Hours Of Mechanical Ventilation Research Articles

Postoperative morbidity and mortality of patients with COVID-19 undergoing cardiovascular surgery: an inverse propensity-weighted study

BackgroundTo evaluate the postoperative morbidity and mortality of patients undergoing cardiovascular surgery during the 2022 nationwide Omicron variant infection wave in China.MethodsThis retrospective cohort study included 403 patients who underwent cardiovascular surgery for the first time during the 2022 wave of the pandemic within 1 month. Among them, 328 patients were preoperatively diagnosed with COVID-19 Omicron variant infection during the pandemic, and 75 patients were negative. The association between Omicron variant exposure and postoperative prognosis was explored by comparing patients with and without COVID-19 exposure. The primary outcome was in-hospital death after cardiovascular surgery. The secondary outcomes were major postoperative morbidity, including myocardial infarction (MI), acute kidney injury (AKI), postoperative mechanical ventilation hours, ICU stay hours, and postoperative length of stay. The data were analyzed using inverse probability of treatment weighting (IPTW) to minimize bias.ResultsWe identified 403 patients who underwent cardiovascular surgery, 328 (81.39%) had Omicron variant infections. In total, 10 patients died in the hospital. Omicron variant infection was associated with a much greater risk of death during cardiovascular surgery after adjustment for IPTW (2.8% vs. 1.3%, adjusted OR 2.185, 95%CI = 1.193 to 10.251, P = 0.041). For major postoperative morbidity, there were no significant differences in terms of myocardial infarction between the two groups (adjusted OR = 0.861, 95%CI = 0.444 to 1.657, P = 0.653), acute kidney injury (adjusted OR = 1.157, 95%CI = 0.287 to 5.155, P = 0.820), postoperative mechanical ventilation hours (B -0.375, 95%CI=-8.438 to 7.808, P = 0.939), ICU stay hours (B 2.452, 95%CI=-13.269 to 8.419, P = 0.660) or postoperative stay (B -1.118, 95%CI=-2.237 to 1.154, P = 0.259) between the two groups.ConclusionPerioperative COVID-19 infection was associated with an increased risk of in-hospital death among patients who underwent cardiovascular surgery during the Omicron variant wave of the pandemic.

Electroacupuncture alleviates ventilator-induced lung injury in mice by inhibiting the TLR4/NF-κB signaling pathway

ObjectiveThis study was aimed to explore the protective effect of electroacupuncture (EA) pretreatment at Zusanli point (ST36) on ventilation-induced lung injury (VILI) and its potential anti-inflammatory mechanism.MethodsHigh tidal volume ventilation was used to induce the VILI in mice, and EA pretreatment at ST36 was given for 7 consecutive days. The wet/dry ratio and pathological injury score of lung tissue, and total protein content of pulmonary alveolar lavage fluid (BALF) were detected after 4 h of mechanical ventilation (MV). Meanwhile, the expressions of TLR4 and NF- κB in lung tissue were evaluated by Western Blot, and the inflammatory factors in lung tissue were detected by ELISA.ResultsAfter four hours of mechanical ventilation, mice with ventilator-induced lung injury showed significant increases in lung wet/dry ratio, tissue damage scores, and protein content in bronchoalveolar lavage fluid. Pro-inflammatory cytokines (IL-6, IL-1β, TNF-α) and TLR4/NF-κB expression levels in the lung were also markedly elevated (P < 0.05). Conversely, ST36 acupuncture point pre-treatment significantly reduced these parameters (P < 0.05).ConclusionEA pretreatment at ST36 could alleviate the inflammatory response for VILI via inhibiting TLR4/NF- κB pathway.

Improvement Gaps to Deal with the Shortage of Lungs for Transplant From a Middle Income Country's Perspective.

Our study aimed to identify the potential causes for the low lung procurement rate in Argentina and to develop strategies to the actual problems in donor management focused on lung retrieval. We performed a crosssectional study in which we analyzed data obtained from digital self-reported surveys conducted on professionals participating in the organ procurement process in Argentina. The surveys included questions on donor management, selection criteria, and resource availability involving increasing lung procurement. Among professionals surveyed, 23.7% did not use advanced hemodynamic monitoring in their donor maintenance and limited their use to central venous pressure. Only 35.8% of participants considered maintaining central venous pressure <10 mm Hg during donor maintenance. With regard to donors with severe deterioration of the ejection fraction, 47.4% of participants would not use restrictive fluid, and only 23.2% would use an advanced monitoring of the hemodynamic status to guide fluid management. Only 27.8% of participants routinely would use steroids to improve lung function in donors. With regard to mechanical ventilation, 80.4% of participants used protective ventilation, but only 4.10% used it adequately. Recruitment maneuvers were routinely used by only 3.1% of those surveyed. With regard to expanded selection criteria (age >55 years, smoking habit of >20 packs/year, positive upper airway cultures, unspecific infiltrates in radiography, and >72 hours of mechanical ventilation), 92.8% of surveyed participants would discount patients with some of these expanded selection criteria without considering offering the lungs for donation. Opportunities for improvement may involve training physicians involved in the donor maintenance process and reviewing the donor selection criteria used to increase adherence to expanded selection criteria.

Associations of Race With Sedation Depth Among Mechanically Ventilated Adults: A Retrospective Cohort Study.

To evaluate the association of race with proportion of time in deep sedation among mechanically ventilated adults. Retrospective cohort study from October 2017 to December 2019. Five hospitals within a single health system. Adult patients who identified race as Black or White who were mechanically ventilated for greater than or equal to 24 hours in one of 12 medical, surgical, cardiovascular, cardiothoracic, or mixed ICUs. None. The exposure was White compared with Black race. The primary outcome was the proportion of time in deep sedation during the first 48 hours of mechanical ventilation, defined as Richmond Agitation-Sedation Scale values of -3 to -5. For the primary analysis, we performed mixed-effects linear regression models including ICU as a random effect, and adjusting for age, sex, English as preferred language, body mass index, Elixhauser comorbidity index, Laboratory-based Acute Physiology Score, Version 2, ICU admission source, admission for a major surgical procedure, and the presence of septic shock. Of the 3337 included patients, 1242 (37%) identified as Black, 1367 (41%) were female, and 1002 (30%) were admitted to a medical ICU. Black patients spent 48% of the first 48 hours of mechanical ventilation in deep sedation, compared with 43% among White patients in unadjusted analysis. After risk adjustment, Black race was significantly associated with more time in early deep sedation (mean difference, 5%; 95% CI, 2-7%; p < 0.01). There are disparities in sedation during the first 48 hours of mechanical ventilation between Black and White patients across a diverse set of ICUs. Future work is needed to determine the clinical significance of these findings, given the known poorer outcomes for patients who experience early deep sedation.

Preoperative Imaging Signs of Cerebral Malperfusion in Acute Type A Aortic Dissection: Influence on Outcomes and Prognostic Implications-A 20-Year Experience.

Acute type A aortic dissection (ATAAD) continues to be a subject of active research due to its high mortality rates and associated complications. Cerebral malperfusion in ATAAD can have a devastating impact on patients' neurological function and overall quality of life. We aimed to explore the risk profile and prognosis in ATAAD patients presenting with preoperative imaging signs of cerebral malperfusion (PSCM). We obtained patient data from our Aortic Dissection Registry, which included 480 consecutive ATAAD cases who underwent surgical repair between 2001 and 2021. Primary endpoint outcomes included the in-hospital and 30-day mortality, postoperative new neurological deficit, mechanical ventilation hours, and intensive care unit (ICU) length of stay. Of the total cohort, 82 patients (17.1%) had PSCM. Both groups had similar distributions in terms of age, sex, and body mass index. The patients in the PSCM group presented with a higher logistic EuroSCORE (47, IQR [31, 64] vs. 24, IQR [15, 39]; p < 0.001) and a higher portion of patients with a previous cardiac surgery (7.3% vs. 2.0%; p = 0.020). Intraoperatively, the bypass, cardioplegia, and aortic cross-clamp times were similar between both groups. However, the patients in the PSCM group received significantly more intraoperative packed red blood cells, fresh frozen plasma, and platelets transfusions (p < 0.05). Following the surgery, the patients who presented with PSCM had markedly longer ventilation hours (108.5 h, IQR [44, 277] vs. 43 h, IQR [16, 158], p < 0.001) and a significantly longer ICU length of stay (7 days, IQR [4, 13] vs. 5 days, IQR [2, 11]; p = 0.013). Additionally, the patients with PSCM had significantly higher rates of postoperative new neurological deficits (35.4% vs. 19.4%; p = 0.002). In the Cox regression analysis, PSCM was associated with significantly poorer long-term survival (hazard ratio (HR) 1.75, 95%CI [1.20-2.53], p = 0.003). Surprisingly, hypertension was shown as a protective factor against long-term mortality (HR: 0.59, 95%CI [0.43-0.82], p = 0.001). PSCM in ATAAD patients is linked to worse postoperative outcomes and poorer long-term survival, emphasizing the need for early recognition and tailored management.

Concomitant CABG vs. CABG Alone - A Comparative Analysis of Early Outcomes

Concomitant CABG is performed in combination with other cardiac procedures (VHD, CHD) while CABG is performed exclusively for CAD. Objective: To compare the mortality and perioperative outcomes between CABG and concomitant CABG for proper quoting of risk &amp; optimizing the treatment decision for improved patient outcomes. Methods: The observational study on retrospective data was conducted at Rehman Medical Institute from December 2020 to December 2022. A total of 169 patients were included, with 89 in the CABG and 80 in the concomitant CABG group. Ethical approval was granted and inclusion criteria were met. Data were analyzed using SPSS 25. Results: A total of 169 patients were included with a mean age of 57.72±10.65 &amp; the majority of the male population (77.5%). Most of the patients had NYHA III (56.1%) &amp; CCS III (43.9%) class symptoms. Hypertension was our most common co-morbidity (58.0%), followed by dyslipidemia (52.3%) &amp; DM (47.3%). Concomitant CABG has the worst parameters in terms of intraoperative characteristics such as a statistically significant higher rate of intraoperative transfusion (p &lt;0.001), prolonged perfusion (p &lt;0.001) &amp; cross-clamp time (p&lt;0.001). Similarly, concomitant CABG patients have the worst postoperative outcomes with a significantly higher incidence of mortality (p &lt;0.001), post-operative transfusion requirement (p 0.008), increased duration of mechanical ventilation hours (p 0.005), extended hours of ICU stay (p 0.02) &amp; higher rates of re-intubation (p 0.03). Conclusions: Concomitant CABG is no doubt a high-risk procedure as signified by its worst outcomes.

Minimally invasive coronary artery bypass (MICS CABG) in Bosnia and Herzegovina: a single centre, single surgeon cohort experience.

Aim This is the first research in Bosnia and Herzegovina presenting minimally invasive coronary artery bypass grafting surgery (MICS CABG) experience, advantages, and outcomes as compared to conventional surgery (OPEN CABG). Methods This retrospective cross-sectional study was conducted between January 2019 and November 2022 and included patients with indication for surgical revascularization. Results Among 237 patients, males predominated, 182 (76.7%), with a mean body mass index (BMI) of 28.4±3.9, median The Society of Thoracic Surgery Risk (STS) score of 1.55 (0.8, 4.0), short term STS score of 11.2 (6.8, 23.7), mean age of 64.8±8.7 (ranging 41-83) years, 122 (51.4%) underwent OPEN CABG and 115 (48.6%) MICS CABG. MICS CABG took less time (p<0.001; OPEN 3.5±0.8h; MICS 2.8±0.8h) and needed less mechanical ventilation (p<0.001, OPEN 17.3±11.9h; MICS 13.0±12.5h) than OPEN CABG. Even though there was no difference in hospitalization length between groups (OPEN (7.5±3.2), MICS (7.1±4.0)), patients receiving MICS (2.9±1.5) spent less time in the ICU (p=0.0013) than OPEN CABG (3.6±2.8). OPEN CABG used also more blood derivatives, red blood cells (OPEN 292 vs MICS 55), plasma (OPEN 270 vs MICS 86) and platelets (OPEN 71 vs MICS 28). Conclusion Patients undergoing MICS CABG in Bosnia and Herzegovina had less mechanical ventilation hours and less ICU duration compared to OPEN CABG even though the hospitalization duration was very similar. MICS CABG takes less time to be conducted, has fewer CPRs postoperatively, uses less blood derivatives including red blood cells, plasma and platelets.

Longitudinal Associations Among Symptoms of Family Intensive Care Unit Syndrome.

Family intensive care unit (ICU) syndrome, a comorbid response to another person's stay in the ICU, is characterized by emotional distress, poor sleep health, and decision fatigue. This pilot study examined associations among symptoms of emotional distress (anxiety and depression), poor sleep health (sleep disturbance), and decision fatigue in a sample of family members of patients in the ICU. The study used a repeated-measures, correlational design. Participants were 32 surrogate decision makers of cognitively impaired adults who had at least 72 consecutive hours of mechanical ventilation within the neurological, cardiothoracic, and medical ICUs at an academic medical center in northeast Ohio. Surrogate decision makers with a diagnosis of hypersomnia, insomnia, central sleep apnea, obstructive sleep apnea, or narcolepsy were excluded. Severity of symptoms of family ICU syndrome was measured at 3 time points in 1 week. Zero-order Spearman correlations of the study variables were interpreted at baseline and partial Spearman correlations of study variables were interpreted 3 days and 7 days after baseline. The study variables showed moderate to large associations at baseline. Baseline anxiety and depression were associated with each other and with decision fatigue at day 3. Baseline sleep disturbance was associated with anxiety, depression, and decision fatigue at day 7. Understanding the temporal dynamics and mechanisms of the symptoms of family ICU syndrome can inform clinical, research, and policy initiatives that enhance the provision of family-centered critical care.

Effects of lung recruitment maneuvers using mechanical ventilator on preterm hemodynamics

Background Lung recruitment maneuvers (LRMs) are a strategy to gradually increase mean positive airway pressure (MAP) to expand the alveoli, leading to decreased pulmonary vascular resistance and increased cardiac output (CO). However, the hemodynamic impact of LRM using assist control volume guarantee (AC-VG) ventilator mode done in preterm infants born at 24 to 32 weeks’ gestation, especially in the first 72 hours of life, remains unknown.&#x0D; Objective To determine the effect of LRM on right- and left cardiac ventricular output (RVO and LVO), ductus arteriosus (DA) diameter and its pulmonary hypertension (PH) flow pattern, as well as superior mesenteric artery (SMA) flow.&#x0D; Method This randomized, controlled, single-blinded clinical trial was performed in 24-32-week preterm neonates with birth weights of &gt;600 grams. Subjects were allocated by block randomization to the LRM and control groups, each containing 55 subjects. We measured RVO, LVO, DA diameter, PH flow pattern, and SMA resistive index (RI) at 1 and 72 hours after mechanical ventilation was applied. We analyzed for hemodynamic differences between the two groups.&#x0D; Results During the initial 72 hours of mechanical ventilation, there were no significant differences between the control vs. LRM groups in mean changes of LVO [41.40 (SD 91.21) vs. 15.65 (SD 82.39) mL/kg/min, respectively; (P=0.138)] or mean changes of RVO [65.56 (SD 151.20) vs. 70.59 (SD 133.95) mL/kg/min, respectively; (P=0.859)]. Median DA diameter reduction was -0.08 [interquartile range (IQR) -0.55; 0.14] mm in the control group and -0.10 (IQR -0.17 to -0.01) mm in the LRM group (P=0.481). Median SMA resistive index was 0.02 (IQR -0.16 to 0.24) vs. 0.01(IQR -0.20 to 0.10) in the control vs. LRM group, respectively. There was no difference in proportion of pulmonary hypertension flow pattern at 72 hours (25.4% vs. 20% in the control vs. LRM group, respectively) (P=0.495).&#x0D; Conclusion When preterm infants of 24-32 weeks gestational age are placed on mechanical ventilation, LRM gives neither additional hemodynamic benefit nor harm compared to standard ventilator settings.

Hypophosphataemia definitions, incidence and associated outcomes in paediatric intensive care: A retrospective cohort study in post-cardiac surgical patients

Hypophosphataemia has been linked to higher morbidity and mortality in intensive care but there is inconsistency in the definition of hypophosphataemia for infants and children. We aimed to determine the incidence of hypophosphataemia in a group of at-risk children in paediatric intensive care unit (PICU) and associations with patient characteristics and clinical outcomes using three different hypophosphataemia thresholds. Retrospective cohort study of 205 post-cardiac surgical patients <2 years of age admitted to Starship Child Health PICU, Auckland, New Zealand. Patient demographics and routine daily biochemistry for 14 days after PICU admission were collected. Rates of sepsis, mortality and length of mechanical ventilation were compared between groups with different serum phosphate concentrations. Out of 205 children, 6 (3%), 50 (24%) and 159 (78%) had hypophosphataemia at thresholds of <0.7, <1.0 and <1.4 mmol/L, respectively. There were no differences in gestational age at birth, sex, ethnicity or mortality in those with and without hypophosphataemia at any threshold. Children with a serum phosphate <1.4 mmol/L had more mean (SD) total hours of mechanical ventilation (85.2 (79.6) vs. 54.9 (36.2) h, P = 0.02) and those with mean serum phosphate <1.0 mmol/L had more mean hours of mechanical ventilation (119.4 (102.8) vs. 65.2 (54.8) h, P < 0.0001), episodes of sepsis (14% vs. 5%, P = 0.03) and longer length of stay (6.4 (4.8-20.7) vs. 4.9 (3.9-6.8) days, P = 0.02). Hypophosphataemia is common in this PICU cohort and serum phosphate <1.0 mmol/L is associated with increased morbidity and length of stay.

Early- vs Late-onset Ventilator-associated Pneumonia in Critically Ill Adults: Comparison of Risk Factors, Outcome, and Microbial Profile.

Ventilator-associated pneumonia (VAP) is one of the most frequent hospital-acquired infections, which develops in mechanically ventilated patients after 48 hours of mechanical ventilation. The purpose of this study was to determine the incidence rate, various risk factors, microbiological profile, and outcome of early- vs late-onset ventilator-associated pneumonia (VAP) in medical intensive care unit (MICU). This prospective study was conducted on 273 patients admitted to the MICU in JIPMER, Puducherry, from October 2018 to September 2019. The incidence of VAP was 39.59 per 1000 ventilation days of MICU patients (93/273). Of these, 53 (56.9%) patients had early-onset VAP and 40 (43.1%) had late-onset VAP. Multiple logistic regression analysis showed that steroid therapy, supine head position, coma or impaired unconsciousness, tracheostomy, and re-intubation were found to be independent predictors of early- and late-onset VAP, respectively. Most cases of VAP were caused by Gram-negative bacteria (90.6%), with nonfermenters contributing to 61.8%. The most frequent pathogens causing early-onset VAP were Acinetobacter baumannii (28.9%) and Pseudomonas aeruginosa (20.6%), while in late-onset VAP, A. baumannii (32.9%) and Klebsiella pneumoniae (21.9%) were the most common. Maximum death rate was seen in patients infected with Escherichia coli (50%) and Stenotrophomonas maltophilia (38.5%). There was no significant association between the presence of VAP and mortality among the studied population. The incidence of VAP in our study was high. There were no significant differences in the prevalence of pathogens associated with early-onset or late-onset VAP. Our study shows that early-onset and late-onset VAP have different risk factors, highlighting the need for developing different preventive and therapeutic strategies. Gunalan A, Sastry AS, Ramanathan V, Sistla S. Early- vs Late-onset Ventilator-associated Pneumonia in Critically Ill Adults: Comparison of Risk Factors, Outcome, and Microbial Profile. Indian J Crit Care Med 2023;27(6):411-415.

502 The Most Common Pathogens Isolated From Mechanically Ventilated Burn Patients With and Without Inhalation Injury

Abstract Introduction The lung microbiota of patients with inhalation injury (INHI) may be distinct from those who do not have INHI. Furthermore, the lung trauma from mechanical ventilation or INHI can increase the risk of ventilator-associated pneumonia (VAP), a leading cause of death in hospital acquired infections. The purpose of this study was to identify the main pathogens isolated from mechanically ventilated patients, with and without INHI, including those that develop VAP to test the hypothesis that INHI itself influences the bacterial present in airways. Methods Data was collected via a single institution retrospective review using the Burn Registry and adjacent health records from 1/1/2019 to 12/31/2021. VAP was defined as a hospital-acquired pneumonia that developed ≥ 48 hours of mechanical ventilation and positive culture was growth of any microorganism. Data were examined for the 3 most common pathogens cultured from respiratory samples obtained via bronchoalveolar lavage (BAL), mini-BAL, or sputum induction. Results The 3 most common pathogens cultured from respiratory samples are presented as the percentage of the cohort in which each pathogen was identified. In all mechanically ventilated patients (n=213), Staphylococcus aureus (15.9%), Pseudomonas aeruginosa (9.9%), and Diphtheroid (9.9%) were most commonly isolated. In all patients with INHI (n=78), S. aureus (21.3%), Diphtheroid (13.3%), and gamma hemolytic Streptococcus (10.7%) were the most common. In all patients with no INHI (n=135), S. aureus (14.1%), P. aeruginosa (10.9%) and Diphtheroid (7.0%) were the most common. In those with INHI and with VAP (n=3), S. aureus (100%) was present in addition to P. aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, and Klebsiella aerogenes which were each in 33% of patients. In those with INHI and without VAP (n=75), S. aureus (17.3%), Diphtheroid (13.3%), and gamma hemolytic Strep. (10.7%) were the most cultured. P. aeruginosa was in 8% of patients. In those with no INHI and with VAP (n=7), the most common bacteria were S. aureus (57.1%) followed by Enterobacter cloacae, P. aeruginosa, gamma hemolytic Strep., Diphtheroid, E. coli, A. baumanii, and S. pneumoniae which were each in 28.6% of patients. In those with no INHI and no VAP (n=128), S. aureus (10.9%), P. aeruginosa (9.4%) were found and alpha hemolytic Strep., Diphtheroid, K. pneumoniae and coagulase negative Staph. were each in 7% of patients. Conclusions All VAP patients had polymicrobial infections. Differences in the most common pathogens of ventilated patients with INHI versus those without INHI were seen. P. aeruginosa was not one of the top 3 pathogens in patients with INHI and MRSA was not one of the top 3 pathogens for either group. Follow up studies with a larger VAP sample size are needed to evaluate whether these trends are significant and generalizable. Applicability of Research to Practice Understanding the microbiology of patients with and without INHI can guide targeted antibiotic treatment.

Validation and Extension of the Association Between Potentially Excess Oxygen Exposure and Death in Mechanically Ventilated Children.

"Cumulative excess oxygen exposure" (CEOE)-previously defined as the mean hourly administered Fio2 above 0.21 when the corresponding hourly Spo2 was 95% or above-was previously shown to be associated with mortality. The objective of this study was to examine the relationship among Fio2, Spo2, and mortality in an independent cohort of mechanically ventilated children. Retrospective cross-sectional study. Quaternary-care PICU. All patients admitted to the PICU between 2012 and 2021 and mechanically ventilated via endotracheal tube for at least 24 hours. None. Among 3,354 patients, 260 (8%) died. Higher CEOE quartile was associated with increased mortality (p = 0.001). The highest CEOE quartile had an 87% increased risk of mortality (95% CI, 7-236) compared with the first CEOE quartile. The hazard ratio for extended CEOE exposure, which included mechanical ventilation data from throughout the patients' mechanical ventilation time rather than only from the first 24 hours of mechanical ventilation, was 1.03 (95% CI, 1.02-1.03). Potentially excess oxygen exposure in patients whose oxygen saturation was at least 95% was associated with increased mortality.

Treatment with levosimendan in an experimental model of early ventilator-induced diaphragmatic dysfunction.

Mechanical ventilation (MV) is a life-saving approach in critically ill patients. However, it may affect the diaphragmatic structure and function, beyond the lungs. Levosimendan is a calcium sensitizer widely used in clinics to improve cardiac contractility in acute heart failure patients. In vitro studies have demonstrated that levosimendan increased force-generating capacity of the diaphragm in chronic obstructive pulmonary disease patients. Thus the aim of this study was to evaluate the effects of levosimendan administration in an animal model of ventilator-induced diaphragmatic dysfunction (VIDD) on muscle contraction and diaphragm muscle cell viability. Sprague-Dawley rats underwent prolonged MV (5 hours). VIDD+Levo group received a starting bolus of levosimendan immediately after intratracheal intubation and then an intravenous infusion of levosimendan throughout the study. Diaphragms were collected for ex vivo contractility measurement (with electric stimulation), histological analysis and Western blot analysis. Healthy rats were used as the control. Levosimendan treatment maintained an adequate mean arterial pressure during the entire experimental protocol, preserved levels of autophagy-related proteins (LC3BI and LC3BII) and the muscular cell diameter demonstrated by histological analysis. Levosimendan did not affect the diaphragmatic contraction or the levels of proteins involved in the protein degradation (atrogin). Our data suggest that levosimendan preserves muscular cell structure (cross-sectional area) and muscle autophagy after 5 hours of MV in a rat model of VIDD. However, levosimendan did not improve diaphragm contractile efficiency.

Effect of ventilator-induced lung injury on blood-brain barrier permeability in rats

To observe the effect of ventilator-induced lung injury (VILI) on blood-brain barrier permeability in rats. Forty-eight healthy clean male Sprague-Dawley (SD) rats were randomly divided into sham operation (Sham) group, low tidal volume (LVT) mechanical ventilation group (LVT group), normal tidal volume (NVT) mechanical ventilation group (NVT group) and high tidal volume (HVT) mechanical ventilation group (HVT group) with 12 rats in each group. After anesthesia, rats in the Sham group were intubated and kept spontaneous breathing. The rats in different tidal volume (VT) groups were mechanically ventilated by endotracheal intubation with VT of 6 mL/kg (LVT group), 10 mL/kg (NVT group), and 20 mL/kg (HVT group), respectively. The inspiration-expiration ratio of the three groups was 1:1, the ventilation frequency was 40 times/min, and the ventilation time was 3 hours. At the end of the experiment, the bronchoalveolar lavage fluid (BALF) of rats was collected, and the levels of pro-inflammatory factors [tumor necrosis factor-α (TNF-α), interleukins (IL-1β and IL-6)] in BALF were detected by enzyme-linked immunosorbent assay (ELISA). The lung tissues of rats were collected, and the lung wet/dry weight (W/D) ratio was calculated. The pathological changes of lung tissues were observed under light microscopy after hematoxylin-eosin (HE) staining, and lung injury scores were performed. The brain tissue of rats was taken to measure the brain water content, and the Evans blue (EB) content of brain tissue was measured to reflect the permeability of the blood-brain barrier. The tight junction proteins in the brain tissues were detected by Western blotting. After 3 hours of mechanical ventilation, with the increase of VT, the degree of lung injury in VILI rats gradually increased. When VT reached 20 mL/kg, lung tissue structure was significantly injured, alveolar wall edema, alveolar congestion, lung interstitial thickening, a large number of inflammatory cells infiltrated, and the lung injury score, lung W/D ratio, and the levels of TNF-α, IL-1β and IL-6 in BALF were significantly higher than those in the Sham group [lung injury score: 10.6±1.1 vs. 1.4±1.0, lung W/D ratio: 6.6±0.8 vs. 3.7±0.6, TNF-α (ng/L): 832.9±97.9 vs. 103.8±23.3, IL-1β (ng/L): 68.9±14.1 vs. 15.7±2.6, IL-6 (ng/L): 70.8±16.4 vs. 20.3±5.4, all P < 0.05]. Lung injury in rats was accompanied by aggravating brain injury. When VT reached 20 mL/kg, brain water content and EB content in brain tissue were significantly higher than those in the Sham group [brain water content: (85.4±3.6)% vs. (68.7±2.7)%, EB content in brain tissue (μg/g): 887±78 vs. 97±14, both P < 0.05], and the protein expressions of claudin-5, occluding and zonula occluden-1 (ZO-1) in the brain tissue were significantly lower than those in the Sham group [claudin-5 protein (claudin-5/β-actin): 0.67±0.12 vs. 1.45±0.19, occludin protein (occludin/β-actin): 0.48±0.11 vs. 0.99±0.21, ZO-1 protein (ZO-1/β-actin): 0.13±0.03 vs. 0.63±0.12, all P < 0.05]. VILI can induce brain edema and increase blood-brain barrier permeability in rats, which may be related to the down-regulation of tight junction protein expression in the brain tissue.

Relationship of Preoperative Thyroid Status with Outcomes of Patients Undergoing Cardiac Surgery Under Cardiopulmonary Bypass

INTRODUCTION: Symptoms of hypothyroidism are often subtle and are easily overlooked specially in patients with a heart disease and symptoms are thought to be from the existing cardiac condition. There is a consensus that patients with known hypothyroidism should have thyroid screening before any major surgery including cardiac surgery and if indicated should be made euthyroid before surgery. AIMS AND OBJECTIVES: To study the correlation of thyroid function test status with postoperative course and outcome (total duration of hospital, duration of ICU stay, hours of mechanical ventilation and in hospital mortality). MATERIAL AND METHODS: This prospective study recruited 151 patients who underwent cardiac surgery under cardiopulmonary bypass, TSH was measured and compared with outcome in these patients. RESULTS: Hours of mechanical ventilation (35.20 ± 20.1 Vs 110.61 ± 71.9 hours), ICU stay (3.3 ± 2.30 vs 5.9 ± 5.56 days) and hospital stay (16.7±4.21 days vs 21.1 ± 6.95 days) was significantly less in euthyroid than patients whose TSH was raised before surgery , also postoperative in hospital mortality was more in patients with raised TSH preoperatively. CONCLUSION: We concluded that patients with Subclinical hypothyroidism (SCHT) and Overt Hypothyroidism (OH) planned for cardiac surgery on cardiopulmonary bypass should be treated and those on levothyroxine replacement should have fair control before undergoing surgery. Keywords: Subclinical Hypothyroidism [SCHT], Overt Hypothyroidism [OH], Cardiopulmonary Bypass, Atrial Fibrillation [AF].

Discriminating Acute Respiratory Distress Syndrome from other forms of respiratory failure via iterative machine learning

Acute Respiratory Distress Syndrome (ARDS) is associated with high morbidity and mortality. Identification of ARDS enables lung protective strategies, quality improvement interventions, and clinical trial enrolment, but remains challenging particularly in the first 24 hours of mechanical ventilation. To address this we built an algorithm capable of discriminating ARDS from other similarly presenting disorders immediately following mechanical ventilation. Specifically, a clinical team examined medical records from 1263 ICU-admitted, mechanically ventilated patients, retrospectively assigning each patient a diagnosis of “ARDS” or “non-ARDS” (e.g., pulmonary edema). Exploiting data readily available in the clinical setting, including patient demographics, laboratory test results from before the initiation of mechanical ventilation, and features extracted by natural language processing of radiology reports, we applied an iterative pre-processing and machine learning framework. The resulting model successfully discriminated ARDS from non-ARDS causes of respiratory failure (AUC = 0.85) among patients meeting Berlin criteria for severe hypoxia. This analysis also highlighted novel patient variables that were informative for identifying ARDS in ICU settings.

Negative Pressure Pulmonary Oedema – Lessons learnt

A 56 year old female patient belonging to American Society of Anaesthesiologists Physical Status (ASA-PS) 1 underwent emergency laparoscopic appendectomy. Surgery was uneventful. After reversal of the neuromuscular blockade and extubation, patient sustained acute upper airway obstruction due to laryngospasm and developed negative pressure pulmonary oedema, which resolved after a period of about 15 hours of mechanical ventilation.

Satisfaction of intensive care unit patients linked to clinical and organisational factors: A cross-sectional multicentre study

BackgroundThe satisfaction of critical care patients with the nursing care they receive is a key indicator of the quality of hospital care. ObjectivesThe objectives of this study were to analyse the level of satisfaction of critical care patients in relation to the nursing care received and to determine the relationship between the level of satisfaction and sociodemographic, clinical, and organisational variables. DesignThis was a prospective, descriptive correlational study. Setting and methodsThe population consisted of all patients discharged from the intensive care units (ICUs) of 19 hospitals in Spain between December 2018 and December 2019. The level of satisfaction was measured using the validated Nursing Intensive Care Satisfaction Scale, and sociodemographic, clinical, and organisational data were collected. ResultsParticipants' mean age (n = 677) was 59.7 (standard deviation: 16.1), and 62.8% of them were men (n = 426). Satisfaction with the nursing care received was 5.66 (SD: 0.68) out of a possible 6. The score for overall satisfaction presented statistically significant relationships with the hours of mechanical ventilation (p = 0.034), with the participant's perception of own health status (p = 0.01), with the participant's perceived degree of own recovery (p = 0.01), with the hospital's complexity level (p = 0.002), with the type of hospital (p = 0.005), and with the type of ICU (p = 0.004). Finally, the logistic regression model shows that the Nursing Intensive Care Satisfaction Scale score was not linked to age or sex but did have a statistically significant relationship with the perceived degree of recovery (p < 0.001) and the type of ICU (p=<0.001). The variables that predicted satisfaction were age, degree of recovery, and the type of ICU. ConclusionSeveral studies show that patient satisfaction is related to the patient's perceived health status and perceived degree of recovery, a finding that is confirmed in our study. Our study moves beyond these outcomes to show that the hours of mechanical ventilation and the characteristics of the hospital also have a significant relationship with patients' satisfaction.

Incidence and Risk Factors Association for Ventilator Associated Pneumonia in Neontal Intensive Care Unit

Introduction: Ventilator Associated Pneumonia (VAP), the nosocomial pneumonia developing in mechanically ventilated patients after 48 hours of mechanical ventilation, is the second commonest nosocomial infection in the neonatal intensive care unit (NICU). VAP occurring within 96 hours of initiation of mechanical ventilation is termed as early VAP and later than that is known as late VAP. The aim of this study was to determine the incidence rate and risk factors of early and late ventilator associated pneumonia in NICU. Methods: The study was conducted from December 2015 to November 2017 in which 40 neonates were ventilated for more than 48 hours of which those who developed VAP as per CDC criteria were enrolled in the study. Birth weight, gestation age, reintubation if needed and number of days of ventilation were noted. Statistical associations were further evaluated between various parameters of VAP and time of development of VAP. Results: Incidence of Early VAP was 12.5% and that of Late VAP was 87.5%. 93.95% neonates who were reintubated developed VAP. Duration of mechanical ventilation and re-intubation were significantly associated with the time of development of VAP. Birth weight and gestation age were statistically insignificant factors in determining VAP. Conclusions: Re-intubation and duration of mechanical ventilation are a significant risk factor for development of late VAP. Gestation age and birth weight have been identified as additional risk factors. Early diagnosis is necessary for appropriate treatment and decreased hospital stay.