Novel Oxygenation and Saturation Indices for Mortality Prediction in COVID-19 ARDS Patients: The Impact of Driving Pressure and Mechanical Power

Background: The oxygenation index (OI) and oxygen saturation index (OSI) are proven mortality predictors in pediatric and adult patients, traditionally using mean airway pressure (Pmean). We introduce novel indices, replacing Pmean with DP (ΔPinsp), MPdyn, and MPtot, assessing their potential for predicting COVID-19 acute respiratory distress syndrome (ARDS) mortality, comparing them to traditional indices. Methods: We studied 361 adult COVID-19 ARDS patients for 7 days, collecting ΔPinsp, MPdyn, and MPtot, OI-ΔPinsp, OI-MPdyn, OI-MPtot, OSI-ΔPinsp, OSI-MPdyn, and OSI-MPtot. We compared these in surviving and non-surviving patients over the first 7 intensive care unit (ICU) days using Mann-Whitney U test. Logistic regression receiver operating characteristic (ROC) analysis assessed AUC and CI values for ICU mortality on day three. We determined cut-off values using Youden's method and conducted multivariate Cox regression on parameter limits. Results: All indices showed significant differences between surviving and non-surviving patients on the third day of ICU care. The AUC values of OI-ΔPinsp were significantly higher than those of P/F and OI-Pmean (P values .0002 and <.0001, respectively). Similarly, AUC and CI values of OSI-ΔPinsp and OSI-MPdyn were significantly higher than those of SpO2/FiO2 and OSI-Pmean values (OSI-ΔPinsp: P < .0001, OSI-MPdyn: P values .047 and .028, respectively). OI-ΔPinsp, OSI-ΔPinsp, OI-MPdyn, OSI-MPdyn, OI-MPtot, and OSI-MPtot had AUC values of 0.72, 0.71, 0.69, 0.68, 0.66, and 0.64, respectively, with cut-off values associated with hazard ratios and P values of 7.06 (HR = 1.84, P = .002), 8.04 (HR = 2.00, P ≤ .0001), 7.12 (HR = 1.68, P = .001), 5.76 (HR = 1.70, P ≤ .0001), 10.43 (HR = 1.52, P = .006), and 10.68 (HR = 1.66, P = .001), respectively. Conclusions: Critical values of all indices were associated to higher ICU mortality rates and extended mechanical ventilation durations. The OI-ΔPinsp, OSI-ΔPinsp, and OSI-MPdyn indices displayed the strongest predictive capabilities for ICU mortality. These novel indices offer valuable insights for intensivists in the clinical management and decision-making process for ARDS patients.

Prone position ventilation for the relief of acute respiratory distress syndrome through improved pulmonary ventilation: Efficacy and safety

BACKGROUND

At present, there is a preliminary clinical consensus that prone position ventilation (PPV) is beneficial to the treatment of acute respiratory distress syndrome (ARDS), and further research on the details of treatment and patients' benefits will help to assess its effectiveness and safety.

AIM

To evaluate the timing, efficacy, and safety of different mechanical ventilation positions (MVP) in treating ARDS.

STUDY DESIGN

The results of clinical trials were directly or indirectly compared by network meta-analysis to compare the effects of different MVP. Two authors independently searched the papers published in PubMed, Embase, Cochrane Library, China Knowledge Infrastructure (CNKI), China Biomedical Discs (CBM), WanFang, and VIP database from January 2000 to August 2022. The outcome indicators were oxygenation index, mechanical ventilation time, ICU hospitalization time, in-hospital mortality, and incidence of adverse events. Two authors independently screened the literature, evaluated the quality of the studies, and completed the data extraction. Stata 14.0 was used to conduct a network Meta-analysis, and the intervention measures were ranked according to the surface under the cumulative ranking curve (SUCRA). Funnel plots were drawn to evaluate publication bias.

RESULTS

According to the inclusion and exclusion criteria, 75 studies (including 6333 patient data) were finally included. According to the analysis results, PPV was the best for improving the oxygenation index. The SUCRA values of mechanical ventilation time, ICU hospitalization time, and in-hospital mortality were ranked as PPV > lateral position ventilation (LPV) > supine position ventilation (SuPV) > semireclining position ventilation (SePV). The SUCRA values in the incidence of adverse events were ranked as LPV > PPV > SuPV > SePV. All outcome measures had good consistency and low statistical heterogeneity. Funnel plot analysis shows that papers reported within three days of mechanical ventilation time, over five days of mechanical ventilation time, and in-hospital mortality were more likely to have publication bias.

CONCLUSIONS

PPV has the best effect on improving the oxygenation index, reducing mechanical ventilation time, shortening ICU hospitalization time, and reducing in-hospital mortality. Early and long-term use of PPV to improve pulmonary ventilatory function will be the key to improving patients' survival and quality of life with ARDS.

RELEVANCE TO CLINICAL PRACTICE

PPV significantly affects patients with ARDS, which can shorten the treatment time and reduce hospital costs. During the treatment, nursing observation should be strengthened to prevent adverse events.

Construction and application of prone position ventilation management scheme for severe COVID-19 patients

Background: Prone position ventilation (PPV) can significantly improve oxygenation index and blood oxygen saturation in most (70%-80%) patients with acute respiratory distress syndrome. However, although PPV is not an invasive procedure, there are many potential PPV-related complications, such as nerve compression, crush injury, venous stasis (e.g., facial oedema), pressure sores, retinal damage, vomiting, and arrhythmia, with an incidence of up to 56.9%. Nursing managers have focused on reducing the occurrence of PPV-related complications and improving safety. Objective: To construct a prone ventilation management scheme for patients with severe coronavirus disease 2019 (COVID-19) and analyse its application effect. Methods: Based on a previous evidence-based study combined with the COVID-19 Diagnosis and Treatment Protocol (Trial Edition 9), a prone ventilation management protocol for severe COVID-19 was formulated and applied to COVID-19 patients in the intensive care unit of a designated hospital. A prospective self-control study was used to compare changes in the oxygenation index and other outcome indicators before and after the intervention. Results: The oxygenation index of patients after intervention (321.22 ± 19.77 mmHg) was significantly higher (p < 0.05) than before intervention (151.59 ± 35.49 mmHg). The difference in oxygenation index in different prone position ventilation durations was statistically significant (p < 0.05). Nursing quality evaluation indicators showed that the implementation rate of gastric residual volume assessment was 100% and the incidence of occupational exposure and cross-infection was 0%; the incidences of pressure ulcers, drug extravasation, and facial oedema were 13.64% (3/22), 4.54% (1/22), and 4.54% (1/22), respectively. The incidence of unplanned extubation, aspiration, and falls/falls was 0%.

Development and Validation of a Rapid and Efficient Prognostic Scoring System for Sepsis Based on Oxygenation Index, Lactate and Glasgow Coma Scale

Objective

To develop a concise scoring system for efficient and rapid assessment of sepsis prognosis applicable to emergency departments.

Methods

This was a single-center retrospective cohort study of patients with sepsis. In this study, a new scoring system (oxygenation index, lactate, and Glasgow coma scale: GOL) was developed through a derivation group, and then the GOL was validated using a validation group. Multivariate logistic regression analysis was performed to investigate the relationship between GOL and 28-day adverse outcomes. The GOL was compared with the previous scoring system using receiver operating characteristic curves (ROC) and decision analysis curves. The endpoints of this study were mortality, mechanical ventilation (MV), and admission to the intensive care unit (AICU).

Results

608 patients were included in the derivation group and 213 patients in the validation group, with 131 and 42 deaths, respectively. In the validation group, lactate (Lac), oxygenation index (PaO₂/FiO₂), and Glasgow coma scale score (GCS), the three best performers in predicting 28-day mortality from receiver operating characteristic curves, were used to construct the GOL. The higher the GOL score, the higher the incidence of death, MV and AICU within 28 days. Multifactorial logistic regression analysis showed that when the GOL was greater than 1, it was an independent risk factor for 28-day mortality, MV, and AICU. In predicting 28-day mortality, GOL was superior to the quick Sequential Organ Failure Assessment (qSOFA), Mortality in Emergency Department Sepsis Score (MEDS), Systemic Inflammatory Response Syndrome Score (SIRS), and Modified Early Warning Score (MEWS), and was comparable to the Acute Physiology and Chronic Health Evaluation (APACHE) II and Sequential Organ Failure Assessment (SOFA).

Conclusion

The GOL is a simple, rapid, and accurate method for early identification of patients at increased risk of in-hospital death from sepsis.

Early vasopressin infusion improves oxygenation in infants with congenital diaphragmatic hernia

Objective

Congenital Diaphragmatic Hernia (CDH) is a complex disease including a diaphragmatic defect, lung hypoplasia, and pulmonary hypertension. Despite its increasing use in neonates, the literature on the use of vasopressin in neonates is limited. The aim of this work is to analyze the changes in clinical and hemodynamic variables in a cohort of CDH infants treated with vasopressin.

Methods

Among CDH infants managed at the Neonatal Intensive Care Unit (NICU) of our hospital from May 2014 to January 2019, all infants who were treated with vasopressin, because of systemic hypotension and pulmonary hypertension, were enrolled in this retrospective study. The primary outcome was the change in oxygenation index (OI) after the start of the infusion of vasopressin. The secondary outcomes were the changes in cerebral and splanchnic fractional tissue oxygen extraction (FTOEc and FTOEs) at near-infrared spectroscopy, to understand the balance between oxygen supply and tissue oxygen consumption after the start of vasopressin infusion. We also reported as secondary outcomes the changes in ratio of arterial oxygen partial pressure (PaO2) to fraction of inspired oxygen (FiO2), heart rate, mean arterial pressure, serum pH, and serum sodium.

Results

We included 27 patients with isolated CDH who received vasopressin administration. OI dramatically dropped when vasopressin infusion started, with a significant reduction according to ANOVA for repeated measures (p = 0.003). A global significant improvement in FTOEc and FTOEs was detected (p = 0.009 and p = 0.004, respectively) as a significant reduction in heart rate (p = 0.019). A global significant improvement in PaO2/FiO2 ratio was observed (p < 0.001) and also at all time points: at 6 h since infusion (p = 0.015), 12 h (p = 0.009), and 24 h (p = 0.006), respectively. A significant reduction in sodium levels was observed as expected side effect (p = 0.012). No significant changes were observed in the remaining outcomes.

Conclusion

Our data suggest that starting early vasopressin infusion in CDH infants with pulmonary hypertension could improve oxygenation index and near-infrared spectroscopy after 12 and 24 h of infusion. These pilot data represent a background for planning future larger randomized trials to evaluate the efficacy and safety of vasopressin for the CDH population.

A single-center PICU present status survey of pediatric sepsis-related acute respiratory distress syndrome

BACKGROUND

To describe the incidence, clinical features, outcomes, and mortality risk factors of sepsis associated with acute respiratory distress syndrome (ARDS) in pediatric patients.

METHODS

Patients were included in the study if they met the 2005 version of the International Pediatric Sepsis Consensus Conference and met the Pediatric Acute Lung Injury Consensus Conference (PALICC) definition within 48 h of sepsis diagnosis. Patients were classified as mild, moderate, and severe by the worst oxygenation index (OI) within 72 h of sepsis-related ARDS diagnosis.

RESULTS

Between January 1, 2015 and March 13, 2020, 9836 patients were admitted to the pediatric intensive care unit (PICU) of the Children's Hospital of Chongqing Medical University and 828 (8.4%) were identified with sepsis and 203 (24.5%) met the PALICC definition with a PICU mortality rate of 24.6% (50/203) and a 90-day mortality rate of 40.9% (83/203). After adjusting for septic shock, the pediatric logistic organ dysfunction 2 (PELOD-2), high-frequency oscillation ventilation (HFOV), and continuous renal replacement therapy (CRRT), the variables that retained an independent association with increased 90-day mortality in pediatric sepsis-related ARDS included ARDS severity, the pediatric risk of mortality III (PRISM III), number of organ dysfunctions and use of vasoactive drug types during PICU stay.

CONCLUSIONS

PICU mortality in pediatric sepsis-related ARDS was high (24.6%) and severity of hypoxemia based on the worst OI value 72 h after meeting the PALICC definition accurately stratified the patient outcomes. ARDS severity, PRISM III score, comorbid multiorgan dysfunction, and use of multiple vasoactive drugs during PICU stay were independent risk factors for 90-day mortality in pediatric sepsis-related ARDS.

The Association Between Oxygenation Status at 24 h After Diagnosis of Pulmonary Acute Respiratory Distress Syndrome and the 30-Day Mortality among Pediatric Oncological Patients

BACKGROUND

Pediatric oncology patients with acute respiratory distress syndrome (ARDS) secondary to pneumonia are at high risk of mortality. Our aim was to describe the epidemiology of ARDS in this clinical population and to identify the association between the oxygenation status at 24 h after diagnosis and the 30-day mortality rates, stratified by the severity of ARDS.

METHODS

This was a retrospective cohort study of 82 pediatric oncology patients, with a median age of 4 years, admitted to our pediatric intensive care unit with a diagnosis of ARDS between 2013 and 2021. Demographic and clinical factors were compared between the survivor (n = 52) and non-survivor (n = 30) groups. Univariate and multivariate Cox proportional hazards regression models were used to determine the association between the oxygenation status at 24 h after diagnosis and the 30-day mortality rates.

RESULTS

The mean airway pressure at ARDS diagnosis, PaO₂/FiO₂ (P/F) ratio, oxygenation index (OI) value, peak inspiratory pressure, and lactate level at 24 h after ARDS diagnosis, as well as complications (i.e., septicemia and more than two extrapulmonary organ failures) and adjunctive continuous renal replacement therapy, were significant mortality risk factors. After adjusting for other covariates, the oxygenation status P/F ratio (Hazard ratio [HR] = 0.98, 95% confidence interval [CI] = 0.96-1.00, P = 0.043) and OI value (HR = 1.12, 95% CI = 1.02-1.23, P = 0.016) at 24 h remained independent mortality risk factors. According to the Kaplan-Meier survival curve, a low P/F ratio (≤ 150) and high OI (>10) were associated with a higher risk of 30-day mortality (50.9 and 52.9%, respectively; both P < 0.05).

CONCLUSION

The P/F ratio and OI value measured at 24 h after ARDS diagnosis can provide a better stratification of patients according to ARDS disease severity to predict the 30-day mortality risk.

Correlation Between the Ratio of Oxygen Saturation to Fraction of Inspired Oxygen and the Ratio of Partial Pressure of Oxygen to Fraction of Inspired Oxygen in Detection and Risk Stratification of Pediatric Acute Respiratory Distress Syndrome

Objective: To measure the correlation between the ratio of oxygen saturation to fraction of inspired oxygen [SpO₂/FiO₂ (SF)] and the ratio of partial pressure of oxygen to fraction of inspired oxygen [PaO₂/FiO₂ (PF)] among children diagnosed with acute respiratory distress syndrome (ARDS).

Methodology: A cross-sectional study was conducted at the pediatric intensive care unit (PICU), National Institute of Child Health (NICH), Karachi, a tertiary care government hospital, from November 2020 to July 2021. One hundred twenty children (of either gender) having the age range of 2 months to 16 years, admitted to PICU with acute onset of respiratory distress, were included in the study. We measured SpO₂, PaO₂, FiO₂ and calculated SF and PF ratios. SPSS (version 23) (Armonk, NY: IBM Corp) was used to analyze data, and the Spearmen's correlation test was applied to measure the relationship between SF and PF ratios.

Results: A total of 120 children were included, the mean age was 40.58±38.88 months and 67 (55.8%) were males. The mean FiO₂ was 76.33%, the mean PaO₂ and SpO₂ were 100.35 mmHg and 94.37%, respectively. The mean PF ratio was 156.34, and the mean SF ratio was 156.45. There was a strong correlation between the SF ratio and the PF ratio (r=0.688; p=0.001).

Conclusion: This study has shown that there is a strong correlation between the SF and PF ratios, and a statistically substantial agreement has been observed.

Thoracoscopic Repair of Neonatal Congenital Diaphragmatic Hernia: Minimizing Open Repair in a Low-Income Country

Aim: To assess the severity of persistent pulmonary hypertension (PPH) in congenital diaphragmatic hernia (CDH) neonates solely using oxygenation index (OI). Study Design: A prospective study was carried out from April 2016 to March 2019, where all confirmed CDH neonates were evaluated for the possibility repair through thoracoscopic approach. The severity of PPH was assessed using OI. It is calculated using the equation: mean airway pressure (MAP) × FiO₂ × 100 ÷ PaO₂. Neonates having OI <5 were considered to have a mild degree of pulmonary hypertension; hence, thoracoscopic repair was offered for them. Results: Thirty-nine CDH cases met the selection criteria; therefore, they underwent thoracoscopic repair. Primary diaphragmatic repair was successfully accomplished thoracoscopically in all neonates without any perioperative complications. Conversion from thoracoscopy to open method occurred in five cases. The causes were due to difficulties encountered during repair and none was due to a pure anesthetic problem or general deterioration during thoracoscopy. Recurrence had occurred in two cases only. Conclusion: OI is a reliable subjective parameter that could be used as an adjuvant to the usually used cardiovascular and pulmonary parameters for thoracoscopic repair decision. With increasing surgical experience, a wider range of neonates may be considered for thoracoscopic CDH repair.

Survival of COVID-19 Patients With Respiratory Failure is Related to Temporal Changes in Gas Exchange and Mechanical Ventilation

Background: Respiratory failure due to coronavirus disease of 2019 (COVID-19) often presents with worsening gas exchange over a period of days. Once patients require mechanical ventilation (MV), the temporal change in gas exchange and its relation to clinical outcome is poorly described. We investigated whether gas exchange over the first 5 days of MV is associated with mortality and ventilator-free days at 28 days in COVID-19. Methods: In a cohort of 294 COVID-19 patients, we used data during the first 5 days of MV to calculate 4 daily respiratory scores: PaO₂/FiO₂ (P/F), oxygenation index (OI), ventilatory ratio (VR), and Murray lung injury score. The association between these scores at early (days 1-3) and late (days 4-5) time points with mortality was evaluated using logistic regression, adjusted for demographics. Correlation with ventilator-free days was assessed (Spearman rank-order coefficients). Results: Overall mortality was 47.6%. Nonsurvivors were older (P < .0001), more male (P = .029), with more preexisting cardiopulmonary disease compared to survivors. Mean PaO₂ and PaCO₂ were similar during this timeframe. However, by days 4 to 5 values for all airway pressures and FiO₂ had diverged, trending lower in survivors and higher in nonsurvivors. The most substantial between-group difference was the temporal change in OI, improving 15% in survivors and worsening 11% in nonsurvivors (P < .05). The adjusted mortality OR was significant for age (1.819, P = .001), OI at days 4 to 5 (2.26, P = .002), and OI percent change (1.90, P = .02). The number of ventilator-free days correlated significantly with late VR (-0.166, P < .05), early and late OI (-0.216, P < .01; -0.278, P < .01, respectively) and early and late P/F (0.158, P < .05; 0.283, P < .01, respectively). Conclusion: Nonsurvivors of COVID-19 needed increasing intensity of MV to sustain gas exchange over the first 5 days, unlike survivors. Temporal change OI, reflecting both PaO₂ and the intensity of MV, is a potential marker of outcome in respiratory failure due to COVID-19.

Effects of comprehensive care on complications, oxygenation indexes and guardian's psychological mood of children with neonatal respiratory distress syndrome

OBJECTIVE

To observe the effects of comprehensive care on complications, oxygenation indexes of children with neonatal respiratory distress syndrome (NRDS), as well as their guardian's psychological mood.

METHODS

Totally 205 cases of children with NRDS admitted to our hospital from February 2018 to December 2019 were recruited and divided into two groups according to different nursing interventions. Cases receiving comprehensive care were included in the research group (RG, n=108), and cases receiving routine care were included in the control group (CG, n=97). The curative effect, improvement of clinical symptoms, complications during nursing process, improvement of oxygenation indexes, degree of lung injury, improvement of physiological health were observed and compared, as well as the improvement of parents' psychological mood and their satisfaction with this nursing intervention.

RESULTS

After care, RG had significantly better improvement of clinical indexes than that in CG, with notably lower PaCO₂ and higher PaO₂ and SaO₂. Besides, children in RG showed remarkably lower Murray score and APACHE-II score, and the patients of children in RG also had lower SAS and SDS scores. The overall response rate (ORR) of children in RG was evidently higher than that in CG, the incidence of total complications in RG was evidently lower than that in CG, and the nursing satisfaction of parents in RG was evidently higher than that in CG.

CONCLUSION

Comprehensive care is effective for children with NRDS, which can improve oxygenation indexes and lung injury, reduce the incidence of complications, and improve the psychological mood of parents.

Comparative Efficacy of Seven Kinds of Chinese Medicine Injections in Acute Lung Injury and Acute Respiratory Distress Syndrome: A Network Meta-analysis of Randomized Controlled Trials

Background: Chinese medicine injection is wildly used in Acute Lung Injury and Acute respiratory distress syndrome (ALI/ARDS) treatment. However, what kinds of CMIs are more effective in the ALI/ARDS treatment is uncertain. Objectives: Compare the efficacy of different CMIs to identify the optimal one for the therapy of ALI/ARDS patients. Data sources: We searched the data up to April 30, 2020 from MEDLINE, EMBASE, The Cochrane Library, Web of Science, the China Science Journal Citation Report (VIP database), WanFang and the China National Knowledge Infrastructure Study selection: Randomized Clinical Trials assessed at least one of the following outcomes: mortality, Oxygenation Index, length of ICU stay, mechanical ventilation duration, APACHEⅡ score, SOFA score and Murray score, for adult patients of ALI/ADRS. Eligible Studies should also use CMIs as complementary therapies in addition to the standard treatment. Data extraction and synthesis: Two reviewers independently assessed the data. Then, we used a Bayesian random-effects network meta-analysis for data synthesis. Results: Twenty-six studies were selected (involved 2073 participants). Seven kinds of CMIs were evaluated. Compared with standard treatment, Xuebijing is associated with lower mortality. Tanreqing and Xuebijing have the best effect on improving the Oxygenation Index. Huangqi, Danshen, Tanreqing and Xuebijing can significantly reduce the APACHE II score (Huangqi works better than Xuebijing). Huangqi and Xuebijing have the best effect on reducing mechanical ventilation duration and Murray score, while Xuebijing has the best effect on shortening the length of ICU stay. Conclusions: As adjuvant drugs, Xuebijing, Tanreqing and Huangqi show certain effects on treating ALI/ARDS in different aspects.

Dynamic assessment of lung injury by ultrasound in patients with acute paraquat poisoning

Objective

To investigate the value of ultrasound in the dynamic assessment of lung injury after acute paraquat poisoning.

Methods

A prospective observational study was performed on patients with paraquat poisoning from admission to day 28 or discharge. Ultrasound assessment of the lungs was performtyed every 48 hours. The correlation of the lung ultrasound score (LUS) with other indicators was analyzed.

Results

Twenty-six patients were enrolled, with an average age of 46 ± 16 years. The average toxic dose was 95 ± 51 mL. The intensive care unit (ICU) stay averaged 9 ± 8 days, and the 28-day mortality was 88.5%. There was a significant negative correlation between LUS and oxygenation index (rho = −0.896) and a significant positive correlation between LUS and carbon dioxide concentration (rho = 0.567). Lung ultrasound and computed tomography imaging correlated closely.

Conclusion

Lung ultrasound can reflect changes in lung status in patients with paraquat poisoning and can be used to evaluate lung injury in these patients.

Trial registration: ChiCTR, ChiCTR-DDD-16010211. Registered 21 December 2016, http://www.chictr.org.cn/listbycreater.aspx.

Asphyxia and Neonatal Respiratory Distress Syndrome Are Independent Predictors of the Non-response to Inhaled Nitric Oxide in the Newborns With PPHN

Aim: Not all the neonates respond with improvement in oxygenation following inhaled nitric oxide treatment (iNO) treatment. The aim of this study was to assess the independent risk factors associated with non-response to iNO during the 2 weeks of postnatal treatment in neonates diagnosed with persistent pulmonary hypertension (PPHN). Materials and Methods: This retrospective cohort study included all newborns with PPHN who received iNO treatment for more than 24 h. Demographic, obstetric, perinatal data and clinical complications were extracted from the hospitalization records. Subjects were divided into two groups according to their response to iNO inspiration during the first 24 h of iNO treatment. No response was defined as an increase in SpO₂ < 5% or the inability to sustain saturation levels in the first 24 h of iNO treatment. For descriptive statistics, χ² and t-test analysis were used to compare categorical and continuous variables between the two groups. To evaluate independent risk factors of non-responsiveness to iNO treatment, binary logistic regression analysis were performed. Results: A total of 75 newborns were included in the study. Sixty-two cases were in the responders group, and 13 cases were in the non-responders group. Univariate analysis showed that asphyxia, neonatal respiratory distress syndrome (NRDS), pulmonary surfactant administration, meconium aspiration syndrome (MAS), the severity of pulmonary hypertension (PH), and high-frequency oscillatory ventilation (HFOV) therapy were the high-risk factors affecting the response to iNO treatment in the newborns with PPHN. The binary logistic regression analysis indicated that asphyxia and NRDS incidence were independent predictors of non-responsiveness to iNO treatment [asphyxia: OR 4.193, 95% CI 1.104-15.927, P = 0.035; NRDS: OR 0.154, 95% CI 0.036-0.647, P = 0.011]. The patients in the non-responders group had shorter iNO inspiration followed by MV duration, supplemental oxygen and hospital stay, and higher mortality. There were no significant differences in IVH, PVL, and BPD between two groups. Conclusion: In the newborns with PPHN, asphyxia and NRDS resulted as the independent risk factors of non-responsiveness to iNO therapy. Asphyxia in the newborns with PPHN is detrimental to the response to iNO treatment, while NRDS is beneficial.

B-Lines for the assessment of extravascular lung water: Just focused or semi-quantitative?

BACKGROUND

B-lines as typical artefacts of lung ultrasound are considered as surrogate measurement for extravascular lung water. However, B-lines develop in the sub-pleural space and do not allow assessment of the whole lung. Here, we present data from the first observational multi-centre study focusing on the correlation between a B-lines score and extravascular lung water in critically ill patients suffering from a variety of diseases.

PATIENTS AND METHODS

In 184 adult patients, 443 measurements were obtained. B-lines were counted and expressed in a score which was compared to extravascular lung water, measured by single-indicator transpulmonary thermodilution. Appropriate correlation coefficients were calculated and receiver operating characteristics (ROC-) curves were plotted.

RESULTS

Overall, B-lines score was correlated with body weight-indexed extravascular lung water characterized by r = .59. The subgroup analysis revealed a correlation coefficient in patients without an infection of r = .44, in those with a pulmonary infection of r = .75 and in those with an abdominal infection of r = .23, respectively. Using ROC-analysis the sensitivity and specificity of B-lines for detecting an increased extravascular lung water (>10 mL/kg) was 63% and 79%, respectively. In patients with a P/F ratio <200 mm Hg, sensitivity and specificity to predict an increased extravascular lung water was 71% and 93%, respectively.

CONCLUSIONS

Assessment of B-lines does not accurately reflect actual extravascular lung water. In presence of an impaired oxygenation, B-lines may reliably indicate increased extravascular lung water as cause of the oxygenation disorders.

Comparison of the Oxygenation Factor and the Oxygenation Ratio in Subjects With ARDS

BACKGROUND

The oxygenation ratio (ie, [Formula: see text]/[Formula: see text]) remains the most commonly used index for assessing oxygenation and disease severity in patients with acute ARDS. However, the oxygenation ratio does not account for mechanical ventilation settings. We hypothesized that the oxygenation factor (ie, oxygenation ratio/mean airway pressure) is superior to the oxygenation ratio in reflecting oxygenation in patients with ARDS and results in a different classification of ARDS severity.

METHODS

In 150 subjects with ARDS (50 severe, 50 moderate, and 50 mild), arterial blood gas, mean airway pressure, static lung compliance, driving pressure, and mechanical power were obtained. The oxygenation ratio and the oxygenation factor were then calculated. Receiver operating characteristic curves were constructed for oxygenation ratio and oxygenation factor at lung compliance > 40 mL/cm H₂O, driving pressure < 15 cm H₂O, and mechanical power < 17 J/min, thresholds that are known to predict survival in patients with ARDS. Subjects were reclassified for ARDS severity on the basis of the oxygenation factor and compared to classification on the basis of the oxygenation ratio.

RESULTS

Areas under the receiver operating characteristic curves for the oxygenation factor were significantly higher than for the oxygenation ratio. Reclassification of ARDS severity using the oxygenation factor did not affect subjects classified as having severe ARDS per the oxygenation ratio. However, 52% of subjects with moderate ARDS per the oxygenation ratio criteria were reclassified as either severe (25 subjects) or mild ARDS (1 subject) on the basis of oxygenation factor criteria. Also, 54% of subjects with mild ARDS per the oxygenation ratio criteria were reclassified as severe (4 subjects), moderate (21 subjects), or non-ARDS (2 subjects) on the basis of oxygenation factor criteria.

CONCLUSIONS

The oxygenation factor was a superior ARDS oxygenation index compared to the oxygenation ratio and should be considered as a substitute criteria for classification of the severity of ARDS. (ClinicalTrials.gov registration NCT03946189.).

Hydrocortisone Improves Oxygenation Index and Systolic Blood Pressure in Term Infants With Persistent Pulmonary Hypertension

Persistent pulmonary hypertension of the newborn (PPHN) is an essential cause for hypoxic respiratory failure with significant morbidity and mortality in term and near-term neonates. Hydrocortisone has been shown to decrease oxygen dependency and pulmonary hypertension in neonates with meconium aspiration syndrome and animal studies, respectively. We hypothesize that hydrocortisone will improve oxygenation in term and near-term infants with pulmonary hypertension. We performed a retrospective chart review of all infant with PPHN who received intravenous hydrocortisone therapy as a rescue for severe PPHN. Clinical response was objectively measured using, oxygenation index (OI), PaO2/FiO2 ratio, and inotrope score before, during, and after the hydrocortisone course. We found that hydrocortisone administration resulted in significant improvement of systolic blood pressure, OI, and PaO2/FiO2. In conclusion, hydrocortisone increased systolic blood pressure and improved oxygenation in term and near-term infants with persistent pulmonary hypertension. Prospective randomized trials are required to evaluate these findings further.

Accuracy of oxygen saturation index in determining the severity of respiratory failure among preterm infants with respiratory distress syndrome

BACKGROUND

To evaluate the severity of respiratory failure among newborns with respiratory distress syndrome (RDS), oxygenation index (OI) has been implemented. In the present study, we assessed the accuracy of oxygen saturation index (OSI) in determining the severity of respiratory failure.

METHODS

A cross-sectional study was carried out in the NICUs of two Iranian Hospitals (Tehran, Iran) in 2018. Preterm neonates with RDS entered the study. Immediately after admission, the severity of RDS was determined based on RDS scoring system. Then, 2 CC of arterial blood was withdrawn and sent to laboratory determining blood gases. Simultaneously, the level of peripheral capillary oxygen saturation (SpO₂) was read using pulse oximeter and recorded. OI and OSI were measured using the formulae. Receiver Operating Characteristic curve, Kappa agreement coefficient and accuracy, sensitivity and specificity was used to compare the OI and OSI results.

RESULTS

In the study, 95 neonates were considered. Based on ROC curves, the appropriate cut off with AUC = 0.99 for severe respiratory failure was OSI >8. The sensitivity, specificity, negative predicted value, and positive predicted value for the OSI Cut off >8 were 100, 98, 0.97 and 100%, respectively. The overall accuracy and Kappa agreement between OSI and OI was 0.96 and 0.98%, respectively.

CONCLUSION

Our results showed that OSI with high sensitivity, specificity values could predict the severity of respiratory failure in preterm neonates with RDS.

The Current State of Pediatric Acute Respiratory Distress Syndrome

Pediatric acute respiratory distress syndrome (PARDS) is a significant cause of morbidity and mortality in children. Children with PARDS often require intensive care admission and mechanical ventilation. Unfortunately, beyond lung protective ventilation, there are limited data to support our management strategies in PARDS. The Pediatric Acute Lung Injury Consensus Conference (PALICC) offered a new definition of PARDS in 2015 that has improved our understanding of the true epidemiology and heterogeneity of the disease as well as risk stratification. Further studies will be crucial to determine optimal management for varying disease severity. This review will present the physiologic basis of PARDS, describe the unique pediatric definition and risk stratification, and summarize the current evidence for current standards of care as well as adjunctive therapies.

Oxygenation impairment after total arch replacement with a stented elephant trunk for type-A dissection

OBJECTIVE

To study the risk factors of oxygenation impairment in patients with type-A acute aortic dissection who underwent total arch replacement with a stented elephant trunk.

METHODS

In this study, 169 consecutive patients were enrolled who were diagnosed with type-A acute aortic dissection and underwent a total arch replacement procedure at the Qilu Hospital of Shandong University between January 2015 and February 2017. Postoperative oxygenation impairment was defined as arterial oxygen partial pressure/inspired oxygen fraction ≤ 200 with positive end expiratory pressure ≥ 5 cm H₂O that occurred within 72 hours of surgery. Perioperative clinical characteristics of all patients were collected and univariable analyses were performed. Risk factors associated with oxygenation impairment identified by univariable analyses were included in the multivariable regression analysis.

RESULTS

The incidence of postoperative oxygenation impairment was 48.5%. Postoperative oxygenation impairment was associated with prolonged mechanical ventilation time, intensive care unit stay, and hospital stay. Multivariable regression analysis demonstrated that body mass index (odds ratio [OR], 1.204; 95% confidence interval [CI], 1.065-1.361; P = .003), preoperative oxygenation impairment (OR, 9.768; 95% CI, 4.159-22.941; P < .001), preoperative homocysteine (OR, 1.080; 95% CI, 1.006-1.158; P = .032), circulatory arrest time (OR, 1.123; 95% CI, 1.044-1.207; P = .002), and plasma transfusion (OR, 1.002; 95% CI, 1.001-1.003; P = .002) were significantly associated with postoperative oxygenation impairment.

CONCLUSIONS

Postoperative oxygenation impairment is a common complication of surgery for type-A acute aortic dissection. Body mass index, preoperative oxygenation impairment, preoperative homocysteine, circulatory arrest time, and plasma transfusion were independent risk factors for oxygenation impairment after a total arch replacement procedure.

Fluid Overload and Renal Angina Index at Admission Are Associated With Worse Outcomes in Critically Ill Children

Objectives: We investigated the association of fluid overload and oxygenation in critically sick children, and their correlation with various outcomes (duration of ventilation, ICU stay, and mortality). We also assessed whether renal angina index (RAI) at admission can predict mortality or acute kidney injury (AKI) on day 3 after admission. Design and setting: Prospective study, pediatric intensive care in a tertiary hospital. Duration: June 2013-June 2014. Patients: Patients were included if they needed invasive mechanical ventilation for >24 h and had an indwelling arterial catheter. Patients with congenital heart disease or those who received renal replacement therapy (RRT) were excluded. Methods: Oxygenation index, fluid overload percent (daily, cumulative), RAI at admission and pediatric logistic organ dysfunction (PELOD) score were obtained in all critically ill children. KDIGO classification was used to define AKI, using both creatinine and urine output criteria. Admission data for determination of RAI included the use of vasopressors, invasive mechanical ventilation, percent fluid overload, and change in kidney function (estimated creatinine clearance). Univariable and multivariable approaches were used to assess the relations between fluid overload, oxygenation index and clinical outcomes. An RAI cutoff >8 was used to predict AKI on day 3 of admission and mortality. Results: One hundred and two patients were recruited. Fluid overload predicted oxygenation index in all patients, independent of age, gender and PELOD score (p < 0.05). Fluid overload was associated with longer duration of ventilation (p < 0.05), controlled for age, gender, and PELOD score. Day-3 AKI rates were higher in patients with a RAI of 8 or more, and higher areas under the RAI curve had better prediction rates for Day-3 AKI. An RAI <8 had high negative predictive values (80-95%) for Day-3 AKI. RAI was better than traditional markers of pediatric severity of illness (PELOD) score for prediction of AKI on day 3. Conclusions: This study emphasizes that positive fluid balance adversely affects intensive care in critically ill children. Further, the RAI prediction model may help optimize treatment and improve clinical prediction of AKI.

Comparison of Prevalence and Outcomes of Pediatric Acute Respiratory Distress Syndrome Using Pediatric Acute Lung Injury Consensus Conference Criteria and Berlin Definition

OBJECTIVES

Our objective was to compare the prevalence and outcomes of pediatric acute respiratory distress syndrome using the Pediatric Acute Lung Injury Consensus Conference (PALICC) criteria and Berlin definitions.

METHODS

We screened case records of all children aged 1 month to 17 years of age admitted to the Pediatric Intensive Care Unit (PICU) over a 3-year period (2015-2017) for presence of any respiratory difficulty at admission or during PICU stay. We applied both PALICC and Berlin criteria to these patients. Data collection included definition and outcome related variables. Data were compared between the "PALICC only group" and the "Berlin with or without PALICC" group using Stata 11.

RESULTS

Of a total of 615 admissions, 246 were identified as having respiratory difficulty at admission or during PICU stay. A total of 61 children (prevalence 9.9%; 95% CI: 7.8-12.4) fulfilled the definition of acute respiratory distress syndrome (ARDS) with either of the two criteria. While 60 children (98%) fulfilled PALICC criteria, only 26 children (43%) fulfilled Berlin definition. There was moderate agreement between the two definitions (Kappa: 0.51; 95% CI: 0.40-0.62; observed agreement 85%). Greater proportion of patients had severe ARDS in the "Berlin with or without PALICC group" as compared to the "PALICC only" group (50 vs. 19%). There was no difference between the groups with regard to key clinical outcomes such as duration of ventilation (7 vs. 8 days) or mortality [51.4 vs. 57.7%: RR (95% CI): 0.99 (0.64-1.5)].

CONCLUSION

In comparison to Berlin definition, the PALICC criteria identified more number of patients with ARDS. Proportion with severe ARDS and complications was greater in the "Berlin with or without PALICC" group as compared to the "PALICC only" group. There were no differences in clinical outcomes between the groups.

Mortality following congenital diaphragmatic hernia repair: the role of anesthesia

BACKGROUND

Mortality following surgical repair of congenital diaphragmatic hernia (CDH) remains high. The volume and type of perioperative intravenous fluid administered, baro-trauma, oxygen toxicity, and the duration of anesthesia are thought to affect outcome in surgical populations.

AIMS

The aim of this retrospective observational study was to determine whether the perioperative volume or type of fluids and/or the duration of anesthesia were associated with postoperative mortality and if mortality was predicted by the oxygenation index (OI) prior to or following CDH surgical repair.

METHODS

The records of infants with a left-sided CDH and without other congenital anomalies, who underwent surgical repair between April 2009 and March 2015, were examined. The oxygenation index was used to "quantify" the severity of lung function abnormality and reported as the best OI on day 1 after birth (OI_BEST ), the OI immediately prior to surgery (OI_PRE ) and at 1, 6, 12, and 24 h postsurgery (OI_1h , OI_6h , OI_12h , OI_24h ), respectively. The change in the OI index (delta OI) was calculated by subtracting OI_PRE from postoperative OIs.

RESULTS

The records of 37 CDH infants (median gestational age 35.8, range 31.5-41.4 weeks) were assessed; six died postoperatively. Neither the duration of anesthesia, the volume of crystalloids or colloids administered, nor the peak inflation pressures used during surgical repair were significantly correlated with postoperative mortality. Neither fetal tracheal occlusion nor use of a parietal patch significantly influenced mortality. The postoperative OI_1h , OI_6h , OI_12h showed weak evidence for a difference between survivors and nonsurvivors. An OI_24h of ≥5.5 predicted mortality with 100% sensitivity (95% CI, confidence intervals (CI) 40-100) and 93.1% specificity (95% CI, 77-99).

CONCLUSION

Neither the volume of intraoperative fluids administered nor the duration of anesthesia was associated with postoperative death. The OI 24 h postsurgery was the best predictor of an increased risk of mortality.

Changes in oxidative stress from tracheal aspirates sampled during chest physical therapy in hospitalized intubated infant patients with pneumonia and secretion retention

OBJECTIVE

This study aimed to show the changes in oxidative stress and clinical condition from either chest physical therapy (CPT) or CPT with aerosol treatment in infant patients with pneumonia.

METHODS

From 52 intubated patients, three groups were composed: groups A, B, and C comprising 21 patients aged 5.3±0.6 months (CPT program), 20 patients aged 5.6±0.7 months (aerosol treatment before CPT program), and eleven patients aged 5.0±0.35 months (control), respectively. CPT was composed of manual percussion and vibration before suction in a specific position for draining secretion and re-expanding collapsed lungs. Groups A and B received three sessions of treatment three times daily for 6 days, when tracheal aspirates were collected for evaluating oxidative stress markers for the thiol group: vitamin E, thiobarbituric acid reactive substances-malondialdehyde, and hyarulonan. Furthermore, lung injury score and oxygenation index (PvO2/FiO2 ratio) were recorded daily.

RESULTS

All parameters in group C did not change statistically during study. The thiol group increased significantly in group A after day 4, and increased significantly on days 3 and 6 when compared to day 1 in group B. Vitamin E levels increased significantly on days 3, 5, and 6 in group A, and days 3, 4, and 6 in group B, when compared to day 1. Whereas, the thiobarbituric acid reactive substances-malondialdehyde adduct showed a significant reduction after day 4 in groups A and B, when compared to day 1. Hyarulonan levels showed a significant reduction after day 3 in group A and on day 2 in group B. In addition, lung injury score decreased slightly and nonsignificantly in groups A and B, whereas the oxygenation index increased significantly after day 4 in group A and on day 6 in group B.

CONCLUSION

These preliminary results suggest that CPT with or without aerosol treatment possibly reduces oxidative stress and enhances oxygenation status in infant patients.

Early High-Frequency Oscillatory Ventilation in Pediatric Acute Respiratory Failure. A Propensity Score Analysis

RATIONALE

The use of high-frequency oscillatory ventilation (HFOV) for acute respiratory failure in children is prevalent despite the lack of efficacy data.

OBJECTIVES

To compare the outcomes of patients with acute respiratory failure managed with HFOV within 24-48 hours of endotracheal intubation with those receiving conventional mechanical ventilation (CMV) and/or late HFOV.

METHODS

This is a secondary analysis of data from the RESTORE (Randomized Evaluation of Sedation Titration for Respiratory Failure) study, a prospective cluster randomized clinical trial conducted between 2009 and 2013 in 31 U.S. pediatric intensive care units. Propensity score analysis, including degree of hypoxia in the model, compared the duration of mechanical ventilation and mortality of patients treated with early HFOV matched with those treated with CMV/late HFOV.

MEASUREMENTS AND MAIN RESULTS

Among 2,449 subjects enrolled in RESTORE, 353 patients (14%) were ever supported on HFOV, of which 210 (59%) had HFOV initiated within 24-48 hours of intubation. The propensity score model predicting the probability of receiving early HFOV included 1,064 patients (181 early HFOV vs. 883 CMV/late HFOV) with significant hypoxia (oxygenation index ≥ 8). The degree of hypoxia was the most significant contributor to the propensity score model. After adjusting for risk category, early HFOV use was associated with a longer duration of mechanical ventilation (hazard ratio, 0.75; 95% confidence interval, 0.64-0.89; P = 0.001) but not with mortality (odds ratio, 1.28; 95% confidence interval, 0.92-1.79; P = 0.15) compared with CMV/late HFOV.

CONCLUSIONS

In adjusted models including important oxygenation variables, early HFOV was associated with a longer duration of mechanical ventilation. These analyses make supporting the current approach to HFOV less convincing.

Clinical significance of dynamic monitoring of blood lactic acid, oxygenation index and C-reactive protein levels in patients with severe pneumonia

The aim of the present study was to analyze the clinical significance of the dynamic monitoring of blood lactic acid levels, the oxygenation index and C-reactive protein (CRP) levels in patients with severe pneumonia. The clinical data of 34 cases with severe pneumonia were collected. According to the clinical outcome, the patients were divided into a survival group (n=26) and a fatality group (n=8). Various factors, including the blood lactic acid level, oxygenation index, CRP level and acute physiology and chronic health evaluation II (APACHE II) score, were retrospectively analyzed in order to investigate whether these values had clinical significance for the prognosis of the patients. No statistically significant differences with regard to age, gender, initial concentrations of blood lactic acid and CRP, and APACHE II scores were observed between the two groups at admission to the Intensive Care Unit. However, the blood lactic acid levels were found to decrease to a normal level within 12-24 h after treatment in the survival group, while the levels were maintained at a higher concentration in the fatality group, even at 72 h after treatment (P<0.05). Furthermore, the oxygenation index in the survival group was significantly higher when compared with that in the fatality group. The oxygenation index was maintained at a normal level in the survival group, while the oxygenation index levels were below normal and continued to decline in the fatality group. A positive correlation was observed between the blood lactic acid level and the APACHE II scores (r=0.656, P<0.05). Therefore, the present study demonstrated that dynamic monitoring of blood lactic acid, oxygenation index and CRP levels in patients with severe pneumonia can be used to evaluate the therapeutic efficiency, in addition to serving as a prognosis indicator, for patients with severe pneumonia.

Factors Associated with Survival during High-Frequency Oscillatory Ventilation in Children

Our aim is to determine indicators of survival in children with severe hypoxic respiratory failure (HRF) after transition to high-frequency oscillatory ventilation (HFOV). Single-center retrospective examination of children with HRF transitioned to HFOV. Blood gases and ventilator settings 24 hours prior to and 48 hours after HFOV in survivors and nonsurvivors were evaluated. Sixty-two children with mean age of 7 years and mean weight of 26 kg were included with an observed mortality of 29%. Mean airway pressures (Paw), oxygenation index (OI), arterial oxygen partial pressure (PaO₂)/fraction of inspired oxygen (FiO₂) (P/F) ratio, pH, bicarbonate, and arterial carbon dioxide partial pressure were similar prior to HFOV in survivors and nonsurvivors. During HFOV, mean OI and P/F ratio improved in both groups with an average Paw increase of ∼10 cm H₂O. Survivors had lower OI than nonsurvivors (21 ± 0.9 vs. 26.5 ± 2.2; p < 0.01) beginning 24 hours after HFOV. P/F ratio appears to diverge by 36 hours, with survivors having P/F ratio >200. Survivors had higher pH than nonsurvivors at 36 hours (7.40 ± 0.01 vs. 7.32 ± 0.02; p < 0.05), higher bicarbonate levels (27.1 ± 0.7 vs. 23.9 ± 1.3 mEq/L), and similar arterial carbon dioxide partial pressure with less oscillatory support (i.e., hertz and amplitude). Inhaled nitric oxide was used in 53% of patients with improvements in oxygenation but with no effect on mortality. HFOV improves oxygenation in children with severe HRF. Nonsurvivors can be distinguished from survivors at 24 to 36 hours during HFOV by higher OI, metabolic acidosis, and higher oscillatory support. These data may assist in prognostication or timing of initiating alternative therapies, such as extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation for congenital diaphragmatic hernia in Japan

BACKGROUND

The aim of this study was to clarify how extracorporeal membrane oxygenation (ECMO) is used to treat congenital diaphragmatic hernia (CDH) in Japan.

METHODS

We completed a nationwide survey of CDH involving 614 infants. The subjects included 43 patients who underwent ECMO. We compared the clinical data of the patients who did and did not survive ≥ 90 days, and analyzed the 24 h blood gas data in isolated CDH cases in both groups.

RESULTS

Of the 43 CDH patients, non-isolated CDH associated with other life-threatening or chromosomal anomalies was diagnosed in six patients. Only one of these six patients was able to discontinue ECMO and survived, and the other five died shortly after birth. The other 37 patients all had isolated CDH. The reason for initiating ECMO in 31 of these patients was persistent pulmonary hypertension of the newborn (PPHN). In the 37 patients with isolated CDH, ECMO was initiated within 24 h after birth. Sixteen patients (37%) survived ≥ 90 days, and intact discharge was possible in eight cases. Among the isolated CDH patients, on ROC analysis of the lowest oxygenation index (OI) to predict 90 day survival, the cut-off was 15.

CONCLUSIONS

ECMO is used to treat PPHN starting from an early period after birth, but the mortality and morbidity are not favorable. For lowest OI, the index used to predict survival following ECMO, the cut-off was 15.

Oxygen saturation index and severity of hypoxic respiratory failure

BACKGROUND

The oxygenation index (OI = mean airway pressure, MAP × FiO2 × 100 : PaO2) is used to assess the severity of hypoxic respiratory failure (HRF) and persistent pulmonary hypertension of the newborn (PPHN). An indwelling arterial line or arterial punctures are necessary to obtain PaO2 for the calculation of OI. Oxygenation can be continuously and noninvasively assessed using pulse oximetry. The use of the oxygen saturation index (OSI = MAP × FiO2 × 100 : SpO2) can be an alternate method of assessing the severity of HRF.

OBJECTIVE

To evaluate the correlation between OSI and OI in the following: (1) neonates with HRF and (2) a lamb model of meconium aspiration syndrome.

METHODS

Human neonates: a retrospective chart review of 74 ventilated late preterm/term neonates with indwelling arterial access and SpO2 values in the first 24 h of life was conducted. OSI and OI were calculated and correlated. Lamb model: arterial blood gases were drawn and preductal SpO2 was documented in 40 term newborn lambs with asphyxia and meconium aspiration. OI and OSI were calculated and correlated with pulmonary vascular resistance (PVR).

RESULTS

Mean values of OSI and OI showed a correlation coefficient of 0.952 in neonates (mean value of 308 observations in 74 neonates) and 0.948 in lambs (mean value of 743 observations in 40 lambs). In lambs, with increasing PVR, there was a decrease in OI and OSI.

CONCLUSION

OSI correlates significantly with OI in infants with HRF. This noninvasive measure may be used to assess the severity of HRF and PPHN in neonates without arterial access.

Non invasive monitoring in mechanically ventilated pediatric patients

Cardiopulmonary monitoring is a key component in the evaluation and management of critically ill patients. Clinicians typically rely on a combination of invasive and non-invasive monitoring to assess cardiac output and adequacy of ventilation. Recent technological advances have led to the introduction: of continuous non-invasive monitors that allow for data to be obtained at the bedside of critically ill patients. These advances help to identify hemodynamic changes and allow for interventions before complications occur. In this manuscript, we highlight several important methods of non-invasive cardiopulmonary monitoring, including capnography, transcutaneous monitoring, pulse oximetry, and near infrared spectroscopy.

The impact of tidal volume on pulmonary complications following minimally invasive esophagectomy: a randomized and controlled study

BACKGROUND

Minimally invasive esophagectomy (MIE) has been advantageous for lowering pulmonary complications compared with open approaches.(1) However, pulmonary complications remain the most common morbidity after surgical resection of esophageal cancer.(2,3) The aim of this prospective, randomized, controlled, clinical trial was designed to see whether low tidal volume (VT) could further minimize pulmonary complications after MIE.

METHODS

Between June 2011 and July 2012, a total of 101 patients who underwent MIE received left-lung ventilation during thoracoscopic esophagectomy. All patients received left-lung ventilation during thoracoscopic esophagectomy. Patients were randomly assigned to a low VT (5 mL/kg + 5 cm H2O positive end-expiratory pressure) preserved ventilation (PV) group (n = 53) and a conventional VT (8 mL/kg) controlled ventilation (CV) group (n = 48) in the thoracic stage. Alveolar lavage fluid was harvested from the ventilated lung at intubation and at 18 hours after surgery for analysis of interleukin (IL)-1ß, IL-6, and IL-8 levels. Clinical characteristics, including patient demographics, operation features, and changes in oxygenation index, were recorded and analyzed. Pulmonary complications were identified and statistically compared between the 2 groups.

RESULTS

The clinical characteristics and operation features were comparable between the 2 groups. IL-1ß, IL-6, and IL-8 expressions in preoperative alveolar lavage fluid were similar between the 2 groups. Significantly lower IL expressions were observed in the PV group than those in the CV group at 18 hours after MIE (IL-1ß, 25.42 ± 31.01 vs 94.96 ± 118.24 pg/mL; IL-6, 30.86 ± 75.78 vs 92.99 ± 72.90 pg/mL; IL-8, 258.75 ± 188.24 vs 403.95 ± 151.44 pg/mL; all P < .05). The 18-hour postoperative oxygenation index was lower in the CV group than that in the PV group (292.85 ± 28.74 vs 326.35 ± 34.43; P = .046). Pulmonary complications were observed in 18 cases of our series, occurring more frequently on the ventilation side (right, 6 cases; and left, 12 cases). All patients were cured by conservative therapy without severe sequelae. The occurrence of pulmonary complications in the PV group was lower than that in the CV group (9.43% vs 27.08%; P = .021).

CONCLUSIONS

Lung injury due to intraoperative single-lung ventilation may contribute to pulmonary complications after MIE. Low VT ventilation could decrease ventilation-associated lung inflammation, thus minimizing pulmonary complications after MIE. Further studies, based on a larger volume of populations, are required to confirm these findings.

Keratinocyte growth factor in acute lung injury to reduce pulmonary dysfunction--a randomised placebo-controlled trial (KARE): study protocol

BACKGROUND

Acute lung injury is a common, devastating clinical syndrome associated with substantial mortality and morbidity with currently no proven therapeutic interventional strategy to improve patient outcomes. The objectives of this study are to test the potential therapeutic effects of keratinocyte growth factor for patients with acute lung injury on oxygenation and biological indicators of acute inflammation, lung epithelial and endothelial function, protease:antiprotease balance, and lung extracellular matrix degradation and turnover.

METHODS/DESIGN

This will be a prospective, randomised, double-blind, allocation-concealed, placebo-controlled, phase 2, multicentre trial. Randomisation will be stratified by presence of severe sepsis requiring vasopressors. Patients in an ICU fulfilling the American-European Consensus Conference Definition of acute lung injury will be randomised in a 1:1 ratio to receive an intravenous bolus of either keratinocyte growth factor (palifermin, 60 μg/kg) or placebo (0.9% sodium chloride solution) daily for a maximum of 6 days. The primary endpoint of this clinical study is to evaluate the efficacy of palifermin to improve the oxygenation index at day 7 or the last available oxygenation index prior to patient discontinuation from the study.A formal statistical analysis plan has been constructed. Analyses will be carried out on an intention-to-treat basis. A single analysis is planned at the end of the trial. P = 0.05 will be considered statistically significant and all tests will be two-sided. For continuously distributed outcomes, differences between groups will be tested using independent-sample t tests, analysis of variance and analysis of covariance with transformation of variables to normality or nonparametric equivalents. The trial will be reported in line with the Consolidated Standards of Reporting Trials (Consort 2010 guidelines).

TRIAL REGISTRATION

ISRCTN95690673.

Inhaled epoprostenol therapy for pulmonary hypertension: Improves oxygenation index more consistently in neonates than in older children

The purpose of this study was to determine the efficacy of inhaled epoprostenol for treatment of acute pulmonary hypertension (PH) in pediatric patients and to formulate a plan for a prospective, randomized study of pulmonary vasodilator therapy in this population. Inhaled epoprostenol is an effective treatment for pediatric PH. A retrospective chart review was conducted of all pediatric patients who received inhaled epoprostenol at a tertiary care hospital between October 2005 and August 2007. The study population was restricted to all patients under 18 years of age who received inhaled epoprostenol for greater than 1 hour and had available data for oxygenation index (OI) calculation. Arterial blood gas values and ventilator settings were collected immediately prior to epoprostenol initiation, and during epoprostenol therapy (as close to 12 hours after initiation as possible). Echocardiograms were reviewed during two time frames: Within 48 hours prior to therapy initiation and within 96 hours after initiation. Of the 20 patients in the study population, 13 were neonates, and the mean OI for these patients improved during epoprostenol administration (mean OI before and during therapy was 25.6±16.3 and 14.5±13.6, respectively, P=0.02). Mean OI for the seven patients greater than 30 days of age was not significantly different during treatment (mean OI before and during therapy was 29.6±15.0 and 25.6±17.8, P=0.56). Improvement in echocardiographic findings (evidence of decreased right-sided pressures or improved right ventricular function) was demonstrated in 20% of all patients. Inhaled epoprostenol is an effective therapy for the treatment of selected pediatric patients with acute PH. Neonates may benefit more consistently from this therapy than older infants and children. A randomized controlled trial is needed to discern the optimal role for inhaled prostanoids in the treatment of acute PH in childhood.

Defining acute lung disease in children with the oxygenation saturation index

OBJECTIVE

To evaluate whether a formula could be derived using oxygen saturation (Spo2) to replace Pao2 that would allow identification of children with acute lung injury and acute respiratory distress syndrome. Definitions of acute lung injury and acute respiratory distress syndrome require arterial blood gases to determine the Pao2/Fio2 ratio of 300 (acute lung injury) and 200 (acute respiratory distress syndrome).

DESIGN

Post hoc data analysis of measurements abstracted from two prospective databases of randomized controlled trials.

SETTING

Academic pediatric intensive care units.

PATIENTS

A total of 255 children enrolled in two large prospective trials of therapeutic intervention for acute lung disease: calfactant and prone positioning.

INTERVENTIONS

Data were abstracted including Pao2, Paco2, pH, Fio2, and mean airway pressure. Repeated-measures analyses, using linear mixed-effects models, were used to build separate prediction equations for the Spo2/Fio2 ratio, oxygenation index [(Fio2 x Mean Airway Pressure)/Pao2], and oxygen saturation index [(Fio2 x Mean Airway Pressure)/Spo2 ]. A generalization of R was used to measure goodness-of-fit. Generalized estimating equations with a logit link were used to calculate the sensitivity and specificity for the cutoffs of Pao2/Fio2 ratio of 200 and 300 and equivalent values of Spo2/Fio2 ratio, oxygenation index, and oxygen saturation index.

MEASUREMENTS AND MAIN RESULTS

An Spo2/Fio2 ratio of 253 and 212 would equal criteria for acute lung injury and acute respiratory distress syndrome, respectively. An oxygenation index of 5.3 would equal acute lung injury criteria, and an oxygenation index of 8.1 would qualify for acute respiratory distress syndrome. An oxygen saturation index, which includes the mean airway pressure and the noninvasive measure of oxygenation, of 6.5 would be equivalent to the acute lung injury criteria, and an oxygen saturation index of 7.8 would equal acute respiratory distress syndrome criteria.

CONCLUSIONS

Noninvasive methods of assessing oxygenation may be utilized with reasonable sensitivity and specificity to define acute lung injury and acute respiratory distress syndrome, and, with prospective validation, have the potential to increase the number of children enrolled into clinical trials.

Improved oxygenation after discontinuing neuromuscular blockade

OBJECTIVE

To evaluate the effects of prolonged neuromuscular blockade (NMB) on oxygenation and duration of mechanical ventilation in children with respiratory failure.

DESIGN

Retrospective case control study.

SETTING

The pediatric intensive care unit (PICU) of a tertiary university hospital.

PATIENTS

All children (n = 68) in the PICU ventilated for pulmonary parenchymal disease for 3 days or longer over a 4 1/2 year period.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Diagnoses, pediatric risk of mortality scoring, indications for, and duration of, mechanical ventilation and neuromuscular blockade, and blood gas data with corresponding ventilator parameters were extracted from the medical records. Twenty-eight patients received NMB at the initiation of mechanical ventilation and this was continued for 72 h or longer. Cessation of NMB was associated with a significant improvement in ventilator parameters and oxygenation index. The subset of children with respiratory syncytial virus disease (RSV) receiving prolonged NMB had longer ventilator courses compared to those in whom NMB was not used, despite similar demographics, severity of illness and oxygenation impairment.

CONCLUSIONS

Stopping NMB is associated with a rapid improvement in oxygenation and prolonged use of NMB in children with RSV is associated with a protracted ventilatory course.

DEFINITION

Oxygenation index (OI)*: Mean Airway Pressure x FiO2 x 100/PaO2* Higher scores represent deterioration in oxygenation.