airway foreign body ( fb ) is one of the common emergencies an ent surgeon must attend to . its clinical presentation is variable , ranging from a clinically asymptomatic state to dire state of respiratory failure needing urgent attention and intervention . rigid bronchoscopy , performed under general anesthesia ( ga ) , exposes the patient to the risk of ga and the complication of the procedure itself . according to righini,1 unnecessary rigid bronchoscopy performed under general anesthesia can expose the child to the risk of perioperative procedure complication ( 817% ) like bronchospasm , desaturation and bleeding , or airway edema . hence , the right decision to perform rb is based on clinical findings and radiological support . my study aims at correlating the clinical presentation and x - ray chest findings with the result of rb ( positive versus negative rb ) . it is very important to ask for the history of choking or aspiration from the parents or care - taker . upon clinical examination , a foreign body in the airway may reveal diminished breath sounds on the affected side or presence of rhonchi or crept . at the same time , the hypothesis of my study is to show the relation of clinical and radiological signs and in cases with presence of fb in the airway . it helps us understand the association of radiological and clinical findings to the results of bronchoscopy to avoid negative bronchoscopy . the objective of my study is to calculate sensitivity , specificity , positive predictive value , and odds ratio of the clinical and radiological signs and to compare them with the rigid bronchoscopy findings . this is a prospective analytical study done over a period of 18 months , from march 2011 to august 2012 . the institutional review board approved the study prior to its undertaking study and the subjects gave their formal consent . the inclusion criteria were all patients with strong clinical suspicion of foreign body in airway with a history of choking , cyanosis , difficulty in breathing , along with the presence of clinical signs , like decreased air entry , cyanosis , or crept . patients of any age and sex who qualified for the inclusion criteria were included . before the procedure after which all patients underwent chest x - ray and at times ct scan of chest whenever indicated . the chest x - ray was looked for radiological signs , presence of foreign body like collapsed segment , consolidation , trapped air or sometimes the foreign body itself when the foreign body was radio opaque . data has been collected broadly into three different categories : ( 1 ) symptomatology , such as the presence or absence of choking , cyanosis , and difficulty in breathing ; ( 2 ) clinical signs , such as the presence or absence of air entry , crept , and rhonchi ; ( 3 ) radiological signs , such as plain chest x - ray findings . after proper clinical evaluation and chest x - ray , all patients underwent rigid bronchoscopy under general anesthesia . after induction of intravenous anesthesia , we performed direct laryngoscopy and inserted the bronchoscope with the help of the laryngoscope in a rotating manner and used a 0-degree telescope to locate the foreign body . once identified , we used optical forceps to hold and to remove the foreign body . however , at times it was not possible to remove fb in the first attempt , and the procedure was repeated after 23 days . the decision to continue or to abandon the procedure depended upon the intraoperative bleeding and oxygen saturation . any amount of bleeding obscuring the surgical procedure and oxygen saturation compromising the anesthetic state of patient led to us to postpone the procedure to the next setting . after extraction of the foreign body , we repeated bronchoscopy to check for any remaining foreign bodies as well as to examine the tracheobronchial tree for any trauma . we analyzed the statistical relation of clinical and chest x - ray findings with rigid bronchoscopy . there were total of 40 rb performed under general anesthesia for the diagnosis and therapeutic reasons . the age of the patient ranged from 8 months to 13 years . of the 40 patients , 29 ( 72.5% ) were men and 11 ( 27.5% ) were women . upon clinical examination , the history of choking was the most common symptom and decreased air entry was the most common finding , as displayed in table 1 . abbreviations : h / o , history of ; sob , shortness of breath . among 40 patients who underwent rb , 32 ( 80% ) had foreign body in their airway , while 8 patients ( 20% ) had negative rb results . when the different clinical manifestations were cross - tabulated with the rigid bronchoscopy findings , history of choking was the only manifestation , which came out to be statistically significant ( p  =  0.043 ) with odds ratio of 5 . the detailed of cross tabulation between rb findings and clinical manifestation are shown in table 2 . similarly , i used data to calculate sensitivity , specificity , positive and negative predictive value for each of the clinical manifestations , as shown in fig the most common symptom of foreign body aspiration was choking ( 67.5% ) , which was the only statistically significant result in this study . similarly , decreased air entry was present in 77% of the patients , but was not significant in our study . however , righini et al1 reveal findings contrary to our study . in their study , the fb aspiration as well as unilateral decreased air entry was statistically significant to the presence of fb in the airway . similarly , a study done by gursu kiyan a ( 2009)3 et al in 192 patients over period of 5 years ( 20032007 ) showed history of aspiration and decreased air entry both were statistically significant , p value was  <  0.0001 in both variable . history of aspiration is important clinical parameter to decide for rb as shown from our study . it is supported by study done by martinot et al.4 he conducted comparative study between rigid and flexible bronchoscopy to find the negative bronchoscopy rate by two different techniques . he adopted a treatment algorithm where he used the child who had history of aspiration were directly channelized to undergo rigid bronchoscopy avoiding the flexible one . this shows asking the history alone is very important and must not be ignored at any cost . similarly , sensitivity and specificity of different clinical and radiological signs are displayed in fig . 1 . however none of the clinical parameters like choking , difficulty in breathing , cyanosis , decreased air entry , rhonchi and crept individually have high sensitivity and specificity together . this might be one of the important factor responsible for predicting the outcome of rigid bronchoscopy . in my study the unilateral decrease in air entry had highest sensitivity of 81% whereas presence of cyanosis and presence of rhonchi on auscultation had very high specificity of 87% . the study done by kiyan et al3 on 192 patients who underwent rigid bronchoscopy , with the presence of wheeze as a symptom , had highest sensitivity at 87.7% , followed by unilateral decreased air entry on auscultation ( i.e. , 78.3% ) . this result slightly varies from this study , as i have not considered wheeze as a symptom during data collection but the sensitivity of unilateral decreased air entry is practically similar . in the same study , the presence of cyanosis had very high specificity , at 98.1% , which was also the highest indicator in our analysis , reaching 87% specificity . in the kiyan et al3 study , the presence of productive cough had also very high specificity , at 96.3% , which was not taken into consideration during my study design . however , the presence of rhonchi had highest specificity in my study , but was not the highest in the study by kiyan et al,3 although the value was similar ( i.e. , 85% ) . the above results signify that there is always a chance of negative bronchoscopy exposing the patients to the hazards of general anesthesia and possible complication of rigid bronchoscopy during the procedure and afterwards . this is because of the inability to identify the single clinical parameter that can almost always predict the presence of foreign in the airway in every case . the rate of negative rigid bronchoscopy was 20% in my study , which is similar to the other studies done by different authors . the literature on negative bronchoscopy includes the study done by oren cavel et al5 displaying different rates on negative bronchoscopy and its complication , shown in table 3 . the rate of negative rigid bronchoscopy ranges from 18% to 43% , with most of them around 20% . abbreviations : fba , foreign body aspiration ; fb , foreign body ; rb , rigid bronchoscopy . hence , the alternative modality of investigation is preferable , especially if the clinician does not find a history of aspiration . also , as suggested by martinot et al4 in the study on a patient scheduled to undergo flexible bronchoscopy who had negative history of aspiration before doing rigid bronchoscopy . the flexible bronchoscopy is an alternative tool to detect fb in airway when there is no definite history of aspiration . however , it is difficult to perform in very young children and also has a chance of negative bronchoscopy : 12% ( righini et al)1 and 38% ( martinot et al).4 
  the other investigating tool in patients with suspicious history of fb in the airway is ct thorax , which for being noninvasive is an alternative to diagnose fb in suspicious cases . the study done by bhat et al6 showed high sensitivity and specificity of ct scan up to 92.3 and 85.5% , respectively , in 20 patients . similarly , a study done by bai et al7 in 45 patients had 100% of sensitivity and specificity in detecting the fb in the airway by using ct scan . besides the high rate of detection of fb by ct scan , it also locates fb in the airway and gives the number of fb , which definitely helps the surgeon to perform rb in a planned manner . rigid bronchoscopy remains the gold standard technique of diagnosis and management of airway fb , however it has a small chance of negative result . similarly , the history of choking is the only clinical parameter which is significantly associated with the presence of fb in airway . hence , in cases with negative history of choking but with clinical suspicion of fb in the air way , subsequent management should be tailored . alternative tools for confirming the presence of fb should be utilized , such as like ct scan of thorax or flexible bronchoscopy .
introduction 
 foreign body in airway is a common emergency in ent practice . as we know , rigid bronchoscopy is the method of choice for removing it , although at times it leads to specialists performing unnecessary bronchoscopy , exposing patients to hazards of general anesthesia.objective 
 the objective of my study is to calculate sensitivity , specificity , positive predictive value , odds ratio from the clinical and radiological signs , comparing with the gold standard , the rigid bronchoscope procedure.method 
 this is a prospective analytical study designed at university teaching hospital and conducted over a period of 18 months , from march 2011 to august 2012 . 
 data collection was broadly classified into three different categories : ( 1 ) symptomatology , such as presence or absence of choking , cyanosis , and difficulty in breathing ; ( 2 ) clinical signs , such as the presence or absence of air entry , crackles , and rhonchi 3 . 
 chest x - ray findings were suggestive of a foreign body.results 
 there were a total of 40 rigid bronchoscopies performed under general anesthesia for the diagnosis and therapeutic reasons . among 40 patients who underwent rigid bronchoscopy , 32 ( 80% ) were found to have varieties of foreign bodies in their airway while 8 patients ( 20% ) had negative bronchoscopy . 
 the history of choking is the only clinical symptoms which came out to be statistically significant ( p  =  0.043 ) with odds ratio of 5.conclusion 
 rigid bronchoscopy is the gold standard technique for diagnosis and procedure of choice to remove fb from airway . 
 regardless , it still presents a small chance of negative result , especially when there is no history of aspiration .