Is atelectasis related to the development of postoperative pneumonia? a retrospective single center study

Factors associated with the development of bacterial pneumonia and the preventive potential of peroral endoscopic myotomy in patients with esophageal motility disorders: a case-control study

BACKGROUND

Patients with esophageal motility disorders (EMDs) sometimes develop bacterial pneumonia (BP). However, factors associated with BP in patients with EMDs and whether peroral endoscopic myotomy (POEM) reduces BP development are unclear. Therefore, this study aimed to identify factors associated with BP development and evaluate the preventive potential of POEM in patients with EMDs.

METHODS

This study included 623 patients diagnosed with EMDs at our institution between April 2015 and March 2023. Factors associated with BP were analyzed by comparing characteristics between patients who developed BP within 1 year before diagnosis using multivariable analysis. The potential of POEM to prevent BP development was assessed using Cox regression analysis, considering treatment status as a time-varying covariate.

RESULTS

Of the 623 patients, 31 (5.0%) developed BP within 1 year before diagnosis. Older age (odds ratio [OR] = 1.29, 95% confidence interval [CI] 1.04-1.59, p = 0.019; 10-year increments), lower body mass index (OR = 0.87, 95% CI 0.78-0.98, p = 0.026), and manometric diagnosis of spastic esophageal disorders (OR = 2.97, 95% CI 1.24-7.16, p = 0.015) were significantly associated with BP. Treatment status of POEM was proved to be a significant factor for developing BP using Cox regression analysis (hazard ratio = 0.17, 95% CI 0.039-0.75, p = 0.019).

CONCLUSIONS

Risk factors associated with BP in patients with EMDs were older age, lower body mass index, and manometric diagnosis of spastic esophageal disorders. POEM could decrease spasm-related bolus reflux, improve patients' nutritional status through resolution of transit disturbance, and reduce respiratory complications, suggesting that POEM could help prevent BP development.

Pulmonary Atelectasis After Sedation With Propofol vs Propofol-Ketamine for Magnetic Resonance Imaging in Children: A Randomized Clinical Trial

Importance

Little is known about the impact of different anesthetic agents used for routine magnetic resonance imaging (MRI) sedation on pulmonary function in children.

Objective

To compare the incidence of pulmonary atelectasis after MRI sedation with propofol vs propofol-ketamine.

Design, Setting, and Participants

This double-masked randomized clinical trial screened 117 consecutive pediatric patients aged 3 to 12 years with American Society of Anesthesiologists physical status I to II undergoing elective MRI under deep sedation from November 2, 2022, to April 28, 2023, at a tertiary referral center. Four patients met the exclusion criteria, and 5 patients refused to participate. The participants and outcome assessors were masked to the group allocation.

Interventions

During the MRI, the propofol group received 0.2 mL/kg of 1% propofol and 2 mL of 0.9% saline followed by a continuous infusion of propofol (200 μg/kg/min) and 0.9% saline (0.04 mL/kg/min). The propofol-ketamine group received 0.2 mL/kg of 0.5% propofol and 1 mg/kg of ketamine followed by a continuous infusion of propofol (100 μg/kg/min) and ketamine (20 μg/kg/min).

Main Outcome and Measure

The incidence of atelectasis assessed by lung ultrasonography examination.

Results

A total of 107 children (median [IQR] age, 5 [4-6] years; 62 male [57.9%]), with 54 in the propofol group and 53 in the propofol-ketamine group, were analyzed in this study. Notably, 48 (88.9%) and 31 (58.5%) patients had atelectasis in the propofol and propofol-ketamine groups, respectively (relative risk, 0.7; 95% CI, 0.5-0.8; P < .001). The incidence of desaturation and interruption of the MRI due to airway intervention or spontaneous movement did not significantly differ between the groups. The propofol-ketamine group showed a faster emergence time than the propofol group (15 [9-23] vs 25 [22-27] minutes in the propofol-ketamine vs propofol group; median difference in time, 9.0 minutes; 95% CI, 6.0-12.0 minutes; P < .001). No patient was withdrawn from the trial due to adverse effects.

Conclusions and Relevance

In this randomized clinical trial, the propofol-ketamine combination reduced sedation-induced atelectasis while allowing for faster emergence compared with propofol alone.

Trial Registration

cris.nih.go.kr Identifier: KCT0007699.

Lung ultrasound assessment of atelectasis following different anesthesia induction techniques in pediatric patients: a propensity score-matched, observational study

INTRODUCTION

Atelectasis is a well-documented complication in pediatric patients undergoing general anesthesia. Its incidence varies significantly based on surgical procedures and anesthesia techniques. Inhalation induction, commonly used to avoid the discomfort of venipuncture, is suspected to cause higher rates of respiratory complications, including atelectasis, compared to intravenous induction. This study aimed to evaluate the impact of inhalation versus intravenous anesthesia induction on atelectasis formation in pediatric patients, as assessed by lung ultrasound (LUS).

METHODS

This propensity score-matched observational study was conducted at a tertiary pediatric hospital in Milan, Italy. Inclusion criteria were children ≤ 18 years undergoing elective surgery with general anesthesia. Patients were divided into inhalation and intravenous induction groups. LUS was performed before and after anesthesia induction to assess lung aeration. The primary endpoint was the global LUS score post-induction, with secondary endpoints including the incidence and distribution of atelectasis.

RESULTS

Of the 326 patients included, 65% underwent inhalation induction and 35% intravenous induction. The global LUS score was significantly higher in the inhalation group (12.0 vs. 4.0, p < 0.001). After propensity score matching (for age, presence of upper respiratory tract infection, duration of induction, and PEEP levels at induction), average treatment effect (ATE) of mask induction was 5.89 (95% CI, 3.21-8.58; p < 0.001) point on LUS global score and a coefficient of 0.35 (OR 1.41) for atelectasis.

DISCUSSION

Inhalation induction is associated with a higher incidence of atelectasis in pediatric patients also when we adjusted for clinically relevant covariates.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT06069414.

A stepwise lung recruitment maneuver using I-gel can improve respiratory parameters: A prospective observational study

I-gel has been used in various clinical situations. The study investigated alterations in respiratory parameters following a stepwise lung recruitment maneuver (LRM) using the i-gel. The research involved 60 patients classified as American Society of Anesthesiologists class I-II, aged 30 to 75 years, undergoing elective urologic surgery. Various respiratory parameters, including lung compliance, airway resistance, leak volume, airway pressure, and oxygen reserve index, were recorded at different time points: before LRM, immediately after LRM, and at 5, 15, and 30 minutes after LRM, as well as at the end of the surgery. The primary outcome was to assess an improvement in lung compliance. Dynamic lung compliance (mean ± SD) was significantly increased from 49.2 ± 1.8 to 70.15 ± 3.2 mL/cmH2O (P < .05) after LRM. Static lung compliance (mean ± SD) was increased considerably from 52.4 ± 1.7 to 65.0 ± 2.5 mL/cmH2O (P < .05) after the LRM. Both parameters maintained a statistically significant increased status for a certain period compared to baseline despite a decreased degree of increment. Airway resistance (mean ± SD) was significantly reduced after the LRM from 12.05 ± 0.56 to 10.41 ± 0.64 L/cmH2O/s (P < .05). Stepwise LRM using i-gel may improve lung compliance and airway resistance. Repeated procedures could lead to prolonged improvements in respiratory parameters.

Lung Ultrasound Score on Postoperative Day 1 Is Predictive of the Occurrence of Pulmonary Complications after Major Abdominal Surgery: A Multicenter Prospective Observational Study

BACKGROUND

Postoperative pulmonary complications after major abdominal surgery are frequent and carry high morbidity and mortality. Early identification of patients at risk of pulmonary complications by lung ultrasound may allow the implementation of preemptive strategies. The authors hypothesized that lung ultrasound score would be associated with pulmonary postoperative complications. The main objective of the study was to evaluate the performance of lung ultrasound score on postoperative day 1 in predicting pulmonary complications after major abdominal surgery. Secondary objectives included the evaluation of other related measures for their potential prediction accuracy.

METHODS

A total of 149 patients scheduled for major abdominal surgery were enrolled in a bicenter observational study. Lung ultrasound score was performed before the surgery and on days 1, 4, and 7 after surgery. Pulmonary complications occurring before postoperative day 10 were recorded.

RESULTS

Lung ultrasound score on postoperative day 1 was higher in patients developing pulmonary complications before day 10 (median, 13; interquartile range, 8.25 to 18; vs. median, 10; interquartile range, 6.5 to 12; Mann-Whitney P = 0.002). The area under the curve for predicting postoperative pulmonary complications before day 10 was 0.65 (95% CI, 0.55 to 0.75; P = 0.003). Lung ultrasound score greater than 12 had a sensitivity of 0.54 (95% CI, 0.40 to 0.67), specificity of 0.77 (95% CI, 0.67 to 0.85), and negative predictive value of 0.74 (95% CI, 0.65 to 0.83). Lung ultrasound score greater than 17 had sensitivity of 0.33 (95% CI, 0.21 to 0.47), specificity of 0.95 (95% CI, 0.88 to 0.98), and positive predictive value of 0.78 (95% CI, 0.56 to 0.93). Anterolateral lung ultrasound score and composite scores using lung ultrasound score and other patient characteristics showed similar predictive accuracies.

CONCLUSIONS

An elevated lung ultrasound score on postoperative day 1 is associated with the occurrence of pulmonary complications within the first 10 days after major abdominal surgery.

EDITOR’S PERSPECTIVE

Lung Ultrasound Abnormalities in Patients Without Pulmonary Pathology Prior to Surgery

Background

The occurrence of lung ultrasound abnormalities in patients without lung disease remains uncertain, while patients with respiratory disease often exhibit such abnormalities.

Objectives

The primary aim was to identify pathological ultrasonographic pulmonary findings and their correlation with baseline diseases and static lung compliance in patients without any pre-existing respiratory conditions.

Methods

This prospective observational study enrolled a series of surgical patients with no history of pulmonary pathology (n = 104). Baseline diseases and patients' physical status classification, based on the American Society of Anesthesiologists (ASA), were documented by reviewing medical records. Prior to surgery, a lung ultrasound was performed to assess pulmonary changes. During surgery with general anesthesia, static lung compliance was measured. The Spearman correlation coefficient was employed to determine the correlation between the two variables.

Results

Twenty-four patients (23.07%) exhibited 1 - 2 B-lines in certain lung fields. Seven patients (6.7%) had an ultrasound B-line score > 0 (indicating ≥ 3 B-lines). Among these patients, the average number of lung fields with ≥ 3 B-lines was 3.71 ± 2.43. Patients with systemic diseases (ASA ≥ 2) displayed a higher number of B-lines compared to ASA I patients (P-value = 0.039). Pleural irregularities were found in 10 patients (9.6%), while atelectasis and pleural effusion were observed in five (4.8%) and four (3.8%) patients, respectively. The mean lung compliance value was 56.78 ± 15.33. No correlation was observed between the total score of the B-lines and lung compliance (Spearman's correlation: rho = -0.028, P-value = 0.812).

Conclusions

Patients without pulmonary pathology may exhibit ultrasound pulmonary abnormalities, which tend to increase with higher ASA scores and do not appear to have a correlation with static lung compliance.