BACKGROUND AND OBJECTIVES

A mounting evidence links dysregulated immune response to cases of fatal pneumonia seen in COVID-19 infection. We aimed to validate the COVID-19-associated Hyperinflammatory Syndrome (cHIS) score, a novel clinical tool devised to identify those at risk for adverse outcomes, in a local population and investigate the relationship of cHIS score taken at admission and the risk of mortality and the need of mechanical ventilation.

This retrospective cohort study analyzed the sociodemographic, clinical, and laboratory data of 1,881 COVID-19 patients admitted at a tertiary hospital in Davao City, Philippines from January to December 2021. We calculated the cHIS score, composed of six clinical and laboratory criteria from admission, and used multivariate logistic regression to determine the risk of mortality and need of mechanical ventilation.

The cHIS score taken at admission, regardless of cut-off value, was a significant predictor of mortality (OR 0.979 [99% CI 0.894-1.064]) and need of mechanical ventilation (OR 0.586 [99% CI 0.4975-0.6745]). Using the Youden Index, a cut-off cHIS score of 3 or more was a better predictor of mortality (sensitivity, 88.59%; specificity, 71.72%), and a cut-off score of 2 or more was a better predictor of need of mechanical ventilation (sensitivity, 84.02%; specificity, 70.82%) than other cutoff cHIS scores.

Among COVID-19 patients, the cHIS score at admission correlated with the risk of mortality and the need of mechanical ventilation. Cutoff scores of 3 and 2 had the optimal sensitivities and specificities to predict the risk of mortality and the need of mechanical ventilation, respectively.

OBJECTIVE: To explore the correlation between mechanical power normalized to dynamic lung compliance (Cdyn-MP) and weaning outcomes and prognosis in mechanically ventilated patients. METHODS: A prospective, observational cohort study was conducted. Patients who underwent invasive mechanical ventilation (IMV) for more than 24 hours and used a T-tube ventilation strategy for extubation in the intensive care unit (ICU) of Lianyungang First People's Hospital and Lianyungang Second People's Hospital between January 2022 and December 2023 were enrolled. The collected data encompassed patients' baseline characteristics, primary causes of ICU admission, vital signs and laboratory indicators during the initial spontaneous breathing trial (SBT), respiratory mechanics parameters within the 4-hour period prior to the SBT, weaning outcomes and prognostic indicators. Mechanical power (MP) and Cdyn-MP were calculated using a simplified MP equation. Univariate and multivariate Logistic regression analyses were utilized to determine the independent risk factors associated with weaning failure in patients undergoing mechanical ventilation. Restricted cubic spline (RCS) analysis and Spearman rank-sum test were employed to investigate the correlation between Cdyn-MP and weaning outcomes as well as prognosis. Receiver operator characteristic curve (ROC curve) was constructed, and the area under the ROC curve (AUC) was computed to evaluate the predictive accuracy of Cdyn-MP for weaning outcomes in mechanically ventilated patients. RESULTS: A total of 366 patients undergoing IMV were enrolled in this study, with 243 cases classified as successful weaning and 123 cases classified as failed weaning. Among them, 23 patients underwent re-intubation within 48 hours after the successful withdrawal of the first SBT, non-invasive ventilation, or died. Compared with the successful weaning group, the patients in the failed weaning group had significantly increased levels of sequential organ failure assessment (SOFA) score, body temperature and respiratory rate (RR) during SBT, and respiratory mechanical parameters within the 4-hour period prior to the SBT [ventilation frequency, positive end-expiratory pressure (PEEP), platform pressure (Pplat), peak inspiratory pressure (Ppeak), dynamic driving pressure (ΔPaw), fraction of inspired oxygen (FiO₂), MP, and Cdyn-MP], dynamic lung compliance (Cdyn) was significantly reduced, and duration of IMV, ICU length of stay, and total length of hospital stay were significantly prolonged. However, there were no statistically significant differences in age, gender, body mass index (BMI), smoking history, main causes of ICU admission, other vital signs [heart rate (HR), mean arterial pressure (MAP), saturation of peripheral oxygen (SpO₂)] and laboratory indicators [white blood cell count (WBC), albumin (Alb), serum creatinine (SCr)] during SBT of patients between the two groups. Univariate Logistic regression analysis was conducted, and variables with P < 0.05 and no multicollinearity with Cdyn-MP were selected for inclusion in the multivariate Logistic regression model. The results demonstrated that SOFA score [odds ratio (OR) = 1.081, 95% confidence interval (95%CI) was 1.008-1.160, P = 0.030], and PEEP (OR = 1.191, 95%CI was 1.075-1.329, P = 0.001), FiO₂ (OR = 1.035, 95%CI was 1.006-1.068, P = 0.021) and Cdyn-MP (OR = 1.190, 95%CI was 1.086-1.309, P < 0.001) within the 4-hour period prior to the SBT were independent risk factors for weaning failure in patients undergoing IMV. The RCS analysis after adjusting for confounding factors showed that as Cdyn-MP within the 4-hour period prior to the SBT increased, the risk of weaning failure in patients undergoing IMV significantly increased (P < 0.001). The Spearman rank correlation test showed that Cdyn-MP within the 4-hour period prior to the SBT was positively correlated with respiratory mechanical parameters including ΔPaw and MP (r values were 0.773 and 0.865, both P < 0.01), and negatively correlated with Cdyn (r = -0.587, P < 0.01). Cdyn-MP within the 4-hour period prior to the SBT was positively correlated with prognostic indicators such as duration of IMV, length of ICU stay, and total length of hospital stay (r values were 0.295, 0.196, and 0.120, all P < 0.05). ROC curve analysis demonstrated that, within the 4-hour period preceding the SBT, Cdyn-MP, MP, Cdyn, and ΔPaw possessed predictive value for weaning failure in patients undergoing IMV. Notably, Cdyn-MP exhibited superior predictive capability, evidenced by an AUC of 0.761, with a 95%CI ranging from 0.712 to 0.810 (P < 0.001). At the optimal cut-off value of 408.5 J/min×cmH₂O/mL×10^-3, the sensitivity was 68.29%, and the specificity was 71.19%. CONCLUSION Cdyn-MP is related to weaning outcomes and prognosis in mechanically ventilated patients, and has good predictive ability in assessing the risk of weaning failure.
Humans ; Prospective Studies ; Ventilator Weaning ; Prognosis ; Respiration, Artificial ; Intensive Care Units ; Lung Compliance ; Female ; Male ; Middle Aged ; Aged

In recent years, prone mechanical ventilation has been widely used to improve oxygenation dysfunction in critically ill patients. During prone mechanical ventilation, the patient's face is compressed for a long time, and due to the difficulty in changing, facial pressure injuries and ocular complications are common and severe. These complications increase patient discomfort, reduce their tolerance and compliance with prone ventilation, and even cause tracheal tube displacement or dislodgement, leading to significant clinical challenges. In order to change this situation, the medical staff of the department of critical care medicine of the Second People's Hospital of Hengshui and the department of critical care medicine of Harrison International Peace Hospital had developed an adjustable facial support pad for prone ventilation, and obtained a National Utility Model Patent of China (ZL 2022 2 3295294.4). The device is composed of a facial support platform, a supporting telescopic foot frame and so on. There are front, back, left and right adjustable tracks below the support cushion platform, which can be adjusted to the best state suitable for the patient's face shape, which can alleviate the facial pressure injuries and ocular complications caused by the different sizes of each patient's face, improve the patient's comfort, and reduce the incidence of facial pressure injury and the occurrence of ocular complications of the patient. The height of the platform is adjusted by the telescopic feet, and there is a hook assembly below, which can be fixed by the clamp of the ventilator tubing, so as to prevent the ventilator tubing from pulling the endotracheal intubation due to the gravity of condensation, resulting in the displacement or even prolapse of the tracheal intubation, and reducing the occurrence of adverse events of tracheal intubation. It is worth promoting in the clinic.
Humans ; Respiration, Artificial/methods* ; Prone Position ; Equipment Design ; Face

Mechanical ventilation (MV) is currently widely used in the treatment of respiratory failure and anesthesia surgery, and is a commonly used respiratory support method for critically ill patients; however, improper usage of MV can lead to ventilator-induced lung injury (VILI), which poses a significant threat to patient life. Alveolar epithelial cell (AEC) has the functions of mechanosensation and mechanotransduction. Physiological mechanical stretching is beneficial for maintaining the lineage homeostasis and normal physiological functions of AEC cells, while excessive mechanical stretching can cause damage to AEC cells. Damage to AEC cells is an important aspect in the occurrence and development of VILI. Understanding the effects of mechanical stretching on AEC cells is crucial for developing safe and effective MV strategies, preventing the occurrence of VILI, and improving the clinical prognosis of VILI patients. From the perspective of cell mechanics, this paper aims to briefly elucidate the mechanical properties of AEC cells, mechanosensation and mechanotransduction of mechanical stretching in AEC cells, and the injury and repair of AEC cells under mechanical stretch stimulation, and potential mechanisms with the goal of helping clinical doctors better understand the pathophysiological mechanism of VILI caused by MV, improve their understanding of VILI, provide safer and more effective strategies for the use of clinical MV, and provide theoretical basis for the prevention and treatment of VILI.
Humans ; Mechanotransduction, Cellular ; Ventilator-Induced Lung Injury ; Stress, Mechanical ; Alveolar Epithelial Cells ; Respiration, Artificial/adverse effects* ; Epithelial Cells ; Pulmonary Alveoli/cytology* ; Animals

Mechanical ventilation is commonly employed for respiratory support in patients with respiratory failure. Despite the optimization of ventilator parameters and treatment methods, mechanical ventilation can still lead to both acute and chronic lung injury in patients with acute respiratory distress syndrome (ARDS) as well as in those without ARDS, a phenomenon referred to as ventilator-induced lung injury (VILI). VILI can be categorized into four types: barotrauma, volumetric injury, atelectasis injury, and biotic injury. Among these, biotic injury, characterized by inflammation, plays a significant role in the pathogenesis of VILI. Numerous studies have investigated the inflammatory mechanisms underlying VILI; however, these mechanisms remain complex and not entirely understood. At present, clinical practice lacks specific prevention and treatment strategies for VILI, aside from the implementation of protective ventilation strategies. Long non-coding RNAs (lncRNA) are a category of non-coding RNA longer than 200 nucleotides. LncRNAs regulate physiological and pathological processes such as cell proliferation, apoptosis, inflammatory response, and immune regulation, this regulation occurs through mechanisms such as modulating gene activity, inhibiting specific states, assisting in transcription initiation, affecting pre-mRNA splicing modifications, influencing translation processes, and expressing biofunctional peptides. They play an important role in the course of multiple diseases. Studies have shown that compared with control animals and cell models, lncRNAs are differentially expressed in VILI animal models and cell stretch models. Experiments have verified that certain lncRNAs play a crucial role in the pathogenesis of VILI by regulating the expression of inflammatory factors, the transformation of macrophage types, neutrophil activation, and cell apoptosis. Given the adverse effects of VILI on mechanical ventilation in critically ill patients, the important role of lncRNAs in biological regulation, and the urgent need to explore more effective strategies for the prevention and treatment of VILI, this paper summarizes the mechanisms through which lncRNA contributes to the VILI process, and discusses its possibility as a diagnostic and therapeutic target of VILI, in order to provide a reference for the clinical treatment of VILI.
RNA, Long Noncoding ; Ventilator-Induced Lung Injury ; Humans ; Respiration, Artificial/adverse effects* ; Animals ; Respiratory Distress Syndrome ; Apoptosis

Since the beginning of the 21st century, the severe respiratory infectious diseases worldwide [such as severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), influenza A H1N1 and novel coronavirus infection have attracted wide attention from all walks of life due to their superior pathogenicity and transmissibility. Aerosols-carrying pathogens are the main transmission route of many severe respiratory infectious diseases, which can lead to severe respiratory failure and even acute respiratory distress syndrome (ARDS) in infected individuals. Mechanical ventilation is the primary treatment for ARDS, and the small tidal volume, appropriate level of positive end-expiratory pressure based lung protective ventilation strategy can effectively reduce the incidence of ventilator-induced lung injury (VILI). However, in the process of clinical treatment, it is sometimes necessary to briefly disconnect the connection between the artificial airway and the ventilator circuit, which will not only cause the residual aerosol in the respiratory system to spill out and pollute the surrounding environment, increase the risk of nosocomial infection including medical staff, but also interfere with the implementation of lung protective ventilation strategy and aggravate ventilator-induced lung injury. In addition, studies have shown that a lot of medical staff have nosocomial infections, especially staff involved in tracheal intubation, extubation and other airway related operations. In addition to enhancing personal protective measures, it is crucial to safeguard healthcare workers from aerosol contamination and minimize associated risks during airway management. At present, there are few researches on the temporary sealing of airway lines and ventilator system, and there is a lack of clear guidance. This review summarizes the research status in related fields to provide a reference for corresponding solutions and programs.
Humans ; Respiratory Distress Syndrome/etiology* ; Respiration, Artificial ; Ventilator-Induced Lung Injury/prevention & control* ; Severe Acute Respiratory Syndrome ; COVID-19 ; Clinical Relevance

OBJECTIVE: To evaluate the safety and clinical therapeutic effect of in-line mechanical in-exsufflation to assist sputum clearance in patients with invasive mechanical ventilation. METHODS: A prospective observational study was conducted at the department of critical care medicine, the First Affiliated Hospital of Sun Yat-sen University from April 2022 to May 2023. Patients who were invasively ventilated and treated with in-line mechanical in-exsufflation to assist sputum clearance were enrolled. Baseline data were collected. Sputum viscosity, oxygenation index, parameters of ventilatory function and respiratory mechanics, clinical pulmonary infection score (CPIS) and vital signs before and after day 1, 2, 3, 5, 7 of use of the in-line mechanical in-exsufflation were assessed and recorded. Statistical analyses were performed by using generalized estimating equation (GEE). RESULTS: A total of 13 invasively ventilated patients using in-line mechanical in-exsufflation were included, all of whom were male and had respiratory failure, with the main cause being cervical spinal cord injury/high-level paraplegia (38.46%). Before the use of the in-line mechanical in-exsufflation, the proportion of patients with sputum viscosity of grade III was 38.46% (5/13) and decreased to 22.22% (2/9) 7 days after treatment with in-line mechanical in-exsufflation. With the prolonged use of the in-line mechanical in-exsufflation, the patients' CPIS scores tended to decrease significantly, with a mean decrease of 0.5 points per day (P < 0.01). Oxygenation improved significantly, with the oxygenation index (PaO₂/FiO₂) increasing by a mean of 23.3 mmHg (1 mmHg ≈ 0.133 kPa) per day and the arterial partial pressure of oxygen increasing by a mean of 12.6 mmHg per day (both P < 0.01). Compared to baseline, the respiratory mechanics of the patients improved significantly 7 days after in-line mechanical in-exsufflation use, with a significant increase in the compliance of respiratory system (Cst) [mL/cmH₂O (1 cmH₂O ≈ 0.098 kPa): 55.6 (50.0, 58.0) vs. 40.9 (37.5, 50.0), P < 0.01], and both the airway resistance and driving pressure (DP) were significantly decreased [airway resistance (cmH₂O×L^-1×s^-1): 9.6 (6.9, 10.5) vs. 12.0 (10.0, 13.0), DP (cmH₂O): 9.0 (9.0, 12.0) vs. 11.0 (10.0, 15.0), both P < 0.01]. At the same time, no new lung collapse was observed during the treatment period. No significant discomfort was reported by patients, and there were no substantial changes in heart rate, systolic blood pressure, diastolic blood pressure, and mean arterial pressure before and after the in-line mechanical in-exsufflation treatment. CONCLUSIONS The combined use of the in-line mechanical in-exsufflation to assist sputum clearance in patients on invasive mechanical ventilation can effectively improve sputum characteristics, oxygenation and respiratory mechanics. The in-line mechanical in-exsufflation was well tolerated by the patients, with no treatment-related adverse events, which demonstrated its effectiveness and safety.
Humans ; Prospective Studies ; Respiration, Artificial/methods* ; Respiratory Insufficiency/therapy* ; Sputum

Prone position ventilation (PPV) is an important protective strategy for lung ventilation, widely used in clinical practice, especially since the novel coronavirus infection pandemic. Since PPV is a non-physiological position, improper implementation and management can lead to serious adverse events such as pressure injury, facial edema, unplanned extubation and (or) reintubation, and even asphyxia. At present, preventive and protective strategies are mainly used to manage PPV-related complications in clinical practice. These strategies not only increase the workload of medical staff and the use of consumables, but also increase the medical cost of patients, further burdening patients and their families economically. To overcome the above problems, the medical staff of the department of critical care medicine of Tianjin Third Central Hospital designed a prone position head auxiliary support device and obtained a national utility model patent (patent number: ZL 2022 2 1751906.3). The device consists of annular plate, folding plate, support frame, reflector and wheel bodies. It serves to reduce pressure on the head and facial skin, while also exposing the mouth, nose, eyes, and ears to the hollow position of the annular plate according to the patient's position. At the same time, the patient's face or side skin can be observed through the lower reflector. The height of the annular plate was adjusted by adjusting the support frame, and the head was raised to reduce facial edema. The setting of strip groove, through hole and hook can sort out the facial pipeline, keep the drainage unobstructed, prevent catheter displacement and unplanned extubation, and has certain clinical promotion and practical value.
Humans ; Prone Position ; Equipment Design ; Respiration, Artificial/methods* ; COVID-19 ; Head ; Patient Positioning

OBJECTIVE: To explore the preventive effect of transcutaneous phrenic nerve stimulation on ventilator-induced diaphragmatic dysfunction (VIDD) in patients requiring invasive mechanical ventilation. METHODS: A randomized controlled trial was conducted. The patients requiring invasive mechanical ventilation admitted to the intensive care unit (ICU) of Jiaxing First Hospital from November 2022 to December 2023 were enrolled. Participants were randomized into the control group and the observation group using a random number table. The control group was given ICU standardized nursing intervention, including turning over and slapping the back, raising the head of the bed, sputum aspiration on demand, aerosol inhalation, oral care, and monitoring of airbag pressure and gastric retention, the observation group was given additional transcutaneous phrenic nerve stimulation intervention on the basis of ICU standardized nursing intervention. The stimulation intensity was set to 10 U, the pulse frequency was set to 40 Hz, and the stimulation frequency was set to 12 times/min. Transcutaneous phrenic nerve stimulation was administered once a day for 30 minutes each time, for a total of 5 days. Diaphragm thickening fraction (DTF) and arterial blood gas parameters on days 1, 3, and 5 of intervention were compared between the two groups. After 5 days of intervention, other parameters including the incidence of VIDD, duration of mechanical ventilation, and length of ICU stay were compared. RESULTS: A total of 120 patients requiring invasive mechanical ventilation were enrolled, with 16 dropouts (dropout rate was 13.33%). Ultimately, 51 patients in the control group and 53 patients in the observation group were analyzed. Baseline characteristics, including gender, age, body mass index (BMI), acute physiology and chronic health evaluation II (APACHE II) score, albumin (Alb), hemoglobin (Hb), and disease type, showed no significant differences between the two groups. DTF in both groups gradually increased over duration of intervention [DTF on days 1, 3, and 5 in the control group was (20.83±2.33)%, (21.92±1.27)%, and (23.93±2.33)%, respectively, and that in the observation group was (20.89±1.96)%, (22.56±1.64)%, and (25.34±2.38)%, respectively], with more significant changes in DTF in the observation group, showing time effects (F_time = 105.975, P < 0.001), intervention effects (F_intervention = 7.378, P = 0.008), and interaction effects (F_interaction = 3.322, P = 0.038). Arterial blood gas parameters did not differ significantly before intervention between the groups, but after 5 days of intervention, arterial partial pressure of oxygen (PaO₂) in the observation group was significantly higher than that in the control group [mmHg (1 mmHg≈0.133 kPa): 100.72±15.75 vs. 93.62±15.54, P < 0.05], and arterial partial pressure of carbon dioxide (PaCO₂) was significantly lower than that in the control group (mmHg: 36.53±3.10 vs. 37.69±2.02, P < 0.05). At 5 days of intervention, the incidence of VIDD in the observation group was significantly lower than that in the control group [15.09% (8/53) vs. 37.25% (19/51), P < 0.05], and both duration of mechanical ventilation and length of ICU stay were significantly shorter than those in the control group [duration of mechanical ventilation (days): 7.93±2.06 vs. 8.77±1.76, length of ICU stay (days): 9.64±2.35 vs. 11.01±2.01, both P < 0.05]. CONCLUSIONS Transcutaneous phrenic nerve stimulation can improve diaphragmatic and respiratory function in patients receiving invasive mechanical ventilation, reduce the incidence of VIDD, and shorten the duration of mechanical ventilation and length of ICU stay.
Humans ; Transcutaneous Electric Nerve Stimulation ; Respiration, Artificial/adverse effects* ; Diaphragm/physiopathology* ; Phrenic Nerve ; Intensive Care Units ; Male ; Female ; Middle Aged

OBJECTIVE: To explore the effects of different endotracheal tube cuff pressure management modes on cuff sealing and the pressure exerted on the tracheal wall. METHODS: A prospective self-controlled study was conducted. Eleven patients undergoing endotracheal intubation and mechanical ventilation with an automatic airway management system (AGs) admitted to the Second Medical Centre of the Chinese People's Liberation Army General Hospital from October 1, 2020, to April 1, 2022, were enrolled as the study subjects. Within 24 hours after the establishment of artificial airway and mechanical ventilation, four cuff pressure management modes were randomly applied to each patient for 24 hours in sequence: automatic cuff pressure management mode [modeI: the safe range of cuff pressure was set at 20-35 cmH₂O (1 cmH₂O≈0.098 kPa), and the CO₂ pressure above the endotracheal tube cuff was automatically detected by AGs every 5 minutes to determine the cuff sealing status, and the cuff pressure was automatically adjusted], constant cuff pressure (25 cmH₂O) management mode (mode II: the cuff pressure was monitored by AGs through a pressure sensor, and the cuff pressure was maintained at 25 cmH₂O via a pressure pump), constant cuff pressure (30 cmH₂O) management mode (mode III: the cuff pressure was monitored by AGs through a pressure sensor, and the cuff pressure was maintained at 30 cmH₂O via a pressure pump), and manual cuff pressure management mode (mode IV: the cuff pressure was manually measured by nurses every 6-8 hours using a cuff pressure gauge to keep the cuff pressure at 25-30 cmH₂O after inflation). The CO₂ pressure above the endotracheal tube cuff (at 60-minute intervals) and the cuff pressure changes (at 50-ms intervals) were recorded to compare the differences in number of cuff leaks [no leak was defined as CO₂ pressure = 0, small leak as 0 < CO₂ pressure < 2 mmHg (1 mmHg≈0.133 kPa), and large leak as CO₂ pressure ≥ 2 mmHg] and cuff pressure among modesI-IV. RESULTS: A total of 24 CO₂ pressure measurements were taken per patient across the four modes, resulting in a total of 264 detections for each mode. Regarding the cuff leak, the total number of leak and large leak in modeIwas significantly lower than that in modes II-IV [total leak: 30 cases (11.36%) vs. 81 cases (30.68%), 70 cases (26.52%), 103 cases (39.02%); large leak: 15 cases (5.68%) vs. 50 cases (18.94%), 48 cases (18.18%), 66 cases (25.00%), all P < 0.05]. There was no significant difference in the number of cuff leak between modes II and III, and mode IV had the most severe cuff leak. In terms of cuff pressure, since mode IV required blocking the cuff tube from the AGs tube and the AGs cuff pressure management module did not actually work, real-time monitoring of cuff pressure was not possible. Therefore, cuff pressure changes were only analyzed in modes I-III. Each of the 11 patients underwent 24-hour cuff pressure monitoring under modes I-III, with 19 008 000 monitoring times for each mode. The cuff pressure in mode I was between that in modes II and III [cmH₂O: 27.09 (26.10, 28.14) vs. 26.60 (25.92, 27.47), 31.01 (30.33, 31.88), both P < 0.01]. Moreover, the number of extreme values of cuff pressure > 50 cmH₂O in mode I was significantly lower than that in modes II and III [19 900 cases (0.105%) vs. 22 297 cases (0.117%), 27 618 cases (0.145%), both P < 0.05]. CONCLUSION Dynamically monitoring the CO₂ pressure above the cuff to guide the adjustment of endotracheal tube cuff pressure can achieve better cuff sealing with a relatively lower cuff pressure load.
Humans ; Intubation, Intratracheal/instrumentation* ; Pressure ; Prospective Studies ; Respiration, Artificial ; Male ; Airway Management/methods* ; Female ; Middle Aged