Through this prospective study, we reported that the vacuum bottle plus non-tunneled catheter drainage of pneumothorax is a safe and efficacious procedure. In addition, we provide a detailed clinical course concerning oxygenation only with watchful waiting, simple air aspiration, and pigtail drainage, which may aid decision -making regarding post procedural pneumothorax.
Simple aspiration of air or fluid through catheter plus vacuum bottle has been performed in many hospitals in Taiwan. Compared with manual drainage, a vacuum bottle-assisted drainage facilitates continuous removal of air or fluids, diminishing the necessity of repeated 3-way stopcock and syringe manipulation which could be annoying and time-consuming during large-volume thoracentesis. Yamagami et al. evaluated 72 post-CT guided biopsy pneumothoraxes that required needle aspiration; the mean volume of air was 527 mL, with the largest volume being 2700mL. In a similar study conducted by Faruqui et al., the mean aspirated air volume was 680 (200-2000) mL. A 50-mL syringe would require approximately 10 to 50 repeated manipulations, which would be laborious and time-consuming16,17.
However, the possibility of large negative pressure exerted by the vacuum bottle on the pleural space makes the safety of this procedure a concern. A rapid re-expansion of the collapse lung may lead to so called re-expansion pulmonary edema. Although rare, the related mortality might be as high as 20%18. The main factors contributing to re-expansion pulmonary edema include collapse of the lung for more than 3 days, use of negative intrapleural pressure to rapidly re-expand the collapse lung, and the removal of more than 1 L of effusion. Feller-Kopman et al. suggested that large-volume thoracentesis is feasible as long as the patient is symptom-free or the end-expiration intrapleural pressure is maintained below -20 cmH2O19. In this study, the time from the development of pneumothorax to intervention were all within hours. Besides, the air drainage flow rate was slow by keeping the formation of air bubble in one straight line throughout the procedure. Lastly, by intermittently monitoring intrapleural pressure during negative pressure drainage, we proved that the vacuum bottle-assisted drainage is safe, and the end-expiratory intrapleural pressure remained less than 20 cmH2O throughout the procedure (Supplementary Fig. S1).
In the current cohort study, 15 out of 21 (71.4%) patients achieved lung expansion by vacuum bottle plus non-tunneled catheter drainage, with the remaining 6 (28.6%) patients requiring pigtail catheter drainage as a rescue. No patient experienced persistent air leak. This finding is comparable with previous studies, which reported a lung expansion rate of approximately 57.1–94.1% by manual needle aspiration1,9,16,17,20−23. The median event-free period in this study was 2 (IQR, 1-4) days in the vacuum bottle plus non-tunneled catheter drainage only group. This finding is compatible with previous studies, wherein the median hospital duration ranged from 1 to 5 days (Table 3) 10–12,16,17,20−24. The event-free duration was almost equal to that in the subgroup of patients in the oxygen only group with size of pneumothorax less than 10% and shorter than that in patients with larger size of pneumothorax in this cohort. Moreover, all patients who required subsequent pigtail placement achieved full lung expansion in this study, with an event-free period of 5 (IQR, 5-8) days, which was comparable to the event-free duration of 6 to 7 days with primary tube thoracostomy reported in previous studies16,20.
Table 3
Comparison of Studies Employing Simple Air Aspiration in Patients with Iatrogenic or Traumatic Pneumothoraxes
| Study design | Enrolment criteria | Method of aspiration | Patient number and success rate*, n (%) | Procedure time and hospital duration | Pain, costs, and complications |
Chen et al., 2021 | Prospective cohort study | Inclusion: Radiographic evidence of pleural line after lung biopsy and the size of pneumothorax ≥ 15% (Rhea’s criteria) Exclusion: Age < 20 years, bleeding tendency, and hemodynamic instability | 16G IV catheter, a 3- way stopcock, drainage set, and vacuum bottle | Total patients: 21 Success: 15 (71.4%) | Procedure time: median 90 (IQR 60-180) seconds Hospital duration: Median 2 (IQR 1-4) days | Pain: - before: median 1 (IQR 0-1) - during: median 1 (IQR 0-1) - after: median 0 (IQR 0-1) Cost: Vacuum bottle plus catheter aspiration: 49 USD Pigtail drainage: 136 USD Complications: nil |
Domokos et al., 202020 | Retrospective cohort study | Inclusion: Pneumothorax with visible rim ≥ 2 cm between the lung margin and the chest wall at the level of the hilum Exclusion: N/A | 16-G or 18-G over the needle cannula, a 3-way stopcock, and 50-mL syringe | Total patients:14 Success: 8 (57.1%) | Hospital duration: 2.0 (IQR 2.0-3.25) days | |
Parlak et al., 201222 | Prospective randomized controlled study | Inclusion: age 18-85 years, first symptomatic pneumothorax or asymptomatic with size ≥ 20% (Light's index) Exclusion: Pregnancy, severe comorbidity, recurrent or tension pneumothorax, limited decision-making, chronic lung disease, HIV or Marfan syndrome | 1.3-mm angio intravenous catheter, a 3-way valve, and 50-mL syringe | Total patients: 25 Success: 17 (68%) ** | Hospital duration: 2.4 ± 2.6 days** | |
Yamagami et al., 200616 | Prospective cohort study | Inclusion: Post CT-guided biopsy with pneumothorax not considered to be small (≥7 slices on post-biopsy CT) irrespective of symptoms Exclusion: N/A | 18-G IV catheter, a 3-way stopcock, and 50-mL syringe under real-time CT fluoroscopy guidance | Total patients: 72 Success: 61 (84.7%) | Hospital duration: - Complete resolution: 1.9 ± 2.0 (1 day, 0-7) days - Partial resolved: 4.1 ± 2.4 (3, 0-8) days | |
Faruqi et al., 200417 | Prospective cohort study | Inclusion: Size of pneumothorax ≥15% of hemithorax or symptomatic Exclusion: Very sick patient or tension pneumothorax | 18-G IV catheter, a 3-way stopcock, and 50-mL syringe | Total patients: 12 Success: 11 (91.7%) | Hospital duration: - Aspiration only: 1.6 days - Aspiration failed followed with intercostal tube: 10 days - Direct with intercostal tube: 8.2 days | Pain: VAS 1.6 (aspiration) VAS 4.2 (failed with intercostal tube) VAS 4.0 (intercostal tube) Cost: Simple aspiration: 90 IRP Direct intercostal tube: 300 IRP |
Yamagami et al., 200224 | Prospective cohort study | Inclusion: Post CT-guided biopsy with pneumothorax not considered to be small (≥7 slices on post-biopsy CT) irrespective of symptoms Exclusion: N/A | 18-G IV catheter, a 3-way stopcock, and 50-mL syringe under real-time CT fluoroscopy guidance | Total patients: 20 Success: 18 (90%) | Hospital duration: 3.60 ± 2.78 (range, 0-9; median, 3) days | |
Yankelevitz et al., 199623 | Prospective cohort study | Inclusion: Post CT-guided biopsy with large size pneumothorax (visually estimated >30% on CT) Exclusion: N/A | 18-G 5-cm IV catheter, a 3-way stopcock, and 50-mL syringe | Total patient:17 Success: 12 (70.6%) | Procedure duration: 10-15min | Complication: nil |
Markos et al., 199021 | Prospective cohort study | Inclusion: Symptomatic pneumothorax (dyspnea, chest pain) visually ≥ 20% of hemithorax by PA CXR Exclusion: Severe respiratory distress, simultaneous bilateral pneumothoraxes, post pneumonectomy | 16-G IV catheter, a 3-way stopcock, and 60-mL syringe | Total patients: 12 Success: 8 (67%) | Hospital duration: success: 1.13 ± 0.35 days failed: 3.50 ± 0.71 days | Cost: No exact amount but mentioning that the cost of simple aspiration is 1/10th of that of the large intercostal catheter Complication: local subcutaneous emphysema (6 patients) and mild vasovagal reaction (2 patients) |
Delius et al., 198911 | Prospective cohort study | Inclusion: Age ≥16 years, simple uncomplicated pneumothorax on chest X-ray Exclusion: Pleural effusion, hemothorax, multiple traumas, respiratory distress, hemodynamic instability | 8-F radiopaque polytetrafluoroethylene (Teflon) catheter with a 3-way stopcock, and a 50-mL syringe | Total patients:79 Success: 59 (74.7%) | Hospital duration: N/A (Discharge after 6 hours) | Cost: catheter aspiration: 868 USD Heimlich valve: 2884 USD Heimlich valve plus suction: 3028 USD Chest tube: 6402 USD Complication: 1 hemothorax; 2 retained sheared catheter tips |
Talbot et al., 198610 | Prospective cohort study | Inclusion: Age ≥16 years, simple uncomplicated pneumothorax on chest X-ray Exclusion: Cardiopulmonary instability, presence of hemothorax, hydrothorax, complex pulmonary disease | 16-G IV catheter, a 3-way stopcock, and a 50-mL syringe | Total patients: 57 Success: 46 (80.7%) | Hospital duration: 5.8 (4-10) days | |
Obeid et al., 198512 | Prospective cohort study | Inclusion: Simple traumatic pneumothorax Exclusion: Hemodynamic unstable; clinically important injuries; hemothorax; hydrothorax; pulmonary disease; respiratory distress | 16-G IV catheter, a 3-way stopcock and a 50-mL syringe | Total patients:17 Success at 1st attempt: 14/17 (82.4%) Success after 2nd attempt: 16/17 (94.1%) | Hospital duration: N/A (no hospitalization) | Cost: Aspiration: 310 USD Chest tube: 3,030 USD |
G: gauge, IV: intravenous, N/A: not applicable |
*Success was defined as aspiration only without subsequent rescue method such as tube thoracostomy. |
**The study did not separate patients with pneumothorax of different etiologies (included both spontaneous pneumothorax and traumatic pneumothorax). |
In this study, discomfort measurement before, during, and after the procedure was recorded as a very low pain score. Most patients reported no pain, except for minimal discomfort while receiving the local anesthesia injection before catheter placement. A similar result was reported by Faruqi et al., and the mean pain scores for simple aspiration and intercostal tube drainage were 1.6 and 4.0 respectively17. Moreover, the lack of indwelling catheter not only alleviated the irritable sensation that occurs owning to the presence of a foreign body object inside the body, which enabled patients to mobilize freely without limitation or fear of tube dislodgement, but also reduced the clinical burden of tube care on the nursing stuff and the medical costs11,21. Finally, no complication occurred in patients who underwent vacuum bottle plus non-tunneled catheter drainage in this study. Hence, we are confident that vacuum bottle plus non-tunneled catheter drainage, similar to previously reported manual simple air aspiration, is a safe and efficient procedure (Table 3)10–12,16,17,20−24.
Unlike other previous studies, we also evaluated the clinical outcomes of the patients in the oxygenation only group and found that the event-free duration differed dramatically with the size of pneumothorax, considering 10% as the cut-off point. As the size of pneumothorax between 10% and 20% remained a gray area for either intervention or watchful waiting, we suggest that initial management should entail simple aspiration by a chest specialist, because a successful air drainage reduced the duration of hospital stay and medical costs, especially in patients with pneumothorax size of 15–20%.
This study has several limitations. First, we did not perform a head-to-head comparison between catheter plus vacuum bottle-assisted air drainage and manual needle aspiration. Besides, a retrospective comparison may preclude validation of the data presented. A direct prospective randomized controlled trial may be required to overcome the limitation in the future. Second, this study was conducted in a single center and with predominantly CT-guided biopsy induced pneumothorax, which may prevent generalization of the findings. Third, there is no universal method adopted by different studies and guidelines. In addition, all these measurements are based on chest radiography, a 2-dimensional imaging modality, which may show disagreement on size of pneumothorax from each other. Further, the pleural line did not appear smooth in most patients, which could render the calculation incorrect for formulas that use only one parameter, such as Light’s formula or the interpleural distance at the hilum level considered by the British Thorax Society. This study adopted Rhea’s criteria, as we consider 3 sites of distance measurement for calculation, which suits most cases of lung collapse with varying shapes of pleural line. More accurate evaluation methods such as CT imaging may be considered and a universal consensus may be required, especially in asymptomatic patients with subjective large pneumothorax. Finally, the results of the current study can be applied only in patients with stable vital signs and not in those receiving positive mechanical ventilation.