Local fluid application and needle insertion in gravity-dependent areas to reduce the risk of pneumothorax during lung nodule localization: a single-center observational study

Introduction

A pulmonary nodule (PN) is a common lesion identified during chest imaging examinations, typically defined as a round or oval-shaped lung shadow with a diameter less than 3 cm. PNs can be either benign or malignant (1). With the widespread use of low-dose computed tomography (LDCT) and increased health awareness in the post-coronavirus disease 2019 (COVID-19) era, the detection rate of PNs has been rising annually. For high-risk PNs (2), radical resection remains the primary treatment approach.

Video-assisted thoracoscopic surgery (VATS) remains the mainstream surgical approach (3). With the growing emphasis on minimally invasive surgery and enhanced recovery concepts, studies have shown that sublobar resection achieves significant efficacy in the surgical treatment of early-stage lung cancer. Due to its advantages, including minimal trauma, reduced loss of lung function, and faster recovery, sublobar resection has rapidly developed and become an important treatment option for early-stage lung cancer. Sublobar resection includes wedge resection and anatomical segmentectomy. In recent years, there has been heated debate about whether sublobar resection could replace lobectomy as the standard surgical approach for early-stage lung cancer (4-6). Sublobar resection, characterized by its smaller resection range and greater preservation of healthy lung tissue, facilitates faster postoperative recovery. When oncological principles are adhered to, selecting appropriate patients for sublobar resection can provide greater benefits (7). However, most ground-glass nodules (GGNs) detected by high-resolution computed tomography (HRCT) are neither palpable nor visible during thoracoscopic surgery (8). Without precise preoperative localization, surgeons face significant challenges in identifying nodules intraoperatively, with failure rates for intraoperative localization of PNs reaching as high as 54% to 63%. A substantial proportion of these cases require conversion to open thoracotomy for localization (9). Therefore, accurate preoperative localization is essential for the successful resection of PNs during thoracoscopic surgery.

Pneumothorax is one of the most common complications during computed tomography (CT)-guided lung puncture localization. During the procedure, the localization needle may penetrate lung tissue, allowing air to enter the pleural cavity (10). The negative pressure created by the rigidity of the chest wall and the elastic recoil of the lung is neutralized by the intruding air (11). Previous large-sample studies have suggested that the incidence of pneumothorax in all CT-guided preoperative puncture localizations is approximately 20–50% (12). Most pneumothoraces caused by localization are small, asymptomatic, and tolerable. However, in clinical practice, a considerable number of patients experience progressive pneumothorax, leading to dyspnea, with severe cases resulting in tension pneumothorax that compromises patient safety and disrupts surgical procedures. Additionally, some patients develop pneumothorax during the localization process, significantly affecting the accuracy of localization and increasing its difficulty. Therefore, reducing the incidence of pneumothorax during preoperative localization of PNs warrants close attention.

Relevant studies have explored strategies to reduce the risk of pneumothorax following CT-guided lung puncture biopsy. These strategies include breath-holding at the end of localization, using autologous blood patches, and saline to seal the puncture tract and close the pleura (13). Research suggests that the use of fluids near the pleura can increase pleural pressure (PPL) by causing pleural cavity deformation (14). Additionally, local fluid application can create localized pleural elevation and compression, which helps reduce the risk of pneumothorax during puncture biopsy (15) (Figure 1).

Figure 1 Schematic diagram of lidocaine injection outside the parietal pleura under CT guidance. CT, computed tomography.

The relationship between patient positioning and the likelihood of pneumothorax during CT-guided lung puncture biopsy has also been studied. Post-biopsy, moving the puncture site to a gravity-dependent position (with the biopsy side downward) reduces pneumothorax risk. This difference can be explained by the physiological characteristics of PPL. Due to the effects of pulmonary blood flow distribution and gravity, the gravitational effect on PPL leads to non-uniform distribution of pleural cavity negative pressure. Non-dependent areas of the lung typically exhibit greater negative PPL (approximately −7 cmH₂O) (16,17), resulting in a larger transpulmonary pressure gradient (the difference between lung pressure and PPL, where airway pressure (PAW) during quiet breathing is approximately 0 cmH₂O). This makes pneumothorax more likely in these regions. Studies have further proposed dividing the pleural cavity into three equal parts: the upper one-third as the non-dependent area and the lower two-thirds as the dependent area (Figure 2). In the gravity-dependent areas, pleural cavity negative pressure is less than in non-dependent areas (approximately −2 cmH₂O) and, in some regions, even approaches PAW. Performing lung biopsy in these dependent areas significantly reduces the risk of pneumothorax (15).

Figure 2 Schematic diagram of pleural cavity partitioning. PAW, airway pressure; PPL, pleural pressure.

The aim of this study is to investigate the use of lidocaine injection outside the parietal pleura and the PPL-gravitational effect in reducing the risk of pneumothorax during preoperative CT-guided percutaneous PN localization. We present this article in accordance with the STROBE reporting checklist (18) (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2026-1-0389/rc).

Methods

Study population

A total of 166 patients who met the initial criteria for preoperative percutaneous solitary PN localization followed by VATS were assessed for eligibility between June 1, 2024, and November 1, 2024. Of these, 16 patients were excluded based on the following pre-specified criteria: (I) severe systemic diseases, including hematological, neurological, cardiovascular, endocrine, or respiratory disorders (n=5); (II) refusal to undergo surgery or inability to cooperate (n=1); (III) severe pleural adhesions (n=3); (IV) significant emphysema, pulmonary fibrosis, or incomplete clinical records (n=2); and (V) lesions located in the middle lobe (n=6). Consequently, the final analytical cohort comprised 150 patients. To visually present the standard enrollment and selection process, a detailed participant flow diagram has been provided (Figure 3).

Figure 3 Flowchart of patient screening, inclusion, and grouping protocols.

The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Ethics Committee of The First Affiliated Hospital of Kunming Medical University. Informed consent was taken from all the patients.

Localization materials and techniques

Locate personnel

To minimize operator-dependent bias and ensure technical consistency, all localization procedures were performed exclusively by a single, highly qualified thoracic clinician. This investigator holds an attending physician rank, possesses a minimum of two years of independent localization experience, and is fully certified in radiological intervention protocols. Consequently, both the manual needle insertion and the real-time CT guidance were executed by the same individual throughout the study period.

Equipment and materials

CT Scanner: Siemens SOMATOM go CT (64-slice, 128-layer CT, equipped with a 3D laser locator, Siemens, Germany). Localization needle: advanced PN localization needles (manufactured by Ningbo SensCure Biotechnology Co., Ltd.). Five and 10 mL syringes. A disposable, graduated anesthetic needle (0.7 mm × 0.9 mm).

Localization steps

Pre-procedure preparation

Before localization, all patients and their families were informed of the procedure and associated risks. Based on preoperative contrast-enhanced CT results, an initial puncture localization plan was developed, including: patient positioning, Selection of puncture site, Puncture pathway (avoiding major blood vessels, trachea, and scapular region), puncture depth.

Procedure and pre-procedure setup (Figure 4, Figure 5)

Figure 4 Schematic diagram of PN localization under CT guidance. (A) After completing the first CT scan, the puncture point is determined with the assistance of the auxiliary metal wire and infrared laser. (B) Conventional use of a 5 mL syringe with 2% lidocaine hydrochloride for layer-by-layer infiltration anesthesia. (C) A 10 mL syringe with a calibrated long anesthesia needle is used to precisely inject 10 mL of 2% lidocaine hydrochloride outside the parietal pleura. (D) The PN localization needle is inserted from the puncture point into the chest wall, but does not enter the pleural cavity. CT, computed tomography; PN, pulmonary nodule.

Figure 5 Diagram of PN localization under CT guidance. (A) The PN localization needle is inserted into the chest wall after anesthesia, but does not enter the pleural cavity. During the procedure, the red arrow tracks the advancement of the core localization needle toward the target nodule (blue circle). (B) The PN localization needle is inserted into the target area adjacent to the nodule. (C) Post-procedural confirmation scan showing the successfully deployed anchoring hook (orange circle) marking the lesion. (D) Diagram showing the precise injection of lidocaine outside the parietal pleura under CT guidance. The black arrow denotes the graduated long anesthesia needle positioned in the extrapleural space. CT, computed tomography; PN, pulmonary nodule.

By 8:00 AM on the day of surgery, patients were positioned in the CT room as per the pre-determined plan. The process and precautions were explained, and real-time communication with the patient was maintained to ensure proper positioning. The neck and abdomen were shielded with lead aprons to reduce radiation exposure. A metallic marker wire was placed on the skin surface at the planned puncture site for the first CT scan. The first scan was performed to confirm the target nodule and determine the puncture plane. Adjustments were made to the planned puncture site if necessary. The scan bed was moved to align with the puncture site, which was confirmed using the surface metallic marker and laser locator (Figure 4A). The relevant localization-related radiological parameters were recorded based on the pre-procedural CT scans, including the distance of skin to lesion (SL), the distance of pleural to lesion (PL), the tumor diameter.

Anesthesia and puncture

The puncture site was disinfected, and sterile drapes were applied. Local anesthesia was administered using a 5 mL syringe with 2% lidocaine, infiltrating layer by layer to the pleural surface (Figure 4B). Following anesthesia, the localization needle was inserted along the planned puncture path and angle. The needle insertion was executed in a strict stepwise manner. After local anesthetic infiltration was completed, the localization needle was introduced into the chest wall; however, it was temporarily halted before breaching the thoracic cavity (Figure 4D, Figure 5A).

CT scan and adjustments

A second CT scan was performed to evaluate the needle’s trajectory and measure the distance between the needle tip and the target area. Fine adjustments to the puncture path were made based on CT images. The needle was advanced along the pre-determined path and depth until the tip reached the target nodule (Figure 5B).

Confirmation and finalization

A third CT scan was performed to confirm the needle’s position. If the needle tip was not in the target area, further adjustments were made. Upon reaching the target, the localization hook was released, and the puncture site and external localization wire were covered with a sterile dressing. A fourth CT scan was performed to verify the hook’s position relative to the target nodule (Figure 5C) and assess complications such as bleeding or pneumothorax.

Post-procedure monitoring

Pain was assessed, and the patient rested for 5 minutes under close observation of vital signs for potential pleural reactions or other complications. Patients without complications were either transferred to the operating room or sent back to the ward to await surgery.

Administration of lidocaine outside the parietal pleura

We use a 2% lidocaine hydrochloride injection solution, which can serve both to exert local compression and to reduce the disturbance to the intrapleural nerves caused by the procedure, thereby lowering adverse reactions. For administration of Lidocaine Outside the Parietal Pleura group, a 10 mL syringe and a disposable calibrated anesthetic needle were used to perform layer-by-layer local infiltration anesthesia with 2% lidocaine hydrochloride (Figure 4C). After completing anesthesia, a subsequent CT scan was performed to adjust the calibrated anesthetic needle’s tip to precisely reach the outside of parietal pleura. A 10 mL syringe was then used to inject 10 mL of 2% lidocaine hydrochloride outside the parietal pleural space (Figure 5D). To monitor for potential local anesthetic systemic toxicity (LAST), all patients were strictly monitored via continuous electrocardiogram (ECG) and pulse oximetry, and assessed for early central nervous system symptoms (such as tinnitus, perioral numbness, metallic taste, or altered mental status). The fixed dose of 10 mL of 2% lidocaine (200 mg) was applied as it fell within the safe clinical threshold (≤4.5 mg/kg) for adult patients in our cohort and no body-weight-based dose adjustments were implemented.

Distinction between dependent and non-dependent areas

According to relevant studies, based on the gravitation effect and gradient distribution of PPL, the thoracic cavity is evenly divided into three sections: the upper one-third is defined as the non-dependent area, and the lower two-thirds as the dependent area. This division is used to classify puncture regions and evaluate the impact of different puncture zones on the incidence of pneumothorax (Figure 3).

Grouping

Based on the preoperative intervention protocol, patients were sequentially allocated into two primary cohorts: the fluid administration group (Group F), where patients received a CT-guided injection of 10 mL of 2% lidocaine solution outside the parietal pleura prior to localization, and the non-fluid administration group (Group nF), where no such injection was administered.

To evaluate the compounding effect of the puncture site, both primary groups were further stratified into four distinct subgroups according to the gravity-dependent or non-dependent anatomical location of the needle insertion point on the lung surface:

• Group FD: fluid application + gravity-dependent area;
• Group FnD: fluid application + non-dependent area;
• Group nFD: non-fluid application + gravity-dependent area;
• Group nFnD: non-fluid application + non-dependent area.

Pain assessment

Post-procedural pain was evaluated using a standard 11-point Numerical Rating Scale (NRS), where 0 indicated “no pain” and 10 indicated “the worst imaginable pain”. Based on the NRS scores, pain severity was categorized into three grades for subsequent analysis: score 0 (no pain), score 1–3 (mild pain), and score 4–6 (moderate pain).

To ensure standardization, the NRS score was explicitly recorded exactly 10 minutes after the completion of the localization procedure, right before the patient was transferred out of the CT room. The assessment was conducted by a dedicated thoracic oncology nurse who was blinded to the patient’s group allocation (i.e., whether the patient received extrapleural lidocaine or not). Patients were instructed on how to use the scale prior to the procedure during the informed consent process.

Statistical methods

The statistical analysis was performed using SPSS 27.0 software. For normally distributed or approximately normally distributed continuous data, the mean ± standard deviation (x±s) was used, and group comparisons were performed using independent sample t-tests. For skewed distribution or ordinal data, the median (interquartile range) [M (P25, P75)] was used, and group comparisons were performed using the rank sum test. Categorical or count data were expressed as frequencies and/or percentages, and group comparisons were performed using the chi-square test or Fisher’s exact test. A P value of <0.05 was considered statistically significant.

Note: (I) after completing the first CT scan, the puncture point A is determined with the assistance of the auxiliary metal wire and infrared laser; (II) conventional use of a 5 mL syringe with 2% lidocaine hydrochloride for layer-by-layer infiltration anesthesia; (III) a 10 mL syringe with a calibrated long anesthesia needle is used to precisely inject 10 mL of 2% lidocaine hydrochloride outside the parietal pleura; (IV) the PN localization needle is inserted from the puncture point into the chest wall, but does not enter the pleural cavity.

Results

Baseline information

There were no significant differences in the distribution of age, gender, smoking history, maximum tumor diameter, PL, SL, tumor location, and tumor stage among the four groups. The FD group had a longer localization time [10.00 (8.00, 10.00) min], more needle adjustments [2 (2.0, 3.0) times], and deeper needle insertion [6.30 (5.30, 7.00)] compared to the other three groups. This may be related to the lidocaine injection technique outside the parietal pleura and the fact that nearly all patients in this group underwent needle insertion from the back, which resulted in deeper insertion (Table 1).

Pneumothorax incidence

Analysis of pneumothorax incidence among the four groups

The pneumothorax incidence was as follows: FD group: 1 case (3%) < FnD group: 4 cases (9%) < nFD group: 6 cases (17%) < nFnD group: 19 cases (51%), with a P value <0.0001, indicating a statistically significant difference (Table 2). Subgroup analysis revealed that the pneumothorax incidence in the FD group (1 case, 3%) was lower than in the FnD group (4 cases, 9%) and the nFD group (6 cases, 17%), but this difference was not statistically significant, which may be related to the extremely low pneumothorax rate in the FD group (Figure 6). Multivariate analysis indicated that the factors associated with pneumothorax were: subpleural injection of lidocaine [P<0.001, odds ratio (OR) =0.10, 95% confidence interval (CI): 0.03–0.31]; the puncture point located in the gravity-dependent area (P=0.003, OR=0.19, 95% CI: 0.06–0.57). The aforementioned two factors are independently associated with a low incidence of pneumothorax; pneumothorax is unrelated to age, gender, smoking history, tumor location, tumor size, and other factors (Table 3).

Figure 6 Pneumothorax incidence. D, gravity-dependent area; F, fluid application area; FD, fluid application + gravity-dependent area; FnD, fluid application + non-dependent area; nD, non-dependent area; nF, non-fluid application area; nFD, non-fluid application + gravity-dependent area; nFnD, non-fluid application + non-dependent area.

Pain severity

In group F (FD + FnD), pain-free patients (score 0) accounted for 53%, while patients with mild pain (score 0–3) accounted for 47% (Figure 7). In group nF (nFD + nFnD), patients with mild pain accounted for 91%, and those with moderate pain (score 4–6) accounted for 9% (P<0.001). Analysis of complications showed that pain was positively correlated with pneumothorax and pleural reactions, with the differences being statistically significant (Figure 8).

Figure 7 Pain severity in Group F vs. Group nF. F, fluid application area; nF, non-fluid application area.

Figure 8 Correlation of complications. *; ***.

Discussion

Pneumothorax is one of the most common complications of CT-guided lung puncture localization. Not only does it affect the accuracy of localization, but it also often causes discomfort after localization and impacts the surgical process. Numerous studies have explored methods to reduce the incidence of pneumothorax following puncture biopsies. Prior work by Brönnimann et al. established the physiological and technical rationale that pleural fluid application before lung puncture and consideration of gravitational PPL gradients may reduce pneumothorax risk during CT-guided lung biopsy (15). The current study extends these concepts to the setting of preoperative PN localization and suggests that similar benefits may be achievable in this related procedural context. This study investigates whether the combined use of subpleural lidocaine injection and pleural cavity pressure-gravity effects can reduce the incidence of pneumothorax during preoperative localization. In the baseline data, variables such as the number of needle adjustments, localization duration, and puncture depth showed statistical significance. Among the groups, the FD group had a longer localization duration, more needle adjustments, and greater puncture depth compared to the other three groups. This may be attributed to the additional procedures for lidocaine injection outside the parietal pleura and the fact that most patients in this group underwent puncture from the back, necessitating deeper needle insertion. However, effective local anesthesia can alleviate the discomfort associated with extended localization durations.

An analysis of pneumothorax incidence among the four groups showed the following: FD group: 1 case (3%) < FnD group: 4 cases (9%) < nFD group: 6 cases (17%) < nFnD group: 19 cases (51%). These findings demonstrate that precise subpleural injection of 10 mL lidocaine can alter the local pleural cavity pressure through pleural cavity deformation and localized compression, thereby reducing transpulmonary pressure and lowering the risk of pneumothorax during puncture localization (14,15). Related studies have shown that the pleural cavity’s negative pressure is not unifor mLy distributed but instead follows a gradient influenced by the gravitational effects on pleural cavity pressure. The upper regions (i.e., non-gravity-dependent zones) exhibit higher negative PPL (16,17). Theoretically, puncturing through this region poses a higher risk of pneumothorax, whereas puncturing in gravity-dependent zones reduces this risk. The findings of this study align with this perspective. In the nFnD group, 7 patients underwent puncture through posterior entry points (non-gravity-dependent zones) in the prone position, among whom 3 cases (42%) developed pneumothorax. This incidence was higher than the 17% observed in the nFD group. Our observations suggest that for these patients, adjusting their position to shift the puncture point from a non-gravity-dependent zone to a gravity-dependent zone can reduce the risk of pneumothorax during CT-guided preoperative localization of PNs. Multivariate analysis indicated that subpleural lidocaine injection and puncture points located in gravity-dependent zones were independently associated with pneumothorax occurrence. We acknowledge that an important baseline imbalance existed, with Group FD demonstrating significantly longer procedure times, more needle adjustments, and greater insertion depths. This phenomenon is largely because lesions requiring a gravity-dependent approach are frequently located in the posterior or lower lung segments, which are highly susceptible to respiratory movement and inherently possess longer pleural-to-nodule trajectories, thereby escalating the procedural complexity. Since these factors are established procedural determinants that could theoretically inflate the risk of pneumothorax, they posed a substantial confounding risk. To address this, we strictly incorporated these variables into our multivariable logistic regression model. Reassuringly, after robustly adjusting for procedure time, needle adjustments, and insertion depth, the combination of local fluid application and gravity-dependent positioning (Group FD) remained an independent protective factor against pneumothorax.

From traditional hookwire localization to the novel anchored needle localization, the material advancements in localization needles have significantly improved patient tolerance and reduced restrictions on patient activity (19). However, clinical practice has revealed that a substantial number of patients still experience unbearable pain during the localization process. This pain-induced lack of cooperation greatly increases the difficulty of localization. This study found that the precise use of subpleural lidocaine not only reduces the incidence of pneumothorax but also alleviates patient discomfort following preoperative localization, thereby enhancing the comfort of CT-guided PN localization. The mechanism is similar to ultrasound-guided preoperative intercostal nerve block (20), where localized nerve block significantly reduces perioperative pain and improves patient comfort. Correlation analysis of post-localization complications indicated a significant association between pain and pneumothorax, underscoring the critical importance of effective analgesia during localization. Notably, in our study, three patients who received lidocaine injections outside the parietal pleura fell asleep during the localization process. No sedative medications were administered to any patients prior to or during the procedure. These three patients maintained completely stable vital signs (heart rate, blood pressure, and oxygen saturation) throughout, woke up immediately upon verbal command, and reported no symptoms suggestive of LAST, such as perioral numbness, tinnitus, or dizziness. No other adverse events related to the extrapleural injection itself were observed.

Although this was an isolated occurrence, it further demonstrates that the application of lidocaine outside the parietal pleura during preoperative localization can enhance patient comfort. This approach is feasible and holds potential for broader clinical adoption.

Pleural reaction is primarily a vagal reflex caused by pleural irritation, manifesting as symptoms such as chest tightness, dyspnea, pallor, bradycardia, and hypotension, which are typical vagal reflex responses. The incidence of pleural reaction after preoperative puncture localization procedures is reported to be 3–5% (21). In this study, the incidence of pleural reaction was analyzed across the four patient groups, with an overall incidence rate of 7%, which aligns with previous studies. Most pleural reactions are transient and have not received sufficient attention or have even been overlooked in many reports. However, severe pleural reactions can result in respiratory and cardiac arrest, with potential mortality if resuscitation is not timely. Studies have shown that psychological factors are closely associated with pleural reactions. Anxiety, fear, and mental stress stemming from concerns about disease and surgical risks can cause hormonal changes that trigger inhibitory reflexes, elevate vagal tone, and reflexively enhance vagal activity, leading to vagal reflexes (22). Additionally, some researchers have suggested that pain stimuli may increase the incidence of pleural reactions. Severe pain stimulates the cerebral cortex and hypothalamus, causing reflex vasodilation, which leads to hypotension and bradycardia, ultimately triggering vagal reflexes. The pleura and arterial vessel walls are rich in sensory nerve endings derived from the vagus nerve, and their compression or traction can reflexively enhance vagal excitability (23). In this study, the use of subpleural lidocaine significantly alleviated pain during the localization process. Correlation analysis of complications revealed a relationship between pain and pleural reaction, indirectly suggesting that external parietal pleural lidocaine injections may reduce the incidence of pleural reactions to some extent. The potential beneficial effects observed in our study might be explained by several biologically plausible hypotheses. These include altered PPL, local compression, vagal modulation, and improved patient comfort. However, as we did not perform direct PPL measurements or formal physiologic monitoring, these mechanisms remain speculative and require further targeted validation.

Importantly, our findings should be interpreted in the context of the pioneering studies by Brönnimann et al., who first demonstrated the relevance of pre-puncture fluid application and gravity-dependent puncture strategy in CT-guided lung biopsy (15). Rather than introducing a de novo concept, the present study provides supportive evidence that these principles may also be applicable to hookwire-style PN localization before thoracoscopic surgery.

The results of this study indicate that patients undergoing puncture in gravity-dependent zones often experience greater puncture depth and more needle adjustments, which consequently leads to a longer localization duration. While these drawbacks can be partly mitigated by effective local anesthesia, they also hold the potential to be addressed through technological advancements. With continuous technological progress, robot-assisted localization has shown promising results in preoperative localization procedures. Studies have reported that robot-assisted localization not only achieves a high success rate (24) but also avoids the repeated needle insertions and adjustments typical of traditional CT-guided localization. This difference may stem from the reliance of conventional CT-guided methods on the operator’s experience, which necessitates frequent adjustments to needle depth and angle based on CT images. Reducing these frequent adjustments may decrease patient discomfort and the risk of related complications (25).

In summary, the injection of subpleural lidocaine and the application of pleural cavity pressure-gravity effects reduce the risk of pneumothorax after preoperative localization, enhance patient comfort, and provide substantial benefits. However, this study has several limitations. First, this is a single-center study with a relatively small number of cases. Second, a simplified model of PPL-gravity effects specific to the patient’s position was used. Third, the amount of lidocaine administered in this study was consistently 10 mL, and the relationship between varying liquid volumes and pneumothorax risk was not investigated. Fourth, patients with severe pulmonary emphysema or fibrosis were excluded, and the diseased lung parenchyma as a potential confounding factor warrants further investigation. Fifth, patients undergoing preoperative localization for multiple PNs, who have a higher probability of pneumothorax, were not included in this study.

Conclusions

Prior to percutaneous CT-guided lung nodule localization, precise injection of 10 mL of lidocaine outside the parietal pleura and choosing an appropriate position to insert the needle from the gravity-dependent area can reduce the incidence of pneumothorax during CT-guided lung nodule localization.

The use of lidocaine outside the parietal pleura can reduce the pain felt by patients during the localization process, increase comfort, and enhance the embodiment of humanistic care.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2026-1-0389/rc

Data Sharing Statement: Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2026-1-0389/dss

Peer Review File: Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2026-1-0389/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2026-1-0389/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Ethics Committee of The First Affiliated Hospital of Kunming Medical University. Informed consent was taken from all the patients.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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