Positive Pressure Mechanical Ventilation Research Articles

Bedside critical care training: A quasi-experimental study in the paediatric emergency department of a referral hospital in Nigeria.

There is a need for critical care services outside intensive care units (ICUs), especially in emergency departments (EDs). However, there is a paucity of skilled manpower for ED critical care or emergency critical care (ECC) in resource-limited settings. To evaluate the impact of bedside training on emergency critical care practices of clinical staff. This was a quasi-experimental study using a pretest - post-test design in a paediatric ED. The intervention was a six-week structured bedside training on bubble continuous positive airway pressure (CPAP) high-flow nasal cannula (HFNC) and mechanical ventilation. Participants' actual ECC practices pre and post training were evaluated, including their perceived proficiency on an uncalibrated 100 mm visual analogue scale (VAS). Descriptive and inferential analyses were done; p<0.05 was considered significant. A total of 35 clinical staff participated in the training, comprising 9 (24.3%) paediatric registrars, 12 (32.5%) senior registrars, 10 (27.0%) nurses, 4 (10.8%) house officers and 2 (5.4%) paediatric consultants. The male:female ratio of the participants was 1:1.6, and their mean (SD) age was 33.24 (6.30 years. Participants' understanding of testing the CPAP circuit, connecting the patient and weaning significantly improved following training (p=0.004). Their capacity to select appropriate HFNC parameters improved (p=0.013). They performed more endotracheal intubations in the post-training period (p=0.001). Their pretest-post-test proficiency in mechanical ventilation increased on VAS (mean scores 45.26+31.99 v. 63.26+22.26; p=0.038). Also, there was a significant increase in their perceived proficiency in paediatric analgesia/sedation (30.83+29.86 v. 49.83+23.90; p=0.029). Short-term bedside critical care training enhanced the self-reported competency of paediatric ED staff. There is a need for on-the-job ECC training and retraining of clinical staff in our setting. Paediatric emergency department clinical staff desire hands-on critical care training in developing settings. Bedside training improves the knowledge and skills of nursing staff in non-invasive ventilation. Bedside training also builds the capacity of medical staff in invasive ventilation in the emergency department. Overall, short-term bedside training enhances the clinical knowledge and self-reported critical care practice of clinical staff in Children's Emergency Room.

Mechanical Ventilation, Past, Present, and Future.

Mechanical ventilation (MV) has played a crucial role in the medical field, particularly in anesthesia and in critical care medicine (CCM) settings. MV has evolved significantly since its inception over 70 years ago and the future promises even more advanced technology. In the past, ventilation was provided manually, intermittently, and it was primarily used for resuscitation or as a last resort for patients with severe respiratory or cardiovascular failure. The earliest MV machines for prolonged ventilatory support and oxygenation were large and cumbersome. They required a significant amount of skills and expertise to operate. These early devices had limited capabilities, battery, power, safety features, alarms, and therefore these often caused harm to patients. Moreover, the physiology of MV was modified when mechanical ventilators moved from negative pressure to positive pressure mechanisms. Monitoring systems were also very limited and therefore the risks related to MV support were difficult to quantify, predict and timely detect for individual patients who were necessarily young with few comorbidities. Technology and devices designed to use tracheostomies versus endotracheal intubation evolved in the last century too and these are currently much more reliable. In the present, positive pressure MV is more sophisticated and widely used for extensive period of time. Modern ventilators use mostly positive pressure systems and are much smaller, more portable than their predecessors, and they are much easier to operate. They can also be programmed to provide different levels of support based on evolving physiological concepts allowing lung-protective ventilation. Monitoring systems are more sophisticated and knowledge related to the physiology of MV is improved. Patients are also more complex and elderly compared to the past. MV experts are informed about risks related to prolonged or aggressive ventilation modalities and settings. One of the most significant advances in MV has been protective lung ventilation, diaphragm protective ventilation including noninvasive ventilation (NIV). Health care professionals are familiar with the use of MV and in many countries, respiratory therapists have been trained for the exclusive purpose of providing safe and professional respiratory support to critically ill patients. Analgo-sedation drugs and techniques are improved, and more sedative drugs are available and this has an impact on recovery, weaning, and overall patients' outcome. Looking toward the future, MV is likely to continue to evolve and improve alongside monitoring techniques and sedatives. There is increasing precision in monitoring global "patient-ventilator" interactions: structure and analysis (asynchrony, desynchrony, etc). One area of development is the use of artificial intelligence (AI) in ventilator technology. AI can be used to monitor patients in real-time, and it can predict when a patient is likely to experience respiratory distress. This allows medical professionals to intervene before a crisis occurs, improving patient outcomes and reducing the need for emergency intervention. This specific area of development is intended as "personalized ventilation." It involves tailoring the ventilator settings to the individual patient, based on their physiology and the specific condition they are being treated for. This approach has the potential to improve patient outcomes by optimizing ventilation and reducing the risk of harm. In conclusion, MV has come a long way since its inception, and it continues to play a critical role in anesthesia and in CCM settings. Advances in technology have made MV safer, more effective, affordable, and more widely available. As technology continues to improve, more advanced and personalized MV will become available, leading to better patients' outcomes and quality of life for those in need.

Air change per hour improvement for positive and negative pressure mechanical ventilation facilities systems

Ventilation reduces indoor pollutants, and this issue has recently received attention. Most scholars adopt ventilation strategies to reduce energy consumption. While natural ventilation does not require ventilation facilities, it also brings many challenges, such as lack of external openings and insufficient air change per hour. Therefore, it is necessary to rely on mechanical ventilation to increase indoor air change per hour. However, mechanical ventilation comes with increased energy consumption, which poses a significant challenge to reducing energy usage at present.To improve energy usage, increase air changes per hour, and reduce the number of fans by half, we propose implementing positive and negative pressure ventilation indoors at the same airflow rate (3000 CMH). The research results showed that positive and negative pressure ventilation increased air changes per hour by 94 % and 62 %, respectively, while also reducing fan energy usage by 50 %. Through visualization, we also discovered the uneven distribution of indoor carbon dioxide levels. This breakthrough is of significant importance for current indoor mechanical ventilation systems and contributes greatly to future near-zero carbon emissions.

Hypertonic treatment of acute respiratory distress syndrome.

Many viral infections, including the COVID-19 infection, are associated with the hindrance of blood oxygenation due to the accumulation of fluid, inflammatory cells, and cell debris in the lung alveoli. This condition is similar to Acute Respiratory Distress Syndrome (ARDS). Mechanical positive-pressure ventilation is often used to treat this condition, even though it might collapse pulmonary capillaries, trapping red blood cells and lowering the lung's functional capillary density. We posit that the hyperosmotic-hyperoncotic infusion should be explored as a supportive treatment for ARDS. As a first step in verifying the feasibility of this ARDS treatment, we model the dynamics of alveolar fluid extraction by osmotic effects. These are induced by increasing blood plasma osmotic pressure in response to the increase of blood NaCl concentration. Our analysis of fluid drainage from a plasma-filled pulmonary alveolus, in response to the intravenous infusion of 100ml of 1.28 molar NaCl solution, shows that alveoli empty of fluid in approximately 15min. These modeling results are in accordance with available experimental and clinical data; no new data were collected. They are used to calculate the temporal change of blood oxygenation, as oxygen diffusion hindrance decreases upon absorption of the alveolar fluid into the pulmonary circulation. Our study suggests the extraordinary speed with which beneficial effects of the proposed ARDS treatment are obtained and highlight its practicality, cost-efficiency, and avoidance of side effects of mechanical origin.

DESIGN AND PROTOTYPE OF AN AUTOMATED POSITIVE SUCTION MECHANICAL VENTILATOR UNDER AN ECONOMIC AND SOCIAL PROJECT ANALYSIS IN LOW-INCOME PATIENTS

The design and prototype of a low-cost portable positive pressure mechanical ventilator for use in cases of mass disasters and resource-limited environments are described. The ventilator provides breaths by compressing a conventional valve bag mask (AMBU) using a pivoting lever, eliminating the need for a human operator for the AMBU. An initial prototype was constructed using acrylic, with measurements of 285 x 350 x 250 mm and a weight of 4.1 kg (9 lb). It is powered by a 12V DC battery-operated electric motor and features an adjustable air volume of up to a maximum of 750 ml. Control is achieved through a human-machine interface using a 16x2 LCD screen displaying RPM and percentage speed data, which are adjusted using an easy-to-use potentiometer. The prototype also includes an overvoltage safety control mode and pilot lights to indicate the equipment's status. Iterations of the device will include a controllable inspiration-to-expiration time ratio, a pressure relief valve, and a battery bank system that allows for 4 hours of autonomy. The prototype manufacturing cost is only $820. Through this ventilator prototype, it is demonstrated that the lever-driven AMBU compression strategy is a viable option to achieve a low-cost, low-consumption portable technology that provides essential ventilator features at a fraction of the cost of existing technology

Risk Factors for Pneumothorax and Its Association with Ventilation in Neonates.

The mode of ventilation that is implicated in pneumothorax is the one at the time of its diagnosis. Although there is evidence that air leak starts many hours before it is clinically evident, there are no prior studies that have investigated the association of pneumothorax with the mode of ventilation few hours before rather than at the time of its diagnosis. A retrospective case-control study was conducted in the neonatal intensive care unit (NICU) between 2006 and 2016 where cases of neonates with pneumothorax were compared with gestational age-matched control neonates without pneumothorax. Respiratory support associated with pneumothorax was classified as the mode of ventilation 6 hours before the clinical diagnosis of pneumothorax. We investigated the factors that were different between cases and controls, and between cases of pneumothorax on bubble continuous positive airway pressure (bCPAP) and invasive mechanical ventilation (IMV). Of the 8,029 neonates admitted in the NICU during the study period, 223 (2.8%) developed pneumothorax. Among these, 127 occurred among 2,980 (4.3%) neonates on bCPAP, 38 among 809 (4.7%) neonates on IMV, and the remaining 58 among 4,240 (1.3%) neonates on room air. Those with pneumothorax were more likely to be male, have higher body weight, require respiratory support and surfactant administration, and have bronchopulmonary dysplasia (BPD). Among those who developed pneumothorax, there were differences in the gestational age, gender, and use of antenatal steroids between those who were on bCPAP as compared to those on IMV. IMV was associated with increased odds of pneumothorax as compared to those on bCPAP in a multivariable regression analysis. Cases on IMV had higher incidence of intraventricular hemorrhage, retinopathy of prematurity, BPD, and necrotizing enterocolitis, as well as longer length of stay as compared to those on bCPAP. Neonates who require any respiratory support have higher incidence of pneumothorax. Among those on respiratory support, those on IMV had higher odds of pneumothorax and worse clinical outcomes as compared to those on bCPAP. · The process of air leak leading to pneumothorax in majority of neonates starts much before it is clinically diagnosed.. · It is possible to detect the air leak early in the process by subtle changes in the signs, symptoms and changes in lung function.. · True association of the ventilation associated with pneumothorax is not at the time of diagnosis of pneumothorax but few hours before it is diagnosed.. · There is higher incidence of pneumothorax in neonates on any respiratory support.. · There is significantly higher incidence of pneumothorax among neonates on invasive ventilations as compared to noninvasive ventilation after correction for all other clinical factors..

Viral loads of parainfluenza virus type 3 and severity of respiratory diseases in children

BackgroundParainfluenza virus type 3 (PIV-3) is one of the common pathogens for respiratory infections in children. Whether viral load of PIV-3 is associated with severity of respiratory diseases in children is not yet known. Our aim was to determine significance of PIV-3 viral load among infected children. MethodsWe conducted a single-center, retrospective study at Tokyo Metropolitan.Children's Medical Center, Japan, from June to August 2021. Hospitalized children were screened with a posterior nasal swab for multiplex PCR, and viral load was subsequently measured from remained samples by real-time PCR. Demographic data were collected from digital charts. PIV-3 positive patients were categorized into mild group with no oxygen demand, moderate group with low-flow oxygen demand and severe group with high-flow nasal cannula oxygen or non-invasive positive pressure ventilation or mechanical ventilation. Viral loads were compared among mild, moderate and severe groups. Results151 patients were positive for PIV-3. We found no statistically significant association among PIV-3 viral load and severity of respiratory diseases (p = 0.35), and no statistically significant association between severity of illness and co-detection of other viruses. In each severity group, relatively high viral load per posterior nasal swab was observed at the time of testing. ConclusionAmong PIV-3 patients, we could not find statistically significant between viral load and their severity, therefore we could not conclude that viral load is a good surrogate marker for clinical severity of PIV-3.

EFFECTIVENESS OF COMMUNICATION BOARD AMONG MECHANICALLY VENTILATED PATIENTS IN TERMS OF SATISFACTION IN THE ICUS

Introduction: Now a days, uses of Positive pressure Mechanical ventilator has been exponentially increased in ICUs around the world. Mechanical Ventilation is one of the common intervention seen in the ICUs. Communicating with Mechanically Ventilated Patient is challenging for doctors, nursing staff, technicians and patients' families. A Communication Board can serve as a bridge between patients and health care team and help them to give holistic care to intubated patients. The overall aim of the study was to evaluate the effectiveness of Communication Board in terms of Satisfaction among Mechanically Ventilated Patients in ICUs.Method:This study adopted Quantitative Research Approach with post test only design and conducted in three ICUs of selected hospital. 50 patients who fullled the criteria were randomly allocated into the Experiment and Comparison group. The Communication Board was used on Experiment group of Mechanically Ventilated Patients during their Weaning Period. Results: The results shows the statistical signicance difference in Experiment and Comparison group of Mechanically Ventilated Patients in terms of Satisfaction after use of Communication Board (t= 16.151, p&lt;0.001). The association between Satisfaction with Socio-Demographic and Clinical Characteristics of Mechanically Ventilated Patients were not statistically signicant. Conclusion: Communication Board is found to be effective in enhancing the Satisfaction among Mechanically Ventilated Patient.

NONINVASIVE MECHANICAL VENTILATION IN COVID-19 RELATED ACUTE RESPIRATORY FAILURE.

Coronavirus disease 2019 (COVID-19) is presented with a wide range of symptoms, from asymptomatic disease to severe and progressive interstitial pneumonia. As part of interstitial pneumonia, respiratory failure is typically presented as hypoxia and is the most common cause of hospitalization. When oxygen therapy fails, continuous positive airway pressure (CPAP) or noninvasive mechanical ventilation (NIV) are used as respiratory support measures of first choice. Noninvasive respiratory support (NIRS) is applied in order to save intensive care unit resources and to avoid complications related to invasive mechanical ventilation. Emerging evidence has shown that the use of CPAP or NIV in the management of acute hypoxemic respiratory failure in COVID-19 reduces the need for intubation and mortality. The advantage of NIRS is the feasibility of its application on wards. NIV could be administered via a face mask or helmet interface. Helmet adheres better than mask and therefore leakage is reduced, a delivery of positive end-expiratory pressure is more accurate, and the risk of nosocomial transmission of infections is lowered. Patients on NIRS must be carefully monitored so that further respiratory deterioration is not overlooked and additional measures of care including timely intubation and invasive mechanical ventilation could be performed if needed.

Awake Craniotomy for Cerebral Abscess with Pulmonary Arteriovenous Malformation

AbstractA cerebral abscess can be a life-threatening complication of pulmonary arteriovenous malformations (PAVM), thus posing significant morbidity if left untreated. We report a case of an incidental finding of a PAVM in a patient diagnosed with cerebral abscess. A 22-year-old male presented to the emergency department with acute onset right-sided weakness in both upper and lower limbs for 1 week. Magnetic resonance imaging showed a ring-enhancing lesion within the left parasagittal frontoparietal region s/o intracerebral abscess. High-resolution computed tomography was done as a protocol in patients posted for surgery due to coronavirus disease 2019 and coincidentally, it showed a single well-defined parenchymal nodule, 4 × 3.4 cm in the lateral basal segment of the left lower lobe. The knowledge of the pathophysiology of PAVM and expected complications during general anesthesia (GA) and positive pressure mechanical ventilation is essential. In such conditions, awake craniotomy under conscious sedation and scalp block may be considered as an alternative to GA.

Hemophagocytic Lymphohistiocytosis Patients Need Intensive Care Can be Successfully Rescued By Timely Using Etoposide-Based HLH Regimens

Objectives:Hemophagocytic lymphohistiocytosis (HLH) patients who need life support and intensive care usually have multiple organ failure and high mortality. However, the clinical characteristics, therapeutic efficacy and outcome in these critically ill HLH patients have remained unclear. Methods: In the study, we analyzed the data of 41 critically ill HLH patients treated in a prospective, non-randomized clinical trial (ChiCTR1800015283). Results: 41 secondary HLH patients need life support and intensive care, the median age was 47 years (9-79 years), 22 males and 19 females. The median sequential organ failure assessment (SOFA) score at diagnosis was 8 (4-17). 70.73% of critically ill HLH patients had septic shock, followed by disseminated intravascular coagulation (DIC, 58.54%) , acute respiratory distress syndrome (53.66%). 22 patients (53.66%) needed invasive or non-invasive positive pressure mechanical ventilation, 26 patients (63.41%) needed vasoactive drugs, and 4 patients (9.76%) needed continuous renal replacement therapy (CRRT). Among 10 patients treated with DEP regimen, the median time to remove ECG monitoring, respiratory support, stop using vasoactive drugs, converting from dominant DIC to non dominant DIC was respectively 8.5 days, 8 days, 6.5 days and 4 days. After 4 weeks, 5 patients achieved PR, and 3 patients were evaluated as NR. However, among 4 patients treated with HLH-94/2004, the median time to remove ECG monitoring, respiratory support, converting from dominant DIC to non dominant DIC was respectively 30 days, 14 days and 4 days. After 4 weeks, 3 patients were evaluated as NR. Up to the last follow-up, the OS rate of 14 patients receiving DEP/ HLH-94/2004 regimens was 78.6%. In contrast, all 27 untreated HLH patients died. Univariate analysis showed that PCT>0.5 ug/l, respiratory failure, renal failure and liver failure were the negative factors affecting survival (p=0.018, 0.003, 0.001, 0.006). Multivariate analysis showed that respiratory failure (P=0.014), renal failure (P=0.019) and liver failure(P=0.049) were independent adverse factors. Conclusion: HLH patients need intensive care timely used etoposide-based HLH regimens especially DEP regimen which might successfully rescue the critically ill patients.

IATROGENIC PNEUMOTHORAX

Iatrogenic (a subtype of traumatic) pneumothorax commonly occurs as a complication of transthoracic puncture biopsy (TTPB), central venous catheterization (especially the subclavian vein), thoracocentesis, positive pressure mechanical ventilation (PPMV), transbronchial (TBB) and pleural biopsy. The incidence has recently been increasing due to the increasing use of invasive diagnostic and therapeutic procedures. The aim of this reseacrh is to present the results and the efficiency in the care of iatrogenic pneumothorax in the pneumophtisiologist practice in general hospital. Material and methods: the analysis includes 290 hospital histories (mainly from the Pulmonology Department, in a much smaller number from other Internal Medicine or Surgery Department at the GOB “September 8”) for a 4-year period (January 2018 - December 2021) with final discharge diagnoses: pleural effusion, pyothorax, lung cancer, pulmonary infiltration, pleural mesothelioma and metastatic pleural fluid - ICD codes: J90, J91, J86.9, C34, C45.0 and C78.2. All underwent an invasive diagnostic or therapeutic procedure. The diagnosis of pneumothorax included a radiological examination (PA-posteroanterior proection and LL -profile chest X-ray). Results: from 290 diagnostic-therapeutic procedures, immediately and up to 24 hours after the intervention, a total of 24 (8.3%) pneumothoraxes were recorded, namely: 15 (27%) out of 54 after TTPB, 3 (4.8%) of 62 after TBB and 3 (2%) of 124 after thoracocenthesis and percutaneous biopsyes of the parietal pleura. In 2 (4%) of 49 cases after lavage of the pleural space, partial pneumothorax was recorded, 1 complete hematopneumothorax after catheterization of the subclavian vein. Thoracic drainage was performed in 12 (50%) (initially in 9, and in 3 after 24 hours due to progression of incomplete lung collapse). Of the remaining 12 patients, the pneumothorax was treated with exufflation in 4, and in 8 conservatively (with a procedure of forced expiration and respiratory exercises). No case requiring a surgical approach has been registered. Conclusion: a condition for successful care of iatrogenic pneumothorax is compliance with standards in the application of diagnostic procedures in pulmonology and related areas, careful observation and efficient application of modern attitudes in care of complications from invasive-interventional diagnostic-therapeutic procedures.

Clinical Observation of Noninvasive Positive Pressure Mechanical Ventilation in the Adjuvant Treatment of Severe Pneumonia Complicated with Respiratory Failure

Clinical Observation of Noninvasive Positive Pressure Mechanical Ventilation in the Adjuvant Treatment of Severe Pneumonia Complicated with Respiratory Failure

Prevalence, clinical manifestations, laboratory findings, treatment, and outcome of intermediate syndrome in anticholinesterase pesticide intoxication of dogs: A retrospective study

Organophosphates and carbamates are important anticholinesterase intoxicants of humans and dogs. Intermediate syndrome (IMS) typically occurs 7–96 h following a toxicity-associated acute cholinergic crisis (ACC), and manifests clinically as weakness of the proximal limb, respiratory, and neck flexor muscles. The aim of this study was to describe the prevalence, clinical findings, and outcome of IMS in dogs. The medical records of a veterinary teaching hospital were searched for dogs diagnosed with ACC, IMS, or both, between 2017 and 2021. Case files were retrospectively reviewed. Six historical IMS cases were additionally reviewed. Thirty-two dogs were diagnosed with anticholinesterase intoxication during the search period, of which 23 (72 %) were only diagnosed with ACC, seven (22 %) progressed from ACC to IMS, and two (6 %) were only diagnosed with IMS. Duration of hospitalisation was longer in the IMS group compared to the ACC only group (P = 0.005). When all dogs with IMS (n = 15, including the six historical cases) were considered, survival was 100 %, including four (27 %) that required positive pressure mechanical ventilation following respiratory failure. Serum butyrylcholine esterase activity, a marker of cholinesterase activity, was below reference interval when first measured in 14 (93 %) of dogs; however, was not a useful as a recovery marker. IMS should be suspected in dogs demonstrating respiratory, neck, and proximal limb muscle paresis or paralysis, especially following clinical signs consistent with ACC. Absence of clinical signs consistent with ACC or butyrylcholine esterase activity within the reference interval does not exclude IMS as a differential.

High-flow nasal oxygen versus conventional oxygen therapy in patients with COVID-19 pneumonia and mild hypoxaemia: a randomised controlled trial

RationaleIn patients with COVID-19 pneumonia and mild hypoxaemia, the clinical benefit of high-flow nasal oxygen (HFNO) remains unclear. We aimed to examine whether HFNO compared with conventional oxygen therapy (COT)...

MO409: GDF-15 is a Predictor of Mortality in Chronic Kidney Disease Patients With Covid-19 Infection

BACKGROUND AND AIMSA cytokine storm drives the pathogenesis of severe coronavirus disease (COVID-19) and several biomarkers with different mechanisms of action have been linked to mortality. Chronic kidney disease (CKD) emerged as a very common risk factor for severe COVID-19. Indeed, CKD patients are at increased risk of premature death from many causes, including, but not limited to, cardiovascular disease (CVD) and infections. In this study, we aimed to investigate the associations between the growth differentiation factor 15 (GDF-15), an established cardiovascular and inflammatory biomarker and outcomes in CKD patients hospitalized for COVID-19.METHODA retrospective study on COVID-19 hospitalized subjects in the acute phase of the disease. A broad range of cytokines (CD25, IL-18, TNF-α, TNF RI, TNF RII, GDF-15, IL-7, LIF, IL-6, CHITINASE3_LIKE1, RAGE and Pentraxin-3) were assessed in plasma (Luminex, ELISA) collected upon hospitalization. A total of 77 subjects were divided into two groups according to their estimated glomerular filtration rate (eGFR, by CKD-EPI formula), ≥45 mL/min (n = 44), or ˂45 mL/min (n = 33).RESULTSWe found no statistical differences between the two groups in terms of demographic features. Among comorbidities, we found a higher percentage of patients with diabetes in the eGFR < 45 group. Likewise, the serum tests upon admission showed in the eGFR < 45 group a higher value of neutrophilic count. Upon hospital admission, the patient groups were comparable in terms of symptoms, time from symptom onset to admission and death or discharge, radiological evidence of pneumonia and respiratory parameters and time of hospitalization. Furthermore, there were no statistical differences between medical therapy during hospitalization, need for respiratory support with Continuous Positive Airways Pressure or Non-Invasive Mechanical Ventilation, or death rather than discharge as the clinical outcome. Serum levels of 20 different compounds were measured in COVID-19 patients admitted to the hospital 4–5 days after the onset of symptoms. Interestingly, we found that patients with lower renal function (eGFR < 45 mL/min) had a significant increase of GDF-15, CD-25 and RAGE and, furthermore, higher serum levels of these molecules were detected in non-survivor patients and in those who needed ventilation. Also, TNFα, TNFR I, TNFR II, IL-7 and LIF had a significant increase in patients with eGFR < 45 mL/min with more elevated levels in non-survivor patients. In univariate analysis low and mid-low GDF-15 quartiles (<4.45 ng/mL) were associated with lower mortality risk, while mid-high and high quartiles (>4.45 ng/mL) were associated with higher mortality risk (Figure 1). Independent association between GDF-15 quartiles and mortality risk was confirmed in Cox model adjusted for eGFR, age, fever, dyspnoea and P/F [hazard ratio (HR) 2.28, 95% confidence interval (CI) 1.53–3.39, P < 0.0001) The strength of association between GDF-15 quartiles and mortality risk was increased in patients with eGFR < 45 mL/min/1.73 m2 (HR 2.53, CI 1.34–4.79) compared with the other eGFR group (HR 1.99, CI 1.17–3.39) (Table 1). CONCLUSIONOur results demonstrate that GDF-15 is an independent predictor of COVID-19 mortality in CKD patients. Given the reported increase of this cytokine with age and its possible mechanistic role in various pathological conditions, our findings suggest that GDF-15 signalling pathway inhibitors may be included as possible therapeutic candidates for COVID-19 in CKD.FIGURE 2:Overall likelihood of survival according to quartile of GDF-15. Kaplan–Meier curves for GDF-15 quartiles adjusted for eGFR, age, fever, dyspnoea and P/F. GDF-15: Growth Differentiation Factor 15, eGFR: estimated glomerular filtration rate, P/F: PaO2/FiO2 ratio.

Physiological and Pathophysiological Consequences of Mechanical Ventilation.

Mechanical ventilation is a life-support system used to ensure blood gas exchange and to assist the respiratory muscles in ventilating the lung during the acute phase of lung disease or following surgery. Positive-pressure mechanical ventilation differs considerably from normal physiologic breathing. This may lead to several negative physiological consequences, both on the lungs and on peripheral organs. First, hemodynamic changes can affect cardiovascular performance, cerebral perfusion pressure (CPP), and drainage of renal veins. Second, the negative effect of mechanical ventilation (compression stress) on the alveolar-capillary membrane and extracellular matrix may cause local and systemic inflammation, promoting lung and peripheral-organ injury. Third, intra-abdominal hypertension may further impair lung and peripheral-organ function during controlled and assisted ventilation. Mechanical ventilation should be optimized and personalized in each patient according to individual clinical needs. Multiple parameters must be adjusted appropriately to minimize ventilator-induced lung injury (VILI), including: inspiratory stress (the respiratory system inspiratory plateau pressure); dynamic strain (the ratio between tidal volume and the end-expiratory lung volume, or inspiratory capacity); static strain (the end-expiratory lung volume determined by positive end-expiratory pressure [PEEP]); driving pressure (the difference between the respiratory system inspiratory plateau pressure and PEEP); and mechanical power (the amount of mechanical energy imparted as a function of respiratory rate). More recently, patient self-inflicted lung injury (P-SILI) has been proposed as a potential mechanism promoting VILI. In the present chapter, we will discuss the physiological and pathophysiological consequences of mechanical ventilation and how to personalize mechanical ventilation parameters.

Prediction of Conventional Oxygen Therapy Failure in COVID-19 Patients With Acute Respiratory Failure by Assessing Serum Lactate Concentration, PaO2/FiO2 Ratio, and Body Temperature.

One of the challenges that emerged during the coronavirus disease 2019 (COVID-19) pandemic and is still relevant today is the need to identify patients with acute respiratory failure (ARF) who could benefit from conventional oxygen therapy (COT) - oxygen supplementation with nasal cannulas, Venturi masks, and non-rebreather masks - without recurring to advanced respiratory therapy, such as high-flow nasal cannula (HFNC), continuous positive airway pressure (CPAP), non-invasive ventilation (NIV), or invasive mechanical ventilation. The aim of the study was to develop a clinical tool able to predict the failure of COT in COVID-19 patients presenting to the emergency department (ED) with ARF. This was a retrospective monocentric cohort study carried out in the ED of the University Hospital of Bologna Sant’Orsola-Malpighi Polyclinic, Italy. The cohort comprised 101 COVID-19 patients with ARF from the first pandemic wave who received COT. This cohort was used to develop a scale that considers serum lactate concentration, partial arterial oxygen pressure/inspired oxygen fraction (PaO2/FiO2) ratio, and body temperature to predict COT failure, referred to as the Lactate, Oxygenation, and Temperature (LOT) score. The highest possible score was 17 points. The LOT score was associated with COT failure (area under the receiver operating curve or AUROC = 0.79, 95% CI 0.69 - 0.89, p < 0.001); the cut-off value of > 5 points had optimal predictive power and showed significantly higher 30-day mortality (log-rank χ2 = 28,828, p < 0.0001). The LOT score was able to effectively predict COT failure in COVID-19 patients with ARF. Patients with LOT score > 5 had a very high risk of therapy failure, and more advanced respiratory therapies must be considered in these patients.

Echocardiography in the intensive care unit: An essential tool for diagnosis, monitoring and guiding clinical decision-making.

In the last years, new trends on patient diagnosis for admission in cardiac intensive care unit (CICU) have been observed, shifting from acute myocardial infarction or acute heart failure to non-cardiac diseases such as sepsis, acute respiratory failure or acute kidney injury. Moreover, thanks to the advances in scientific knowledge and higher availability, there has been increasing use of positive pressure mechanical ventilation which has its implications on the heart. Therefore, there is a growing need for Cardiac intensivists to quickly, noninvasively and repeatedly evaluate various hemodynamic conditions and the response to therapy. Transthoracic critical care echocardiography (CCE) currently represents an essential tool in CICU, as it is used to evaluate biventricular function and complications following acute coronary syndromes, identify the mechanisms of circulatory failure, acute valvular pathologies, tailoring and titrating intravenous treatment or mechanical circulatory support. This could be completed with trans-esophageal echocardiography (TOE), advanced echocardiography and lung ultrasound to provide a thorough evaluation and monitoring of CICU patients. However, CCE could sometimes be challenging as the acquisition of good-quality images is limited by mechanical ventilation, suboptimal patient position or recent surgery with drains on the chest. Moreover, there are some technical caveats that one should bear in mind while performing CCE in order to optimize its use and avoid misleading findings. The aim of this review is to highlight the key role of CCE, providing an updated overview of its main applications and possible pitfalls in order to facilitate its use in CICU for clinical decision-making.

Use of Lung Ultrasound for Assessment of Lung Recruitment Maneuvers in Patients with ARDS

BACKGROUND: Positive pressure mechanical ventilation is a non-physiological intervention that saves lives but is not free of important side effects. It invariably results in different degrees of collapse of small airways. Recruitment maneuver (RM) aims to resolve lung collapse by a brief and controlled increment in airway pressure while positive end-expiratory pressure (PEEP) afterward keeps the lungs open. Therefore, ideally RM and PEEP selection must be individualized and this can only be done when guided by specific monitoring tools since lung’s opening and closing pressures vary among patients with different lung conditions. AIM: The aim of this study was to explore the clinical value of ultrasonic monitoring in the assessment of pulmonary recruitment and the best PEEP. PATIENTS AND METHODS: This study was conducted on 120 patients, 30 were excluded as in whom lung collapse cannot be confirmed then the rest were 90 patients from whom another 25 patients excluded as they were hemodynamically unstable the rest 65 patients were divided into two groups: Group A: Included 50 mechanically ventilated patients with ARDS, underwent lung recruitment using lung ultrasound and Group B: Included 15 mechanically ventilated patients with ARDS, underwent lung recruitment using oxygenation index. This prospective study was held at many critical care departments around Egypt. RESULTS: We noticed that lung recruitment in both groups significantly increased Pao2/Fio2 ratio immediately after recruitment compared with basal state and also significantly increase dynamic compliance compared with basal state. The increase in PF ratio immediately was significantly more in ultrasound group than in oxygenation group. Furthermore, we noticed that that P/F ratio 12 h after recruitment decreased compared with P/F ratio immediately after recruitment but significantly increased compared with basal state before recruitment and also we found that the increase in P/F ratio 12 h after recruitment was more significantly in lung ultrasound group than in oxygenation group. Furthermore, we noticed that lung recruitment (both lung ultrasound and oxygenation group) significantly increase RV function using TAPSE compared with basal state. Both opening pressure and optimal PEEP were significantly higher in lung ultrasound group than in oxygenation group. In our study, opening pressure was 37.28 ± 1.25 in lung ultrasound group and was 36.67±0.98 in oxygenation group and optimal PEEP was 14.64 ± 1.08 in lung ultrasound group and was 13.13 ± 0.74 in oxygenation group. CONCLUSION: Lung US is an effective mean of evaluating and guiding alveolar recruitment in ARDS. Compared with the maximal oxygenation–guided method, the protocol for reaeration in US-guided lung recruitment achieved a higher opening pressure, resulted in greater improvements in lung aeration, and substantially reduced lung heterogeneity in ARDS.