High-Frequency Positive Pressure Ventilation as Primary Rescue Strategy for Patients with Congenital Diaphragmatic Hernia: A Comparison to High-Frequency Oscillatory Ventilation

Objective The aim of this article was to evaluate high-frequency positive pressure ventilation (HFPPV) compared with high-frequency oscillatory ventilation (HFOV) as a rescue ventilation strategy for patients with congenital diaphragmatic hernia (CDH). HFPPV is a pressure-controlled conventional ventilation method utilizing high respiratory rate and low positive end-expiratory pressure. Study Design Seventy-seven patients diagnosed with CDH from January 2005 to September 2019 who were treated with stepwise progression from HFPPV to HFOV versus only HFOV were included. Fisher's exact test and the Kruskal–Wallis test were used to compare outcomes. Results Patients treated with HFPPV + HFOV had higher survival to discharge (80 vs. 50%, p = 0.007) and to surgical intervention (95.6 vs. 68.8%, p = 0.003), with average age at repair 2 days earlier (p = 0.004). Need for extracorporeal membrane oxygenation (p = 0.490), inhaled nitric oxide (p = 0.585), supplemental oxygen (p = 0.341), and pulmonary hypertension medications (p = 0.381) were similar. Conclusion In CDH patients who fail respiratory support with conventional ventilation, HFPPV may be used as an intermediary mode of rescue ventilation prior to HFOV without adverse effects. Key Points

Title: Clinical Profile of Persistent Pulmonary Hypertension in Neonates with Role of Sildenafil in its Outcome: Rural India NICU Experience

Background: Persistent pulmonary hypertension of newborn (PPHN) result from failure of normal fall in pulmonary vascular resistance at or shortly after birth. It is associated with high mortality and morbidity. Objectives: To estimate incidence, risk factors; and outcome within limited resources – conventional ventilation, sildenafil, dobutamine and milrinone therapy. Methods: This prospective study was carried out on cases of PPHN admitted between March 2017 to August 2018. PPHN was suspected clinically, and then confirmed by echocardiography. Results: Out of 2811 inborn live births 12 (0.43%) developed PPHN. Out of total 942 NICU admissions, PPHN was diagnosed in 40(4.2%). 32 (80%) were full term, 6 (15%) were late preterm and 2(5%) were post term neonates. 25(62.5%) were male. Major etiological factors were asphyxia 19(47.5%), EOS (early onset sepsis) 18(45%) and MAS (meconium aspiration syndrome) 12(30%). 20(50%) responded to oral sildenafil and dobutamine therapy, 6 more responded with addition of milrinone. The overall survival rate was 26(65%) and poor outcome in 14 (35%) in our study. Median duration of respiratory support was 1.5(1 – 6) days in those with poor outcome and 6(4 – 7) in those survived. Duration of hospital stay was 1.5(1 – 6) days in poor outcome and 17(13 – 22) in those survived. Conclusions: Asphyxia, EOS and MAS are common causes of PPHN. Severity of respiratory distress on admission is correlated with mortality rather than etiological factors. Conventional ventilation, dobutamine, sildenafil and milrinone therapy are mainstay of treatment of PPHN cases in resource limited settings, and helps to reduce mortality to some extent.

Effect of INTELLiVENT-ASV versus Conventional Ventilation on Ventilation Intensity in Patients with COVID-19 ARDS—An Observational Study

Driving pressure (ΔP) and mechanical power (MP) are associated with outcomes in critically ill patients, irrespective of the presence of Acute Respiratory Distress Syndrome (ARDS). INTELLiVENT-ASV, a fully automated ventilatory mode, controls the settings that affect ΔP and MP. This study compared the intensity of ventilation (ΔP and MP) with INTELLiVENT-ASV versus conventional ventilation in a cohort of COVID-19 ARDS patients in two intensive care units in the Netherlands. The coprimary endpoints were ΔP and MP before and after converting from conventional ventilation to INTELLiVENT-ASV. Compared to conventional ventilation, INTELLiVENT-ASV delivered ventilation with a lower ΔP and less MP. With conventional ventilation, ΔP was 13 cmH2O, and MP was 21.5 and 24.8 J/min, whereas with INTELLiVENT-ASV, ΔP was 11 and 10 cmH2O (mean difference –2 cm H2O (95 %CI –2.5 to –1.2 cm H2O), p < 0.001) and MP was 18.8 and 17.5 J/min (mean difference –7.3 J/Min (95% CI –8.8 to –5.8 J/min), p < 0.001). Conversion from conventional ventilation to INTELLiVENT-ASV resulted in a lower intensity of ventilation. These findings may favor the use of INTELLiVENT-ASV in COVID-19 ARDS patients, but future studies remain needed to see if the reduction in the intensity of ventilation translates into clinical benefits.

Comparing the Intellivent-ASV® Mode with Conventional Ventilation Modes during Weaning after Uncomplicated Cardiac Surgery

The objective: to compare efficacy and safety of Intellivent-ASV® with conventional ventilation modes during weaning in the patients after cardiac surgery.Subjects and methods. In this randomized controlled trial, 40 adult patients were ventilated with conventional ventilation modes and 40 with Intellivent-ASV after uncomplicated cardiac surgery. Eight physicians were involved in the study.Care of both groups was standardized, except for the modes of postoperative ventilation.We compared:- The physician’s workload, through accounting number of manual ventilator settings and time they spent near the ventilator in every group,- Duration of tracheal intubation in ICU,- Evaluation of ventilation safety by considering driving pressure, mechanical power, positive end expiratory pressure, and tidal volume level,- The frequency of adverse events, postoperative complications, and lethality.Results. There were significant differences in the duration of respiratory support in ICU: 226 ± 31 min (Intellivent Group) vs 271 ± 78 min (Control Group) (p = 0.0013).In Intellivent Group, the number of manual ventilator settings and time spent by physicians near the ventilator before tracheal extubation were significantly lower: 0 vs 4 (2–6), and 35 (25–53) sec vs 164 ± 69 sec respectively (p < 0.001 in both cases).Intellivent-ASV provided significantly more protective ventilation through reduction in the driving pressure, tidal volume, FiO2 and PEEP levels but no difference was noted between paO2/FiO2 ratio. ∆P and Vt were significantly lower in Intellivent Group – ∆P on mechanical ventilation was 6 (5–7) cm H2O vs 7.25 (6.5–9.5) cm H2O (p < 0.001); Vt on mechanical ventilation was 6 (5.2–7) vs 7 (6–9.5) ml/kg/PBW (p = 0.000003). PEEP and FiO2 levels were also significantly lower in Intellivent Group, PEEP on mechanical ventilation was 5 (5–7.5) cm H2O vs 7 (5–11.5) cm H2O and FiO2 level was 26 (22–30) % vs 34 (30–40) %.There were no significant differences between the groups in frequency of adverse events and duration of ICU and hospital stay.Conclusion. Application of Intellivent-ASV mode after uncomplicated cardiac surgery provides more protective mechanical ventilation and reduces the physician’s workload without compromising the quality of respiratory support and safety of patients.

The Influences of three Intraoperative Ventilatory Strategies on Arterial Oxygenation in Morbid Obese Patients Undergoing Laparoscopic Bariatric Surgery

Background: Maintaining satisfactory ventilation for obese patients undergoing bariatric surgery frequently poses a challenge for anesthetists. The optimal ventilation strategy during pneumoperitoneum remains obscure in obese patients. In this study, we investigated the effect of conventional ventilation, inverse ratio ventilation (IRV) and alveolar recruitment maneuver (RM) on arterial oxygenation, lung mechanics and hemodynamics in morbid obese patients undergoing laparoscopic bariatric surgery. Methods: 105 adult obese patients scheduled for elective laparoscopic bariatric surgery were randomly allocated into three groups: Conventional ratio ventilation (I:E ratio was 1:2, PEEP 5 cmH2O and no RM), Inverse Ratio Group (IRVG) (I:E ratio was 2:1 and PEEP 5 cmH2O and No RM ) and Recruitment Maneuver Group (RMG) ( RM was done and I:E ratio was 1:2). Arterial blood gases and respiratory mechanics were recorded after induction of anesthesia (T1), 5 minutes (T2), 30 minutes (T3), 60 minutes (T4) after the beginning of pneumoperitoneum and at the end of the surgery (T5). Cardiac output was recorded at (T1), (T2), (T3) and (T5). Results: At T3, T4 and T5, arterial oxygen tension was higher in RMG than IRVG than CG (P ˂ 0.05). At T3, T4 and T5, the mean airway pressure and dynamic compliance (Cdyn) were significantly higher in IRVG and RMG compared with CG (P ˂ 0.05) while at those times, the mean air way pressure and Cdyn in IRVG and RMG were comparable. Cardiac output result were comparable between all groups throughout the study period (P ˃ 0.05). Conclusions: RM and IRV had provided better arterial oxygenation and respiratory mechanics compared to conventional ventilation in morbid obese patients undergoing laparoscopic bariatric surgery. However, RM had better gas exchange than IRV.

Extracorporeal Membrane Oxygenation Use in Thoracic Surgery

This narrative review is focused on the application of extracorporeal membrane oxygenation (ECMO) in thoracic surgery, exclusive of lung transplantation. Although the use of ECMO in this indication is still rare, it allows surgery to be performed in patients where conventional ventilation is not feasible—especially in single lung patients, sleeve lobectomy or pneumonectomy and tracheal or carinal reconstructions. Comparisons with other techniques, various ECMO configurations, the management of anticoagulation, anesthesia, hypoxemia during surgery and the use of ECMO in case of postoperative respiratory failure are reviewed and supported by two cases of perioperative ECMO use, and an overview of published case series.

Implementation and feasibility of inverse-ratio Airway Pressure Release Ventilation (APRV): Switching from Conventional Ventilation to APRV in Two French ICUs.

Background:To evaluate the switching of patients mechanically ventilated on Pressure Support or Volume Control to inverse-ratio Airway Pressure Release Ventilation (APRV) during the COVID-19 pandemic.Methods:We performed a single-center retrospective observational analysis in two ICUs in a tertiary referral university teaching hospital in France. Were included patients with Covid-19 pneumonia requiring invasive ventilation with a PaO2:FiO2 ratio lower than 200 mmHg who performed a 6-hour trial of inverse-ratio APRV.Results:Seventeen consecutive patients who completed a 6-hour APRV trial in April 2020 were included. Three patients who were unable to be maintained on APRV due to an immediate fall in SpO2 were not included. In 12/17 patients (71%), the increase in PaO2:FiO2 ratio was greater than 20%. Mean (± standard deviation) PaO2:FiO2 ratio increased from 126 (± 28) mmHg to 178 (± 53) mmHg after 6 hours of APRV (p<0.001). Two patients presented a decrease in PaO2:FiO2 ratio after 6 hours of APRV. There was no appearance of significant hemodynamic impairment during APRV and an eventual increase in PaCO2 during the first hour of APRV was managed by increasing the respiratory rate (i.e. shortening T-high) and/or increasing tidal volume (i.e. increasing T-low).Conclusions:Switching from Conventional Ventilation (Pressure Support or Volume Assist Control) to inverse-ratio APRV for a 6-hour period in two ICUs that were not previously familiar with this ventilation technique was well tolerated, and associated with a marked improvement in oxygenation. Further studies evaluating inverse-ratio APRV in acute respiratory failure are warranted.Trial registration:NCT04386369