Yield of Percutaneous Needle Lung Aspiration in Lung Abscess: DISCUSSION part 2
The distribution of the bacteria obtained in our patients differs from that seen in other series. The main difference has been the lower role of anaerobes. Anaerobes have been present in only 57 percent of our cases with a positive culture, as compared to 72 percent in the series of Estrera et al, 84 percent in the series of Beerens and Tahon-Castell, or 87 percent in that of Bartlett. This difference may be explained, at least in part, because of the different composition of the series and because of taxonomic changes that have been recently introduced and that have led to classification of different species of Peptostreptococcus and Peptococcus as aerobic or microaerophilic streptococci. The frequency with which different species of anaerobes have been found in our series has been similar to that seen in other series if we exclude the absence of Bacteroides fragilis among our patients. With regard to aerobes, there have been some remarkable facts because of their possible therapeutic implications. One is a relatively more frequent finding of different species of Hemophilus and Staph aureus in our series, often as the sole bacteria responsible for the abscess. On the other hand, in a patient in whom LAs offered a mixed culture (unidentified pigmenting Bacteroides and A Iwoffi), blood cultures were positive for the aerobic bacteria, a fact that clearly implies a pathogenic role for this microorganism.
We wish to note that PLA has been of great aid in establishing the correct antibiotic treatment in our cases. The results of in vitro susceptibility testing of isolates from LAs changed the initial antibiotic trial in almost half of our patients (47 percent). In 17 patients, this change of treatment was due to finding one or more types of bacteria resistant to clindamycin or tobramycin (in 11 patients or 22 percent), or finding bacteria with greater susceptibility to other antibiotics (in six patients or 12 percent). In six other patients with a satisfactory clinical response to treatment with clindamycin and monobacterial isolates of LAs showing different species of microaerophilic Streptococcus and of penicillin-susceptible aerobic bacteria, this drug was substituted for clindamycin. It is important to remark that had we advised the use of penicillin instead of clindamycin in the initial antibiotic trial, this would have produced a greater number of patients with bacteria resistant to the initial trial or with greater susceptibility to different antibiotic associations. viagra plus
It has been known for many years that an appreciable number of patients with a lung abscess have an underlying bronchogenic carcinoma. The incidence of this association has been recorded in the medical literature as varying from 7.6 to 17.5 percent of the patients with a lung abscess. The most employed diagnostic method in the diagnosis of carcinoma associated with lung abscess has been fiberoptic bronchoscopy. In most recent series, its diagnostic accuracy has ranged from 56.7 percettt in the series of Sosenko and Glassroth to 70 perceift in the series of Wallace et al. The limitations of these results have made other diagnostic techniques necessary in a significant number of patients, including methods as invasive as thoracotomy. In this setting the results achieved with cytologic examination of LAs seem quite promising to us. Of the 33 patients in whom cytologic study of LAs was performed, it was diagnostic of bronchogenic carcinoma in seven cases, with corroboration of this fact by other diagnostic methods in all seven cases. With negative cytology of LAs, an associated carcinoma was demonstrated in only one case.
Complications of PLA in our series may be considered small if compared to other series that have used needles of larger caliber. The only complication in our series was iatrogenic pneumothorax in seven patients (14 percent), five of whom (10 percent) required the insertion of a small chest tube for resolution. It is of interest to point to the lack of pyopneumothorax as a complication in our series.
The favorable outcome in our patients and the low rate of surgical treatment suggest the benefit of using long-term therapy with antibiotics selected on the basis of bacterial isolates of LA cultures; however, PLA is an invasive diagnostic method, and therefore we do not recommend this technique in every patient with a cavitated pulmonary lesion. We find it suitable for patients with hospital-acquired pulmonary infection, giant lung abscess, lack of response to initial empiric antibiotic treatment, and those cases presenting with a severe clinical picture. This technique could also be adequate for patients with lung abscess who lack foul sputum and predisposing factors. canadian pharmacy viagra