Effects of respiratory mechanics on the capnogram phases: importance of dynamic compliance of the respiratory system

INTRODUCTION: The slope of phase III of the capnogram (S(III)) relates to progressive emptying of the alveoli, a ventilation/perfusion mismatch, and ventilation inhomogeneity. S(III )depends not only on the airway geometry, but also on the dynamic respiratory compliance (Crs); this latter effect has not been evaluated. Accordingly, we established the value of S(III )for monitoring airway resistance during mechanical ventilation. METHODS: Sidestream capnography was performed during mechanical ventilation in patients undergoing elective cardiac surgery (n = 144). The airway resistance (Raw), total respiratory resistance and Crs displayed by the ventilator, the partial pressure of arterial oxygen (PaO(2)) and S(III )were measured in time domain (S(T-III)) and in a smaller cohort (n = 68) by volumetry (S(V-III)) with and without normalization to the average CO(2 )phase III concentration. Measurements were performed at positive end-expiratory pressure (PEEP) levels of 3, 6 and 9 cmH(2)O in patients with healthy lungs (Group HL), and in patients with respiratory symptoms involving low (Group LC), medium (Group MC) or high Crs (Group HC). RESULTS: S(T-III )and S(V-III )exhibited similar PEEP dependencies and distribution between the protocol groups formed on the basis of Crs. A wide interindividual scatter was observed in the overall Raw-S(T-III )relationship, which was primarily affected by Crs. Decreases in Raw with increasing PEEP were reflected in sharp falls in S(III )in Group HC, and in moderate decreases in S(III )in Group MC, whereas S(T-III )was insensitive to changes in airway caliber in Groups LC and HL. CONCLUSIONS: S(III )assessed in the time domain and by volumetry provide meaningful information about alterations in airway caliber, but only within an individual patient. Although S(T-III )may be of value for bedside monitoring of the airway properties, its sensitivity depends on Crs. Thus, assessment of the capnogram shape should always be coupled with Crs when the airway resistance or oxygenation are evaluated

Comparison of sedation and general anaesthesia for transcatheter aortic valve implantation on cerebral oxygen saturation and neurocognitive outcome

BACKGROUND: Transcatheter aortic valve implantation (TAVI) is a treatment strategy for patients with severe aortic stenosis. Although general anaesthesia (TAVI-GA) and sedation (TAVI-S) have previously been described for TAVI, the difference in safety and efficacy of both methods has not been studied in a randomized trial. METHODS: The INSERT trial was a single centre, controlled parallel-group trial with balanced randomization. Sixty-six patients (68-94 yr) with acquired aortic stenosis undergoing transfemoral CoreValve were assigned to TAVI-GA or TAVI-S. Comparable operative risk was determined from risk-scores (EUROscore, STS-Score). Monitoring and anaesthetic drugs were standardized. Near-Infrared-Spectroscopy was used to monitor cerebral-oxymetry blinded. Primary outcome was the perioperative cumulative cerebral desaturation. As secondary outcomes, changes in neurocognitive function and respiratory and haemodynamic adverse events were evaluated. RESULTS: Of 66 included patients, 62 (TAVI-GA: n=31, TAVI-S: n=31) were finally analysed. Baseline characteristics were comparable. In 24 patients (39%) cerebral desaturation was observed. Cumulative cerebral desaturation was comparable (TAVI-GA:(median [IQR]) (0[0/1308] s%) vs. TAVI-S:(0[0/276] s%); P=0.505) between the groups. Neurocognitive function did not change within and between groups. Adverse events were more frequently observed in TAVI-S patients (P<0.001). Bradypnoea (n=16, 52%) and the need for airway manoeuvres (n=11, 36%) or bag-mask-ventilation (n=6, 19%) were the most common respiratory adverse events. CONCLUSIONS: Cerebral desaturation occurred in both patient groups, but there was no significant difference between the two groups. Based on primary outcome, both methods were shown to be comparable. Neurocognitive outcome was similar. The higher incidence of adverse events in the sedation group suggests a potential advantage of general anaesthesia. CLINICAL TRIAL REGISTRATION: NCT 01251328

Mitochondrial oxodicarboxylate carrier deficiency is associated with mitochondrial DNA depletion and spinal muscular atrophy-like disease.

PURPOSE: To understand the role of the mitochondrial oxodicarboxylate carrier (SLC25A21) in the development of spinal muscular atrophy-like disease. METHODS: We identified a novel pathogenic variant in a patient by whole-exome sequencing. The pathogenicity of the mutation was studied by transport assays, computer modeling, followed by targeted metabolic testing and in vitro studies in human fibroblasts and neurons. RESULTS: The patient carries a homozygous pathogenic variant c.695A>G; p.(Lys232Arg) in the SLC25A21 gene, encoding the mitochondrial oxodicarboxylate carrier, and developed spinal muscular atrophy and mitochondrial myopathy. Transport assays show that the mutation renders SLC25A21 dysfunctional and 2-oxoadipate cannot be imported into the mitochondrial matrix. Computer models of central metabolism predicted that impaired transport of oxodicarboxylate disrupts the pathways of lysine and tryptophan degradation, and causes accumulation of 2-oxoadipate, pipecolic acid, and quinolinic acid, which was confirmed in the patient's urine by targeted metabolomics. Exposure to 2-oxoadipate and quinolinic acid decreased the level of mitochondrial complexes in neuronal cells (SH-SY5Y) and induced apoptosis. CONCLUSION: Mitochondrial oxodicarboxylate carrier deficiency leads to mitochondrial dysfunction and the accumulation of oxoadipate and quinolinic acid, which in turn cause toxicity in spinal motor neurons leading to spinal muscular atrophy-like disease

Biallelic C1QBP Mutations Cause Severe Neonatal-, Childhood-, or Later-Onset Cardiomyopathy Associated with Combined Respiratory-Chain Deficiencies

Complement component 1 Q subcomponent-binding protein (C1QBP; also known as p32) is a multi-compartmental protein whose precise function remains unknown. It is an evolutionary conserved multifunctional protein localized primarily in the mitochondrial matrix and has roles in inflammation and infection processes, mitochondrial ribosome biogenesis, and regulation of apoptosis and nuclear transcription. It has an N-terminal mitochondrial targeting peptide that is proteolytically processed after import into the mitochondrial matrix, where it forms a homotrimeric complex organized in a doughnut-shaped structure. Although C1QBP has been reported to exert pleiotropic effects on many cellular processes, we report here four individuals from unrelated families where biallelic mutations in C1QBP cause a defect in mitochondrial energy metabolism. Infants presented with cardiomyopathy accompanied by multisystemic involvement (liver, kidney, and brain), and children and adults presented with myopathy and progressive external ophthalmoplegia. Multiple mitochondrial respiratory-chain defects, associated with the accumulation of multiple deletions of mitochondrial DNA in the later-onset myopathic cases, were identified in all affected individuals. Steady-state C1QBP levels were decreased in all individuals’ samples, leading to combined respiratory-chain enzyme deficiency of complexes I, III, and IV. C1qbp−/− mouse embryonic fibroblasts (MEFs) resembled the human disease phenotype by showing multiple defects in oxidative phosphorylation (OXPHOS). Complementation with wild-type, but not mutagenized, C1qbp restored OXPHOS protein levels and mitochondrial enzyme activities in C1qbp−/− MEFs. C1QBP deficiency represents an important mitochondrial disorder associated with a clinical spectrum ranging from infantile lactic acidosis to childhood (cardio)myopathy and late-onset progressive external ophthalmoplegia

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Assessing the level of radiation experienced by anesthesiologists during transfemoral Transcatheter Aortic Valve Implantation and protection by a lead cap

OBJECTIVE Transfemoral Transcatheter Aortic Valve Implantation (TAVI) has become a standard therapy for patients with aortic valve stenosis. Fluoroscopic imaging is essential for TAVI with the anesthesiologist's workplace close to patient's head side. While the use of lead-caps has been shown to be useful for interventional cardiologists, data are lacking for anesthesiologists. METHODS A protective cap with a 0.35 lead-equivalent was worn on 15 working days by one anesthesiologist. Six detectors (three outside, three inside) were analyzed to determine the reduction of radiation. Literature search was conducted between April and October 2018. RESULTS In the observational period, 32 TAVI procedures were conducted. A maximum radiation dose of 0.55 mSv was detected by the dosimeters at the outside of the cap. The dosimeters inside the cap, in contrast, displayed a constant radiation dose of 0.08 mSv. CONCLUSION The anesthesiologist's head is exposed to significant radiation during TAVI and it can be protected by wearing a lead-cap

Comparison of latest generation supra-annular and intra-annular self-expanding transcatheter heart valves

Background This study compares two latest-generation self-expanding transcatheter heart valves (THV), the supra-annular ACURATE neo (Boston Scientific) and the intra-annular Centera THV (Edwards Lifesciences). Methods In this single center observational cohort trial 317 patients treated with the ACURATE neo and 78 patients treated with the Centera TVH were included. The main endpoints were device success and the early safety endpoint at 30 days. Results Besides higher incidence of diabetes mellitus and higher body mass index in patients treated with the ACURATE neo THV, there were no baseline differences between the groups. Device success was similar in both groups (neo: 91.8% vs. Centera: 93.6%; P=0.598), with numerically higher rates of moderate to severe paravalvular leakage in the ACURATE neo group (4.7% vs. 1.3%; P=0.214). At 30 days all-cause mortality rates were low in both groups (0.3% vs. 0%; P=0.620) and no difference occurred in the early safety at 30 days (19.3% vs. 16.7%; P=0.599). However, all-cause stroke rates were significantly higher in patients treated with the Centera THV (6.4 vs. 1.6%; P=0.015). Conclusions The ACURATE neo and the Centera THV show low mortality rates as well as comparable, favorable hemodynamics. The finding of higher stroke rates at 30 days with the repositionable Centera SE-THV needs further assessment

Influence of marital status in patients undergoing transcatheter aortic valve implantation

Background Marital status has been described to affect outcome in cardiovascular diseases, however its impact on patients undergoing transcatheter aortic valve implantation (TAVI) is unknown. We therefore aimed to assess the impact of marital status in patients undergoing TAVI. Methods Between 2011 and 2015, 779 patients undergoing transfemoral TAVI with known marital status were included in the analysis. The primary endpoint of the study was the composite of cardiac death and readmission for congestive heart failure (CHF) at one year. Results Mean age was 80.7±5.9 years, 47.8% were female and median logistic EuroScore was 12.7% (8.13-19.39%). Forty-three point three percent of patients were not married. Compared to married patients, unmarried patients were older (82.4±5.5 vs. 79.5±5.8 years; P<0.001), more often female (73.3% vs. 28.3%; P<0.001), presented with a higher logistic EuroScore [13.1% (9.5-21.5%) vs. 11.7% (7.0-18.5%); P<0.001], and more symptomatic with New York Heart Association functional class III/IV (69.7% vs. 60.6%; P=0.009). At one year the incidence of the primary endpoint was higher in unmarried patients (18.7% vs. 12.0%; P=0.011) which was mainly driven by more admissions for CHF (14.1% vs. 7.8%; P=0.007). After multivariable adjustment, marital status was borderline significant regarding CHF (HR 0.61, 95% CI: 0.37-1.02; P=0.06) but not the primary endpoint. Conclusions Unmarried patients undergoing TAVI showed a higher incidence of cardiac death or CHF at one year. Hence, marital status should be taken into account in patients with aortic stenosis subjected to TAVI. Whether closer monitoring and intensified medical follow-up improves outcomes remains to be investigated in future studies