Punção transtraqueal: comparação entre duas alíquotas de solução salina quanto ao rendimento de espécime para dosagem da alfa-amilase em pacientes sem evidência clínica de hipersecreção traqueobrônquica

Abstract

Until today there is no reference in medical literature about the volume of saline necessary to be infused through transtracheal puncture (TTP) within tracheobronchial tree of patients without clinical evidence of hypersecretion to obtain a return of fluid sufficient for biochemical, microbiological or cytological analyses. Due the fact that the airways Bellow the vocal cords is sterile in persons without pulmonary disease the collection of specimen through TTP is very accurate in diagnosing lung infections (BARTLETT, 1977; BARTLETT; ROSENBLATT; FINEGOLD, 1973; GOLIN et al., 1979; PECORA, 1959, 1974). The alpha amylase activity of bronchial secretions has the potential of been useful in diagnosing saliva aspiration (CLARKE et al., 1981; NANDAPALAN; MCILWAIN; ENGLAND, 1995; NANDAPALAN; MCILWAIN; HAMILTON, 1995). It can be useful also in monitoring saliva aspiration in others situations such as: during mechanical ventilation, enteral nutrition and lung diseases of Unknown origin. To do this is necessary to determine the normal value of alpha amylase activity. The present study had as objective to use TTP in patients without tracheobronchial hypersecretion to evaluate the efficacy of two volumes of saline (NS).In case of test positivity the alpha amylase activity was determined. The 81 patients were randomized in two groups. In group1 (n = 36) was infused 5 ml of NS and in group 2 (n = 45) it was infused 10ml of the same solution. The patients were sedated with a solution composed of diazepam and meperidine until reaching levels 2 or 3 in Ramsay’s scale. The anterior cervical region was prepared and anesthetized with 2% lidocaine .The tracheobronchial tree was anesthetized with 10ml 2% lidocaine infused with a 25/7G needle. Finally, the TTP was undertaken with 14G needle and a catheter was introduced in tracheobronchial tree trough the needle (Biocat®). The saline volume drawed was infused through the catheter and immediately aspirated with a negative pressure of 30 to 40 mmHg. The returned volume was measured with syringes of 1 or 3ml according with the amount aspirated. The test was considered positive when was aspirated a volume of at least 0,5ml. Due the viscosity of tracheobronchial secretions it was necessary to dilute the specimen with saline and correct the value of alpha amylase activity. Group 1was positive in 75% and group in 86%, without statistical significance (p = 0.18). The alpha amylase activity ranged from 120 to 10.000 Ui/L without difference between the groups (p=0.40).In conclusion there were no statistical differences in test positivity and alpha amylase activity between the two groups in patients without clinical and endoscopical evidence of hypersecretion.