Chest tube removal at different gas flows in prolonged air leak: a randomized non-inferiority trial

OBJECTIVES

To evaluate the safety and feasibility of removing drainage tubes at larger size of air leak in patients with prolonged air leak after pulmonary surgery.

METHODS

Ninety-five patients who underwent pulmonary surgery with prolonged air leak in our centre were enrolled in this randomized controlled, single-centre, non-inferiority study. The drainage tube was clamped with a stable size of air leak observed over the last 6 h, which was quantified by gas flow rate using the digital drainage system. The control group (n = 48) and the study group (n = 46) had their drainage tube clamped at 0-20 ml/min and 60-80 ml/min, respectively. We continuously monitored clinical symptoms, conducted imaging and laboratory examinations, and decided whether to reopen the drainage tube.

RESULTS

The reopening rate in the study group was not lower than that in the control group (2.08% vs 6.52%, P > 0.05). The absolute difference in reopening rate was 4.44% (95% confidence interval -0.038 to 0.126), with an upper limit of 12.6% below the non-inferiority margin (15%). There were significant differences in the length of stay [16.5 (13-24.75) vs 13.5 (12-19.25), P = 0.017] and the duration of drainage [12 (9.25-18.50) vs 10 (8-12.25), P = 0.007] between the control and study groups. No notable differences were observed in chest X-ray results 14 days after discharge or in the readmission rate.

CONCLUSIONS

For patients with prolonged air leak, removing drainage tubes at larger size of air leak demonstrated similar safety compared to smaller size of air leak, and can shorten both length of stay and drainage duration.

CLINICAL TRIAL REGISTRATION NUMBER

Name of registry: Gas flow threshold for safe removal of chest drainage in patients with alveolar-pleural fistula prolonged air leak after pulmonary surgery. Registration number: ChiCTR2200067120. URL: https://www.chictr.org.cn/.

Safety and efficacy of vacuum bottle plus catheter for drainage of iatrogenic pneumothorax

Background

Iatrogenic pneumothorax is common after thoracic procedures. For patients with pneumothorax larger than 15%, simple aspiration is suggested. Although vacuum bottle plus non-tunneled catheter drainage has been performed in many institutions, its safety and efficacy remain to be assessed.

Methods

Through this prospective cohort study (NCT03724721), we evaluated the safety and efficacy of vacuum bottle plus non-tunneled catheter drainage. Patients older than 20 years old who developed post-procedural pneumothorax were enrolled. A non-tunneled catheter was placed at the intersection of the midclavicular line and the second intercostal space. A 3-way stopcock, a drainage set, and a digital pressure gauge were connected. The stopcock was manipulated to connect the pleural space to the pressure gauge for measurement of end-expiration intrapleural pressure or to the vacuum bottle for air drainage. The rate of successful drainage, the end-expiration intrapleural pressure before, during, and after the procedure and the duration of hospitalization were recorded.

Results

From August 2018 to February 2020, 21 patients underwent vacuum bottle plus catheter drainage (intervention group) and 31 patients received conservative treatment (control group). The end-expiration intrapleural pressure of all patients remained less than − 20 cmH₂O during drainage. No procedure related complication was observed. Large pneumothorax (≥ 15%) was associated with higher risk of persistent air leak (Odds ratio 12, 95% CI 1.2–569.7). Vacuum bottle assisted air drainage yielded shorter event-free duration than that of conservative treatment (2 days vs 5 days [interquartile range 1–4 days vs 3–7 days], p < .05). Vacuum bottle assisted air drainage also help identifying patients with persistent pneumothorax and necessitate the subsequent management. The event-free duration of persistent air leak in the intervention group was also comparable with that of conservative treatment (5 days vs 5 days [interquartile range 5–8 days vs 3–7 days], p = .45).

Conclusions

Vacuum bottle plus catheter drainage of iatrogenic pneumothorax is a safe and efficient procedure. It may be considered as an alternative management of stable post-procedural pneumothorax with size larger than 15%.

Trial registration The study protocol was approved by the Research Ethics Committee of National Taiwan University Hospital (No. 201805105DINA) on 6th August, 2018. The first participant was enrolled on 23rd August, 2018 after Research Ethics Committee approval. This clinical trial complete registration at U.S. National Library of Medicine clinicaltrials.gov with identifier NCT03724721 and URL: https://clinicaltrials.gov/ct2/show/NCT03724721 on 30th October, 2018.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02009-8.

Usefulness of monitoring intrapleural pressure with digital chest drainage system for the management of air leakage after lung resection

OBJECTIVES

The objective of this study was to determine the variation in intrapleural pressure (IPP) with and without air leakage using a digital chest drainage system (DCS) for each pressure setting.

METHODS

In this retrospective single-centre study, we analysed 49,553 h of air leakage after anatomical lung resection in 714 patients between 2018 and 2020. The transition of mean IPP and mean air leak flow was monitored using DCS, and the association between mean IPP and mean air leak flow was examined. The relationship between the transition of mean IPP and air leakage according to the varying suction pressures on DCS was also investigated.

RESULTS

Overall, 272 patients (38.1%) showed air leakage after surgery. The mean IPP in patients without air leakage was -12.0 ± 2.9 cmH2O and maintained at about -12 cmH2O constantly, while the mean IPP in patients with air leakage was -8.3 ± 1.9 cmH2O, which changed to -12 cmH2O instantly if air leakage disappeared (P < 0.001). Among patients with air leakage, the mean IPP changed more distinctly in patients with mild suction management than in those with conventional suction management (-5.0 ± 2.6 to -11.5 ± 4.2 and -8.8 ± 1.3 to -12.1 ± 2.5 cmH2O, respectively; P < 0.001).

CONCLUSIONS

The change in IPP on a DCS is useful for detecting air leakage. Furthermore, management with a mild suction setting on DCS makes it easy to recognize the disappearance of postoperative air leakage.

Work in progress report of a multicentre retrospective observational study to evaluate the association between the airflows and the intrapleural pressures digitally recorded after video-assisted lobectomy

OBJECTIVES

Digital chest drainage systems allow real-time and continuous monitoring and recording of air leak flow rate and intrapleural pressure (IPP) from the immediate postoperative period to the chest drainage removal. A multicentre retrospective observational analysis of consecutive patients undergoing pulmonary lobectomy for lung cancer was performed to evaluate the association between the airflow and IPP digitally recorded during the immediate postoperative period after video-assisted thoracic surgery (VATS) lobectomy for lung cancer. Here, we present a work in progress report.

METHODS

All patients treated with VATS lobectomies for lung cancer were included. Multiple airflow measurements and minimum and maximum IPP through the chest tubes were digitally monitored and recorded using microelectronic mechanical sensor technology. The PALs were defined as an air leak lasting >5 days from the conclusion of the surgical procedure. The cessation of air leaks was defined as an airflow <10 ml/min during 6 consecutive hours.

RESULTS

This analysis comprised 76 patients who underwent VATS lobectomy for lung cancer. Nineteen patients (25%) showed prolonged air leaks (PAL) (≥5 days). The operative time was higher in the PAL group (mean difference = 44 min) without a statistically significant difference. Before the 7th postoperative hours, there were no statistically significant differences in IPPs.

CONCLUSIONS

Patients with PAL showed less negative IPP in the first 24 postoperative hours. Therefore, the 7th-24th postoperative hours were critical in PAL prediction since the mechanism for PAL seems to develop after the 7th postoperative hour.

Assessment of Differential Pressures in Chest Drainage Systems: Is What You See What You Get?

BACKGROUND

Dry-suction chest drainage systems are used to achieve proper drainage of the pleural space after cardiothoracic operations. Data on the actual intrapleural pressure during the use of these systems is lacking. The present study was performed to evaluate pressure differences across the circuit using an ex vivo model.

METHODS

An ex vivo apparatus coupled to a hospital-grade pleural drainage system was devised to provide calibrated levels of suction and air leak. Simultaneous pressure measurements were obtained at the system outlet and the simulated patient entry site. Trials were conducted with increasing levels of water between the patient and drainage modules at various levels of suction and leak pressures. Signals were recorded at 100 Hz and analyzed using two-way ANOVA.

RESULTS

With no obstruction, the drainage system provided precise levels of negative pressure at the patient level (10-40 cm H₂O). Addition of fluid in the drainage tubing caused significant differences in transmitted suction (P < 0.001). With increasing air leakage and fluid volume, the pressure differential between the system and patient increased significantly (1.14 to 36.69 cm H₂O, P < 0.001). In the off-suction setting, increasing levels of obstruction to 22 cm of water led to development of positive intrapleural pressures (2.6 to 11.1 cm H₂O, P < 0.001).

CONCLUSIONS

While commercially available chest drainage systems are able to provide predictable levels of suction at the device, intrapleural pressures can be highly variable and depend on complete patency of connecting tubes. Systems capable of modulating the level of suction based on actual intrapleural pressures may enhance recovery after procedures requiring tube thoracotomy.

Asymmetrical intrapleural pressure distribution: a cause for scoliosis? A computational analysis

PURPOSE

The mechanical link between the pleural physiology and the development of scoliosis is still unresolved. The intrapleural pressure (IPP) which is distributed across the inner chest wall has yet been widely neglected in etiology debates. With this study, we attempted to investigate the mechanical influence of the IPP distribution on the shape of the spinal curvature.

METHODS

A finite element model of pleura, chest and spine was created based on CT data of a patient with no visual deformities. Different IPP distributions at a static end of expiration condition were investigated, such as the influence of an asymmetry in the IPP distribution between the left and right hemithorax. The results were then compared to clinical data.

RESULTS

The application of the IPP resulted in a compressive force of 22.3 N and a flexion moment of 2.8 N m at S1. An asymmetrical pressure between the left and right hemithorax resulted in lateral deviation of the spine towards the side of the reduced negative pressure. In particular, the pressure within the dorsal section of the rib cage had a strong influence on the vertebral rotation, while the pressure in medial and ventral region affected the lateral displacement.

CONCLUSIONS

An asymmetrical IPP caused spinal deformation patterns which were comparable to deformation patterns seen in scoliotic spines. The calculated reaction forces suggest that the IPP contributes in counterbalancing the weight of the intrathoracic organs. The study confirms the potential relevance of the IPP for spinal biomechanics and pathologies, such as adolescent idiopathic scoliosis.

Systemic air embolism during pleural lavage for empyema

Pleural lavage has been considered a convenient and safe method that is often performed for empyema. We report a case of systemic air embolism that developed during pleural lavage. A 53-year-old man with empyema in the organizing phase suddenly developed paralysis of the left side of the body and altered level of consciousness during pleural lavage, which was performed in a sitting position without negative pressure suction. Systemic air embolism was diagnosed based on computed tomography. In this case, use of fibrinolytic agents, positioning during pleural lavage, and pressure in an empyema cavity may have predisposed to development of systemic air embolism. Conversion from thoracoscopic therapy to open decortication or fenestration should be considered to prevent this type of complication.