U-Shape Relationship between Plasma Leucine Level and Mortality in the Intensive Care Unit

Patients in the intensive care unit (ICU) are at high risk of mortality which is not well predicted. Previous studies noted that leucine has prognostic value in a variety of diseases. This study investigated whether leucine concentration was a useful biomarker of metabolic and nutritional status and 6-month mortality in ICU. We recruited 454 subjects admitted to ICU (348 and 106 in the initiation and validation cohorts, respectively) with an acute physiology and chronic health evaluation (APACHE II) score ≥ 15 . We measured plasma leucine concentrations, traditional biomarkers, and calculated APACHE II and sequential organ failure assessment (SOFA) scores. Leucine levels were weakly correlated with albumin, prealbumin, and transferrin levels ( r = 0.30 , 0.12, and 0.15, p = 0.001 , 0.029, and 0.007, respectively). During follow-up, 116 (33.3%) patients died. Compared to patients with leucine levels between 109 and 174 μM, patients with leucine > 174 μ M or <109 μM had a lower cumulative survival rate. Death was also associated with age, higher APACHE II and SOFA scores, C-reactive protein, and longer stays in the ICU, but with lower albumin, prealbumin, and transferrin. Patients with leucine levels > 174 μ M had higher alanine aminotransferase levels, but no significant differences in other variables; patients with leucine levels < 109 μ M had higher APACHE II and SOFA scores, higher incidence of using inotropic agents, longer ICU and hospital stays, but lower albumin and transferrin levels. Multivariable analysis demonstrated that leucine > 174 μ M was an independent predictor of mortality, especially early mortality. However, among patients who stayed in ICU longer than two weeks, leucine < 109 μ M was an independent predictor of mortality. In addition, leucine < 109 μ M was associated with worse ventilator weaning profiles. These findings were similar in the validation cohort. Our study demonstrated a U-shape relationship between leucine levels and mortality rate in ICU.

Demons syndrome with pericardial effusion followed by intensive care unit-acquired weakness: A case report and literature review

Demons syndrome is defined by hydrothorax and ascites associated with a benign genital tumor that resolves after resection of the tumor. However, Demons syndrome with pericardial effusion has never been reported. Intensive care unit–acquired weakness is a neurological sequela to sepsis/systemic inflammatory response syndrome, or multi-organ failure. A 47-year-old, nulligravid, Japanese woman, was transferred to our hospital for refractory heart failure and a ruptured ovarian tumor. She had an 11-cm left ovarian tumor with ascites, hydrothorax, and pericardial effusion; she was intubated for pulmonary hypertension and admitted to the intensive care unit for septic shock. Four days later, a left salpingo-oophorectomy was performed for Demons syndrome with pericardial effusion. The histological diagnosis indicated a serous cystadenoma with fibrotic changes. Following surgery, ventilator weaning was delayed due to intensive care unit–acquired weakness. The association between Demons syndrome and pericardial effusion should be recognized to ensure early treatment and for preventing sequalae from the disease.

Electrical Impedance Tomography Predicts Weaning Success in Adult Patients With Delayed Upper Abdominal Surgery: A Single-Center Retrospective Study

Objective: To evaluate the predictive value of electrical impedance tomography (EIT) in patients with delayed ventilator withdrawal after upper abdominal surgery.Methods: We retrospectively analyzed data of patients who were ventilated &gt;24 h after upper abdominal surgery between January 2018 and August 2019. The patients were divided into successful (group S) and failed (group F) weaning groups. EIT recordings were obtained at 0, 5, 15, and 30 min of spontaneous breathing trials (SBTs) with SBT at 0 min set as baseline. We assessed the change in delta end-expiratory lung impedance and tidal volume ratio (ΔEELI/VT) from baseline, the change in compliance change percentage variation (|Δ(CW-CL)|) from baseline, the standard deviation of regional ventilation delay index (RVDSD), and global inhomogeneity (GI) using generalized estimation equation analyses. Receiver operating characteristic curve analyses were performed to evaluate the predictive value of parameters indicating weaning success.Results: Among the 32 included patients, ventilation weaning was successful in 23 patients but failed in nine. Generalized estimation equation analysis showed that compared with group F, the ΔEELI/VT was lower, and the GI, RVDSD, and (|Δ(CW-CL)|) were higher in group S. For predicting withdrawal failure, the areas under the curve of the ΔEELI/VT, (|Δ(CW-CL)|), and the RVDSD were 0.819, 0.918, and 0.918, and 0.816, 0.884, and 0.918 at 15 and 30 min during the SBTs, respectively.Conclusion: The electrical impedance tomography may predict the success rate of ventilator weaning in patients with delayed ventilator withdrawal after upper abdominal surgery.

Clinical Outcomes and Cost of Ventilator Weaning and Endotracheal Extubation Guided by An Established Ventilator Weaning Protocol in Patients Undergoing Elective Cardiac Surgery

Objective: To compare successful early extubation rates, complications, and cost before and after the use of anestablished ventilator weaning protocol in patients undergoing elective cardiac surgery.Materials and Methods: Subjects were adult patients undergoing elective cardiac surgery who were clinically stablewithin 2 hours after surgery. The control group underwent conventional ventilator weaning at the discretion of theirattending staff. The intervention group underwent protocol-guided ventilator weaning. The primary outcome wasa successful early extubation (within 6 hours after surgery). Secondary outcomes were complications from weaningto 24 hours after surgery, and the relevant cost related to respiratory and cardiovascular care within 24 hours afteradmission to the postoperative intensive care unit.Results: The primary outcome occurred in 37 out of 65 patients (56.9%) in the intervention group and in 5 out of65 patients (7.7%) in the control group (adjusted odds ratio 20.6; 95% confidence interval 6.7–62.9, p<0.001). Thecomplication rates were not statistically different between the intervention and control groups (26.2% vs. 20.0%,p=0.41). The relevant cost, approximated by the service charges, related to respiratory and cardiovascular care wassignificantly less in the intervention group than in the control group (median 2,491 vs. 2,711 Thai baht, p<0.001).Conclusion: The use of the established ventilator weaning protocol after elective cardiac surgery was associated witha higher rate of successful early extubation and lower cost related to respiratory and cardiovascular care comparedto the conventional practices of ventilator weaning and extubation. The rates of overall complications were notsignificantly different.

Design of a Clinical Practice Guideline in Nurse-Led Ventilator-Weaning for Nursing Training

Cardiothoracic intensive care unit (CICU) nurses have shared the role and responsibility for ventilator-weaning to expedite decision-making in patient care. However, the actions taken are based on individual's unstructured training experience as there is no clinical practice guideline (CPG) for nurses in Malaysia. Hence, this study aims to design a CPG for the process of weaning from mechanical ventilation (MV) for a structured nursing training in a CICU at the National Heart Institute (Institut Jantung Negara, IJN) Malaysia. The Fuzzy Delphi Method (FDM) was employed to seek consensus among a panel of 30 experts in cardiac clinical practice on the guidelines. First, five experts were interviewed and their responses were transcribed and analyzed to develop the items for a FDM questionnaire. The questionnaire, comprising of 73 items, was distributed to the panel and their responses were analyzed for consensus on the design of the CPG. The findings suggested that the requirements expected for the nurses include: (a) the ability to interpret arterial blood gases, (b) knowledge and skills on the basics of mechanical ventilation, and (c) having a minimum 1-year working experience in the ICU. On the other hand, the CPG should mainly focus on developing an ability to identify criteria of patient eligible for weaning from MV. The learning content should focus on: (a) developing the understanding and reasoning for weaning and extubating and (b) technique/algorithm for extubating and weaning. Also, the experts agreed that the log book/competency book should be used for evaluation of the program. The CPG for structured nursing training at IJN in the context of the study is important for developing the professionalism of CICU nurses in IJN and could be used for training nurses in other CICUs, so that decision for ventilator-weaning from postcardiac surgery could be expedited.

Spontaneous pneumothorax, with or without pulmonary cysts, in patients with COVID-19 pneumonia

Introduction: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) affects mainly the lungs causing pneumonia and complications like acute respiratory distress syndrome. Pneumothorax is a rare manifestation of the disease. This report is a description of a series of patients with COVID-19 and spontaneous pneumothorax, some of them with associated pulmonary cysts. Methodology: Cases were collected retrospectively. We included clinical data from medical records and described radiologic findings. Patients that developed pneumothorax during mechanical ventilation were excluded. Results: Ten cases were included in this report, nine of them were male. The median age of our series was 62 years (IQR = 57-68). The median days since the onset of symptoms until the development of pneumothorax was 27 (IQR = 17-31), most cases developed after the second week of the diagnosis of pneumonia. Two cases required invasive mechanical ventilation, but pneumothorax occurred after ventilator weaning. Three cases showed subpleural pulmonary cysts. Conclusions: Cysts and pneumothorax are rare manifestations of SARS-CoV-2 pneumonia with mechanisms not completely understood. This report highlights the role of CT scan in diagnosis of COVID-19 complications.

Influence of Dexmedetomidine on Diaphragm Function and Postoperative Outcomes in ICU Patients with Mechanical Ventilation

Objective. To probe into the influence of dexmedetomidine (DEX) on diaphragm function and postoperative outcomes of mechanically ventilated patients in the intensive care unit (ICU). Methods. 84 patients with mechanical ventilation (MV) in the ICU of our hospital were selected as the research participants, including 38 patients in the control group (CG) sedated with midazolam (MZ) and 46 patients in the research group (RG) with DEX sedation. Ramsay sedation score, visual analogue scale (VAS), and restlessness score (RS) were used to evaluate their state before sedation (T0), as well as 2 h (T1), 6 h (T2), and 24 h (T3) after sedation, and the alterations of mean arterial pressure (MAP) and heart rate (HR) were recorded. Serum cortisol (Cor), adrenocorticotropic hormone (ACTH), superoxide dismutase (SOD), malondialdehyde (MDA), interleukin- (IL-) 1β, IL-6, and tumor necrosis factor-α (TNF-α) were measured before and 24 h after sedation. The end-inspiratory diaphragm thickness (DTei) and end-expiratory diaphragm thickness (DTee) were measured within 2 h after the initiation of MV and 5 min after the spontaneous breathing test (SBT), and the diaphragm thickening fraction (DTF) was calculated. Finally, the ventilator weaning, MV time, and the incidence of adverse reactions (ADs) of the two groups were counted. Results. T0 and T3 witnessed no distinct difference in Ramsay, VAS, and RS scores between the two arms ( P > 0.05 ), but at T1 and T2, RG had better sedation state and lower VAS and RS scores than CG ( P < 0.05 ), with more stable vital signs ( P < 0.05 ). After sedation, the contents of oxidative stress and inflammatory factors in RG were lower, while DTee, DTei, and DTF were higher, versus CG ( P < 0.05 ). Moreover, RG presented higher success rate of first ventilator weaning, less MV time, and lower incidence of ADs than CG ( P < 0.05 ). Conclusions. DEX is effective in mechanically ventilated patients in the ICU, which can protect patients against diaphragm function damage, improve the success rate of ventilator weaning, and benefit the postoperative outcome, with excellent and rapid sedation effect and less stress damage to patients.

Phrenic nerve stimulation prevents diaphragm atrophy in patients with respiratory failure on mechanical ventilation

Background Diaphragm atrophy and dysfunction is a major problem among critically ill patients on mechanical ventilation. Ventilator-induced diaphragmatic dysfunction is thought to play a major role, resulting in a failure of weaning. Stimulation of the phrenic nerves and resulting diaphragm contraction could potentially prevent or treat this atrophy. The subject of this study is to determine the effectiveness of diaphragm stimulation in preventing atrophy by measuring changes in its thickness. Methods A total of 12 patients in the intervention group and 10 patients in the control group were enrolled. Diaphragm thickness was measured by ultrasound in both groups at the beginning of study enrollment (hour 0), after 24 hours, and at study completion (hour 48). The obtained data were then statistically analyzed and both groups were compared. Results The results showed that the baseline diaphragm thickness in the interventional group was (1.98 ± 0.52) mm and after 48 hours of phrenic nerve stimulation increased to (2.20 ± 0.45) mm (p=0.001). The baseline diaphragm thickness of (2.00 ± 0.33) mm decreased in the control group after 48 hours of mechanical ventilation to (1.72 ± 0.20) mm (p<0.001). Conclusions Our study demonstrates that induced contraction of the diaphragm by pacing the phrenic nerve not only reduces the rate of its atrophy during mechanical ventilation but also leads to an increase in its thickness – the main determinant of the muscle strength required for spontaneous ventilation and successful ventilator weaning. Trial registration: The study was registered with ClinicalTrials.gov (18/06/2018, NCT03559933, https://clinicaltrials.gov/ct2/show/NCT03559933).

Methods of Weaning From Mechanical Ventilation in Adult: A Network Meta-Analysis

Background/Objective: The aim of study is to assess the efficacy of each ventilator weaning method for ventilated patients in intensive care units (ICUs).Methods: A systematic search was conducted using PubMed, Embase, and China National Knowledge Infrastructure to identify randomized control studies on ventilated patients regarding extubation associated outcomes (weaning success or failure, proportion requiring re-intubation, or mortality) from inception until April 01, 2020. Commonly used ventilation modes involved pressure support ventilation, synchronized intermittent mandatory ventilation, automatic tube compensation, continuous positive airway pressure, adaptive support ventilation, neurally adjusted ventilatory assist, proportional assisted ventilation, and SmartCare. Pooled estimates regarding extubation associated outcomes were calculated using network meta-analysis.Results: Thirty-nine randomized controlled trials including 5,953 patients met inclusion criteria. SmartCare and proportional assist ventilation were found to be effective methods in increasing weaning success (odds ratio, 2.72, 95% confidence interval (CI), 1.33–5.58, P-score: 0.84; odds ratio, 2.56, 95% CI, 1.60–4.11, P-score: 0.83; respectively). Besides, proportional assist ventilation had superior in reducing proportion requiring re-intubation rate (odds ratio, 0.48, 95% CI, 0.25–0.92, P-score: 0.89) and mortality (odds ratio, 0.48, 95% CI, 0.26–0.92, P-score: 0.91) than others.Conclusion: In general consideration, our study provided evidence that weaning with proportional assist ventilation has a high probability of being the most effective ventilation mode for patients with mechanical ventilation regarding a higher rate of weaning success, a lower proportion requiring reintubation, and a lower mortality rate than other ventilation modes.