Decrease In PaCO2 Research Articles

The value of N-acetylcysteine bronchoalveolar lavage in patients with severe traumatic brain injury combined with ventilator-associated pneumonia

In order to improve the treatment of patients with ventilator-associated pneumonia (VAP) in severe traumatic brain injury (TBI) and to effectively suppress the inflammatory response and enhance blood oxygen indicators, we conducted an innovative bronchoalveolar lavage (BAL) treatment using N-acetylcysteine (NAC). To conduct this study, we divided patients with VAP in severe TBI into a control (CTRL) group and a BAL group. The control group received BAL with saline, while the BAL group received BAL with NAC in addition to standard care. We compared the clinical treatment, degree of inflammation, blood oxygen index, and safety of both groups pre- and post-BAL. The results showed that BAL with NAC was more effective in reducing the duration of antibiotic use, imaging uptake, fever reduction, mechanical ventilation, and ICU stay, as well as CPIS and APACHE II scores. Moreover, the BAL group demonstrated greater improvement in ventilation, as indicated by increased values of PaO2, SaO2, and OI, and a more substantial decrease in PaCO2. Furthermore, BAL treatment effectively suppressed the level of inflammatory response in the body and more significantly reduced TNF-α, CPR, PCT and MIP-1α levels. Adjuvant treatment with BAL effectively improved clinical outcomes and reduced mortality in severe TBI patients with VAP, while maintaining a high level of safety during the BAL operation. Therefore, BAL using NAC holds significant potential in the salvage of patients with severe TBI combined with VAP.

Lung ultrasound score evaluation of the effect of pressure-controlled ventilation volume-guaranteed on patients undergoing laparoscopic-assisted radical gastrectomy.

Laparoscopic-assisted radical gastrectomy (LARG) is the standard treatment for early-stage gastric carcinoma (GC). However, the negative impact of this procedure on respiratory function requires the optimized intraoperative management of patients in terms of ventilation. To investigate the influence of pressure-controlled ventilation volume-guaranteed (PCV-VG) and volume-controlled ventilation (VCV) on blood gas analysis and pulmonary ventilation in patients undergoing LARG for GC based on the lung ultrasound score (LUS). The study included 103 patients with GC undergoing LARG from May 2020 to May 2023, with 52 cases undergoing PCV-VG (research group) and 51 cases undergoing VCV (control group). LUS were recorded at the time of entering the operating room (T0), 20 minutes after anesthesia with endotracheal intubation (T1), 30 minutes after artificial pneumoperitoneum (PP) establishment (T2), and 15 minutes after endotracheal tube removal (T5). For blood gas analysis, arterial partial pressure of oxygen (PaO2) and partial pressure of carbon dioxide (PaCO2) were observed. Peak airway pressure (Ppeak), plateau pressure (Pplat), mean airway pressure (Pmean), and dynamic pulmonary compliance (Cdyn) were recorded at T1 and T2, 1 hour after PP establishment (T3), and at the end of the operation (T4). Postoperative pulmonary complications (PPCs) were recorded. Pre- and postoperative serum interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) were measured by enzyme-linked immunosorbent assay. Compared with those at T0, the whole, anterior, lateral, posterior, upper, lower, left, and right lung LUS of the research group were significantly reduced at T1, T2, and T5; in the control group, the LUS of the whole and partial lung regions (posterior, lower, and right lung) decreased significantly at T2, while at T5, the LUS of the whole and some regions (lateral, lower, and left lung) increased significantly. In comparison with the control group, the whole and regional LUS of the research group were reduced at T1, T2, and T5, with an increase in PaO2, decrease in PaCO2, reduction in Ppeak at T1 to T4, increase in Pmean and Cdyn, and decrease in Pplat at T4, all significant. The research group showed a significantly lower incidence of PPCs than the control group within 3 days postoperatively. Postoperative IL-1β, IL-6, and TNF-α significantly increased in both groups, with even higher levels in the control group. LUS can indicate intraoperative non-uniformity and postural changes in pulmonary ventilation under PCV-VG and VCV. Under the lung protective ventilation strategy, the PCV-VG mode more significantly improved intraoperative lung ventilation in patients undergoing LARG for GC and reduced lung injury-related cytokine production, thereby alleviating lung injury.

Carbon Dioxide Targets in Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome.

Target values for arterial carbon dioxide tension (PaCO2) in extracorporeal membrane oxygenation (ECMO) for acute respiratory distress syndrome (ARDS) are unknown. We hypothesized that lower PaCO2 values on ECMO would be associated with lighter sedation. We used data from two independent patient cohorts with ARDS spending 1,177 days (discovery cohort, 69 patients) and 516 days (validation cohort, 70 patients) on ECMO and evaluated the associations between daily PaCO2, pH, and bicarbonate (HCO3) with sedation. Median PaCO2 was 41 (interquartile range [IQR] = 37-46) mm Hg and 41 (IQR = 37-45) mm Hg in the discovery and the validation cohort, respectively. Lower PaCO2 and higher pH but not bicarbonate (HCO3) served as significant predictors for reaching a Richmond Agitation Sedation Scale (RASS) target range of -2 to +1 (lightly sedated to restless). After multivariable adjustment for mortality, tracheostomy, prone positioning, vasoactive inotropic score, Simplified Acute Physiology Score (SAPS) II or Sequential Organ Failure Assessment (SOFA) Score and day on ECMO, only PaCO2 remained significantly associated with the RASS target range (adjusted odds ratio 1.1 [95% confidence interval (CI) = 1.01-1.21], p = 0.032 and 1.29 [95% CI = 1.1-1.51], p = 0.001 per mm Hg decrease in PaCO2 for the discovery and the validation cohort, respectively). A PaCO2 ≤40 mm Hg, as determined by the concordance probability method, was associated with a significantly increased probability of a sedation level within the RASS target range in both patient cohorts (adjusted odds ratio = 2.92 [95% CI = 1.17-7.24], p = 0.021 and 6.82 [95% CI = 1.50-31.0], p = 0.013 for the discovery and the validation cohort, respectively).

Effect of lung breather on hospital stay in patients with acquired pneumonia: a randomized clinical study

INTRODUCTION. Acquired pneumonia is a severe medical condition that is addressed as life-threating issue requiring intensive care. The Medical Breather device can activate and strengthen both the inspiratory and expiratory muscles, so it can be useful for patients with pneumonia. AIM. To investigate the breather effect on length of hospital stay in patients with pneumonia. MATERIALS AND METHODS. Sixty participants diagnosed with acquired pneumonia “30 women, 30 men stayed in hospital in ICU for two weeks; aged 30–40 years old” selected from chest department of Kasr Al-Aini Intensive Care Unit (ICU) at Cairo University. They were randomly allocated into equal groups; Group A received respiratory training via incentive spirometer, and traditional chest physiotherapy; and Group B received respiratory training via Breather, and traditional chest physiotherapy, both received 3 session daily/2 weeks. Diaphragmatic excursion, Respiratory Distress Observation Scale, and ICU discharge were assessed before and after the treatment. RESULTS. Both groups revealed significant improvement after the treatment, while Breather group showed a high significant increase in pH 1.23 %, PaO2 11.79 %, SaO2 6.1 %, and diaphragmatic excursion by 36.97 %, also decrease in PaCO2 2.78 %, RDOS 39.06 % and NEWS2 by 50.72 % in comparison to incentive spirometer group that recorded significant increase in pH 0.68 %, PaO2 6.69 %, SaO2 by 2.66 %, and diaphragmatic excursions by 8.15 %, also significant decrease in PaCO2 12.12 %, RDOS 15.01 % and NEWS2 by 20.93 %. HCO3 revealed no significant difference post treatment (p 0.05). DISCUSSION. Breather usage in inspiratory musculatures training (IMT) gained Maximum Inspiratory Pressure (Pimax) significant improvement. IMT enforces both diaphragm and accessory respiratory musculatures. Probably functional capabilities improvements based on enhanced respiratory musculatures’ both endurance and strength that improve pulmonary oxygen uptake thus minimize dyspnea severity. Respiratory muscles training program improves not only cognitive function. Moreover, IMT could be addressed as a prime component of respiratory training in combine with expiratory one that is why whom has preserved pulmonary function. CONCLUSION. Breather as a respiratory training technique has remarkable results in reducing hospital stays in patients with acquired pneumonia, and significant positive effects on diaphragmatic function, oxygenation levels. Therefore, it is recommended to use Breather for routine acquired pneumonia care. REGISTRATION: Clinicaltrials.gov identifier: No NCT06062862; registered April 30, 2022.

Effects of extracorporeal CO2 removal on gas exchange and ventilator settings: a systematic review and meta-analysis

PurposeA systematic review and meta-analysis to evaluate the impact of extracorporeal carbon dioxide removal (ECCO2R) on gas exchange and respiratory settings in critically ill adults with respiratory failure.MethodsWe conducted a comprehensive database search, including observational studies and randomized controlled trials (RCTs) from January 2000 to March 2022, targeting adult ICU patients undergoing ECCO2R. Primary outcomes were changes in gas exchange and ventilator settings 24 h after ECCO2R initiation, estimated as mean of differences, or proportions for adverse events (AEs); with subgroup analyses for disease indication and technology. Across RCTs, we assessed mortality, length of stay, ventilation days, and AEs as mean differences or odds ratios.ResultsA total of 49 studies encompassing 1672 patients were included. ECCO2R was associated with a significant decrease in PaCO2, plateau pressure, and tidal volume and an increase in pH across all patient groups, at an overall 19% adverse event rate. In ARDS and lung transplant patients, the PaO2/FiO2 ratio increased significantly while ventilator settings were variable. “Higher extraction” systems reduced PaCO2 and respiratory rate more efficiently. The three available RCTs did not demonstrate an effect on mortality, but a significantly longer ICU and hospital stay associated with ECCO2R.ConclusionsECCO2R effectively reduces PaCO2 and acidosis allowing for less invasive ventilation. “Higher extraction” systems may be more efficient to achieve this goal. However, as RCTs have not shown a mortality benefit but increase AEs, ECCO2R’s effects on clinical outcome remain unclear. Future studies should target patient groups that may benefit from ECCO2R.PROSPERO Registration No: CRD 42020154110 (on January 24, 2021).Graphical abstract

Characterizing the Relationship Between Arterial Carbon Dioxide Trajectory and Serial Brain Biomarkers with Central Nervous System Injury During Veno-Venous Extracorporeal Membrane Oxygenation: A Prospective Cohort Study

BackgroundCentral nervous system (CNS) injury following initiation of veno-venous extracorporeal membrane oxygenation (VV-ECMO) is common. An acute decrease in partial pressure of arterial carbon dioxide (PaCO2) following VV-ECMO initiation has been suggested as an etiological factor, but the challenges of diagnosing CNS injuries has made discerning a relationship between PaCO2 and CNS injury difficult.MethodsWe conducted a prospective cohort study of adult patients undergoing VV-ECMO for acute respiratory failure. Arterial blood gas measurements were obtained prior to initiation of VV-ECMO, and at every 2–4 h for the first 24 h. Neuroimaging was conducted within the first 7–14 days in patients who were suspected of having neurological injury or unable to be examined because of sedation. We collected blood biospecimens to measure brain biomarkers [neurofilament light (NF-L); glial fibrillary acidic protein (GFAP); and phosphorylated-tau 181] in the first 7 days following initiation of VV-ECMO. We assessed the relationship between both PaCO2 over the first 24 h and brain biomarkers with CNS injury using mixed methods linear regression. Finally, we explored the effects of absolute change of PaCO2 on serum levels of neurological biomarkers by separate mixed methods linear regression for each biomarker using three PaCO2 exposures hypothesized to result in CNS injury.ResultsIn our cohort, 12 of 59 (20%) patients had overt CNS injury identified on head computed tomography. The PaCO2 decrease with VV-ECMO initiation was steeper in patients who developed a CNS injury (− 0.32%, 95% confidence interval − 0.25 to − 0.39) compared with those without (− 0.18%, 95% confidence interval − 0.14 to − 0.21, P interaction < 0.001). The mean concentration of NF-L increased over time and was higher in those with a CNS injury (464 [739]) compared with those without (127 [257]; P = 0.001). GFAP was higher in those with a CNS injury (4278 [11,653] pg/ml) compared with those without (116 [108] pg/ml; P < 0.001). The mean NF-L, GFAP, and tau over time in patients stratified by the three thresholds of absolute change of PaCO2 showed no differences and had no significant interaction for time.ConclusionsAlthough rapid decreases in PaCO2 following initiation of VV-ECMO were slightly greater in patients who had CNS injuries versus those without, data overlap and absence of relationships between PaCO2 and brain biomarkers suggests other pathophysiologic variables are likely at play.

Does PaCO2 correction have an impact on survival of patients with chronic respiratory failure and long-term non-invasive ventilation?

Background and objectiveNon-invasive ventilation (NIV) improves survival of patients with chronic respiratory failure (CRF). Most often, pressure settings are made to normalize arterial blood gases. However, this objective is not always achieved due to intolerance to increased pressure or poor compliance. Few studies have assessed the effect of persistent hypercapnia on ventilated patients’ survival. Data from the Pays de la Loire Respiratory Health Research Institute cohort were analyzed to answer this question. Study design and methodsNIV-treated adults enrolled between 2009 and 2019 were divided into 5 subgroups: obesity-hypoventilation syndrome (OHS), COPD, obese COPD, neuromuscular disease (NMD) and chest wall disease (CWD). PaCO2 correction was defined as the achievement of a PaCO2 < 6 kPa or a 20% decrease in baseline PaCO₂ in COPD patients. The endpoint was all-cause mortality. Follow-up was censored in case of NIV discontinuation. ResultsData from 431 patients were analyzed. Median survival was 103 months and 148 patients died. Overall, PaCO2 correction was achieved in 74% of patients. Bivariate analysis did not show any survival difference between patients who achievedPaCO₂ correction and those who remained hypercapnic: overall population: p = 0.74; COPD: p = 0.97; obese COPD: p = 0.28; OHS: p = 0.93; NMD: p = 0.84; CWD: p = 0.28. ConclusionModerate residual hypercapnia under NIV does not negatively impact survival in CRF patients. In individuals with poor tolerance of pressure increases, residual hypercapnia can therefore be tolerated under long-term NIV. Larger studies, especially with a higher number of patients with residual PaCO2 > 7 kPa, are needed to confirm these results.

Low-flow ECCO2R conjoined with renal replacement therapy platform to manage pulmonary vascular dysfunction with refractory hypercapnia in ARDS

BackgroundHypercapnia worsens lung vascular dysfunction during acute respiratory distress syndrome (ARDS). We tested whether an extracorporeal carbon dioxide removal (ECCO2R) device based on a renal replacement therapy platform (Prismalung®) may reduce PaCO2 and alleviate lung vascular dysfunction in ARDS patients with refractory hypercapnia. MethodsWe planned to prospectively include 20 patients with moderate-to-severe ARDS, pulmonary vascular dysfunction on echocardiography, and PaCO2 ≥ 48 mmHg despite instrumental dead space reduction and the increase in respiratory rate. Hemodynamics, echocardiography, respiratory mechanics, and arterial blood gases were recorded at 2 (H2), 6 (H6) and 24 (H24) hours as ECCO2R treatment was continued for at least 24 h. ResultsOnly eight patients were included, and the study was stopped due to worldwide shortage of ECCO2R membranes and the pandemic. Only one patient fulfilled the primary endpoint criterion (decrease in PaCO2 of more than 20 %) at H2, but this objective was achieved in half of patients (n = 4) at H6. The percentage of patients with a PaCO2 value < 48 mmHg increased with time, from 0/8 (0 %) at H0, to 3/8 (37.5 %) at H2 and 4/8 (50 %) at H6 (p = 0.04). There was no major change in hemodynamic and echocardiographic variables with ECCO2R, except for a significant decrease in heart rate. ECCO2R was prematurely discontinued before H24 in five (62.5 %) patients, due to membrane clotting in all cases. ConclusionsThis pilot study testing showed a narrow efficacy and high rate of membrane thrombosis with the first version of the system. Improved versions should be tested in future trials. Trial registrationRegistered at clinicaltrials.gov, identifier: NCT03303807, Registered: October 6, 2017, https://clinicaltrials.gov/ct2/show/NCT03303807.

Intracranial hemorrhage in a large cohort of patients supported with veno-venous ECMO. A retrospective single-center analysis.

Intracranial bleeding (ICB) is a serious complication during veno-venous extracorporeal membrane oxygenation (V-V ECMO), with potentially fatal consequences. This study aimed to evaluate the incidence, time of detection of ICB among patients treated with V-V ECMO and potential risk factors for developing ICB during V-V ECMO. Five hundred fifty six patients were included in this retrospective single center analysis. Median time on V-V ECMO was 9 (IQR 6-15) days. Intracranial bleeding during V-V ECMO was detected in 10.9% of all patients (61 patients with ICB). Only 17 patients with ICB presented obvious clinical symptoms. Intracranial bleeding was detected on cerebral imaging in median after 5 days (IQR 1-14) after starting V-V ECMO. Overall survival to hospital discharge was 63.7% (ICB: 29.5%). Risk factors of ICB before starting V-V ECMO in univariable analysis were platelets <100/nl (OR: 3.82), creatinine >1.5mg/dl (OR: 1.98), norepinephrine >2.5mg/h (OR: 2.5), ASAT >80U/L (OR: 1.86), blood-urea >100mg/dl (OR: 1.81) and LDH >550u/L (OR: 2.07). Factors associated with cannulation were rapid decrease in paCO2 >35mmHg (OR: 2.56) and rapid decrease in norepinephrine >1mg/h (OR: 2.53). Multivariable analysis revealed low platelets, high paCO2 before ECMO, and rapid drop in paCO2 after V-V ECMO initiation as significant risk factors for ICB. The results emphasize that ICB is a frequent complication during V-V ECMO. Many bleedings were incidental findings, therefore screening for ICB is advisable. The univariate risk factors reflect the underlying disease severity, coagulation disorders and peri-cannulation factors, and may help to identify patients at risk.

Evaluation of diaphragm functions with diaphragm ultrasound and pulmonary function tests in individuals with Friedreich's ataxia.

It is known that the correlation of pulmonary function tests (PFT) with muscle dysfunction is insufficient. Here, we aimed to evaluate the diaphragm functions in individuals with Friedreich's ataxia (FRDA) and to examine its relationship with respiratory parameters and disease severity. This prospective study, conducted between November and December 2022, at Erciyes University, included 14 individuals with genetically confirmed FRDA and an age- and gender-matched healthy control group of eight individuals. We examined pulmonary functions with spirometric methods and evaluated diaphragm excursion, and diaphragm thickness-expiratory (Tde) and - end of inspiration (Tdi) with ultrasonography during calm breathing. Thickening fraction (TF) calculated. Also, we examined PaCO2 at rest. The neurological status of individuals was assessed using the Scale for the Assessment and Rating of Ataxia (SARA). The mean values of FEV1(lt), FEV1(%), FVC (lt), and FVC (%) were higher in the control group (p; <0.001, 0.013, <0.001, and 0.009, respectively). Also, mean Tdi, Tde, excursion and TF were lower in the FRDA group compared to the control group (p = 0.005, 0.294,0.005, and 0.019, respectively). The mean excursion value was 1.13 ± 0.54cm in the FRDA group and 1.71 ± 0.49cm in the control group. There is a strong, negative, and statistically significant correlation between SARA total score with excursion and TF (r = -0.7432, p = 0.002; r = -0.697, p = 0.008). There is no statistically significant relationship between excursion and BMI, standing-to-supine decrease in FVC, FEV1, and PaCO2. Also, the relationship between maximal inspiratory pressure (PImax) and excursion was moderate. Diaphragm ultrasound may reveal respiratory dysfunction better than PFT. Diaphragm excursion and TF are associated with disease scores in individuals with FDRA. Further studies are needed regarding the detection of alveolar hypoventilation.

Effect of external dead space removal on CO2 homeostasis in mechanically ventilated adult Covid-19 patients.

Patients with Covid-19 respiratory failure present with hypoxemia, often in combination with hypercapnia. In this prospective, observational study we examined the effect of removing external dead space (DS) on CO2 -homeostasis in mechanically ventilated Covid-19 patients. In addition, volumetric capnography was validated for its ability to estimate external DS volume using in vitro measured DS volumes as reference. In total, 10 patients with acute respiratory distress syndrome from Covid-19 were included. Volumetric capnography, mechanical ventilation, and arterial blood gas data were analyzed before and after removal of external DS and analyzed for potentially significant changes in response to DS removal. Measurements of external DS were obtained in circuit using volumetric capnography and compared to actual measured DS volumes off the circuit. After the removal of external DS, the alveolar minute ventilation and CO2 elimination improved, notwithstanding unchanged respiratory rate and tidal volumes. The increase in CO2 elimination was associated with a decrease in arterial CO2 partial pressure (PaCO2 ). The volumetric capnography method for assessment of external DS showed a low bias of -9 mL (lower limit of agreement -40, 95% CI -60 to -20 mL, upper limit of agreement 21 mL, 95% CI: 1-40 mL) and a percentage error of 48% compared to absolute values measured in vitro. Removal of external DS increased alveolar minute ventilation and CO2 elimination in Covid-19 patients with respiratory failure in the current study. This was associated with a decrease in PaCO2 . This may indicate a decreased CO2 production due to decreased work of breathing and more effective gas-exchange in response to DS removal. In addition, volumetric capnography appears to be a clinically feasible method for continuous measurement of external DS in the current study and may be of value in optimizing ventilator treatment.

Cerebrovascular Complications of COVID-19 on Venovenous Extracorporeal Membrane Oxygenation.

Evidence of cerebrovascular complications in COVID-19 requiring venovenous extracorporeal membrane oxygenation (ECMO) is limited. Our study aims to characterize the prevalence and risk factors of stroke secondary to COVID-19 in patients on venovenous ECMO. We analyzed prospectively collected observational data, using univariable and multivariable survival modeling to identify risk factors for stroke. Cox proportional hazards and Fine-Gray models were used, with death and discharge treated as competing risks. Three hundred eighty institutions in 53 countries in the COVID-19 Critical Care Consortium (COVID Critical) registry. Adult COVID-19 patients who were supported by venovenous ECMO. None. Five hundred ninety-five patients (median age [interquartile range], 51 yr [42-59 yr]; male: 70.8%) had venovenous ECMO support. Forty-three patients (7.2%) suffered strokes, 83.7% of which were hemorrhagic. In multivariable survival analysis, obesity (adjusted hazard ratio [aHR], 2.19; 95% CI, 1.05-4.59) and use of vasopressors before ECMO (aHR, 2.37; 95% CI, 1.08-5.22) were associated with an increased risk of stroke. Forty-eight-hour post-ECMO Pa co2 -pre-ECMO Pa co2 /pre-ECMO Pa co2 (relative ΔPa co2 ) of negative 26% and 48-hour post-ECMO Pa o2 -pre-ECMO Pa o2 /pre-ECMO Pa o2 (relative ΔPa o2 ) of positive 24% at 48 hours of ECMO initiation were observed in stroke patients in comparison to relative ΔPa co2 of negative 17% and relative ΔPa o2 of positive 7% in the nonstroke group. Patients with acute stroke had a 79% in-hospital mortality compared with 45% mortality for stroke-free patients. Our study highlights the association of obesity and pre-ECMO vasopressor use with the development of stroke in COVID-19 patients on venovenous ECMO. Also, the importance of relative decrease in Pa co2 and moderate hyperoxia within 48 hours after ECMO initiation were additional risk factors.

High-flow nasal cannula oxygen therapy is superior to conventional oxygen therapy but not to non-invasive mechanical ventilation in reducing intubation rate in hypoxia and dyspnea due to acute heart failure: a systematic review and meta-analysis.

High-flow nasal cannula oxygen therapy is superior to conventional oxygen therapy but not to non-invasive mechanical ventilation in reducing intubation rate in hypoxia and dyspnea due to acute heart failure: a systematic review and meta-analysis.

Effect of pulmonary rehabilitation programme including either O2 inhalation or noninvasive ventilation in patients with chronic obstructive pulmonary disease.

Pulmonary rehabilitation (PR) is crucial in managing chronic obstructive pulmonary disease (COPD) and enhancing functional capacity and health status. Oxygen therapy and noninvasive ventilation (NIV) may be needed to be incorporated into rehabilitation to augment the effectiveness of physical training. To compare and assess the impact of the PR programme alone and with augmentation with O2 or NIV on COPD patients. Seventy-five COPD patients were equally divided into three groups: group 1 patients performed 8 week-PR programme only. Group 2 performed the PR programme while receiving O2. Group 3 completed the PR programme plus NIV. Modified Borg scale, VO2 max, modified Medical Research Council Dyspnea Scale, 6-minute walk test, COPD assessment test score, spirometric measures and arterial blood gases were assessed before and after the programme. The outcome measurements showed meaningful improvement compared with the baseline in the three studied groups. However, VO2 max in group 3 showed higher significant improvement than both groups 1 and 2. Regarding 6-minute walk test, groups 2 and 3 had a higher significant improvement than group 1. COPD assessment test score in group 3 showed higher significant improvement than groups 1 and 2. Arterial blood gases in groups 2 and 3 showed significant increase in partial pressure of arterial oxygen and arterial oxygen saturation, but group 3 only had a significant decrease in PaCO2. O2 supplementation and NIV help severe to very severe COPD patients to perform higher exercise intensity, so they augment the benefits of PR.

Застосування відеоасистованих операцій зі зменшення об’єму легені при бульозній емфіземі легень в клінічній практиці

Abstract. Bullous emphysema of the lungs (BEL) is a chronic pulmonary disease, induced by the weakening of the alveoli walls in the lungs, resulting in abnormally large air spaces (bullae), which are filled with air, even when the patient exhales. Object and research methods. The practical experience of performing video-assisted (VATS) lung volume reduction (LVR) operations in 2 cases with BEL is given. Results and their discussion. After performing the LVR patients had improved breathing, reduced manifestations of respiratory failure and angina pectoris, increased blood gas parameters: an increase in SpO2 from 86 % to 96 %, a decrease in PaCO2 from 47 mmHg up to 40 mmHg. Conclusions. LVR is an effective method of treatment of BEL, in the presence of isolated bulls, this operation causes a significant reduction in respiratory failure, especially in patients with bronchial asthma and coronary artery disease.

Targeted temperature management and PbtO2 in traumatic brain injury

IntroductionTargeted Temperature Management (TTM) to normothermia is widely used in traumatic brain injury (TBI). We investigated the effects to of TTM to normothermia patients with TBI (GCS≤12) monitored with multimodality monitoring, to better understand the physiological consequences of this intervention. Research questionIn TBI patients cooled to normothermia and in which brain oxygenation deteriorates, are there changes in physiological parameters which are pertinent to brain oxygenation? Material and method102 TBI patients with continuous recordings of intracranial pressure (ICP) and brain oxygen tension (PbtO2) were studied retrospectively. Non-continuous arterial carbon dioxide (PaCO2) and oxygen (PaO2) tensions, and core body temperature (Tc) were added. PaO2 and PaCO2 were also corrected for Tc. Transitions from elevated Tc to normothermia were identified in 39 patients. The 8 h pre and post the transition to normothermia were compared. Data is given as median [IQR] or mean (SD). ResultsOverall, normothermia reduced ICP (12 [9–18] −11 [8–17] mmHg, p < 0.009) and Tcore (38.3 [0.3]-36.9 [0.4] oC, p < 0.001), but not PbtO2 (23.3 [16.6]-24.4 [17.2–28.7] mmHg, NS). Normothermia was associated with a fall in PbtO2 in 18 patients (24.5 [9.3] −20.8 [7.6] mmHg). Only in those with a fall in PbtO2 with cooling did ICP (15 [10.8–18.5] −12 [7.8–17.3] mmHg, p = 0.002), and temperature corrected PaCO2 (5.3 [0.5]- 4.9 [0.8] kPa, p = 0.001) decrease. Discussion and conclusionA reduction in PbtO2 was only present in the subgroup of patients with a fall in temperature corrected PaCO2 with cooling. This suggests that even modest temperature changes could result in occult hyperventilation in some patients. pH stat correction of ventilation may be an important factor to consider in future TTM protocols.

Association Between Early Change in Arterial Carbon Dioxide Tension and Outcomes in Neonates Treated by Extracorporeal Membrane Oxygenation.

The primary objective was to investigate the association between partial pressure of carbon dioxide (PaCO 2 ) change after extracorporeal membrane oxygenation (ECMO) initiation and neurologic outcome in neonates treated for respiratory failure. A retrospective analysis of the Extracorporeal Life Support Organization (ELSO) database including newborns supported by ECMO for respiratory indication during 2015-2020. The closest Pre-ECMO (Pre-ECMO PaCO 2 ) and at 24 hours after ECMO initiation (H24 PaCO 2 ) PaCO 2 values allowed to calculate the relative change in PaCO 2 (Rel Δ PaCO 2 = [H24 PaCO 2 - Pre-ECMO PaCO 2 ]/Pre-ECMO PaCO 2 ). The primary outcome was the onset of any acute neurologic event (ANE), defined as cerebral bleeding, ischemic stroke, clinical or electrical seizure, or brain death during ECMO. We included 3,583 newborns (median age 1 day [interquartile range {IQR}, 1-3], median weight 3.2 kg [IQR, 2.8-3.6]) from 198 ELSO centers. The median Rel Δ PaCO 2 value was -29.9% [IQR, -46.2 to -8.5]. Six hundred nine (17%) of them had ANE (405 cerebral bleedings, 111 ischemic strokes, 225 seizures, and 6 brain deaths). Patients with a decrease of PaCO 2 > 50% were more likely to develop ANE than others (odds ratio [OR] 1.78, 95% confidence interval [CI], 1.31-2.42, p < 0.001). This was still observed after adjustment for all clinically relevant confounding factors (adjusted OR 1.94, 95% CI, 1.29-2.92, p = 0.001). A significant decrease in PaCO 2 after ECMO start is associated with ANE among neonates requiring ECMO for respiratory failure. Cautious PaCO 2 decrease should be considered after start of ECMO therapy.

Is disposable continuous positive airway pressure system effective for the management of acute hypercapnic respiratory failure?

This study aimed to investigate the effectiveness of disposable continuous positive airway pressure (DCPAP) system in decreasing the partial pressure of carbon dioxide (PaCO2) levels in patients with acute hypercapnic respiratory failure (AHRF). This retrospective observational study included patients treated in the emergency department (ED) with respiratory distress and PaCO2 > 45mmHg. Patients were divided into two groups (DCPAP and non-DCPAP), depending on the treatment received to treat AHRF. The difference between the baseline PaCO2 levels in the first blood gas obtained from patients at the time of admission and the follow-up blood gas after treatment. Then, the calculated PaCO2 decrease was divided by the time elapsed to obtain the rate of decrease in PaCO2 levels in mmHg/min. The statistical analyses were performed using SPSS version 18.0 software. A p value of < 0.05 was considered statistically significant. A total of 61 patients were included in the study, 31 patients in the DCPAP group and 30 patients in the non-DCPAP group. The mean age of the patients was 74.03 ± 10.04, and the male/female was 23/38. The study demonstrated a statistically significant difference between the DCPAP and non-DCPAP groups in terms of PaCO2 decreasing rate, and it was found to be twice higher in the DCPAP group (0.11 ± 0.07mmHg/min) than in the non-DCPAP group (0.05 ± 0.06mmHg/min). The study demonstrated that the treatment of AHRF patients with a DCPAP provides a faster decrease in PaCO2 levels in hypercapnic patients compared to standard medical therapy alone.

Hypoxemia in the presence or absence of systemic inflammation does not increase blood lactate levels in healthy volunteers.

Elevated lactate levels are a sign of critical illness and may result from insufficient oxygen delivery. We investigated whether hypoxemia and/or systemic inflammation, results in increased lactate levels in healthy volunteers. 30 healthy volunteers were exposed to either 3.5 h of hypoxemia (FiO2 ± 11.5%), normoxemic endotoxemia (FiO2 21%, administration of 2 ng/kg endotoxin), or hypoxemic endotoxemia (n = 10 per group). Blood lactate, hemoglobin, SpO2, PaO2, PaCO2, pH, and hemodynamic parameters were serially measured. Hypoxemic treatment resulted in lower SpO2 (81.7 ± 2.6 and 81.4 ± 2.4% in the hypoxemia and hypoxemic endotoxemia groups, respectively) and hyperventilation with a PaCO2 decrease of 0.8 ± 0.5 and 1.5 ± 0.6 kPa and an increase in pH. Arterial oxygen content (CaO2) decreased by 20.5 ± 2.9 and 23.5 ± 4.4%, respectively. Lactate levels were slightly, but significantly higher in both hypoxemic groups compared with the normoxemic endotoxemia group over time (p < 0.0001 for both groups), but remained below 2.3 mmol/L in all subjects. Whereas PaO2 and SpO2 did not correlate with lactate levels, PaCO2, pH and CaO2 did. Hypoxemia, in the absence or presence of inflammation does not result in relevant increases of lactate. The small increases in lactate observed are likely to be due to hyperventilation-related decreases in glycolysis.

Airway Pressure Release Ventilation for Acute Respiratory Failure Due to Coronavirus Disease 2019: A Systematic Review and Meta-Analysis.

Objective: To explore the evidence surrounding the use of Airway Pressure Release Ventilation (APRV) in patients with coronavirus disease 2019 (COVID-19). Methods: A Systematic electronic search of PUBMED, EMBASE, and the WHO COVID-19 database. We also searched the grey literature via Google and preprint servers (medRxive and research square). Eligible studies included randomised controlled trials and observational studies comparing APRV to conventional mechanical ventilation (CMV) in adults with acute hypoxemic respiratory failure due to COVID-19 and reporting at least one of the following outcomes; in-hospital mortality, ventilator free days (VFDs), ICU length of stay (LOS), changes in gas exchange parameters, and barotrauma. Two authors independently screened and selected articles for inclusion and extracted data in a pre-specified form. Results: Of 181 articles screened, seven studies (one randomised controlled trial, two cohort studies, and four before-after studies) were included comprising 354 patients. APRV was initiated at a mean of 1.2-13 days after intubation. APRV wasn't associated with improved mortality compared to CMV (relative risk [RR], 1.20; 95% CI 0.70-2.05; I2, 61%) neither better VFDs (ratio of means [RoM], 0.80; 95% CI, 0.52-1.24; I2, 0%) nor ICU LOS (RoM, 1.10; 95% CI, 0.79-1.51; I2, 57%). Compared to CMV, APRV was associated with a 33% increase in PaO2/FiO2 ratio (RoM, 1.33; 95% CI, 1.21-1.48; I2, 29%) and a 9% decrease in PaCO2 (RoM, 1.09; 95% CI, 1.02-1.15; I2, 0%). There was no significant increased risk of barotrauma compared to CMV (RR, 1.55; 95% CI, 0.60-4.00; I2, 0%). Conclusions: In adult patients with COVID-19 requiring mechanical ventilation, APRV is associated with improved gas exchange but not mortality nor VFDs when compared with CMV. The results were limited by high uncertainty given the low quality of the available studies and limited number of patients. Adequately powered and well-designed clinical trials to define the role of APRV in COVID-19 patients are still needed. Registration: PROSPERO; CRD42021291234.