Presentación de estados financieros

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situation over drives the respiratory centre in the medulla and thus manifests as shortness of breath.

Fever, a constant problem in para-pneumonic effusions, was observed in low grade in some cases of tuberculous effusions but none in the malignant cases. Fever and chest pain can be explained by the on-going inflammatory process. As documented by Herbert²⁷, pleuritic chest pain, fever and cough are the clinical presentation of empyema, which normally blends with the pneumonic process.

Weight loss was a major problem in the malignant effusions. Cachexia has been documented as the commonest cause of cancer death. Toxohomone and cytotoxic polypeptides have been postulated as the cause, although with no clear evidence yet

. It is also believed that interleukins play a very important role in cancer cachexia. Chronic empyema is associated with both anaemia and anorexia, which contribute to the weight loss.

The major physical signs on the chest were reduced chest excursion, stony dullness to percussion, and reduced air entry to the hemithorax. As noted earlier, right sided effusion was found to be almost double that of the left in this study. The reason for this may be related to the anatomical disposition of the right major bronchus as a direct continuation of the trachea. Furthermore, the predisposing lesions such as lung malignancy, pulmonary tuberculosis, pneumonia were commoner on the right. Bilateral cases were due to a diffuse pulmonary pathology such as tuberculosis, bronchopneumonia, or bilateral dissemination of secondary malignant lesion.

Radiological features were blunting of costo-phrenic angle, opacification of the hemithorax, and classical meniscus sign in some cases. Radiological confirmation is mandatory because it helps to plan appropriate treatment. The radiological findings usually confirmed the clinical suspicion of pleural effusion.

Pleural fluid aspiration is very helpful in initial assessment of physical and biochemical characteristics of pleural effusions. The physical appearance noted in this study were straw colour, serosanguinous and purulent. Whereas purulent fluid was commoner in the para-pneumonic effusions, the straw colored fluid was commoner in the tuberculous effusions while the sero-sanguinous fluid was commoner in the malignant effusions.

Physical appearance of pleural fluid however, is not specific and the finding of straw colored or sero-sanguinous effusion, demands for a more detailed assessment of the patientand further analysis of the fluid.

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Mean values for the specific gravity, protein concentration, and LDH were elevated. This is in keeping with the criteria presented by Light¹⁵ for exudative conditions. The mean glucose concentration of 30mg/dl and 32mg/dl in para-pneumonic and tuberculous effusions respectively were much lower than that of the malignant effusions (46mg/dl). Lipid estimation was basically within normal range except for the lone case of chylothorax complicating thoracotomy for empyema thoracis, where the triglyceride level was 300mg/dl. Loss of this high volume of triglycerides in chylothorax is of major nutritional significance. The sodium and potassium levels were similar to that of serum, while the bicarbonate level of 18mg/dl each in para-pneumonic and tuberculous effusions were slightly more acidic than the malignant ones which showed an average bicarbonate level of 21mg/dl.

High LDH level, as earlier explained is due to high cellular turnover and lyses which releases this enzyme into the fluid. Specifically, the mean LDH concentration in tuberculous effusions (1706IU) was found to be higher than that of para-pneumonic (1504IU) and the malignant ones (1304IU). The average glucose was 36 mg/dl. This relatively low level is attributed to the high metabolic activity in the pleural space which utilizes the available glucose. The low concentration of glucose was noted more specifically in the para-pneumonic (30mg/dl) and the tuberculous (32mg/dl) ones. The low PH, averaging 7.1 in this study is also attributed to high metabolic activity and its products such as lactic acid especially in a relatively anerobic environment of the pleural fluid. The lowest PH of 7.0 was found in the tuberculous effusions.

Cytological analysis was relevant only in malignant pleural effusion. Positive results were recorded in only one third of cases. The features of a positive result were pleomorphic cells with increased nuclear cytoplasmic ratio as well as nuclear hyperchromicity. There was indeed a low cytology yield in this study compared to the findings of Erozan

whereby initial cytology yield was up to 63%, and rising to 77% in subsequent samples. Perhaps what is important is that a negative yield could become positive on subsequent sampling and since false positive cytology almost never occurs according to Hausheer

, it is therefore possible that a second and even a third sampling could have improved the yield. Seeding of malignant cells into the pleural fluid is responsible for this finding.

Cell count confirms lymphocytosis of the pleural fluid which is in keeping with tuberculous effusion. These are chronic inflammatory cells in contrast to the relative

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neutrophilia found in para-pneumonic and empyematous effusions.

Acid-Fast Bacilli test was conducted on tuberculous effusions only. It was positive in only two cases (6.25%). The reason is captured in the pathogenesis which involves tuberculous pleuritis. This is a hypersensitivity reaction involving the pleural membranes and capillaries and not due to a direct invasion of the pleura by the mycobacterium. It is possible that biopsy of the pleural tissue may increase the yield of mycobacterium but we have not specifically biopsied the pleura in this study.

About a third of the para-pneumonic effusions (26.3%) yielded a positive result on Gram staining. The high rate of negative Gram-stain in para-pneumonic effusion and empyema (73.68%) is difficult to explain in this study, but some scholars believe that self antibiotics medication and abuse before and during presentation, could be responsible.⁴

Neoplastic disease was observed to be the commonest cause of pleural effusion and closely followed by tuberculosis with para-pneumonic cases as least common. That malignant pleural effusion assumes this position was supported by Leff ⁶⁰ whose study showed that malignant pleural effusion accounts for 25% of all cases of pleural effusion (including medical causes) in a General Hospital setting. Rising incidence of neoplastic diseases and late presentation is responsible for this. Breast carcinoma stands out as the commonest cause of malignant pleural effusion in this study contributing 65% of cases followed by lung cancer and soft tissue sarcoma both contributing. Intra-abdominal malignancies and parotid carcinoma contributed a little. This is in sharp contrast to the findings of Hausheer⁷⁷in United States, where lung carcinoma was the commonest with 35% and breast second commonest with 23%. The rising incidence of smoking and its direct relationship with lung cancer in their environment and the rising incidence of breast cancer and late presentation in our environment is probably responsible for this disparity. It was stated earlier in the review that some investigators report that up to 50% of patients afflicted with cancer will develop malignant pleural effusion sometime during their disease⁶².

All cases involved in this study were treated with tube- thoracostomy drainage as part or all of the treatment required. A sound understanding of the basic principles of chest drainage system by both the attending physician and nursing staff is of primary importance, and time spent communicating this to the understanding of the attending nursing staff is well spent⁸⁵. In their five year retrospective study involving 65 patients, Ekwunife⁸⁶ affirmed that though tube-thoracostomy is a simple and efficacious procedure for the treatment of pleural space collection, premature tube dislodgement

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was the commonest complication observed accounting for 50% of all complications, and advised that safety of procedure should be improved by adequate training. Various modifications of this drainage system have been adapted to suit different circumstances.

From Ibadan Nigeria, Adebo⁸⁷ reported that their preferred method of chest drainage consists of insertion under local anesthesia of the tubular end of an Aldon’s Urobag equivalent to number 34 Argyle chest tube, beveled, fenestrated and placed within the fifth or sixth intercostal space in the mid–axillary line. Similar studies in the past had confirmed the efficacy of this system in the evacuation of fluid from the pleural space⁸⁸. Tube-thoracostomy/underwater seal drainage system was pivotal in the treatment of these cases and proved to be quite reliable in the relief of symptoms, consequently all the patients benefited from it. In-fact 84.2% of all the para-pneumonic effusions needed no further treatment except antibiotics. A recognized sequel of untreated or unresponsive parapneumonic and tuberculous effusions is empyema thoracis. Indeed, three cases each progressed to empyema thoracis at one month evaluation in this study.

For tuberculous effusions, standard anti-tuberculous drugs include 600mg rifampicin tabs, 300mg isoniazid tabs, 1g pyrazinamide tabs, 500mg ethambutol tabs, and 50mg pyridoxine for most adults for duration of 9-12 months. This dose is usually modified according to body weight in younger patients. One of the choice antibiotics in parapneumonic effusions is augmentin which is administered parenterally (1.2g 8hrly) for a week but continued orally (625mg 8hrly) for the next three weeks, but it is normal practice to adjust dose for weight and height in children.

Malignant effusions require a further pleurodesis as an additional treatment. It aims at forestalling recurrence. It has been noted that the mean time for fluid reaccumulation is as short as four days, with a 98% recurrence rate at 30 days⁵⁹. Therefore, pleurodesis with a sclerosing agent such as tetracycline suspension is of paramount importance. In this study, about two thirds of malignant effusions had no recurrence at one month re-evaluation. The rest still had effusion due to persistence or recurrence, and needed repeat drainage and pleurodesis. Tetracycline suspension recorded a pleurodesis success rate of between 60–70% in this study. This was similar to Ezeome’s⁷³ results on malignant pleural effusions in Enugu South East Nigeria, and also that of Atimomo ⁷⁶ in Lagos, south west Nigeria. Both studies had used tetracycline suspension as the sclerosant. Although better results have been documented by Hausheer⁷⁷ using talc powder, there should be no hesitation in using tetracycline suspension, which is very accessible, cheap and has equally demonstrated a good promise as a sclerosing agent.

The commonest complication of treatment observed in this study was

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premature/accidental dislodgement of chest tube. This is in agreement with similar findings by Ekwunife^86. Though we observed it in only 33.7% of our cases compared to 50% in theirs it is highly recommended that safety of the procedure should be improved by adequate training of insertion procedure. Other complications include stoma sepsis, pneumothorax, empyema thoracis. Chylothorax is a recognized complication of decortication and it occurs when the thoracic lymphatic channels are inadvertently damaged. It is rare in occurrence but it is of major nutritional significance.

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