Adjuvant Transthoracic Negative-Pressure Ventilation in Nonintubated Thoracoscopic Surgery

BACKGROUND

To minimize the risks of barotrauma during nonintubated thoracoscopic-surgery under spontaneous ventilation, we investigated an adjuvant transthoracic negative-pressure ventilation (NPV) method in patients operated on due to severe emphysema or interstitial lung disease.

METHODS

In this retrospective study, NPV was employed for temporary low oxygen saturation and to achieve end-operative lung re-expansion during nonintubated lung volume reduction surgery (LVRS) for severe emphysema (30 patients, LVRS group) and in the nonintubated wedge resection of undetermined interstitial lung disease (30 patients, wedge-group). The results were compared following 1:1 propensity score matching with equivalent control groups undergoing the same procedures under spontaneous ventilation, with adjuvant positive-pressure ventilation (PPV) performed on-demand through the laryngeal mask. The primary outcomes were changes (preoperative-postoperative value) in the arterial oxygen tension/fraction of the inspired oxygen ratio (ΔPO₂/FiO₂;) and ΔPaCO₂, and lung expansion completeness on a 24 h postoperative chest radiograph (CXR-score, 2: full or 1: incomplete).

RESULTS

Intergroup comparisons (NPV vs. PPV) showed no differences in demographic and pulmonary function. NPV could be accomplished in all instances with no conversion to general anesthesia with intubation. In the LVRS group, NPV improved ΔPO₂/FiO₂ (9.3 ± 16 vs. 25.3 ± 30.5, p = 0.027) and ΔPaCO₂ (-2.2 ± 3.15 mmHg vs. 0.03 ± 0.18 mmHg, p = 0.008) with no difference in the CXR score, whereas in the wedge group, both ΔPO₂/FiO₂ (3.1 ± 8.2 vs. 9.9 ± 13.8, p = 0.035) and the CXR score (1.9 ± 0.3 vs. 1.6 ± 0.5, p = 0.04) were better in the NPV subgroup. There was no mortality and no intergroup difference in morbidity.

CONCLUSIONS

In this retrospective study, NITS with adjuvant transthoracic NPV resulted in better 24 h oxygenation measures than PPV in both the LVRS and wedge groups, and in better lung expansion according to the CXR score in the wedge group.

A New Traceless Technique for Cosmetic Closure of Minimally Invasive Incision and Chest Tube Fixation After Uniportal Video-Assisted Thoracoscopic Surgery

Background

With uniportal video-assisted thoracoscopic surgery (VATS) becoming mainstream, how to make the incision cosmetic has attracted much attention. This study aimed to introduce a new traceless method for cosmetic closure of the incision and a special procedure for chest tube fixation after uniportal VATS and to evaluate the feasibility, effectiveness, and safety of this new technique.

Methods

In this retrospective study, a total of 258 consecutive patients who underwent uniportal VATS were included. Among them, 127 patients were treated with a conventional method, and 131 patients were treated with a new method.

Results

Patients in the new method group had a significantly less incidence of subcutaneous emphysema after the chest tube was removed. The incidence of pneumothorax after the chest tube was removed and fat liquefaction of chest incision was not significantly different between the two groups. No differences in the incidence of pneumothorax after chest tube removal and fat liquefaction of postsurgical incision were found between the two groups. Additionally, there was also no significant difference in follow-up items.

Conclusions

Taken together, our results showed that this new method for minimally invasive incision closure and chest tube fixation after uniportal VATS was as feasible, effective, and safe as the conventional one but more cosmetic.

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.

Rescue blanket as a provisional seal for penetrating chest wounds in a new ex vivo porcine model

BACKGROUND

Open pneumothorax after a penetrating thorax trauma is a life-threatening disease with high mortality. Emergency application of a chest seal allowing the release of trapped air is the optimum initial therapy until surgical chest drainage is available.

METHODS

In a newly developed experimental porcine model of open pneumothorax we tested three different materials regarding their applicability for acute treatment of sucking chest wounds in pre-hospital emergency care, namely a commonly used rescue blanket (RB), plastic foil from a gauze package (packaging material, PM) and a commercial chest seal (CS).

RESULTS

An ex vivo open pneumothorax model using a porcine chest wall and a vacuum-assisted drainage system was successfully established. Rescue blanket segments sized 70 x 100 mm achieved significantly higher rates of successful sealing than did plastic foils from a gauze package sized 100 x 100 mm when the devices were applied to the moistened chest wall and fixed on three sides (5/5 (100%) vs. 0/5 (0%), p=0.002). Loosely fixed rescue blankets efficiently released injected air (10/10, 100%) and consequently sealed the wound in all cases (10/10).

CONCLUSIONS

Rescue blankets, applied wet, are appropriate chest seals with good occlusive and adherence properties. Fixation on two sides of the dressing is sufficient to allow trapped air to exit and sufficient sealing of the chest wound. Rescue blankets were superior to plastic foils from a gauze package and were seen to function as a potent makeshift chest seal when no commercial chest seal is available.

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.

A Retrospective Case-Control Study on the Chest Wall and Lung Characteristics in Patients with Primary Spontaneous Pneumothorax

BACKGROUND Primary spontaneous pneumothorax (PSP) is reported to be more common in young men who are thin and tall. This retrospective study aimed to analyze the clinical and chest wall characteristics associated with PSP. MATERIAL AND METHODS Between January 2008 to December 2017, the clinical and imaging data of 99 patients at first presentation with PSP were compared with 82 age-matched healthy controls. Computed tomography (CT) imaging was used to measure the anteroposterior and transverse diameters of the chest at four levels, including the aortic arch, tracheal bifurcation, right inferior pulmonary vein, and lower sternal edge. Chest deformity was calculated as the ratio of the transverse diameter of the hemithorax divided by anteroposterior diameter. Lung volume and average lung density of 32 cases with PSP were measured and compared with 10 patients without PSP. Intrapleural pressure of 43 cases PSP who were treated with a closed chest drain was measured and compared with 39 patients with mediastinal tumor who underwent thoracoscopic surgery. RESULTS Patients with PSP showed a normal age distribution with a median of 17-18 years. The patients with PSP had significantly reduced anteroposterior and transverse diameters of the chest when compared with controls at four levels on CT (p<0.01). The lung volumes in patients with PSP were significantly reduced when compared with the controls (p<0.05), as were the minimum intrapleural pressure and pressure difference (p<0.05). CONCLUSIONS The findings support that chest wall dimensions may be associated with lung development, which are contributing factors in PSP.

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.

Pleural Pressure Differences Before Removal Are Greater in Patients Who Develop Residual Pneumothorax Post Chest Drain Removal

Aim of study: We aimed to investigate whether the difference in pleural pressures (ΔP) is wider among patients who develop a residual pneumothorax after chest tube removal following lung resection surgery. Materials and methods: Ninety-eight patients who underwent lung resection were included in the study over a period of 12 months. The ΔP prior to chest tube removal in patients who developed a residual pneumothorax after chest tube removal was compared with that of patients who did not develop this complication. The receiver operating characteristic (ROC) curve analysis was performed to identify cutoff values of ΔP for the prediction of residual pneumothorax. Logistic regression analysis was used to formulate a prediction model for the occurrence of residual pneumothorax based on ΔP. Results: Thirteen patients who developed a residual pneumothorax were compared with 85 patients without this complication. The ΔP in the residual pneumothorax group was significantly higher (10.8 versus 4.2 cm H₂O, p < 0.01). The ΔP in patients who required intervention was also significantly higher (14.8 versus 4.2 cm H₂O, p < 0.01). A ΔP cutoff value of 8 cm H₂O was predictive of the occurrence of residual pneumothorax (sensitivity 85.6%, specificity 84.6%) and a value of 12 cm H₂O was predictive of intervention (sensitivity 84%, specificity 85%). Increasing ΔP was an independent predictor of the occurrence of residual pneumothorax (p = 0.008) on the multivariate logistic regression model. Conclusion: Patients with wide ΔP before chest drain removal may be complicated with residual pneumothorax.

Changes of pleural pressure after thoracic surgery

Background

The negative pressure of the pleural cavity is critical to maintain lung expansion. However, the actual values of pleural pressure according to the phase of respiration after various types of pulmonary resection have not been well reported. The aim of this study was to measure the pleural pressure directly and to compare the results according to the extent of pulmonary resection.

Methods

We manufactured a high-resolution digital manometer with which pleural pressure can be measured directly. A total of 43 patients who underwent thoracic surgery (lobectomy in 23, minimal resections in 20) were enrolled. The maximum, minimum, and mean pleural pressure was recorded during normal quiet breathing, forced breathing, and coughing, separately.

Results

During normal quiet breathing, the average values of pleural pressure at end inspiration, end expiration, and the mean pleural pressure were -17.7, -7.0 and -11.2 cmH₂O in lobectomy group, and -14.3, -4.6, -8.3 cmH₂O in the minimal/no-resection group, respectively. The mean pleural pressure was significantly lower in lobectomy group compared to the minimal/no-resection group (P=0.026). During forced respiration, the same values were -44.0, -4.2 and -18.9 cmH₂O in the lobectomy group, and -29.8, -0.1 and -12.7 cmH₂O in the minimal/no-resection group. All of the pleural pressure values in lobectomy group were significantly lower compared to minimal/no-resection group (P=0.029, P=0.015, P=0.019, respectively). The maximal pressures during coughing were not statistically different between the two groups (38.4 vs. 34.4 cmH₂O, P=0.687).

Conclusions

We reported the actual pleural pressure changes according to the phase of respiration and type of surgery using a digital manometer. In lobectomy patients, the pleural pressure was highly negative compared to the minimal/no-resection group, especially during deep inspiration.

Optimization of Chest Tube Management to Expedite Rehabilitation of Lung Cancer Patients After Video-Assisted Thoracic Surgery: A Meta-Analysis and Systematic Review

BACKGROUND

The aim of this meta-analysis and systematic review of published evidence was to optimize chest tube management for fast-track rehabilitation of lung cancer patients after video-assisted thoracic surgery (VATS).

METHODS

The PubMed, Web of Science, and EMBASE databases were searched to identify all studies that addressed the issue of chest tube management after VATS for lung cancer. Finally, 35 articles were included for analysis, i.e., 29 randomized controlled trials and 6 clinical trials.

RESULTS

After synthesis of the published evidence, the following protocol for chest tube drainage was formulated: (1) after VATS lung wedge resection, chest tube drainage can be omitted in selected cases; (2) normally, one 28Fr chest tube (or 19Fr Blake drain) is placed; (3) the use of a digital monitoring system is recommended; (4) in case of increasing pneumothorax or severe air leakage supported by digital recording system, the tube should be placed with active suction; and (5) the chest tube can be removed within 48 h postoperatively when air leakage is resolved and fluid drainage is <400 mL/day.

CONCLUSIONS

Further multicenter studies are warranted based on the variations of body sizes among different ethnicities.

The Society for Translational Medicine: clinical practice guidelines for the postoperative management of chest tube for patients undergoing lobectomy

The Society for Translational Medicine and The Chinese Society for Thoracic and Cardiovascular Surgery conducted a systematic review of the literature in an attempt to improve our understanding in the postoperative management of chest tubes of patients undergoing pulmonary lobectomy. Recommendations were produced and classified based on an internationally accepted GRADE system. The following recommendations were extracted in the present review: (I) chest tubes can be removed safely with daily pleural fluid of up to 450 mL (non-chylous and non-sanguinous), which may reduce chest tube duration and hospital length of stay (2B); (II) in rare instances, e.g., persistent abundant fluid production, the use of PrR_P/B <0.5 when evaluating fluid output to determine chest tube removal might be beneficial (2B); (III) it is recommended that one chest tube is adequate following pulmonary lobectomy, except for hemorrhage and space problems (2A); (IV) chest tube clearance by milking and stripping is not recommended after lung resection (2B); (V) chest tube suction is not necessary for patients undergoing lobectomy after first postoperative day (2A); (VI) regulated chest tube suction [-11 (-1.08 kPa) to -20 (1.96 kPa) cmH₂O depending upon the type of lobectomy] is not superior to regulated seal [-2 (0.196 kPa) cmH₂O] when electronic drainage systems are used after lobectomy by thoracotomy (2B); (VII) chest tube removal recommended at the end of expiration and may be slightly superior to removal at the end of inspiration (2A); (VIII) electronic drainage systems are recommended in the management of chest tube in patients undergoing lobectomy (2B).

Pleural pressure theory revisited: a role for capillary equilibrium

BACKGROUND

Theories elucidating pleural pressures should explain all observations including the equal and opposite recoil of the chest wall and lungs, the less than expected pleural hydrostatic gradient and its variation at lobar margins, why pleural pressures are negative and how pleural fluid circulation functions.

METHODS

A theoretical model describing equilibrium between buoyancy, hydrostatic forces, and capillary forces is proposed. The capillary equilibrium model described depends on control of pleural fluid volume and protein content, powered by an active pleural pump.

RESULTS

The interaction between buoyancy forces, hydrostatic pressure and capillary pressure was calculated, and values for pleural thickness and pressure were determined using values for surface tension, contact angle, pleural fluid and lung densities found in the literature. Modelling can explain the issue of the differing hydrostatic vertical pleural pressure gradient at the lobar margins for buoyancy forces between the pleural fluid and the lung floating in the pleural fluid according to Archimedes' hydrostatic paradox. The capillary equilibrium model satisfies all salient requirements for a pleural pressure model, with negative pressures maximal at the apex, equal and opposite forces in the lung and chest wall, and circulatory pump action.

CONCLUSIONS

This model predicts that pleural effusions cannot occur in emphysema unless concomitant heart failure increases lung density. This model also explains how the non-confluence of the lung with the chest wall (e.g., lobar margins) makes the pleural pressure more negative, and why pleural pressures would be higher after an upper lobectomy compared to a lower lobectomy. Pathological changes in pleural fluid composition and lung density alter the equilibrium between capillarity and buoyancy hydrostatic pressure to promote pleural effusion formation.

Chest Tube Management after Surgery for Pneumothorax

There is scant evidence on the management of chest tubes after surgery for pneumothorax. Most of the current knowledge is extrapolated from studies performed on subjects with lung cancer. This article reviews the existing literature with particular focus on the effect of suction and no suction on the duration of air leak after lung resection and surgery for pneumothorax. Moreover, the role of regulated suction, which seems to provide some benefit in reducing pneumothorax recurrence after bullectomy and pleurodesis, is discussed. Finally, a personal view on the management of chest tubes after surgery for pneumothorax is provided.

Air leak after lung resection: pathophysiology and patients' implications

Protocols for the management of air leaks are critical aspects in the postoperative course of patients following lung resections. Many investigations in the last decade are focusing on the chest tube modalities or preventative measures, however, little is known about the pathophysiology of air leak and the patient perception of this common complication. This review concentrates on understanding the reasons why a pulmonary parenchyma may start to leak or an air leak may be longer than others. Experimental works support the notion that lung overdistension may favor air leak. These studies may represent the basis of future investigations. Furthermore, the standardization of nomenclature in the field of pleural space management and the creation of novel air leak scoring systems have contributed to improve the knowledge among thoracic surgeons and facilitate the organization of trials on this matter. We tried to summarize available evidences about the patient perception of a prolonged air leak and about what would be useful for them in order to prevent worsening of their quality of life. Future investigations are warranted to better understand the pathophysiologic mechanisms responsible of prolonged air leak in order to define tailored treatments and protocols. Improving the care at home with web-based telemonitoring or real time connected chest drainage may in a future improve the quality of life of the patients experience this complication and also enhance hospital finances.

Multicenter international randomized comparison of objective and subjective outcomes between electronic and traditional chest drainage systems

BACKGROUND

The aim of this study was to assess the impact of digital versus traditional drainage devices on chest tube removal and patient satisfaction.

METHODS

A randomized trial of digital versus traditional devices after lobectomy/segmentectomy was conducted at 4 international centers (United Kingdom, Europe, Asia, United States). Patients were managed with overnight suction followed by gravity drainage. Chest tubes were removed when an air leak was not evident anymore and the drained fluid was less than 400 mL/d.

RESULTS

The groups (digital, 191 patients; traditional, 190 patients) were well matched for baseline and surgical characteristics. There were 325 lobectomies/bilobectomies and 56 segmentectomies, 308 of which were performed by video-assisted thoracic surgery (VATS). Patients randomized to digital systems had a significantly shorter air leak duration (1.0 versus 2.2 days; p=0.001), duration of chest tube placement (3.6 versus 4.7 days; p=0.0001), and postoperative length of stay (4.6 versus 5.6 days; p<0.0001). Subjective end points revealed a perceived improved ability to arise from bed (p=0.008), system convenience for patients and personnel (p=0.02), and the potential for being comfortable when discharged home with the device (p=0.06). A mean difference of 2.6 days from air leak cessation to tube removal was observed, which was similar in the 2 groups (p=0.7). Multivariable regression analysis showed that duration of chest tube placement after air leak cessation was directly associated with the amount of fluid drained during the first 48 hours (p=0.01) and the duration of air leak (p=0.008), independent of hospital location.

CONCLUSIONS

Patients managed with digital drainage systems experienced a shorter duration of chest tube placement, shorter hospital stays, and higher satisfaction scores compared with those managed with traditional devices. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT01747889.).