Introduction

Previous articles confirmed the high incidence of pleural effusions diagnosis in Emergency Department. Using criteria based on the physical examination and evaluation of chest roentgenograms, an annual incidence of 8.4% was recorded. This incidence would probably be higher if diagnostic modalities such as ultrasound were employed [₁, ₂]. Large effusions can compress the underlying lung, resulting in atelectasis and impaired gas exchange [₃]. Current common practices to drain uncomplicated pleural effusions include thoracentesis via small gauge needles, use of large-bore chest tubes, or small-bore pigtail catheters placed under radioscopic guidance. Each technique has its advantages and limitations [₄, ₅]. Aim of this prospective observational study was to avoid repeated thoracentesis and drain large effusions using an indwelling 16 G single lumen central venous catheter (CVC).

Patients And Methods

Patients

Methods

Procedure was performed with the patient lying in a semi-recumbent manner at an angle of 45°. Ipsilateral arm was raised over the head and, eventually, held in place by the nurse assistant (Fig. 1).

Figure 1

Figure 1: Insertion position procedure.

Insertion site was determined by chest examination. Local anesthetic (Lidocaine 2%, 5 ml; Ropivacaine 5%, 5 ml) was infiltrated from subcutaneous tissue down parietal pleura with a 21 G needle. Insertion kit used was Arrow™ 16 G CVC set (Arrow, Reading, Pennsylvania, USA). 16 G Trocar needle was inserted into specified intercostal space in the mid-axillary line. Seldinger technique was applied with the flexible guide wire inserted 2 cm beyond distance of Trocar needle. Tract was subsequently dilated prior insertion of catheter. Length of catheter in the pleural space ranged from 5 to 15 cm, the final depth being dependent on the ease of aspiration of the pleural fluid. Catheter was then connected to a drainage bag via a three-way stopcock. Chest radiograph was performed routinely post catheter insertion. Daily and total volumes of pleural fluid drained were recorded. Means and standard deviations of pleural fluid drained volumes at 1, 6, and 24 hours post catheter insertion are presented.

Results

Mean volumes drained at 1, 6 and 24 hours were 454±241 ml, 756±403 ml and 1,010±469 ml, respectively. As we did not simultaneously determine serum lactate dehydrogenate levels and serum total protein levels, we classified exudates as having pleural fluid lactate dehydrogenate levels ≥200 I.U. [₆] or pleural fluid total protein levels ≥30 g/l [₇]. 37 samples were classified as exudates and 16 samples as transudates. Results for one sample were not available. No patients had pneumothorax on first roentgenogram performed within 8 – 12 hours after catheter insertion. There were no instances of hemothorax or re-expansion pulmonary edema. None of the catheters slipped out and there were no accidental disconnections of drainage system. Longest duration of in situ catheter was 14 days, and drained a total of 5,050 ml over this period. Daily drainage ranged from 70 to 1,700 ml/day. There were no instances of catheter blockage despite fibrinous material being seen in the collection bag of 2 (3.57%) patients.

Discussion

Single puncture thoracentesis has been found to be a safe technique [₈] although there are still reservations about its use [₉, ₁₀]. Procedure may need to be repeated frequently, however, and may thus cause some discomfort to the patient and an increased risk of complications associated with repeated puncture. Bedside placement of large-bore chest tubes, 24–32 F in diameter, is an alternative technique but its limitations are that the indwelling chest tubes are often associated with much patient discomfort and a relatively higher risk of mechanical complications. This can be overcome using fine pigtail catheters of 8.0 – 14.0 F, and is usually placed under ultrasound guidance by radiologists [₁₁]. This article describes use of similar flexible tube, but smaller in diameter, which can be kept in situ to facilitate continuous drainage and thus avoid patient discomfort and potential complications from repeated thoracentesis. Our patients reported minimal, if any, discomfort from the catheter. Ultrasound-guided techniques have been advocated for use [₉, ₁₀]. Thoracentesis under ultrasound guidance is not complication free, however [₁₂]. Insertion is frequently delayed and patients may need to be transported to the radiology department for the procedure. Our complication rate is no worsening than those reported in literature [₅, ₁₀, ₁₃]. First reported use of a CVC to aspirate a pleural effusion might be attributed to Cooper who used it in a single patient to aspirate an effusion, after which it was removed [₁₄]. We have been unable to trace any other published material on this technique except for follow-up correspondence [₁₅]. Our study has also shown feasibility and safety of using a urine drainage bag instead of a water seal system. The bag is always placed below level of patient's chest. We do not routinely flush the drainage system. The catheter is removed if pleural drainage is less than 100 ml for two consecutive days. There are several potential advantages of this technique over repeated thoracentesis, use of pigtail catheters and use of conventional large-bore chest drains. This single lumen catheter is well tolerated with minimal patient discomfort, and is not associated with catheter blockage, problems with the drainage system and with infection. Technique thus avoids need for repeated punctures, which are painful.

Conclusion

This article provides data on use of 16 G indwelling CVC to drain large non-loculated pleural effusions in the Emergency Department. It appears that this technique is useful and safe in selected individuals. Non-ultrasound guided placement of small-bore catheters such as central lines provide effective and safe drainage of pleural effusions with minimal discomfort.