Spontaneous Breathing Research Articles

Comparing pressure support ventilation to spontaneous breathing trial during ventilator weaning after surgery: impact on postoperative atelectasis

Comparing pressure support ventilation to spontaneous breathing trial during ventilator weaning after surgery: impact on postoperative atelectasis

Bispectral Index Guidance Reduced Target Plasma Propofol Concentration During ERCP in Patients with Liver Cirrhosis.

The primary aim of this study was to investigate the guidance effect of the bispectral index (BIS) on the target plasma concentration (TPC) of propofol required for deep sedation during endoscopic retrograde cholangiopancreatography (ERCP). Second, to identify propofol consumption, recovery time, and adverse events. A total of 42 consecutive patients with liver cirrhosis and 43 consecutive patients with healthy livers were enrolled. Propofol was administered via a target control infusion (TCI) syringe pump (Marsh Model) at BIS 60-70. Patients were not intubated, were placed in the prone position, and underwent spontaneous breathing. Propofol TPCs (μg mL-1) and BIS values were recorded at T0 (baseline), T1 (5 min after induction), T2 (5 min into ERCP), T3 (15 min), T4 (30 min), and T5 (recovery). TPCs and propofol consumption were lower in patients with cirrhosis than in those without cirrhosis (T4: 2.7±0.5 vs. 3.3±0.4 μg mL-1), P=0.001, and 270.4±6.9 mg vs. 390.8±13.4 mg, P=0.001), respectively. Patients with cirrhosis required more time to recover (8.5±2 vs. 6.2±0.9 min, P=0.001), despite comparable ERCP durations (31.1±11.1 vs. 34±12.5 min, P=0.28). A significant decline in TPC values among patients with cirrhosis with time (T1: 3.3±0.3, T2: 3.1±0.3, T3: 2.9±0.4, T4: 2.7±0.5 μg mL-1, P=0.001), indicating a cumulative effect. One patient with cirrhosis required bag-mask ventilation, while three patients without cirrhosis were converted to general anaesthesia. Combining the TCI Marsh pharmacokinetic model with BIS monitoring lowered the TPC levels required for deep sedation in patients with cirrhosis compared with healthy patients and allowed for individual variations. The prone position in deeply sedated and non-intubated spontaneous breathing patients is not without the risk of hypoxia.

Heart rate variability-based prediction of early cardiotoxicity in breast-cancer patients treated with anthracyclines and trastuzumab

Abstract Background Cardiotoxicity is a recognized complication in breast cancer (BC) patients undergoing chemotherapy with anthracyclines with or without trastuzumab. However, the prognostic value of heart rate variability (HRV) indexes for early cardiotoxicity development remains unknown. Purpose This study aimed to investigate cardiac autonomic responses to physiological stimuli in BC patients treated with anthracyclines with or without trastuzumab, and to evaluate the predictive value of transthoracic echocardiography (TTE) findings and HRV indexes for early cardiotoxicity. Methods A prospective cohort study involving 50 BC patients was conducted at a tertiary hospital with TTE assessments performed before and three months after chemotherapy. HRV indexes were obtained from continuous electrocardiograms in supine position with spontaneous breathing, active standing, and supine position with controlled breathing. The magnitude of change (Δ) between supine-standing and supine-controlled breathing was calculated. Variables were compared using t-test or ANOVA. Cardiotoxicity predictive value was assessed by ROC curve analysis. A p value of < 0.05 was considered significant. Results In our cohort, the mean age was 50 ± 8 years, and reported comorbidities included diabetes (n= 9), hypertension (n= 17), and dyslipidemia (n= 11). Twenty-three patients fulfilled echocardiographic and troponin cardiotoxicity criteria or both. TTE revealed reduced left atrial conduit strain in the cardiotoxicity group. Mean heart rate increased during all maneuvers at follow-up, with no differences in HRV indexes between patients with or without cardiotoxicity. However, a lower Δ in supine-controlled breathing of several HRV indexes predicted early cardiotoxicity identified by echocardiography (e.g. SDNN ≤ -8.44 ms: Sensitivity = 75%, Specificity = 69%). Conclusion BC patients treated with chemotherapy maintain cardiac autonomic responses to physiological stimuli after 3 months of chemotherapy. However, a lower Δ during active standing and controlled breathing before chemotherapy may predict early cardiotoxicity.Table 1.ROC curve analysisFigure 1.HRV-indexes

Relationships between capnogram parameters by mainstream and sidestream techniques at different breathing frequencies

Capnography, routinely used in operating rooms and intensive care units, reveals essential information on lung ventilation and ventilation–perfusion matching. Mainstream capnography directly measures CO2 in the breathing circuit for accurate analysis and is considered a reference technique. Sidestream capnography, however, analyzes gas away from the patient leading to potentially less accurate measures. While these methodological differences impact the capnogram indices in mechanically ventilated patients, such assessments during spontaneous breathing are essentially lacking. Accordingly, we aimed to compare mainstream and sidestream capnography in spontaneously breathing subjects, focusing on differences in capnogram shape and dead space indices at various respiratory rates. Simultaneous mainstream and sidestream time and volumetric capnography were performed on spontaneously breathing adults (n = 35). Measurements were performed during controlled low (10/min), medium (12/min), and high (20/min) breathing rates as a challenge. Correlation and Bland–Altman analyses were used to assess trends and agreements between time and volumetric capnography indices obtained by the mainstream and sidestream techniques, including end-tidal CO2 (ETCO2), shape factors reflecting the slopes of phases 2 and 3, and anatomical and physiological dead space fractions. ETCO2 and physiological dead space measured by mainstream and sidestream techniques showed excellent correlations (r > 0.90, p < 0.001 for all breathing rates) and agreements. While strong correlations and moderate agreements were evidenced in the parameters reflecting the late phase of expiration (phase 3 slope and exhaled CO2 volume), these relationships were weaker for indices related to the early phase of expiration (phase 2 slope, anatomical dead space). Changing breathing frequency caused significant alterations in all capnography parameters, which were detectable by both mainstream and sidestream techniques. Sidestream capnography cannot substitute the more accurate mainstream technique for measuring the absolute values of shape factors and ventilation dead space fractions. However, sidestream capnography is also able to detect and track changes in uneven alveolar emptying, ventilation–perfusion matching and ventilation dead space fraction in spontaneously breathing subjects.

Hemodynamic monitoring during weaning from mechanical ventilation in critically ill pediatric patients: a prospective observational study

BackgroundCardiovascular dysfunction is a significant factor contributing to weaning failure in mechanically ventilated children. Understanding the cardiopulmonary pathophysiological changes that occur during weaning is a prerequisite for the early recognition of weaning failure of cardiovascular origin. This study aimed to assess the effect of weaning trials on central hemodynamics and to identify the indices predictive of cardiac-related weaning failure.MethodsThis prospective observational study was conducted in the Pediatric Intensive Care Unit (PICU) and included mechanically ventilated patients aged between 2 and 30 months who were on minimal ventilatory settings and ready for weaning. Patients who were hemodynamically unstable, diagnosed with neuromuscular diseases, or diagnosed with cardiac diseases were excluded. Hemodynamic parameters were evaluated during weaning from ventilation via echocardiography and noninvasive cardiometry during pressure support (PS) ventilation and at the end of the spontaneous breathing trial (SBT).ResultsThe study included 50 patients, comprising 30 males (60%) and 20 females (40%) with ages ranging from 2 to 30 months. Echocardiography revealed a significant increase in the cardiac index (CI), tricuspid annular plane systolic excursion (TAPSE), and the E/A ratio at the end of SBT. Moreover, right ventricular systolic pressure (RVSP) significantly decreased. Noninvasive cardiometry revealed a significant increase in the index of contractility (ICON) and CI at the end of SBT (p-value = 0.023 and < 0.001, respectively). Of the 12 (25%) patients who failed their first extubation trial, they exhibited a significantly lower CI and TAPSE (p values = 0.001 and 0.001, respectively).ConclusionThis study identified that weaning from mechanical ventilation in children is associated with hemodynamic changes, which can impact weaning success and reveal potential ventricular dysfunction. Bedside echocardiography was found to detect cardiac dysfunctions during weaning, and noninvasive cardiometry was considered a reliable tool that supports echocardiography for detecting changing trends in CI in PICUs. However, accurate values should be confirmed by echocardiography.

The effect of histological and subclinical chorioamnionitis and funisitis on breathing effort in premature infants at birth: a retrospective cohort study

Antenatal inflammation in the form of chorioamnionitis (fetal membranes; HCA) and funisitis (umbilical vessels; FUN) is a major risk factor for preterm birth. Exposure to HCA + FUN affects infants by releasing mediators that may suppress respiratory drive. While the association between clinical chorioamnionitis (CCA) and (depressed) spontaneous breathing has been described, we have investigated the association between breathing and HCA + FUN. Infants born < 30 weeks’ gestation with available placental pathology assessments were included. Infants were compared at multiple levels: infants with vs without HCA + FUN (comparison 1) and infants with subclinical HCA + FUN vs infants without any chorioamnionitis (comparison 2). The primary outcome was breathing effort, defined as minute volume (MV) of spontaneous breathing in the first 5 min after birth. We also assessed tidal volume (Vt), respiratory rate (RR), heart rate (HR), oxygen saturation (SpO2) and oxygen requirement (FiO2). Regression analyses were performed to control for confounding factors. One hundred eighty-six infants were included (n = 75 infants with HCA + FUN vs. n = 111 infants without HCA + FUN). Comparison 1: Infants with HCA + FUN had lower gestational ages 26+5 (25+0–28+1; median (IQR) and lower birthweights (mean ± SD; 943 ± 264) compared to infants without HCA + FUN (28+4 (27+0–29+1) weeks, p < 0.001 and 1023 ± 270 g, p = 0.049). Comparison 2: Subclinical HCA + FUN was diagnosed in 46/75 HCA + FUN infants. Infants with subclinical HCA + FUN had lower gestational ages (26+6 (25+1–28+3) vs. 28+4 (27+2–29+1) weeks, p < 0.001) without significant differences for birthweights (987 ± 248 vs. 1027 ± 267 g, p = 0.389) compared to infants without any chorioamnionitis (n = 102 infants). After adjustment, HCA + FUN was associated with lower MV (p = 0.025), but subclinical HCA + FUN was not (p = 0.226). HCA + FUN and subclinical HCA + FUN were associated with lower Vt (p = 0.003; p = 0.014), SpO2 at 5 min (p = 0.021; 0.036) and SpO2/FiO2 ratio (p = 0.028; p = 0.040).Conclusion: HCA + FUN and subclinical HCA + FUN are associated with reduced oxygenation and parameters that reflect breathing effort in premature infants at birth.What is Known:• Acute antenatal inflammation, in the form of chorioamnionitis (fetal membranes) and funisitis (umbilical vessels), affects a large proportion of premature infants.• Clinical chorioamnionitis is associated with reduced breathing effort and oxygenation in premature infants at birth.What is New:• Histological and subclinical chorioamnionitis and funisitis are associated with reduced breathing effort parameters and oxygenation in premature infants at birth.

Spontaneous breathing trials should be adapted for each patient according to the critical illness. A new individualised approach: the GLOBAL WEAN study.

Spontaneous breathing trials (SBT) evaluate the patient's capacity to maintain inspiratory effort after extubation. SBT practices are heterogeneous and not individualised. The objective of this study was to assess which SBT best reproduces inspiratory effort after extubation in five critical illnesses. In this multicentre randomized cross-over study, adult intensive care unit patients under invasive mechanical ventilation for at least 24-h and ready for extubation, underwent three 15-min SBTs in random order: pressure support ventilation level of 7-cmH2O with positive end-expiratory pressure (PEEP) level of 0-cmH2O (PSV7PEEP0), PSV 0-cmH2O with PEEP 0-cmH2O (PSV0PEEP0) and T-piece trial. Primary outcome was the variation of pressure-time-product per minute (PTPmin) between each SBT and 20-min after extubation. Five categories of critical illnesses were selected: abdominal surgery, brain injury, chest trauma, chronic obstructive pulmonary disease (COPD) and miscellaneous. Five hundred measures of effort from 100 patients were analysed. PTPmin (cmH2O s/min, median and interquartile range, IQR) was 256 (208-321) after extubation, 192 (127-281) at the end of PSV7PEEP0 (p < 0.001 in comparison to after extubation), 291 (235-347) at the end of PSV0PEEP0 and 262 (198-338) at the end of T-piece (both no different from after extubation). One method of SBT in patients with brain injury (PSV0PEEP0), two in abdominal surgery (PSV0PEEP0 and T-piece) and miscellaneous patients (PSV7PEEP0 and T-piece) and all three methods in chest trauma and COPD exacerbation patients replicated reasonably accurately the postextubation effort to breathe. Unassisted SBTs, namely PSV0PEEP0 and T-piece trial, are the most appropriate to replicate the postextubation effort to breathe.

Extubation Advisor: Implementation and Evaluation of A Novel Extubation Clinical Decision Support Tool.

Extubation Advisor (EA) is a novel software tool that generates a synoptic report for each Spontaneous Breathing Trial (SBT) conducted to inform extubation decision-making. To assess bedside EA implementation, perceptions of utility, and identify barriers and facilitators of use. We conducted a phase I mixed-methods interventional study in three mixed intensive care unit (ICUs) in two academic hospitals. We interviewed critical care physicians (MDs) and respiratory therapists (RTs) regarding user-centered design principles and usability. We evaluated our ability to consent participants (feasibility threshold 50%), capture complete data (threshold 90%), generate and review EA reports in real-time (thresholds 75% and 80%, respectively), and MD perception of tool usefulness (6-point Likert scale). We analyzed interview transcripts using inductive coding to identify facilitators and barriers to EA implementation and perceived benefit of tool use. We enrolled 31 patients who underwent 70 SBTs. Although consent rates [31/31 (100%], complete data capture [68/68 (100%)], and EA report generation [68/70 (97.1%)] exceeded feasibility thresholds, reports were reviewed by MDs for [55/70 (78.6%)] SBTs. Mean MD usefulness score was 4.0/6. Based on feedback obtained from 36 interviews (15 MDs, 21 RTs), we revised the EA report twice and identified facilitators (ability to track patient progress, enhance extubation decision-making, and provide support in resource-limited settings) and barriers (resource constraints, need for education) to tool implementation. Half of respondents (9 MDs, 9 RTs; combined 50%) perceived definite or potential benefit to EA tool use. This is the first study of a waveform-based variability-derived, predictive clinical decision support tool evaluated in adult ICUs. Our findings support the feasibility of integrating the EA tool into bedside workflow. Clinical trials are needed to assess the utility of the EA tool in practice and its impact on extubation decision-making and outcomes. NCT04708509.

Spontaneous breathing trials: how and for how long?

Guidelines recommend systematic performance of a spontaneous breathing trial (SBT) before extubation in ICUs, the objective being to reduce the risk of reintubation. In theory, a more challenging SBT performed with a T-piece may further reduce the risk of reintubation, whereas a less challenging SBT performed with pressure-support ventilation (PSV) may hasten extubation. Recent findings show that a more challenging SBT with a T-piece or for a prolonged duration do not help to reduce the risk of reintubation. In contrast, a less challenging SBT with PSV is easier to pass than a T-piece, and may hasten extubation without increased risk of reintubation. Although SBT with PSV and additional positive end-expiratory pressure is indeed a less challenging SBT, further studies are needed to generalize such an easy trial in daily practice. Earlier screening for a first SBT may also decrease time to extubation without increased risk of reintubation. Lastly, reconnection to the ventilator for a short period after successful SBT facilitates recovery from the SBT-induced alveolar derecruitment. Several recent clinical trials have improved assessment of the most adequate way to perform SBT before extubation.

Echocardiographic Assessment of Central Venous Pressure using Inferior Vena Cava Indices: An Estimate Guide for Right Atrial Pressure

Purpose: To assess the correlation between inferior vena cava echocardiographic indices and central venous pressure, right atrial pressure and thus to practice, assessment of inferior vena cava, as a guide for the status of right side of the heart. Materials and Methods: In this descriptive cross-sectional study, a total of (60) patients (males and females) with their age ranging between (18–80) years were admitted to the respiratory care unit. Echocardiographic assessment of inferior vena cava hemodynamics (IVC expiratory, IVC inspiratory diameters and IVC collapsibility index) were carried out. In addition to the standard echocardiography examination, right heart function measurements (Tricuspid Annular Plane Systolic Excursion and right atrial area), in spontaneously and mechanically ventilated, patients were done. Findings: Both IVCe and IVCi diameters showed strong negative correlation with collapsibility index, (r= -0.920 for IVCe and r= -0.964 for IVCi) (P&lt;0.001). There was a positive correlation between TAPSE and IVC-CI (r=0.857, P&lt;0.001). Moreover, RA area was negatively correlated with collapsibility index (r = -0.892, P &lt;0.001). IVC-CI in mechanically ventilated patients (40.11± 1.782) compared to spontaneous breathing (48.91± 1.811) (P &lt;0.001) Implications to Theory, Practice and Policy: There was a linear relationship of IVC collapsibility index with TAPSE but an inverse relation with RA area. Evaluation of IVC diameter and its collapsibility index was an easy and non-invasive method to estimate CVP and RAP and so evaluate right heart performance of critically ill patients. Its use is more helpful in patients who are spontaneously breathing than those who are mechanically ventilated. The study tried to find an estimate predictor of right atrial pressure.

Combined lung and diaphragm ultrasound predicts extubation outcomes in ARDS: a prospective study

BackgroundExtubation failure is a crucial issue for acute respiratory distress syndrome (ARDS). Ultrasound of the lung and diaphragm is individually valuable for predicting extubation outcomes. We aimed to determine whether combined lung and diaphragmatic ultrasound could improve the accuracy of predicting the extubation of ARDS patients.MethodsThis was a prospective cohort study of ARDS patients who were ready for extubation. The lung ultrasound score (LUS), diaphragmatic displacement (DD), diaphragm thickening fraction (DTF), and diaphragmatic-rapid shallow breathing index (D-RSBI) were measured at the end of the spontaneous breathing trial. The primary outcome was extubation success. Logistic regression was used to combine these indicators, and the predictive performance of the single and combined indicators was evaluated through receiver operating characteristic (ROC) curves, the Hosmer–Lemeshow Ĉ‐test, and the Brier score. Multivariate logistic regression was used to determine the association between combined ultrasound indicators and extubation success.ResultsThis study enrolled 132 eligible patients from January 2019 to December 2022. A total of 71% (94/132) of patients were successfully extubated from mechanical ventilation. The combination of LUS and D-RSBI had the largest area under the ROC curves, the lowest Brier score, and the greatest calibration. After formula transformation, LUS + 2.43 × D-RSBI ≤ 14.273 was significantly associated with extubation success in ARDS patients.ConclusionsIn ARDS patients receiving mechanical ventilation, the combination of LUS and D-RSBI was more accurate than a single parameter alone in predicting extubation outcomes. This combined approach could help refine extubation protocols in critical care.Clinical trial registration This study is registered online with the Chinese Clinical Trial Registry (ChiCTR), http://www.chictr.org.cn, ChiCTR1800019340 (Registration time: 2018/11/06).

Y Reverse: Modified technique in challenging airway management.

Self-expanding Y-metal stents (SEMS) are best suited lesions with involvement of the carina and proximal main bronchi; however, Y-stents can be difficult to place. These difficulties guided us to develop a modification of the classic technique that addresses some of the challenges during positioning. We present the Y reverse technique for Y stent insertion using a combination of rigid and flexible bronchoscopy. This retrospective study included 15 consecutive patients, suffering from tracheal-carina-lower main bronchi complex, hospitalized at the Thoracic Surgery Unit of the Vanvitelli University of Naples between October 2021 and October 2023. patients in which the length of the stenosis of the right bronchi was greater than that of the left bronchi, advanced oncological conditions, severe respiratory failure; exclusion criteria: Karnofsky scale with <40 points. All patients were admitted to the hospital and treated with Y-stent insertion using the modified technique Y reverse. The comparison between the group undergoing the Y reverse technique with the group undergoing the traditional positioning of the Y prosthesis has shown an improvement in respiratory function; prolongation of the mean survival time; improvement in SpO2 in spontaneous breathing; reduction mean time procedure. p < 0.05 was considered as statistically significant. Y Reverse is a safe and effective procedure that provides rapid symptom relief in individuals who have critical central airway obstruction near the distal portion of the trachea, carina, and main right and left bronchi.

Analysis of the positive expiratory pressure valves of coupled oronasal mask

Positive expiratory pressure (PEP) is a technique used in respiratory physiotherapy to treat diseases related to the respiratory system through spontaneous breathing. This equipment consists of an oronasal mask coupled to a T connector with a unidirectional valve. Studies that evaluate whether the pressure level in the one-way valve corresponds to the actual pressure level provided are scarce in the scientific literature. In order to investigate the failures, bench tests were carried out on the spring-loaded valves, using a U-tube manometer. This pressure was exerted on the valve using a syringe that generated air flow inside the U-tube, allowing analysis numerical value of the measured pressure and the specified values of the valve, thus verifying the disparity of these measured values in relation to the PEP values operated by valves (0 to 20 cmH2O) from the three manufacturers under study. PEPs generated by spring-loaded valves from all three manufacturers were higher than pressures in the range of 2.5 to 20 cmH2O, with significant differences between manufacturers. This bench study showed inaccurate operation of all spring-loaded PEP valves of the three manufactures. The results obtained and the performance of the valves require a reevaluation of manufacturing procedures to preserve product quality and efficacy in clinical application.

Assessment of Respiratory Muscles, Lung Parenchyma, and Cardiac Function by Ultrasound for Predicting Weaning Failure in Critically Ill Adults: A Prospective Observational Study.

The parasternal intercostal muscle activity, a marker of accessory muscle usage, is found to correlate inversely with the pressure-generating capacity of the diaphragm and level of support of mechanical ventilation. The primary objective of our study was to determine whether the parasternal intercostal muscle thickening fraction (PMTF) measured by ultrasonography can predict weaning. We also evaluated whether addition of lung ultrasound score and echocardiographic assessment can add on to predicting weaning failure. This prospective observational study conducted in a mixed medical-surgical intensive care unit, included 60 adult patients who were eligible for a spontaneous breathing trial (SBT) after being invasively mechanically ventilated for more than 48 hours. Ultrasound of respiratory muscles, lung parenchyma, and echocardiographic assessment were performed before and after 120 minutes of SBT. Parasternal intercostal muscles were imaged with a high frequency linear probe on the right second intercostal space 5 cm lateral to the sternal margin. PMTF was calculated as (maximum-minimum thickness)/minimum thickness. Among 60 patients, SBT failure was seen in 11 patients and extubation failed in 8 patients. PMTF (%) was significantly higher in the weaning failure group (13.33 [8.33-19.05]) as compared to patients with successful weaning (6.67 [6.06-11.54]). Diaphragmatic thickening fraction (DTF) correlated inversely to PMTF in patients with weaning failure. A pre-SBT PMTF cut-off of ≥7.7% and post-SBT cut-off of ≥15.38% were good predictors of weaning failure and extubation failure, respectively. PMTF has good discriminatory power to predict weaning outcomes (area under the receiver operating characteristic curve: 0.74 [0.59-0.88]). Pre-SBT PMTF had similar power as DTF to predict weaning failure.

Comparing the Effects of Two Surfactant Administration Methods: Minimally Invasive Surfactant Therapy (MIST) with Intubation (INSURE) in Infants with Respiratory Distress Syndrome.

The aim of this study is to investigate and compare the effects of administering a surfactant through a fine intra-tracheal catheter during spontaneous breathing with the usual INSURE method in premature infants. In this clinical trial, premature babies with respiratory distress syndrome who required surfactant administration were randomly assigned to two groups: an intervention group (MIST) and a control group (INSURE). The treatment results were compared in terms of complications related to treatment (desaturation, apnea, bradycardia, and surfactant reflux), respiratory complications (requirement for mechanical ventilation, duration of nCPAP, duration of oxygen requirement, frequency of pneumothorax, and pulmonary hemorrhage), complications related to prematurity (incidence of IVH, NEC, BPD, and PDA), the need for a second dose of surfactant, and the duration of hospitalization. a total of 160 premature babies with a gestational age of 26-34 weeks were randomly divided into two groups. The results showed that the need for mechanical ventilation, the duration of CPAP needed, and the duration of oxygen therapy were significantly lower in the MIST group than in the INSURE group. Additionally, the incidence of BPD was less common in the MIST group compared to the INSURE group. However, surfactant reflux was more common in the MIST group than in the INSURE group. There were no significant differences between the two groups in other outcomes, including the length of hospital stay and complications such as IVH, PDA, NEC, pneumothorax, and pulmonary hemorrhage. The results of this research demonstrate that the less invasive method of surfactant therapy (MIST) is a feasible, effective, and low-risk alternative to the INSURE method.

Predictive Value of Diaphragm and Lung Ultrasonography for Weaning Failure in Critically Ill Patients with Acute Respiratory Failure Due to COVID-19 Pneumonia.

This study analyzed weaning characteristics and assessed the association of clinical and ultrasonographic indices-maximum inspiratory pressure (MIP), rapid shallow breathing index (RSBI), peak flow expiratory (PFE), diaphragm-thickening fraction (DTF), diaphragm thickness (DT), diaphragm excursion (DE), diaphragm-RSBI (D-RSBI), and lung ultrasound (LUS) patterns-with weaning failure. This retrospective cohort study included critically ill COVID-19 patients aged 18 and older who had been on invasive mechanical ventilation for at least 48 h and undergoing weaning. Exclusion criteria included absence of ultrasound assessments, neuromuscular diseases, and chronic cardio-respiratory dysfunction. Among 61 patients, 44.3% experienced weaning failure, 27.9% failed the spontaneous breathing trial (SBT), 16.4% were re-intubated within 48 h, and 28% required tracheostomy. Weaning failure was associated with prolonged ventilation (29 vs. 7 days, p < 0.001), extended oxygen therapy, longer ICU stays, and higher ICU mortality. These patients had higher pressure support, lower oxygenation levels, a higher RSBI, and a lower MIP. While PEF, DTF, DE, and D-RSBI showed no significant differences, both right and left diaphragm thicknesses and the inspiratory thickness of the left diaphragm were reduced in failure cases. LUS scores were significantly higher before and after SBT in the failure group. Bivariate analysis identified RSBI [OR = 1.04 (95% CI = 1.01-1.07), p = 0.010], MIP [OR = 0.92 (95% CI = 0.86-0.99), p = 0.018], and LUS [OR = 1.15 (95% CI = 0.98-1.35), p = 0.025] as predictors of weaning failure; however, these associations were not confirmed in multivariate analysis. Ultrasound provides supplementary information during weaning, but no definitive association between ultrasound indices and weaning failure was confirmed in this study.

Frequency of Screening and Spontaneous Breathing Trial Techniques

The optimal screening frequency and spontaneous breathing trial (SBT) technique to liberate adults from ventilators are unknown. To compare the effects of screening frequency (once-daily screening vs more frequent screening) and SBT technique (pressure-supported SBT with a pressure support level that was >0-≤8 cm H2O and a positive end-expiratory pressure [PEEP] level that was >0-≤5 cm H2O vs T-piece SBT) on the time to successful extubation. Randomized clinical trial with a 2 × 2 factorial design including critically ill adults who were receiving invasive mechanical ventilation for at least 24 hours, who were capable of initiating spontaneous breaths or triggering ventilators, and who were receiving a fractional concentration of inspired oxygen that was 70% or less and a PEEP level of 12 cm H2O or less. Recruitment was between January 2018 and February 2022 at 23 intensive care units in North America; last follow-up occurred October 18, 2022. Participants were enrolled early to enable protocolized screening (more frequent vs once daily) to identify the earliest that patients met criteria to undergo pressure-supported or T-piece SBT lasting 30 to 120 minutes. Time to successful extubation (time when unsupported, spontaneous breathing began and was sustained for ≥48 hours after extubation). Of 797 patients (198 in the once-daily screening and pressure-supported SBT group, 204 in once-daily screening and T-piece SBT, 195 in more frequent screening and pressure-supported SBT, and 200 in more frequent screening and T-piece SBT), the mean age was 62.4 (SD, 18.4) years and 472 (59.2%) were men. There were no statistically significant differences by screening frequency (hazard ratio [HR], 0.88 [95% CI, 0.76-1.03]; P = .12) or by SBT technique (HR, 1.06 [95% CI, 0.91-1.23]; P = .45). The median time to successful extubation was 2.0 days (95% CI, 1.7-2.7) for once-daily screening and pressure-supported SBT, 3.1 days (95% CI, 2.7-4.8) for once-daily screening and T-piece SBT, 3.9 days (95% CI, 2.9-4.7) for more frequent screening and pressure-supported SBT, and 2.9 days (95% CI, 2.0-3.1) for more frequent screening and T-piece SBT. An unexpected interaction between screening frequency and SBT technique required pairwise contrasts that revealed more frequent screening (vs once-daily screening) and pressure-supported SBT increased the time to successful extubation (HR, 0.70 [95% CI, 0.50-0.96]; P = .02). Once-daily screening and pressure-supported SBT (vs T-piece SBT) did not reduce the time to successful extubation (HR, 1.30 [95% CI, 0.98-1.70]; P = .08). Among critically ill adults who received invasive mechanical ventilation for more than 24 hours, screening frequency (once-daily vs more frequent screening) and SBT technique (pressure-supported vs T-piece SBT) did not change the time to successful extubation. However, an unexpected and statistically significant interaction was identified; protocolized more frequent screening combined with pressure-supported SBTs increased the time to first successful extubation. ClinicalTrials.gov Identifiers: NCT02399267 and NCT02969226.

Алгоритм количественной оценки кардиореспираторной синхронизации для характеристики функционального состояния и межсистемных взаимодействий у спортсменов

Introduction. The rhythm of the heart (heart rate, HR) is closely related to the rhythm of breathing. The phenomenon of respiratory sinus arrhythmia (an increase in heart rate during inhalation and a decrease during exhalation) is well known. Cardiorespiratory interactions and synchronization of these two signals are evaluated differently in the literature. The purpose of this work was to propose and test an approach to assess cardiorespiratory synchronization – the calculation of the cross-correlation coefficient between heart rate and respiration curve, for a more objective characterization of an athlete’s bodily states. Methods. A photoplethysmogram and respiration were recorded in 45 healthy athletes (18-25 years old) in three situations: rest, paced breathing at 6 times per minute (resonant frequency) and the performance of a sensorimotor task (tapping with the rhythmic metronome sounds and then reproducing a given rhythm from memory). For the HR and respiration curves, filtering and smoothing algorithms using the Savitsky-Goley method were applied sequentially, and then the cross-correlation coefficient between the two curves was calculated. The spectral parameters of heart rate variability (LF and HF) were also obtained, since during spontaneous breathing its contribution to the HR is reflected in HF band, and when breathing at a resonant frequency, a peak occurs at a frequency of 0.1 Hz in the LF band. Results. The cross-correlation coefficient, as well as the peak of HR spectral power at 0.1 Hz, increases significantly when breathing at a resonant frequency. The relationship between these indicators is most accurately described not by a linear, but by a logarithmic dependence. When performing a sensorimotor task, the so-called respiratory waves in the heart rhythm spectrum (HF) do not change from rest to tapping by a metronome and then to holding the rhythm by memory. At the same time, the cross-correlation coefficient demonstrates significant changes between these situations. In addition, a significant correlation was found between the change in the cross-correlation coefficient and the stability of rhythm maintenance (from memory): an increase in the cardiorespiratory synchronization leads to a decrease in motor rhythm stability. Conclusion. Assessment of cardiorespiratory synchronization due to the peculiarities of both signals (changes in heart rate and respiratory phases) requires preliminary preparation of data arrays: filtering and smoothing the stepped curve of heart rate dynamics. The calculation of the cross-correlation coefficient can be used to assess cardiorespiratory synchronization in real time and is likely to be applicable in short time fragments to assess emotional reactions and other short-term fluctuations in psychophysiological conditions, where the classical method of assessing changes in heart rhythm in the frequency or time domains is not applicable.

Successful emergency management of hemorrhagic shock due to carotid artery aneurysm: the role of awake intubation in difficult airway control

We describe the clinical scenario, analyze the decision-making process in airway management, and application of the Difficult Airway Society (DAS) guidelines for awake tracheal intubation (ATI) in a patient involving life-threatening bleeding from an internal carotid artery aneurysm caused by a fistula following radiotherapy for tongue cancer at Hong Ngoc Phuc Truong Minh General Hospital, on March, 2024. A 53-year-old male, diagnosed with tongue cancer, underwent surgery. Days before admission, he experienced pain and bleeding from the right lateral neck due to an internal carotid artery aneurysm. An attempt at tracheal intubation for endovascular intervention at another hospital failed. Upon arrival at our emergency department, he exhibited massive neck hemorrhage, remained conscious, pale, with ongoing bleeding from a right neck fistula, and limited cervical motion due to irritation. A treatment strategy for permanent occlusion of the aneurysm was devised. Awake tracheal intubation using a fiberoptic scope via the nasal route was performed. The patient received light sedation with midazolam, and the airway was topicalized with 10% lidocaine spray over the mouth, tongue, and oropharyngeal mucosa. Continuous monitoring of heart rate, ECG, and oxygen saturation showed no decrease in oxygen levels, and the patient maintained spontaneous breathing throughout. Intensive treatment with crystalloid fluids and blood transfusion, along with right internal carotid embolization with a spring coil, effectively prevented massive hemorrhage. The patient was successfully extubated after three days in the ICU and discharged 15 days post-surgery without any neurological deficits. Keywords: Awake Tracheal Intubation; Difficult Airway Management; Fiberoptic Scope; Emergency Airway Management Citation: Ba NTT. Successful emergency management of hemorrhagic shock due to carotid artery aneurysm: the role of awake intubation in difficult airway control. Anaesth. pain intensive care 2024;28(5):955−959. DOI: 10.35975/apic.v28i5.2572 Received: January 03, 2024; Reviewed: May 05, 2024; Accepted: June 11, 2024

Family-Led Coaching of Patients During Weaning From Sedation and Mechanical Ventilation in the ICU.

ICU patients are weaned from sedation and mechanical ventilation through spontaneous awakening trials (SATs) and spontaneous breathing trials (SBTs). Weaning can be distressing for patients and their families. Family-led coaching could reassure patients and reduce stress for families by engaging them in patient care. This study developed and piloted a family-led coaching tool to support patients undergoing SATs/SBTs. Patient and family member dyads were recruited from 2 medical-surgical ICUs in Calgary, Canada (February 3-August 1, 2023). Surveys were administered to collect family (1) demographics, (2) anxiety and satisfaction with ICU care, (3) feedback on the tool, and (4) attitudes about family presence during SATs/SBTs (also collected from clinicians). Tool feasibility was determined by calculating the proportions of (1) eligible patients who were recommended for participation in the study by clinicians and (2) families approached who consented to participate in the study. One thousand one hundred fifty patients were admitted to the study ICUs during the study period of which 819 received mechanical ventilation, and 42 were recommended by bedside clinicians for participation in the study. Twenty-five dyads were approached, 21 dyads consented to participate, and one withdrew consent before data collection. Of the enrolled families, 12 (60%) reported the coaching tool to be useful, and 5 (25%) recommended minor suggestions such as "shortening" the tool. Fourteen (70%) families reported positive experiences (through open-ended feedback) with being present for the SAT/SBT. State-Trait Anxiety Inventory (Y1) scores (scale range 20-80 points) significantly decreased in families from the first (pre coaching) to the second (post coaching) measures (mean decrease 8.2 points, SD 10.3, P = .001). All clinicians indicated they were comfortable with family presence and/or coaching during SATs/SBTs. Family-led coaching of patients during SATs/SBTs appears to be feasible, favorably perceived by families and clinicians, and potentially associated with lower family anxiety.