposes an additional oxidative stress on patients with chronic renal failure by activation of granulocytes on dialyzer membranes resulting in an imbalance between oxidants and antioxidants. In this regard, a number of reports, either measuring specific analytes or enzymes, or estimating the total antioxidant activity of the plasma have given contradictory and inconclusive results. To investigate the oxidative stress status in Iranian HD patients, in this study, we evaluated GSH and FRAP levels along with Ca and pH in the blood of these patients.

Methods: Along with 20 healthy age and gender matched control subjects, 24 patients underwent dialysis, three times per week, for four hours in each session. Before and after dialysis, blood was taken for biochemical and liver function tests and to evaluate oxidative stress markers and measure Ca and pH levels.

Results: There was a significant decrease in FRAP and GSH levels after dialysis compared to those before treatment. Dialysis caused an increase in pH and Ca levels compared to levels in control subjects after dialysis.

Conclusion: In general, before dialysis, there is a balance between oxidants and antioxidants however, due to higher levels of oxidants as well as the possible binding of antioxidants to the dialyzer membrane during dialysis, an imbalance occurs. The instability in the balance of oxidants and antioxidants may be the major cause of cellular oxidative damage found in HD patients. This study indicates that there is a significant level of oxidative stress in renal chronic patients and this stress is augmented by dialysis. Antioxidant therapy should be considered in these patients.

Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 Background: Post-intubation tracheal stenosis is a serious problem and surgical resection is the method of choice in long segment tracheal stenosis treatment. The aim of this study was to review the results of surgical treatment of long segment post intubation tracheal stenosis and the role of bilateral hyoid bone cutting in supra- hyoid release technique.
Methods: Between 2004 to 2008, 14 patients with proximal long segment tracheal stenosis with resection of more than 40% of trachea length were evaluated regarding surgical technique and post-operative results.
Results: The mean age of patients was 22.2±0.4 years. Etiology in all patients were head trauma and prolonged intubation and all patients had tracheostomy at the time of trearment. Average time between surgery and first admission was 4.5±0.5 months. Average length of stenosis and resected segment were 3.6±0.5 and 4.3±0.5cm respectively. Average increased length of trachea after bilateral hyoid bone cutting was 1.1±0.3cm. Postoperative complications occurred in one patient with wound infection, and 4 patients had stenosis recurrence which was treated in 3 patients using multiple dilation. Quality of life 2 years after surgery in 71% of patients were classified in good and excellent group. We didn't have any mortality.
Conclusion: Based on the fact that surgery is the best method of treatment in long and multi segment tracheal stenosis and tension in suture line is a serious problem, we recommend extended releasing technique including bilateral hyoid cutting in surgical treatment of these patients.

Background: Inadequate ventilation, esophageal intubation and difficult intubation are the most common adverse respiratory outcomes in patient undergoing anesthesia .The aim of this study was to compare Mallampati test in supine and sitting positions in traditional approach and during phonation for predicting difficult laryngoscopy and intubation.
Methods: In this study performed in Imam Khomeini Hospital in Tehran, Iran, Mallampati test was performed on 661 patients who met the inclusion criteria for the study. The test was done in supine and sitting positions with and without phonation by a rater who was blind to Mallampati test. Subsequently, laryngoscopy view and difficult intubation were evaluated in the four aforesaid positions by Mallampati test for predicting difficult laryngoscopy and intubation. For each situations, sensitivity, specificity, positive and negative predictive values and accuracy were calculated.
Results: Overall, 28 (4.2%) patients had difficult laryngoscopy and 9 (1.4%) patients had difficult intubation. The highest sensitivity for Mallampati test in predicting difficult laryngoscopy and intubation was in supine and sitting positions without phonation, and the highest specificity was seen in sitting position with phonation. Negative predictive values were more than 95% in all different positions for Mallampati tests and the highest positive predictive value was seen in supine position with phonation.
Conclusion: According to our findings, the highest correlation between Mallampati test and different positions in predicting difficult laryngoscopy and intubation was seen in supine position with phonation. Phonation improved Mallampati score in supine rather than sitting position.