Role of Lung Ultrasound in the Detection of Postoperative Pulmonary Complications in Pediatric Patients: A Prospective Observational Study

ESICM-ESPNIC international expert consensus on quantitative lung ultrasound in intensive care

PURPOSE

To provide an international expert consensus on technical aspects and clinical applications of quantitative lung ultrasound in adult, paediatric and neonatal intensive care.

METHODS

The European Society of Intensive Care (ESICM) and the European Society of Paediatric and Neonatal Intensive Care (ESPNIC) endorsed the project. We selected an international panel of 20 adult, paediatric and neonatal intensive care experts with clinical and research expertise in quantitative lung ultrasound, plus two non-voting methodologists. Fourteen clinical questions were proposed by the chairs to the panel, who voted for their priority (1-9 Likert-type scale) and proposed modifications/supplementing (two-round vote). All the questions achieved the predefined threshold (mean score > 5) and 14 groups of 3 mixed adult/paediatric experts were identified to develop the statements for each clinical question; predefined groups of experts in the fields of adult and paediatric/neonatal intensive care voted statements specific for these subgroups. An iterative approach was used to obtain the final consensus statements (two-round vote, 1-9 Likert-type scale); statements were classified as with agreement (range 7-9), uncertainty (4-6), disagreement (1-3) when the median score and ≥ 75% of votes laid within a specific range.

RESULTS

A total of 46 statements were produced (4 adults-only, 4 paediatric/neonatal-only, 38 interdisciplinary); all obtained agreement. This result was also achieved by acknowledging in the statements the current limitations of quantitative lung ultrasound.

CONCLUSION

This consensus guides the use of quantitative lung ultrasound in adult, paediatric and neonatal intensive care and helps identify the fields where further research will be needed in the future.

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 .

Perioperative Lung Ultrasound Findings in Elective Intra-Abdominal Surgery: Associations with Postoperative Pulmonary Complications

Background: For patients undergoing abdominal surgery, postoperative pulmonary complications (PPCs) are a major source of morbidity and mortality. The use of point-of-care ultrasonography (POCUS), and specifically POCUS of the lungs, has seen many advancements in recent years. Objectives: We hypothesize that perioperative lung ultrasonography can be used as a predictor for PPCs. Methods: In a Single, 1000 beds, trauma level I medical center, patients presenting for elective intra-abdominal surgery with no severe pulmonary or cardiac diseases were evaluated preoperatively with a standardized 12-point lung ultrasound exam. A second identical exam was performed after surgery in the post-anesthesia care unit. PPCs were also documented. All lung ultrasound exams were presented to a blinded researcher and a lung ultrasound score (LUS) was calculated. Statistical analysis comparing pre- and postoperative LUS and PPC scores were performed. Results: A total of 61 patients were evaluated. The pre-surgery median LUS was 0 (in the range of 0-6) and the post-surgery median LUS was 3 (in the range of 0-14). The pre- to postsurgical LUS delta was 3.4 (standard deviation of 3.3). A postoperative LUS of 6 or more was defined as "high." A High LUS did not correlate with prolonged post-anesthesia care unit or hospital stay, prolonged oxygen support, or number of desaturation events. Conclusion: For elective abdominal surgery in relatively healthy patients, preoperative LUS usually begins at a normal level and becomes worse after general anesthesia. However, this difference in LUS is not significantly associated with clinically relevant postoperative pulmonary complications such as prolonged oxygen therapy, pneumonia, and noninvasive or invasive mechanical ventilation. Trial registration: Clinicaltrials.gov identifier: NCT05502926. Summary: This paper explores the use of point-of-care ultrasonography as a predictor for postoperative pulmonary complications. The findings suggest that while the lung ultrasound score worsens with general anesthesia, the differences are not significantly associated with postoperative pulmonary complications.

Lung ultrasound for evaluating perioperative atelectasis and aeration in the post-anesthesia care unit

PURPOSE

Lung ultrasound is widely accepted as a reliable, noninvasive tool for evaluating lung status at the bedside. We assessed the impact of perioperative variables on atelectasis and lung aeration using lung ultrasound, and their correlation with postoperative oxygenation in patients undergoing general anesthesia.

METHODS

This prospective observational study evaluated 93 consecutive patients scheduled to undergo elective non-cardiothoracic surgery under general anesthesia. Lung ultrasound was performed 5 min after admission to the post-anesthesia care unit (PACU). Twelve pulmonary quadrants were selected for each ultrasound examination. The lung ultrasound scores and atelectasis status were calculated. The oxygenation assessment was obtained by arterial blood gas analysis before discharge from the PACU.

RESULTS

Thirty-two patients (34%) had atelectasis in at least one of the 12 evaluated segments, whereas 12 patients (13%) had atelectasis in at least three segments. The proportion of B-lines (≥ 3) and atelectasis in the inferolateral and posterior regions was significantly higher than in other regions. Patients with lung ultrasound scores ≥ 5 had a higher body mass index and lower PaO2 before discharge from the PACU than those with scores < 5. Patients with atelectasis had higher body mass indices and lung ultrasound scores. The presence of ≥ 2 regions of atelectasis was associated with lower PaO2. Using multivariate analysis, body mass index, intraoperative body position, and sex independently correlated with lung ultrasound scores. Age and lung ultrasound scores independently correlated with hypoxemia.

CONCLUSION

Lung ultrasound enables early postoperative evaluation of atelectasis and lung aeration, which are closely associated with postoperative oxygenation.

Prognostic value of the early lung ultrasound B-line score for postoperative pulmonary insufficiency in patients undergoing thoracic surgery: an observational study

BACKGROUND

Postoperative pulmonary insufficiency (PPI) is an important contributor to morbidity and mortality after thoracic surgery. Lung ultrasound is a reliable tool for assessing respiratory function. We sought to determine the clinical value of the early lung ultrasound B-line score for predicting changes in pulmonary function after thoracic surgery.

METHODS

Eighty-nine patients undergoing elective lung surgery were included in this study. The B-line score was determined 30 min after removal of the endotracheal tube, and the PaO2/FiO2 ratio was recorded 30 min after extubation and on the third postoperative day. Patients were divided into normal (PaO2/FiO2 ≥ 300) and PPI (PaO2/FiO2 < 300) groups according to their PaO2/FiO2 ratios. A multivariate logistic regression model was used to identify independent predictors of postoperative pulmonary insufficiency. Receiver operating characteristic (ROC) analysis was performed for significantly correlated variables.

RESULTS

Eighty-nine patients undergoing elective lung surgery were included in this study. We evaluated 69 patients in the normal group and 20 in the PPI group. Patients conforming to NYHA class 3 at administration were significantly more represented in the PPI group (5.8 and 55%; p < 0.001). B-line scores were significantly higher in the PPI group than in the normal group (16; IQR 13-21 vs. 7; IQR 5-10; p < 0.001). The B-line score was an independent risk factor (OR = 1.349 95% CI 1.154-1.578; p < 0.001), and its best cutoff value for predicting PPI was 12 (sensitivity: 77.5%; specificity: 66.7%).

CONCLUSIONS

Lung ultrasound B-line scores 30 min after extubation are effective in predicting early PPI in patients undergoing thoracic surgery. Trial registration This study was registered with the Chinese Clinical Trials Registry (ChiCTR2000040374).

Efficacy of prophylactic high-flow nasal cannula therapy for postoperative pulmonary complications after pediatric cardiac surgery: a prospective single-arm study

PURPOSE

This study investigated the incidence of postoperative pulmonary complications (PPC) when high-flow nasal cannula therapy (HFNC) is used prophylactically after pediatric cardiac surgery, and evaluated its efficacy.

METHODS

This was a single-arm prospective interventional study that was conducted in a tertiary teaching hospital with eight beds in the pediatric cardiac ICU after approval by the Ethics Committee. One-hundred children under the age of 48 months who were scheduled for cardiac surgery for congenital heart disease were recruited. HFNC was used for 24 h after extubation at a 2 L/kg/min flow rate. The primary outcome was the incidence of PPC within 48 h after extubation. PPC was defined as atelectasis and acute respiratory failure meeting certain criteria. We considered prophylactic HFNC as effective if the prevalence of PPC was < 10%, based on previous reports of reintubation rates of 6%-9% after pediatric cardiac surgery.

RESULTS

A total of 91 patients were finally included in the analysis. The incidence of PPC within 48 h after extubation was 18.7%, whereas atelectasis was observed in 13.2%, and acute respiratory failure in 8.8%. Reintubation rate within 48 h after extubation was 0%.

CONCLUSIONS

We found the incidence of PPC with prophylactic HFNC after planned extubation after pediatric cardiac surgery. However, the incidence was > 10%; therefore, we could not demonstrate its efficacy in this single-arm study. Further studies are needed to investigate whether the HFNC could be adapted as first-line oxygen therapy after pediatric cardiac surgery.

Utility of Lung Ultrasound in the Estimation of Extravascular Lung Water in a Pediatric Population-A Prospective Observational Study

OBJECTIVE

Lung ultrasound (LUS) is a promising bedside modality for the estimation of extravascular lung water index (EVLWI), but has not been validated against objective measures in children. This study aimed to investigate the correlation of LUS B-line scoring with EVLWI, thresholds indicating elevated EVLWI, and its outcome following pediatric cardiac surgery.

DESIGN

Prospective observational study.

SETTING

Cardiothoracic surgical intensive care unit in a tertiary care teaching hospital.

PARTICIPANTS

Children younger than 12 years undergoing elective complete surgical correction of cyanotic or acyanotic congenital heart disease (Aristotle score ≤9), excluding neonates, those weighing <3.5 kg, and those with thoracic deformities, pulmonary pathology, and hemodynamic instability.

INTERVENTIONS

Extravascular lung water index measurement by transpulmonary thermodilution, along with concurrent LUS B-line and Chest-X ray (CXR) scoring.

MEASUREMENTS AND MAIN RESULTS

LUS B-line score had a moderate correlation with EVLWI (Pearson's correlation coefficient 0.57; 95% CI 0.44-0.69). LUS B-line scores showed acceptable discrimination only for higher thresholds of EVLWI (sensitivity 82% and 79%, respectively, for EVLWI >20 mL/kg v sensitivity and specificity 57% and 80% for EVLWI >10 mL/kg). Age, body surface area, vasoactive-inotropic score (VIS), chest X-ray score, and EVLWI but not LUS B-line score were significant predictors for duration of mechanical ventilation in this cohort.

CONCLUSIONS

LUS B-line scoring has limited utility in semiquantitative estimation of EVLWI at lower thresholds of EVLWI in pediatric cardiac surgical patients. It may have better discrimination and acceptable sensitivity and specificity at higher thresholds of EVLWI. Contrasting with multiple reports of clinical utility, these results call for wider evaluation of LUS and its clinical modifiers like age, pathology, and pretest probability in estimation of EVLWI.