Hypoxemia in Young Children Undergoing One-lung Ventilation: A Retrospective Cohort Study

Effect of one-lung ventilation in children undergoing lateral thoracotomy cardiac surgery with cardiopulmonary bypass on postoperative atelectasis and postoperative pulmonary complications

BACKGROUND

Right lateral thoracotomy is increasingly used because of its cosmetic benefits, shorter hospital stays, rapid return to full activity, and ease of reoperation in pediatric patients with uncomplicated congenital heart disease. Currently, one-lung ventilation (OLV) is used in these children to facilitate surgical exposure. We aimed to assess the effect of OLV on postoperative outcomes.

METHODS

Children aged 6 months to 6 years undergoing right lateral thoracotomy cardiac surgery with cardiopulmonary bypass (CPB) were randomized into an OLV group or a control group. For the OLV group, the tidal volume was 5 ml/kg with 6 cmH₂O positive end-expiratory pressure from the incision until the end of CPB, whereas patients in the control group received two-lung ventilation, except during vena cava occlusion. Lung ultrasonography was performed twice in the supine position for each patient: first, 3 min after intubation before surgery (T1), and second, 3 min after lung recruitment maneuvers at the end of surgery (T2). The primary outcome was the incidence of postoperative pulmonary complications within 72 h of surgery and significant atelectasis (defined by a consolidation score of ≥ 2 in any region) at T2.

RESULTS

Overall, 54/96 (56.3%) children developed postoperative pulmonary complications after lateral thoracotomy cardiac surgery with CPB. The incidence of postoperative pulmonary complications was 52.1% (25/48) and 60.4% (29/48) in the OLV and control groups, respectively (odds ratio: 0.712; 95% confidence interval: 0.317-1.600; p = .411). At the end of surgery, the incidence of significant atelectasis was 37.5% in the OLV group compared to 64.6% in the control group (odds ratio: 0.329; 95% confidence interval: 0.143-0.756; p = .008). The consolidation score of the left lung (dependent lung) in the OLV group was significantly lower than that in the control group (p = .007); there was no significant difference in the right lung's postoperative consolidation score between the two groups (p = .051).

CONCLUSIONS

There was no significant difference in the incidence of postoperative pulmonary complications within 72 h of surgery between the two groups. However, children who underwent right lateral thoracotomy cardiac surgery with CPB in the OLV group showed a low incidence of atelectasis at the end of surgery.

TRIAL REGISTRATION

ChiCTR, ChiCTR2100048720. Registered on July 13, 2021, www.chictr.org.cn .

Bronchial Blocker Versus Endobronchial Intubation in Young Children Undergoing One-Lung Ventilation: A Multicenter Retrospective Cohort Study

BACKGROUND

Thoracic surgery and one-lung ventilation in young children carry significant risks. Approaches to one-lung ventilation in young children include endobronchial intubation (mainstem intubation) and use of a bronchial blocker. We hypothesized that endobronchial intubation is associated with a greater prevalence of airway complications compared to use of a bronchial blocker.

METHODS

The Multicenter Perioperative Outcomes Group database was queried from 2004 to 2022 for one-lung ventilation cases in children, 2 months to 3 years of age, inclusive. Airway notes and free-text comments were manually reviewed for airway complications. Documented airway complications were considered the primary outcome and were divided into "Moderate" and "Critical." Moderate airway complications were bronchial blocker or endotracheal tube movement leading to loss of isolation, hypoxemia requiring ventilatory intervention, bronchial blocker migration into the trachea, significant impairment of ventilation, and other. Critical complications included reintubation or airway replacement intraoperatively, complete endotracheal tube occlusion, cardiac arrest or airway-related bradycardia, and procedure aborted due to an airway issue. An adjusted propensity score-matched analysis was then used to assess the impact of a bronchial blocker on the outcomes of moderate and critical complications.

RESULTS

After exclusions, 704 patients were included in the primary analysis. In unadjusted analyses, no statistically significant difference was observed in moderate airway complications between endobronchial intubation and bronchial blocker cohorts: 37 of 444 (8.3%; 95% confidence interval [CI], 5.9%-11.3%) vs 28 of 260 (10.8%; 95% CI, 7.3%-15.2%) with P = .281. In the unadjusted analysis, the prevalence of critical airway complications was significantly higher in the endobronchial intubation cohort compared to the bronchial blocker cohort: 28 of 444 (6.3%; 95% CI, 4.2%-9.0%) vs 5 of 260 (1.9%; 95% CI, 0.6%-4.4%) with P = .008. In the propensity-matched cohort analysis, endobronchial intubation was associated with a slightly increased risk of critical complications compared to use of a bronchial blocker: 14 of 243 (5.8%; 95% CI, 2.8%-8.7%) vs 5 of 243 (2.1%; 95% CI, 0.3%-3.8%) with P = .035.

CONCLUSIONS

Endobronchial intubation might be associated with a slightly increased risk of critical airway complications compared to use of a bronchial blocker in young children undergoing thoracic surgery and one-lung ventilation. Further, prospective studies are needed before a definitive change in practice is recommended.

Association of mechanical power and postoperative pulmonary complications among young children undergoing video-assisted thoracic surgery: A retrospective study

BACKGROUND

Previous studies have discussed the correlation between mechanical power (MP) and lung injury. However, evidence regarding the relationship between MP and postoperative pulmonary complications (PPCs) in children remains limited, specifically during one-lung ventilation (OLV).

OBJECTIVES

Propensity score matching was employed to generate low MP and high MP groups to verify the relationship between MP and PPCs. Multivariable logistic regression was performed to identify risk factors of PPCs in young children undergoing video-assisted thoracic surgery (VATS).

DESIGN

A retrospective study.

SETTING

Single-site tertiary children's hospital.

PATIENTS

Children aged ≤2 years who underwent VATS between January 2018 and February 2023.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

The incidence of PPCs.

RESULTS

Overall, 581 (median age, 6 months [interquartile range: 5-9.24 months]) children were enrolled. The median [interquartile range] MP during OLV were 2.17 [1.84 to 2.64) J min-1. One hundred and nine (18.76%) children developed PPCs. MP decreased modestly during the study period (2.63 to 1.99 J min-1; P < 0.0001). In the propensity score matched cohort for MP (221 matched pairs), MP (median MP 2.63 vs. 1.84 J min-1) was not associated with a reduction in PPCs (adjusted odds ratio, 1.43; 95% CI, 0.87 to 2.37; P = 0.16). In the propensity score matched cohort for dynamic components of MP (139 matched pairs), dynamic components (mean 2.848 vs. 4.162 J min-1) was not associated with a reduction in PPCs (adjusted odds ratio, 1.62; 95% CI, 0.85 to 3.10; P  = 0.15).The multiple logistic analysis revealed PPCs within 7 days of surgery were associated with male gender, OLV duration >90 min, less surgeon's experience and lower positive end-expiratory pressure (PEEP) value.

CONCLUSIONS

MP and dynamic components were not associated with PPCs in young children undergoing VATS, whereas PPCs were associated with male gender, OLV duration >90 min, less surgeon's experience and lower PEEP value.

TRIAL REGISTRATION

ChiCTR2300074649.

Infant bronchial tree simulator: Success of a built-from-scratch model for single lung isolation

BACKGROUND

One-lung ventilation in infants is a high-risk procedure. Complications include endotracheal tube occlusion, with grave consequences. Although there are commercially available bronchoscopy simulators, there are no realistic models of infant patients. This limits access to training opportunities that would ensure safe and efficient lung isolation. To bridge this gap, we developesd a realistic infant bronchial tree model for single lung intubation and evaluated preliminary validity evidence of its features and clinicians' ability to perform critical skills associated with pediatric one-lung ventilation.

METHODS

Using computed tomography imaging, a stereolithography file of an infant airway was generated to 3D print a model. This model was inserted into a commercially available airway trainer to allow lung isolation using standard bronchoscopy techniques. Ten experienced pediatric anesthesiologists independently evaluated the simulator's physical attributes, realism, value, and relevance using a 29-item paper survey and rated using 4-point rating scales (4 = highest). Participants' ability to complete 5 critical tasks was self-reported using 5-point rating scales (5 = too easy). Item and domain mean ratings were calculated, and comments reviewed.

RESULTS

Overall, reviews were positive, with mean scores indicating adequate realism and high value. Specific challenges were associated with right mainstem bronchus and upper lobe takeoff. Performance scores indicated that most tasks were "somewhat easy to perform," suggesting that the model's anatomy did not hinder physicians' ability to perform one-lung ventilation.

CONCLUSION

Preliminary findings indicate that the novel simulator holds promise for training in lung isolation techniques after refinement. Future research will target refinement, expanding evaluation, and developing a comprehensive curriculum and competency assessment program.

Risk of pulmonary complications after video-assisted thoracoscopic pulmonary resection in children

BACKGROUND

Postoperative pulmonary complications (PPCs) are associated with high mortality and morbidity rates. Children are more susceptible to PPCs owing to smaller functional residual capacity and greater closing volume. Risk factors of PPCs in children undergoing lung resection remain unclear.

METHODS

This retrospective study enrolled children who underwent video-assisted thoracoscopic surgery between January 2018 and February 2023. The primary outcome was PPC occurrence. Multivariate logistic regression was used to analyze risk factors for PPCs.

RESULTS

Overall, 640 children were analyzed; their median age was 7 (interquartile range: 5-11) months, and the median tidal volume was 7.66 (6.59-8.49) mL/kg. One hundred and seventeen (18.3%) developed PPCs. PPCs were independently associated with male sex (odds ratio [OR], 1.83; 95% confidence interval [CI], 1.17-2.88; P=0.008), longer OLV duration (OR, 1.01; 95% CI, 1.0-1.01; P=0.001), and less surgeon's experience (OR, 1.67; 95% CI, 1.03-2.7; P=0.036). When low-tidal-volume cutoff was defined as <8 mL/kg, PEEP level was a protective factor for PPCs (OR, 0.83; 95% CI, 0.69-1.00; P=0.046). Additionally, PPCs were associated with increased hospital stay (P<0.001).

CONCLUSIONS

Male sex, longer OLV duration, less surgeon's experience, and lower PEEP were risk factors of PPCs in children undergoing video-assisted thoracoscopic surgery. Our findings may serve as targets for prospective studies investigating specific ventilation strategies for children.

Effects of individualised lung-protective ventilation with lung dynamic compliance-guided positive end-expiratory pressure titration on postoperative pulmonary complications of paediatric video-assisted thoracoscopic surgery: protocol for a randomised controlled trial

INTRODUCTION

Lung-protective ventilation strategies (LPVS) for one-lung ventilation (OLV) in paediatric patients pose greater challenges than in adults. Optimising LPVS for paediatric OLV to mitigate postoperative pulmonary complications (PPCs) has emerged as a current research focal point. However, there remains a divergence of opinions concerning the individualised setting and application of positive end-expiratory pressure (PEEP). Lung dynamic compliance (Cdyn) can serve as a reflection of the lung's physiological state in children during OLV and is a readily obtainable parameter. This study protocol is formulated to assess the effectiveness of Cdyn-guided PEEP titration on PPCs during paediatric OLV.

METHODS AND ANALYSIS

This study constitutes a single-centre, prospective, double-blind, randomised controlled trial. The trial aims to recruit 60 paediatric patients scheduled for video-assisted thoracoscopic surgery. These eligible patients will be randomly assigned to either the Cdyn-guided PEEP group or the conventional PEEP group during general anaesthesia for OLV. The primary outcome will involve assessing the incidence of PPCs at 7 days after surgery. Secondary outcomes will encompass the evaluation of the modified lung ultrasound score following surgery, as well as monitoring the oxygenation index, driving pressure and Cdyn during mechanical ventilation. Data collection will be performed by investigators who are kept blinded to the interventions.

ETHICS AND DISSEMINATION

The Clinical Trial Ethics Committee at Shenzhen Children's Hospital has conferred ethical approvals for this trial (approval number: 2022076). Results from this trial will be disseminated in peer-reviewed journals and presented at professional symposiums.

TRAIL REGISTRATION NUMBER

NCT05386901.

Identifying risk factors for hypoxemia during emergence from anesthesia in patients undergoing robot-assisted laparoscopic radical prostatectomy

Robot-assisted laparoscopic radical prostatectomy (RALP) has emerged as an effective treatment for prostate cancer with obvious advantages. This study aims to identify risk factors related to hypoxemia during the emergence from anesthesia in patients undergoing RALP. A cohort of 316 patients undergoing RALP was divided into two groups: the hypoxemia group (N = 134) and the non-hypoxemia group (N = 182), based on their postoperative oxygen fraction. Comprehensive data were collected from the hospital information system, including preoperative baseline parameters, intraoperative data, and postoperative recovery profiles. Risk factors were examined using multiple logistic regression analysis. The study showed that 38.9% of patients had low preoperative partial pressure of oxygen (PaO2) levels. Several clinical parameters showed significant differences between the hypoxemia group and the non-hypoxemia group, including weight (P < 0.0001), BMI (P < 0.0001), diabetes mellitus (P = 0.044), history of emphysema and pulmonary alveoli (P < 0.0001), low preoperative PaO2 (P < 0.0001), preoperative white blood cell count (P = 0.012), preoperative albumin (P = 0.048), intraoperative bleeding (P = 0.043), intraoperative CO2 accumulation (P = 0.001), duration of surgery (P = 0.046), postoperative hemoglobin level (P = 0.002), postoperative hypoxemia (P = 0.002), and early postoperative fever (P = 0.006). Multiple logistic regression analysis revealed BMI (adjusted odds ratio = 0.696, 95% confidence interval 0.612-0.719), low preoperative PaO2 (adjusted odds ratio = 9.119, 95% confidence interval 4.834-17.203), and history of emphysema and pulmonary alveoli (adjusted odds ratio = 2.804, 95% confidence interval 1.432-5.491) as independent factors significantly associated with hypoxemia on emergence from anesthesia in patients undergoing RALP. Our results demonstrate that BMI, lower preoperative PaO2, and a history of emphysema and pulmonary alveolar disease are independent risk factors associated with hypoxemia on emergence from anesthesia in patients undergoing RALP. These findings provide a theoretical framework for surgeons and anesthesiologists to facilitate strategies to mitigate postoperative hypoxemia in this unique patient population.

Hypoxemia in School-age Children Undergoing One-lung Ventilation: A Retrospective Cohort Study from the Multicenter Perioperative Outcomes Group

BACKGROUND

Risk factors for hypoxemia in school-age children undergoing one-lung ventilation remain poorly understood. The hypothesis was that certain modifiable and nonmodifiable factors may be associated with increased risk of hypoxemia in school-age children undergoing one-lung ventilation and thoracic surgery.

METHODS

The Multicenter Perioperative Outcomes Group database was queried for children 4 to 17 yr of age undergoing one-lung ventilation. Patients undergoing vascular or cardiac procedures were excluded. The original cohort was divided into two cohorts: 4 to 9 and 10 to 17 yr of age inclusive. All records were reviewed electronically for the primary outcome of hypoxemia during one-lung ventilation, which was defined as an oxygen saturation measured by pulse oximetry (Spo2) less than 90% for 3 min or longer continuously, while severe hypoxemia was defined as Spo2 less than 90% for 5 min or longer. Potential modifiable and nonmodifiable risk factors associated with these outcomes were evaluated using separate multivariable least absolute shrinkage and selection operator regression analyses for each cohort. The covariates evaluated included age, extremes of weight, American Society of Anesthesiologists Physical Status of III or higher, duration of one-lung ventilation, preoperative Spo2 less than 98%, approach to one-lung ventilation, right operative side, video-assisted thoracoscopic surgery, lower tidal volume ventilation (defined as tidal volume of 6 ml/kg or less and positive end-expiratory pressure of 4 cm H2O or greater for more than 80% of the duration of one-lung ventilation), and procedure type.

RESULTS

The prevalence of hypoxemia in the 4- to 9-yr-old cohort and the 10- to 17-yr-old cohort was 24 of 228 (10.5% [95% CI, 6.5 to 14.5%]) and 76 of 1,012 (7.5% [95% CI, 5.9 to 9.1%]), respectively. The prevalence of severe hypoxemia in both cohorts was 14 of 228 (6.1% [95% CI, 3.0 to 9.3%]) and 47 of 1,012 (4.6% [95% CI, 3.3 to 5.8%]). Initial Spo2 less than 98% was associated with hypoxemia in the 4- to 9-yr-old cohort (odds ratio, 4.20 [95% CI, 1.61 to 6.29]). Initial Spo2 less than 98% (odds ratio, 2.76 [95% CI, 1.69 to 4.48]), extremes of weight (odds ratio, 2.18 [95% CI, 1.29 to 3.61]), and right-sided cases (odds ratio, 2.33 [95% CI, 1.41 to 3.92]) were associated with an increased risk of hypoxemia in the older cohort. Increasing age (1-yr increment; odds ratio, 0.88 [95% CI, 0.80 to 0.97]) was associated with a decreased risk of hypoxemia.

CONCLUSIONS

An initial room air oxygen saturation of less than 98% was associated with an increased risk of hypoxemia in all children 4 to 17 yr of age. Extremes of weight, right-sided cases, and decreasing age were associated with an increased risk of hypoxemia in children 10 to 17 yr of age.

EDITOR’S PERSPECTIVE

One-lung ventilation with a bronchial blocker in thoracic patients

BACKGROUND

Lung isolation is a technique used in a multitude of surgeries to ensure single-lung ventilation with collapse of the contralateral lung, as to achieve improved access and visualization of relevant anatomical structures. Despite being accepted and having favorable outcomes, bronchial blockers (BBs) are not to this day the main device of choice among anaesthesiologists.

METHODS

In this retrospective and descriptive study, we analyzed the safety and efficacy of a BB in all types of thoracic surgeries in our centre between 2015 and 2022, excluding patients with massive hemoptysis or empyema, or who had undergone a prior pneumonectomy.

RESULTS

One hundred and thirty-four patients were intervened due to lung cancer (67.9%), respiratory disease (23.9%), and non-respiratory disease (8.2%) undergoing lung surgeries (65.7%), pleural and mediastinal surgeries (29.9%), chest wall surgeries (3.0%) and other surgeries (1.5%). In most cases, lung collapse was considered excellent (63.9%) or good (33.1%) with only 4 cases (3.0%) of poor lung collapse. More than 90% of patients did not present intraoperative or immediate postoperative complications. No statistically significant differences were found between lung collapse and the demographic, clinical or BB-related variables (p > 0.05). However, we found a significatively higher proportion of excellent lung collapses in VATS surgeries and lateral decubitus positioning, as well as a significatively less proportion of poor lung collapses (p < 0.05). Moreover, there was a significantly higher proportion of excellent lung collapses when the BB was placed in the left bronchus (p < 0.05).

CONCLUSIONS

With these results, in our experience BBs constitute an effective alternative, capable of achieving pulmonary collapse in all kinds of thoracic procedures with satisfactory safety rates due to their minimal complications.

[Anesthetic Management in Pediatric Thoracic Surgery]

Pediatric thoracic anesthesia is a challenging task. Specific implications arise from the patients' developmental stage, the disease and the intervention. An interdisciplinary management plan includes relevant factors. The main aspects are airway management, analgesic techniques and cardiorespiratory therapeutic strategies adapted to the underlying pathophysiology. Every step should be designed to provide optimal care. This article provides insight to specific airway, respiratory and regional anesthesia management in pediatric patients.

Error traps in pediatric one-lung ventilation

With the advent of thoracoscopic surgery, the benefits of lung isolation in children have been increasingly recognized. However, because of the small airway dimensions, equipment limitations in size and maneuverability, and limited respiratory reserve, one-lung ventilation in children remains challenging. This article highlights some of the most common error traps in the management of pediatric lung isolation and focuses on practical solutions for their management. The error traps discussed are as follows: (1) the failure to take into consideration relevant aspects of tracheobronchial anatomy when selecting the size of the lung isolation device, (2) failure to execute correct placement of the device chosen for lung isolation, (3) failure to maintain lung isolation related to surgical manipulation and isolation device movement, (4) failure to select appropriate ventilator strategies during one-lung ventilation, and (5) failure to appropriately manage and treat hypoxemia in the setting of one-lung ventilation.

Chronic hypoxia prolongs postoperative mechanical ventilation and reduces the left atrial pressure threshold in children with tetralogy of Fallot

BACKGROUND

Chronic hypoxia induces pulmonary microvascular endothelial dysfunction. The left atrial pressure (LAP) represents the hydrostatic pressure of pulmonary microcirculation. The conjunction of the LAP and any abnormal pulmonary microvascular endothelial barrier function will have an impact on pulmonary exudation, resulting in prolonged mechanical ventilation. This study aimed to investigate the tolerance threshold of the pulmonary microcirculation to LAP in children with tetralogy of Fallot (TOF) to avoid prolonged mechanical ventilation after surgery.

METHODS

This retrospective study included 297 Chinese patients who underwent TOF correction at Fuwai Hospital. Patients were categorized according to their preoperative oxygen saturation (SpO₂) level. One-to-one propensity score matching (PSM) revealed a total of 126 participants in the SpO₂< 90% and SpO₂≥ 90% groups. Between-group comparisons were conducted to verify the correlation between hypoxia and prolonged mechanical ventilation. A subgroup analysis was performed to reveal the significant role of postoperative LAP stewardship on prolonged mechanical ventilation.

RESULTS

Failure to extubate within the first 48 h (23.81% vs. 9.52%, P = 0.031) and prolonged mechanical ventilation (26.98% vs. 11.11%, P = 0.023) were more commonly observed in children with preoperative SpO₂ < 90%. The incidence of prolonged mechanical ventilation consistently increased with LAP in both the SpO₂ < 90% and SpO₂ ≥ 90% groups, although LAP was still within the normal range (6-12 mmHg). Children in chronic hypoxic conditions tolerated lower LAP well. The tolerance threshold for postoperative LAP in children diagnosed with TOF under chronic hypoxic conditions was identified as 7 mmHg.

CONCLUSIONS

Children in a chronic hypoxic state may suffer from a high incidence of prolonged mechanical ventilation after surgical correction of TOF and may not tolerate higher postoperative LAP. To improve pulmonary prognosis, it is better to control and maintain the postoperative LAP at a lower state (≤7 mmHg) in children with chronic hypoxia.

Association of regional cerebral oxygen saturation and postoperative pulmonary complications in pediatric patients undergoing one-lung ventilation: A propensity score matched analysis of a prospective cohort study

BACKGROUND

Previous studies of the relationship of regional cerebral oxygen saturation (rScO2) and postoperative pulmonary complications (PPCs) in pediatric patients are not well established, and further investigation is warranted. The aim of this prospective study was to determine whether a decrease in intraoperative rScO2 is associated with PPCs in children undergoing thoracoscopic surgery requiring one-lung ventilation (OLV).

METHODS

One hundred and six children of ages 3 months to 8 years who received one-lung ventilation were enrolled in the study. Upon entering the operating room, regional cerebral oxygen saturation was continuously monitored bilaterally by near-infrared spectroscopy. Patients were divided into low rScO2 (L-rScO2) or high rScO2 (H- rScO2) groups according to whether the lowest intraoperative rScO2 value was 15% lower than the baseline value. Outcome is defined as PPCs occurring within 7 days after surgery.

RESULTS

After propensity score matching, 23 pediatric patients with decreased rScO2 and 46 pediatric patients without a decrease in rScO2 were included in this study. According to logistic regression analysis, patients in the H- rScO2 group were less likely to have PPCs than those in the L-rScO2 group (OR = 3.16; 95% CI = 1.05-9.5; P = 0.04). Moreover, intraoperative rScO2 reduction was associated with an increase in the severity of PPCs (OR = 3.90; 95% CI = 1.19-12.80; P = 0.025).

CONCLUSIONS

The decrease in regional cerebral oxygen saturation during surgery increases the likelihood of postoperative pulmonary complications.