Survey of Ventilator Waveform Interpretation Among ICU Professionals

BACKGROUND

The interpretation of ventilator waveforms is essential for effective and safe mechanical ventilation but requires specialized training and expertise. This study aimed to investigate the ability of ICU professionals to interpret ventilator waveforms, identify areas requiring further education and training, and explore the factors influencing their interpretation skills.

METHODS

We conducted an international online anonymous survey of ICU professionals (physicians, nurses, and respiratory therapists [RTs]), with ≥ 1 y of experience working in the ICU. The survey consisted of demographic information and 15 multiple-choice questions related to ventilator waveforms. Results were compared between professions using descriptive statistics, and logistic regression (expressed as odds ratios [ORs; 95% CI]) was performed to identify factors associated with high performance, which was defined by a threshold of 60% correct answers.

RESULTS

A total of 1,832 professionals from 31 countries or regions completed the survey; 53% of respondents answered ≥ 60% of the questions correctly. The 3 questions with the most correct responses were related to waveforms that demonstrated condensation (90%), pressure overshoot (79%), and bronchospasm (75%). Conversely, the 3 questions with the fewest correct responses were waveforms that demonstrated early cycle leading to double trigger (43%), severe under assistance (flow starvation) (37%), and early/reverse trigger (31%). Factors significantly associated with ≥ 60% correct answers included years of ICU working experience (≥ 10 y, OR 1.6 [1.2-2.0], P < .001), profession (RT, OR 2.8 [2.1-3.7], P < .001), highest degree earned (graduate, OR 1.7 [1.3-2.2], P < .001), workplace (teaching hospital, OR 1.4 [1.1-1.7], P = .008), and prior ventilator waveforms training (OR 1.7 [1.3-2.2], P < .001).

CONCLUSIONS

Slightly over half respondents correctly identified ≥ 60% of waveforms demonstrating patient-ventilator discordance. High performance was associated with ≥ 10 years of ICU working experience, RT profession, graduate degree, working in a teaching hospital, and prior ventilator waveforms training. Some discordances were poorly recognized across all groups of surveyed professionals.

Simulated ventilation of two patients with a single ventilator in a pandemic setting

Simultaneous ventilation of two patients may lead to hypoventilation in one patient and hyperinflation in the other patient. In a simulation of ventilation in two patients using artificial lungs, we voluntarily directed gas flow to one patient by using three-dimensional-printed Y-adapters and stenosis adapters during volume- and pressure-controlled ventilation in the first set up. We continuously modified the model using a special one-way valve on the flow-limited side and measured it in pressure-controlled ventilation with the flow sensor of the ventilator adjusted on both sides in a second and third setup. In the first setup, volume- or pressure-controlled ventilation resulted in comparable minute volumes in both lungs, even when one side was obstructed to 3 mm. In the second setup, with a 3-mm flow limitation, we had a minute ventilation of 9.4 ± 0.3 vs. 3.5 ± 0.1 L/min. In the third setup, ventilation with a 3-mm flow limitation resulted in minute ventilation of 7.2 ± 0.2 vs. 5.70 L/min at a compliance of 30 vs. 70 mL/mbar. It is possible to override the safety features of a modern intensive care ventilator and thus direct tidal volumes in different lung conditions to one lung using three-dimensional-printed flow limiters. While this ventilation setting was technically feasible in a bench model, it would be unstable, if not dangerous, in a clinical situation.

[Research on the Quality Control of Routine Reusable Pipeline and Disposable Pipeline of Ventilator]

Objective

To explore the effect of routine reusable pipeline and disposable pipeline on ventilator quality control results.

Methods

17 ventilators were randomly selected to conduct quality control using routine reusable pipeline and disposable pipeline respectively. Quality control data were recorded and then paired t-test method was used to analyze whether the difference between the two pipelines was significant or not.

Results

There were no significant differences in respiratory rate, tidal volume and end airway pressure between the two types of pipes ( P＞0.05). The airway peak pressure of routine reusable pipeline was significantly higher than disposable pipeline ( P＜0.05), but the difference was very small, only about 0.2 mbar which would not affect the conclusion of quality control.

Conclusion

Quality control of ventilator is not affected by routine reusable pipeline and disposable pipeline, which can be replaced by each other.

Activity of Daily Living and Walking Ability of Patients with Severe COVID-19 at Discharge from an Acute Care Hospital

Objectives

The effectiveness of acute rehabilitation treatment for severe coronavirus disease 2019 (COVID-19) has not yet been established. This study examined the efficacy of treatment provided to patients with severe COVID-19 in an acute care facility.

Methods

A total of 98 patients with severe COVID-19 requiring inpatient management in our intensive care unit (ICU) were included between December 2020 and October 2021. They were divided into two groups: those who received physiotherapy (PT group; n=44) and those who did not receive physiotherapy (non-PT group; n=54). Their backgrounds, clinical characteristics, and activities of daily life (ADL) at discharge were compared to examine factors that influenced the need for physiotherapy (PT). We also evaluated the effect of PT on ADL by comparing the Barthel Index (BI) before PT and at discharge.

Results

The PT group patients were significantly older, had longer hospital and ICU stays, and used invasive mechanical ventilators (IMV) more frequently than those in the non-PT group. More patients in the non-PT group were able to walk at discharge than in the PT group. The PT group patients showed significant improvement in BI and ADL at discharge when compared with BI at the start of PT, regardless of whether an IMV was used.

Conclusions

Older patients with severe COVID-19 with prolonged hospitalization or ICU stay or on an IMV are prone to a decline in ADL and may need to be considered for early PT.

Prediction of fluid responsiveness for patients in shock using a ventilator disconnection test combined with the pulse contour-derived cardiac index

BACKGROUND

Finding a simple and reliable method to predict and assess fluid responsiveness has long been of clinical interest.

OBJECTIVE

To investigate the predictive value of a ventilator disconnection (DV) test combined with the pulse contour-derived cardiac output (PiCCO) index on fluid responsiveness for patients in shock.

METHODS

Thirty-two patients were chosen for the study. Patients who were in shock, received mechanical ventilation, and met the inclusion criteria were selected. Patients were divided into a fluid-responsive group (14 patients) and fluid-unresponsive group (18 patients) based on whether the increase in cardiac index (Δ CI) was > 10% or not, respectively, following the fluid challenge test. Changes in heart rate, pulse oximeter-measured oxygen saturation, mean arterial pressure (MAP), and CI before and after passive leg raising (PLR), DV, and fluid challenge tests were observed. We used Pearson's correlation coefficient to analyze an increase in the MAP (Δ MAP) and Δ CI before and after the PLR, DV, and fluid challenge tests; the sensitivity and specificity of the Δ MAP and Δ CI in the PLR and DV tests for predicting fluid response were also analyzed by plotting the receiver operating characteristic (ROC) curves.

RESULTS

CI results in the PLR and DV tests, as well as the fluid challenge test, were significantly higher in the fluid-responsive group compared with before the test (P< 0.05). The Δ CI before and after the PLR, DV, and fluid challenge tests were positively correlated among patients in the fluid-responsive group. The area under the ROC curve for the post-PLR test CI and the post-DV CI for predicting fluid responsiveness was 0.869 (95% confidence interval (CI) [0.735-1.000, P= 0.000]) and 0.937 (95% CI [0.829-1.000, P= 0.000]), respectively, in patients in the fluid-responsive group. The sensitivity and specificity of the post-DV CI for predicting fluid responsiveness in all patients was 100.0% and 88.9%, respectively, using a 5% increase as the cut-off value.

CONCLUSION

Application of DV, combined with PiCCO, has a high predictive value for fluid responsiveness among patients in shock.

Early Versus Late Initiation of Hydrocortisone in Patients With Septic Shock: A Prospective Study

Introduction The optimal timing of corticosteroid initiation in septic shock patients is debatable. The Surviving Sepsis Campaign Guidelines recommended adding hydrocortisone to septic shock patients who require a vasopressor with a dose of norepinephrine ≥ 0.25 mcg/kg/min for at least four hours. Nevertheless, the best time to initiate hydrocortisone remains uncertain. Objective Assessing the impact of early (≤3 hours) versus late (>3 hours) initiation of hydrocortisone in septic patients. Methodology We compared the outcomes of septic shock patients who received hydrocortisone within three hours versus those who started treatment after three hours. The inclusion criteria encompassed septic shock patients aged 18 or older who received at least one dose of hydrocortisone. Exclusion criteria included pregnancy, do-not-resuscitate orders, the absence of empirical intravenous antibiotics, recent corticosteroid use, recent cardiac arrest, and a history of adrenal insufficiency. Results Eighty-one patients were included (54% were males). The mean age was 59 years, and 56.8% of patients were in the early group. The time needed to discontinue vasopressors was 25 and 37 hours for the early and late groups, respectively (p = 0.009), and more patients achieved reversal of shock (35 vs. 24 patients) and had shorter ICU stays (17 days vs. 20 days). Conclusion Initiating hydrocortisone early, within three hours, reduced the time needed to discontinue vasopressors among the study population. However, both early and late initiation strategies yielded comparable outcomes in terms of ICU mortality, ICU length of stay, and shock reversal.

Development and evaluation of simulation-based scenario education program for professional oral hygiene care in intubated patient

PURPOSE

This study was conducted to develop a professional oral hygiene care (POHC) simulation education program for intubated patients and to evaluate the suitability of education by evaluating the performance confidence (PC), critical thinking disposition (CT), and learning satisfaction (LS) of dental hygiene students.

METHODS

This study developed a POHC simulation education program (theory, skill training, scenario education, and debriefing) for intubated patients through expert validation and consisted of a single-group pre- and postexperiment design. The subjects were 3rd and 4th year students at the Department of Dental Hygiene in Wonju City, and a total of 30 people were enrolled. The collected data were analyzed using the PASW Statistics version 23.0. The content validity test was measured by the CVI (Content validity index) value, and the PC, CT, and LS of the subjects before and after participating in the program were analyzed using a paired t-test. The significance level (α) was based on .05.

RESULTS

After the program, the PC improved from 4.29 ± 0.43 to 4.54 ± 0.44, and there was a significant difference (p = .004). CT improved from 3.73 ± 0.36 to 3.84 ± 0.36, but there was no significant difference (p = .062), and prudence improved from 4.21 ± 0.33 to 4.43 ± 0.27, and there was significant difference. (p = .001). LS increased from 4.66 ± 0.36 to 4.90 ± 0.16 after education, and there was a significant difference (p = .002).

CONCLUSION(S)

Simulation education program improved dental hygiene students' POHC performance confidence. Various scenarios will need to be developed in the future, and it is necessary to evaluate simulation education within the dental hygiene curriculum and identify areas for improvement.

A retrospective analysis of COVID-19 tracheostomies: Early versus late tracheostomy

Objectives

To assess the impact of early tracheostomy (ET) versus late tracheostomy (LT) placement on mortality and decannulation rates of COVID patients.

Methods

A retrospective chart review was performed of all patients infected with COVID-19 who underwent tracheostomy tube placement in an Ochsner-affiliated hospital from March 2020 to May 2022. Patients were identified using the electronic medical record and data was collated using the "Epic SlicerDicer" tool. Descriptive statistics were gathered and compared between patients who underwent ET placement and those who underwent LT placement. Patient demographics, previous medical history, tracheostomy procedural details, arterial blood gases, complications, and outcomes including time to wean from the ventilator, and time to decannulation were recorded.

Results

Two-hundred nineteen patients were included in the study. There were no statistically significant differences in liberation from mechanical ventilation rates between early and LT (62% vs. 55%, p = .19), or in decannulation rates (40% vs. 32%, p = .14). The mean duration of time to liberation from mechanical ventilation for early trach was 13.88 versus 18.17 days for late trach, however, no statistically significant difference was found (p = .12). Similarly, mean duration of time to decannulation was 41.17 days for early versus 47.72 for late trach (p = .15).

Conclusion

Contrary to some studies in the literature, the results presented here suggest ETs are not associated with hastened liberation from mechanical ventilation or increased decannulation rates. Further prospective studies may be warranted in assessing the impact of early versus LT in the COVID patient population.

Level of Evidence

III.

[Design of Portable Noninvasive Positive Pressure Ventilator System Based on Threshold Trigger of Flow Rate Change]

In order to effectively treat respiratory diseases, a non-invasive positive pressure ventilator system is designed, the overall structure design of the system is proposed, and the hardware construction is completed. The breathing state of the patient is identified by the threshold triggering method of the flow rate of change, and the calculation of the flow rate of change is realized by the least squares method. At the same time, the breathing parameters are calculated in real time according to the flow-time and pressure-time characteristic curves. In addition, CMV, CPAP, BiPAP and PSV ventilation modes are also implemented. Finally, the parameter measurement accuracy and ventilation mode setting tests are carried out. The results show that the calculation of key breathing parameters provided by the system meets the relevant standards, and supports the stable output of 4 ventilation modes at the same time, provides breathing treatment for patients, and meets the basic functional requirements of the ventilator.

[Research and Design of Automatic Test System for Ventilator Performance]

Ventilator is an important medical instrument which can replace the function of autonomous ventilation artificially. Its safety and reliability are related to the health and even life safety of patients. With the publishing of the new national standard and international standard for ventilators, higher requirements are put forward for the detection and evaluation. This study mainly introduces an automatic test system for ventilator performance. The test system is based on PF-300 air-flow analyzer of Imtmedical and standard simulation lung. The automatic switch module of simulation lung is developed, and the automatic test system of ventilator is designed using the software development platform based on Python. It can not only automatically test all ventilation control parameters and monitoring parameters of the ventilator, but also realize automatic data recording, form reports and data analysis, and improve the efficiency and quality of inspection, detection and quality control.

Mechanical Power Is Associated With Mortality in Pediatric Acute Respiratory Distress Syndrome

OBJECTIVES

Mechanical power (MP) transferred from the ventilator to the lungs has been proposed as a summary variable that may impact mortality in children with acute respiratory distress syndrome (ARDS). To date, no study has shown an association between higher MP and mortality in children with ARDS.

DESIGN

Secondary analysis of a prospective observational study.

SETTING

Single-center, tertiary, academic PICU.

PATIENTS

Five hundred forty-six intubated children with ARDS enrolled between January 2013 and December 2019 receiving pressure-controlled ventilation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Higher MP was associated with increased mortality (adjusted hazard ratio [HR] 1.34 per 1 sd increase, 95% CI 1.08-1.65; p = 0.007). When assessing the contribution of individual components of MP, only positive end-expiratory pressure (PEEP) was associated with mortality (HR 1.32; p = 0.007), whereas tidal volume, respiratory rate, and driving pressure (ΔP = [peak inspiratory pressure (PIP)-PEEP]) were not. Finally, we tested whether there remained an association when specific terms were removed from the MP equation by calculating MP from static strain (remove ΔP), MP from dynamic strain (remove PEEP), and mechanical energy (remove respiratory rate). MP from static strain (HR 1.44; p < 0.001), MP from dynamic strain (HR 1.25; p = 0.042), and mechanical energy (HR 1.29; p = 0.009) were all associated with mortality. MP was associated with ventilator-free days only when using MP normalized to predicted body weight, but not when using measured weight.

CONCLUSIONS

Higher MP was associated with mortality in pediatric ARDS, and PEEP appears to be the component most consistently driving this association. As higher PEEP is used in sicker patients, the association between MP and mortality may reflect a marker of illness severity rather than MP itself being causal for mortality. However, our results support future trials testing different levels of PEEP in children with ARDS as a potential means to improve outcome.

Evaluation of safety and effectiveness of remdesivir in treating COVID-19 patients after emergency use authorization study

Background: This study aimed to determine the real-world safety and effectiveness of remdesivir in hospitalized adult COVID-19 patients with moderate-to-critical disease in Indonesia. Methods: A multicenter, retrospective cohort study was conducted at four COVID-19 referral hospitals in Jakarta. A total of 587 patients were included, of whom 243 received remdesivir within 72 h of admission. The safety endpoints were the proportions of patients with any adverse event (AE), any grade 3 AE, and AE of each system organ class. The effectiveness endpoints were ICU admission >24 h from baseline, live discharge and mortality at day 14, live discharge and mortality at day 28, and virologic conversion. Patients who received remdesivir within 72 h of admission were considered the treatment group, and those who did not were the control group. Multivariate adjustments were performed using a modified Poisson regression. Results: The study found no significant differences in safety endpoints between the two groups. However, the effectiveness endpoints showed that remdesivir was associated with a decreased risk of ICU admission >24 h from baseline (RR 0.71, 95% CI 0.52-0.96), an increased probability of live discharge at day 14 (RR 1.37, 95% CI 1.08-1.74), and an increased probability of live discharge at day 28 (RR 1.28, 95% CI 1.05-1.57). The rate of virologic conversion was not significantly different between the two groups. Conclusion: The study concludes that remdesivir is safe and effective in the treatment of moderate-to-critical COVID-19 in a real-world setting in Indonesia.

Bronchopulmonary Dysplasia: Ongoing Challenges from Definitions to Clinical Care

Bronchopulmonary dysplasia (BPD) is the most common complication of extreme prematurity. Its etiology is multifactorial and is attributed to genetic susceptibility to prenatal and postnatal factors. As advancements in neonatology have led to the increased survival of premature infants, a parallel increase in the incidence of BPD has occurred. Over time, the definition and diagnostic criteria for BPD have evolved, as have management strategies. However, challenges continue to exist in the management of these infants, which is not surprising given the complexity of the disease. We summarize the key diagnostic criteria and provide insight into the challenges related to various aspects of BPD definitions, data comparisons, and clinical care implementation.

Assessment of the Peradeniya Organophosphorus Poisoning Scale as a Severity and Prognostic Marker in Patients With Acute Organophosphorus Poisoning Presenting to an Emergency Medicine Department

Background Organophosphorus (OP) compound poisoning is the most common toxicological medical emergency in India, where the majority of the population lives on agriculture. The Peradeniya Organophosphorus Poisoning (POP) scale can be a simple and effective system to determine the need for ventilatory support early in the course of admission. The objective of this study was to evaluate the prognostic value of the clinical parameters of the POP scale in predicting the severity of organophosphorus compound poisoning, by comparing early predicted patient prognosis evaluated by the POP scale on admission with the patient outcome. Methods This was a prospective observational study of acute organophosphorus compound poisoning presenting to the emergency department of Sir Sayajirao General (SSG) Hospital and Medical College, Baroda. We included patients over 12 years of age with a history of, or symptoms suggestive of, acute OP poisoning. The patients received initial resuscitation according to airway, breathing, circulation, disability, and exposure simultaneously with decontamination and gastric lavage by Ryle's tube. They also received the standard antidotes of atropine and pralidoxime immediately. We applied the POP scale to each patient upon admission and graded the poisoning severity as mild (a POP scale score of 0-3), moderate (4-7), or severe (8-11). This scale assessed the patients' need for mechanical ventilation and ICU management and their final clinical outcome. Results We enrolled 60 patients in the study. Most of them were under 20 years of age, and 65% of them were male. Social laborers were the major population, and most of them had suicidal intention. Monocrotophos was the most commonly consumed OP compound. Most of the patients were brought to the hospital within two to six hours of consumption. Vomiting and profuse secretions were the primary presenting symptoms. A majority of the patients (47) fell into the mild POP scale range. None of the patients had severe poisoning. Out of 60 patients, 49 patients improved and 11 patients died. Seven patients (15%) with mild POP scale scores and four patients (31%) with moderate scores died. Overall, 61.7% of patients with mild POP scale scores and 100% of patients with moderate scores needed mechanical ventilation. Conclusion The POP scale is an effective tool to measure severity and make a prognosis in patients with acute OP compound exposure. It may be a simple, inexpensive tool that may help predict the need for ventilatory support at admission. Early identification of danger signs may help in the reduction of mortality and morbidity when resources are limited. However, we found incorporating other clinical parameters and biochemical markers provides better prognostication than using the POP scale alone.

Pneumoperitoneum in a Patient With COVID-19 and Acute Respiratory Distress Syndrome Without Pneumothorax

We present a case report of pneumoperitoneum, pneumomediastinum, and subcutaneous emphysema in a patient with COVID-19 pneumonia-causing acute respiratory distress syndrome (ARDS) without any pneumothorax occurring. Pneumothorax, pneumomediastinum, and subcutaneous emphysema are known complications of barotrauma due to positive pressure from mechanical ventilation which is necessary for patients suffering from a severe case of COVID-19. In our literature search, we could not find any reported case of pneumoperitoneum without pneumothorax occurring. Our case is an important addition to the literature presenting a rare complication of mechanical ventilation in patients with ARDS.

Clinical Outcome Comparison of Patients Requiring Extracorporeal Membrane Oxygenation With or Without COVID-19 Infection

In severe COVID-19-related respiratory failure, extracorporeal membrane oxygenation (ECMO) is a useful modality that is used to provide effective oxygenation and ventilation to the patient. This descriptive study aimed to investigate and compare the outcomes between COVID-19-infected patients and patients who were not infected and required ECMO support. A retrospective study was undertaken on a cohort of 82 adult patients ([Formula: see text]18-year-old) who required venoarterial (VA-ECMO) and venovenous (VV-ECMO) ECMO between January 2019 and December 2022 in a single academic center. Patients who were cannulated for COVID-19-related respiratory failure (C-group) were compared to patients who were cannulated for non-COVID etiologies (non-group). Patients were excluded if data were missing regarding cannulation, decannulation, presenting diagnosis, and survival status. Categorical data were reported as counts and percentages, and continuous data were reported as means with 95% confidence intervals. Out of the 82 included ECMO patients, 33 (40.2%) were cannulated for COVID-related reasons, and 49 (59.8%) were cannulated for reasons other than COVID-19 infection. Compared to the non-group, the C-group had a higher in-hospital (75.8% vs. 55.1%) and overall mortality rate (78.8% vs. 61.2%). The C-group also had an average hospital length of stay (LOS) of 46.6 ± 13.2 days and an average intensive care unit (ICU) LOS of 44.1 ± 13.3 days. The non-group had an average hospital LOS of 24.8 ± 6.6 days and an average ICU LOS of 20.8 ± 5.9 days. Subgroup analysis of patients only treated with VV-ECMO yielded a greater in-hospital mortality rate for the C-group compared to the non-group (75.0% vs. 42.1%). COVID-19-infected patients may experience different morbidity and mortality rates as well as clinical presentations compared to non-COVID-infected patients when requiring ECMO support.

Sleep disturbances in parental caregivers and patients with congenital central hypoventilation syndrome

STUDY OBJECTIVES

Congenital central hypoventilation syndrome (CCHS) is a rare disease characterized by impaired control of breathing caused by paired-like homeobox 2B (PHOX2B) gene variants, necessitating lifelong assisted ventilation (AV). This study aimed to assess sleep quality in patients with CCHS and their parents using sleep questionnaires.

METHODS

Parents of patients with CCHS completed the Pittsburgh Sleep Quality Index (PSQI) regarding their sleep and the Sleep Disturbance Scale for Children (SDSC) regarding their child's sleep.

RESULTS

Twenty participants completed the questionnaires. The median (interquartile range) ages of the parents and patients were 41.5 (38.5-51.5) and 11.5 (7.4-16.7) years, respectively. The median (interquartile range) PSQI and SDSC scores were elevated at 6.5 (4-10) and 41.5 (34-51.5), respectively, suggesting that parents and patients with CCHS can experience sleep disturbances and poor sleep quality. There were no significant differences in SDSC (P = 1.0) and PSQI (P = .76) scores for AV with or without tracheostomy. Similarly, there were no significant differences in SDSC (P = .22) and PSQI (P = .34) scores based on PHOX2B genotypes. There was a moderately strong, significant, and positive correlation between the CCHS SDSC scores and parental PSQI scores (r = .48, P = .03), suggesting that sleep disturbances in patients with CCHS were associated with poor parental sleep quality. There was no difference in the median parental sleep duration between those with and without nighttime home nursing (P = .09).

CONCLUSIONS

Patients with CCHS and their parents are at risk for sleep disturbances regardless of their AV modality and PHOX2B genotype. In addition to AV management, patients with CCHS and their parents should be assessed for sleep disturbances.

CITATION

Finch CE, Leu RM, Harford K-L, Westbrook AL, Kasi AS. Sleep disturbances in parental caregivers and patients with congenital central hypoventilation syndrome. J Clin Sleep Med. 2023;19(3):549-554.

The impact of the coronavirus pandemic on sedation in critical care: volatile anesthetics in the ICU

PURPOSE OF REVIEW

To reflect on the impact of the coronavirus pandemic on sedation for mechanically ventilated patients.

RECENT FINDINGS

Shortages of intravenous sedatives during coronavirus pandemic renewed interest in using widely available inhaled anaesthetics for sedation of critically ill patients. Universally used for surgical anaesthesia, inhaled anaesthetics may offer therapeutic advantages in patients with acute lung injury with good sedation profiles, rapid clearance and lower lung inflammation in pilot trials. However, enabling ICU sedation with inhaled anaesthetics required technological and human resource innovation during the chaos of the global pandemic. The disruption of standard sedation practices is challenging during normal operations, yet pandemic facilitated innovation in this field by fostering cross-discipline collaboration supported by healthcare professionals, hospitals, research institutes and regulators.

SUMMARY

Although further research is needed to establish the role of inhaled anaesthetics in critical care sedation toolkit, maintaining the spirit of innovation ignited during the recent coronavirus pandemic would require ongoing collaboration and streamlining of processes among healthcare, research and regulatory institutions.

Closed Endotracheal Suction Systems for COVID-19: Rapid Review

BACKGROUND

The increase in admissions to intensive care units (ICUs) in 2020 and the morbidity and mortality associated with SARS-CoV-2 infection pose a challenge to the analysis of evidence of health interventions carried out in ICUs. One of the most common interventions in patients infected with the virus and admitted to ICUs is endotracheal aspiration. Endotracheal suctioning has also been considered one of the most contaminating interventions.

OBJECTIVE

This review aims to analyze the benefits and risks of endotracheal suctioning using closed suction systems (CSS) in COVID-19 patients.

METHODS

A rapid review was carried out using the following databases: PubMed, MEDLINE, CINAHL, LILACS, the Cochrane Library, and IBECS. The data search included articles in English and Spanish, published between 2010 and 2020, concerning adult patients, and using the key words "endotracheal," "suction," and "closed system."

RESULTS

A total of 15 articles were included. The benefits and risks were divided into 3 categories: patient, care, and organization. Relating to the patient, we found differences in cardiorespiratory variables and changes in the ventilator, for example, improvement in patients with elevated positive and end-expiratory pressure due to maladaptation and alveolar collapse. Relating to care, we found a shorter suctioning time, by up to 1 minute. Relating to organization, we found fewer microorganisms on staff gloves. Other conflicting results between studies were related to ventilator-associated pneumonia, bacterial colonization, or mortality.

CONCLUSIONS

Aside from the need for quality research comparing open suction systems and CSS as used to treat COVID-19 patients, closed endotracheal suctioning has benefits in terms of shorter stay in the ICU and reduced environmental contamination, preventing ventilator disconnection from the patient, reducing the suctioning time-though it does produce the greatest number of mucosal occlusions-and preventing interpatient and patient-staff environmental contamination. New evidence in the context of the SARS-CoV-2 virus is required in order to compare results and establish new guidelines.

Early Light Sedation Increased the Duration of Mechanical Ventilation in Patients With Severe Lung Injury

Introduction

The international guidelines recommend light sedation management for patients receiving mechanical ventilation. One of the benefits of light sedation management during mechanical ventilation is the preservation of spontaneous breathing, which leads to improved gas-exchange and patient outcomes. Conversely, recent experimental animal studies have suggested that strong spontaneous breathing effort may cause worsening of lung injury, especially in severe lung injury cases. The association between depth of sedation and patient outcomes may depend on the severity of lung injury.

Objective

This study aimed to describe the patients' clinical outcomes under deep or light sedation during the first 48 h of mechanical ventilation and investigate the association of light sedation on patient outcomes for each severity of lung injury.

Methods

The researchers performed a retrospective observational study at a university hospital in Japan. Patients aged ≥20 years, who received mechanical ventilation for at least 48 h were enrolled.

Results

A total of 413 patient cases were analyzed. Light sedation was associated with significantly shorter 28-day ventilator-free days compared with deep sedation in patients with severe lung injury (0 [IQR 0-5] days vs. 16 [0-19] days, P = .038). In the groups of patients with moderate and mild lung injury, the sedation depth was not associated with ventilator-free days. After adjusting for the positive end-expiratory pressure and APACHE II score, it was found that light sedation decreased the number of ventilator-free days in patients with severe lung injury (-10.8 days, 95% CI -19.2 to -2.5, P = .012).

Conclusion

Early light sedation for severe lung injury may be associated with fewer ventilator-free days.

Critical Incident Reports Related to Ventilator Use: Analysis of the Japan Quality Council National Database

OBJECTIVE

This study aimed to assess the factors associated with medical device incidents.

METHODS

In this mixed-methods study, we used incident reporting data from the Japan Council for Quality Health Care. Of the 232 medical device-related reports that were downloaded, 34 (14.7%) were ventilator-associated incidents. Data related to patients, situations, and incidents were collected and coded.

RESULTS

The frequencies of ventilator-associated accidents were 20 (58.8%) during the daytime and 14 (41.2%) during the night/early morning. Ventilator-associated accidents occurred more frequently in the hospital room (n = 22 [64.7%]) than in the intensive care unit (n = 4 [11.8%]). Problems with ventilators occurred in only 4 cases (11.8%); in most cases, medical professionals experienced difficulty with the use or management of ventilators (n = 30 [88.2%]), and 50% of them were due to misuse/misapplication of ventilators (n = 17 [50.0%]). Ventilator-associated accidents were caused by an entanglement of complex factors-hardware, software, environment, liveware, and liveware-liveware interaction. Communication and alarm-related errors were reported to be related, as were intuitiveness or complicated specifications of the device.

CONCLUSIONS

Our study revealed that ventilator-associated accidents were caused by an entanglement of complex factors and were related to inadequate communication among caregivers and families. Moreover, alarms were overlooked owing to inattentiveness. Mistakes were generally caused by a lack of experience, insufficient training, or outright negligence. To reduce the occurrence of ventilator-associated accidents, hospital administrators should develop protocols for employment of new devices. Medical devices should be developed from the perspective of human engineering, which could be one of the systems approaches.

Role of chest radiograph in predicting the need for ventilator support in COVID-19 patients

Background

COVID-19 disease, a pandemic for more than two years, has major morbidity and mortality related to pulmonary involvement. Chest radiography is the main imaging tool for critically ill patients. As the availability of arterial blood gas analysis is limited in the Level I and II healthcare centres, which are major partners in providing healthcare in resource-limited times, we planned the present study.

Objectives

To assess the role of chest radiography in predicting the need for oxygen/ventilator support in critically ill COVID-19 patients.

Methods

This hospital-based, retrospective study included 135 patients who needed oxygen/ventilator support and had optimal-quality chest radiographs at admission. All the chest X-rays were evaluated and a severity score was calculated on a predesigned pro forma. Statistical evaluation of the data obtained was done using appropriate tools and methods.

Results

Males outnumbered females, with a mean age of 54.35 ± 14.49 years. More than 72% of patients included in our study needed ventilator support while the rest needed oxygen support. There was a significant statistical correlation between the chest radiograph severity score and SPO₂ /PaO₂ levels in our study. Using a cut-off value >8 for the chest radiograph severity score in predicting the need for ventilator support in a Covid-19 patient, the sensitivity, specificity and accuracy was 85.7%, 92.5% and 89.5%, respectively.

Conclusion

Chest radiography remains the mainstay of imaging in critically ill COVID-19 patients when they are on multiple life-support systems. Though arterial blood gas analysis is the gold standard tool for assessing the need for oxygen/ventilator support in these patients, the severity score obtained from the initial chest radiograph at the time of admission may also be used as a screening tool. Chest radiography may predict the need for oxygen/ventilator support, allowing time for patients to be moved to an appropriate-level healthcare centre, thus limiting morbidity and mortality.

Novel Technology Deployed for Remote Ventilator Management by Respiratory Therapists During the COVID-19 Pandemic: Lessons Learned

A novel remote ventilator management (control) technology (Omnitool) was implemented for use with ICU patients during the COVID-19 pandemic to mitigate in-person respiratory therapist interactions and preserve personal protective equipment. In the latter half of 2020, eight mechanical ventilators were purchased and enabled for Omnitool deployment through the application of a vendor software option. Subsequently, these ventilators were outfitted with commercially available informatics hardware that permitted remote communication and management via the existing hospital network. In total, 17 patients with COVID-19 respiratory failure were placed on Omnitool enabled ventilators between January 1, 2021-April 30, 2021. The median Omnitool use days was 10. Deployment of a novel remote ventilator management technology is feasible; however, further study is needed to simplify the set up and utilization of the system. Future demands for remote ventilator management are predictable, whether in rural areas, military scenarios without adequate RT staffing, or in circumstances with new and easily transmissible toxic infections, and will continue to encourage the development of relatively easy to apply informatics-based solutions. Herein we share five lessons learned from our Omnitool deployment.

Ventilator-assisted priming of an anaesthesia circuit (VAP technique): An exploratory study

Background and Aims

The speed of inhalational induction depends on a variety of factors, of which priming the breathing circuit with volatile anaesthetics plays a vital role. This study compared ventilator-assisted priming (VAP) and a passive priming technique using different fresh gas flows (FGFs) in neonatal, paediatric, and adult anaesthetic circuits.

Methods

In both techniques, FGF with 100% oxygen and 8% sevoflurane vaporiser concentration were set at 2 Lmin^-1, 4 Lmin^-1, and 8 Lmin^-1, representing three groups FGF-2, FGF-4, and FGF-8, respectively. The time taken to achieve 6% sevoflurane concentration at the patient end of the circuit was measured. In addition to this, we explored various combinations of tidal volumes and respiratory rates in the VAP technique and recorded the priming time with each combination. The amount of sevoflurane consumed for priming in both techniques was also calculated.

Results

VAP was three times faster than passive priming in all the FGF groups in the three circuits. In the VAP technique, the shortest priming times were similar for FGF-4 and FGF-8 (P > 0.05) but were significantly higher for FGF-2 (P = 0.001) in the three circuits. Sevoflurane consumption did not differ in FGF-2 and FGF-4 groups, whereas it doubled in the FGF-8 group using the VAP technique in all three circuits.

Conclusion

The VAP technique provides a quick and effective method for priming to achieve a high anaesthetic concentration within the breathing circuit for inhalational induction.

[Using the Model of Motivation to Improve the Accuracy of Nurses Conducting Aerosol Therapy in Mechanically Ventilated Patients]

ACKGROUND & PROBLEMS

Aerosol therapy is increasingly used in pulmonary critical care and in patients with respiratory disease. However, improper application of the aerosol delivery device will decrease the therapeutic effect as well as increase the incidence of pulmonary infection. An initial assessment conducted in our intensive care unit found an accuracy rate for nursing staff aerosol-therapy execution of only 55.9%. Possible reasons identified for this low rate included lack of learning experience and resources, lack of related standard operating procedures, lack of related performance assessments, complicated / unfamiliar device assembly procedure, diffuse storage of device components, and a lack of illustrations.

PURPOSE

This project was developed to increase the accuracy rate of performing aerosol therapy to over 90% in our intensive care unit.

METHODS

We designed diverse learning materials using the model of motivation, developed an evaluation system, simplified the assembly of components based on evidence-based research, improved the storage situation, and added reference illustrations.

RESULTS

The accuracy rate in aerosol therapy execution for our nursing staff increased from 55.9% to 95.0% after the intervention.

CONCLUSIONS

This project used the model of motivation to develop the teaching materials. By using diverse teaching methods, including both in-person classes and online interactive quizzes, we realized high learning satisfaction and efficacy. Along with simplifying equipment handling, improving the working environment, enhancing nurses' aerosol therapy techniques, establishing standard operating procedure guidelines, and adding an evaluation system, we standardized the entire procedure for potential promotion to other intensive care units.

Oxygenation and Respiratory System Compliance Associated With Pulmonary Contusion

BACKGROUND

Blunt pulmonary contusions are associated with severe chest injuries and are independently associated with worse outcomes. Previous preclinical studies suggest that contusion progression precipitates poor pulmonary function; however, there are few current clinical data to corroborate this hypothesis. We examined pulmonary dynamics and oxygenation in subjects with pulmonary contusions to evaluate for impaired respiratory function.

METHODS

A chest injury database was reviewed for pulmonary contusions over 5 years at an urban trauma center. This database was expanded to capture mechanical ventilation parameters for the first 7 days on all patients with pulmonary contusion and who were intubated. Daily [Formula: see text]:[Formula: see text], oxygenation indexes (OI), and dynamic compliances were calculated. Pulmonary contusions were stratified by severity. The Fisher exact and chi square tests were performed on categorical variables, and Mann-Whitney U-tests were performed on continuous variables. Significance was assessed at a level of 0.05.

RESULTS A TOTAL OF

1,176 patients presented with pulmonary contusions, of whom, 301 subjects (25.6%) required intubation and had available invasive mechanical ventilation data. Of these, 144 (47.8%) had mild-moderate pulmonary contusion and 157 (52.2%) had severe pulmonary contusion. Overall injury severity score was high, with a median injury severity score of 29 (interquartile range, 22-38). The median duration of mechanical ventilation for mild-moderate pulmonary contusion was 7 d versus 10 d for severe pulmonary contusion (P = .048). All the subjects displayed moderate hypoxemia, which worsened until day 4-5 after intubation. Severe pulmonary contusion was associated with significantly worse early hypoxia on day 1 and day 2 versus mild-moderate pulmonary contusion. Severe pulmonary contusion also had a higher oxygenation index than mild-moderate pulmonary contusion. This trend persisted after adjustment for other factors, including transfusion and fluid administration.

CONCLUSIONS

Pulmonary contusions played an important role in the course of subjects who were acutely injured and required mechanical ventilation. Contusions were associated with hypoxemia not fully characterized by [Formula: see text]: [Formula: see text], and severe contusions had durable elevations in the oxygenation index despite confounders.

Numerical modeling and development of a dual lung simulator using partitioned fluid-structure interaction approach for ventilator testing

New designs of mechanical ventilators require extensive testing before utilizing the ventilator on a patient. Test lungs are commonly used to understand the behavior of new designs of ventilators and the lung mechanics. The current study aims to develop a numerical model of dual test lungs utilizing the partitioned fluid-structure interaction (FSI) approach and test it against the available experimental data of volume-controlled ventilation. Two breathing rates of 12 and 18 bpm were studied at two different tidal volumes of 500 and 600 ml for spontaneous breathing. It is found that with an increase in the compliance (tidal volume/pressure rise) of the lung, the peak pressure rise inside the test lung decreases irrespective of the breathing rate. The maximum average pressure of 44.73, 27.45, and 14 cm H₂ O is observed for static lung compliances of 10, 21 , and 39 ml/cm H₂ O, respectively at a tidal volume of 600 ml. Similarly, the maximum von-misses stress was higher (498 kPa) for the lung with lower compliance (10 ml/cm H₂ O) as compared to the lung with higher compliance (39 ml/cm H₂ O) at the end of inspiration. This study forms a basis for using computational methods to model simple lung simulators that can effectively investigate the lung mechanics for both spontaneous and ventilated breathing. Thus, it can be utilized as a reference to test novel designs of mechanical ventilators.

An analysis of early volume resuscitation and the association with prolonged mechanical ventilation

BACKGROUND

Previous studies have found that intravenous fluid administration within the first 24 h may be associated with prolonged mechanical ventilation (PMV). We examined the association between initial 24 h fluids and PMV in combat casualties.

METHODS

This is a secondary analysis of a previously described dataset from the Department of Defense Trauma Registry (DODTR). We included casualties with at least 24 h on the ventilator and no significant traumatic brain injury. The definition of PMV and associations were constructed using univariable and multivariable logistic regression models.

RESULTS

We identified 1508 casualties available for analysis for this study - 1275 in the non-PMV cohort (<9 days on ventilator vs. 233 in the PMV cohort (≥9 days on ventilator). Explosives comprised the most common mechanism of injury for both groups (72% vs. 75%) followed by firearms (21% vs. 16%). The composite injury severity score (ISS) was lower in the non-PMV cohort (18 vs. 30, p < .001). There were lower volumes of all resuscitation fluid within the first 24 h in the non-PMV cohort. When adjusting for composite ISS and mechanism of injury in a multivariable logistic regression model with PMV as the outcome, crystalloid volume (unit odds ratio [UOR] 1.07) and colloid volume (UOR 1.03) were both associated with PMV.

CONCLUSIONS

We found that volume of resuscitation fluids were substantially higher in the PMV cohort. Our findings suggest the need for caution with the routine use of crystalloid and colloid in the first 24 h of resuscitation.

How Common SOFA and Ventilator Time Trial Criteria Would Have Performed During the COVID-19 Pandemic: An Observational Simulated Cohort Study

OBJECTIVES

To evaluate how key aspects of New York State Ventilator Allocation Guidelines (NYSVAG)-Sequential Organ Failure Assessment score criteria and ventilator time trials -might perform with respect to the frequency of ventilator reallocation and survival to hospital discharge in a simulated cohort of coronavirus disease (COVID-19) patients.

METHODS

Single center retrospective observational and simulation cohort study of 884 critically ill COVID-19 patients undergoing ventilator allocation per NYSVAG.

RESULTS

In total, 742 patients (83.9%) would have had their ventilator reallocated during the 11-day observation period, 280 (37.7%) of whom would have otherwise survived to hospital discharge if provided with a ventilator. Only 65 (18.1%) of the observed surviving patients would have survived by NYSVAG. Extending ventilator time trials from 2 to 5 days resulted in a 49.2% increase in simulated survival to discharge.

CONCLUSIONS

In the setting of a protracted respiratory pandemic, implementation of NYSVAG or similar protocols could lead to a high degree of ventilator reallocation, including withdrawal from patients who might otherwise survive. Longer ventilator time trials might lead to improved survival for COVID-19 patients given their protracted respiratory failure. Further studies are needed to understand the survival of patients receiving reallocated ventilators to determine whether implementation of NYSVAG would improve overall survival.

Unto the least of these: Caring for the vulnerable in the time of COVID

As the COVID-19 pandemic initially unfolded in early 2020, medical systems were rapidly overwhelmed with critically ill patients. Intensive care resources were strained and, in some cases, insufficient. Concepts of triage and allocation of life-saving resources, once only hypothetical, were called into action. Vulnerable elderly, chronically ill, and disabled patients found themselves subject to protocols and guidelines that singled them out for disparate access to treatments. In this article, I overview the historical background of the early COVID-19 crisis, frontline triage guidelines in Italy and New York City, the conceptual nature of triage, the problematic practice of reallocation, the ethical principles that were challenged, how Judeo-Christian teachings inform these issues, and conflicts of physician duties with attendant moral distress. I close with a set of normative guideline statements that could help define a path through the extreme scarcities of a catastrophic pandemic crisis surge.

Implementation and challenges of portable blood gas measurements in air medical transport

OBJECTIVES

Ventilator management in prehospital settings using end-tidal CO₂ can lead to inappropriate ventilation in the absence of point of care blood gas (POCBG) measurements. Implementation of POCBG testing in helicopter Emergency Medical Services (HEMS) is limited in part because of concern for preanalytical and analytical errors due to altitude, vibration, and other associated environmental factors and due to insufficient documentation of implementation challenges.

METHODS

We performed accuracy and precision verification studies using standard materials tested pre-, in-, and post-flight (n=10) in a large HEMS agency. Quality assurance error log data were extracted and summarized for common POCBG errors during the first 31 months of use and air medical transport personnel were surveyed regarding POCBG use (n=63).

RESULTS

No clinically significant differences were found between pre-, in-, and post-flight blood gas measurements. Error log data demonstrated a reduction in device errors over time. Survey participants found troubleshooting device errors and learning new clinical processes to be the largest barriers to implementation. Continued challenges for participants coincided with error log data including temperature and sampling difficulties. Survey participants indicated that POCBG testing improved patient management.

CONCLUSIONS

POCBG testing does not appear to be compromised by the HEMS environment. Temperature excursions can be reduced by use of insulated transport bags with heating and cooling packs. Availability of POCBG results in air medical transport appeared to improve ventilator management, increase recognition of ventilation-perfusion mismatch, and improve patient tolerance of ventilation.

Methicillin-Resistant Staphylococcus aureus Hospital-Acquired Pneumonia/Ventilator-Associated Pneumonia

Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP). MRSA pneumonia is associated with significant morbidity and mortality. Several virulence factors allow S. aureus to become an effective pathogen. The polysaccharide intracellular adhesin allows for the production of biofilms, some strains can produce capsular polysaccharides that protect against phagocytosis, microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) allow for colonization of epithelial surfaces, and S. aureus secretes several exotoxins that aid in tissue destruction. The α-hemolysin exotoxin secreted by S. aureus is one of the most important virulence factors for the bacteria. The diagnosis of MRSA pneumonia can be challenging; the infection may present as a mild respiratory infection or severe respiratory failure and septic shock. Many individuals are colonized with MRSA and thus a positive nasopharyngeal swab does not confirm infection in the lower respiratory tract. The management of MRSA pneumonia has evolved. Historically, vancomycin has been the primary antibiotic used to treat MRSA pneumonia. Over the past decade, prospective studies have shown that linezolid leads to higher rates of clinical cure. Monoclonal antibodies are being studied as potential therapeutic options. MRSA is an important cause of HAP/VAP; novel diagnostics may facilitate rapid diagnosis of this infection and the available literature should be used to make informed decisions on management.

Modeling Outcomes Using Sequential Organ Failure Assessment (SOFA) Score-Based Ventilator Triage Guidelines During the COVID-19 Pandemic

OBJECTIVE

To model performance of the Sequential Organ Failure Assessment (SOFA) score-based ventilator allocation guidelines during the COVID-19 pandemic.

METHODS

A retrospective cohort study design was used. Study sites included 3 New York City hospitals in a single academic medical center. We included a random sample (205) of adult patients who were intubated (1002) from March 25, 2020, till April 29, 2020. Protocol criteria adapted from the New York State's 2015 guidelines were applied to determine which patients would have had mechanical ventilation withheld or withdrawn.

RESULTS

117 (57%) patients would have been identified for ventilator withdrawal or withholding based on the triage guidelines. Of those 117 patients, 28 (24%) survived hospitalization. Overall, 65 (32%) patients survived to discharge.

CONCLUSION

Triage protocols aim to maximize survival by redirecting ventilators to those most likely to survive. Over 50% of this sample would have been identified as candidates for ventilator exclusion. Clinical judgment would therefore still be needed in ventilator reallocation, thus re-introducing bias and moral distress. This data suggests limited utility for SOFA score-based ventilator rationing. It raises the question of whether there is sufficient ethical justification to impose a life-ending decision based on a SOFA scoring method on some patients in order to offer potential benefit to a modest number of others.

A Novel Ventilator Design for COVID-19 and Resource-Limited Settings

There has existed a severe ventilator deficit in much of the world for many years, due in part to the high cost and complexity of traditional ICU ventilators. This was highlighted and exacerbated by the emergence of the COVID-19 pandemic, during which the increase in ventilator production rapidly overran the global supply chains for components. In response, we propose a new approach to ventilator design that meets the performance requirements for COVID-19 patients, while using components that minimise interference with the existing ventilator supply chains. The majority of current ventilator designs use proportional valves and flow sensors, which remain in short supply over a year into the pandemic. In the proposed design, the core components are on-off valves. Unlike proportional valves, on-off valves are widely available, but accurate control of ventilation using on-off valves is not straightforward. Our proposed solution combines four on-off valves, a two-litre reservoir, an oxygen sensor and two pressure sensors. Benchtop testing of a prototype was performed with a commercially available flow analyser and test lungs. We investigated the accuracy and precision of the prototype using both compressed gas supplies and a portable oxygen concentrator, and demonstrated the long-term durability over 15 days. The precision and accuracy of ventilation parameters were within the ranges specified in international guidelines in all tests. A numerical model of the system was developed and validated against experimental data. The model was used to determine usable ranges of valve flow coefficients to increase supply chain flexibility. This new design provides the performance necessary for the majority of patients that require ventilation. Applications include COVID-19 as well as pneumonia, influenza, and tuberculosis, which remain major causes of mortality in low and middle income countries. The robustness, energy efficiency, ease of maintenance, price and availability of on-off valves are all advantageous over proportional valves. As a result, the proposed ventilator design will cost significantly less to manufacture and maintain than current market designs and has the potential to increase global ventilator availability.

Adjusting ventilator settings to avoid air trapping in extremely premature infants reduces the need for tracheostomy and length of stay

Despite the improving understanding of how lung mechanics and tidal volume requirements evolve during the evolution of bronchopulmonary dysplasia (BPD), clinical management continues to be heterogeneous and inconsistent at many institutions. Recent reports have examined the use of high tidal-volume low respiratory rate strategies in these patients once disease has been well established to help facilitate their eventual extubation and improve their long-term neurodevelopmental outcomes. In this retrospective observational research study, we describe how intentional adjustment of ventilator settings based on patient lung mechanics by an interdisciplinary BPD team improved the care of the at-risk population of infants, reduced the need for tracheostomies, as well as length of stay over a period of over 3 years. The team aimed to establish consistency in the management of these children using a high tidal volume, low-rate approach, and titrating PEEP to address the autoPEEP and bronchomalacia that is frequently observed in this patient population.

Device-Associated Hospital-Acquired Infections: Does Active Surveillance With Bundle Care Offer a Pathway to Minimize Them?

Background and objective

The prevalence of hospital-acquired infections (HAIs) is underreported in developing nations due to a lack of systematic active surveillance. This study reports the burden of device-associated HAIs (DA-HAIs) based on two years of active surveillance with in situ bundle care in closed intensive care units (ICUs) of a tertiary care hospital.

Materials and methods

A prospective surveillance study was carried out in 140-bedded ICUs (2,100-bed hospital) of a tertiary care private medical college hospital. Daily active surveillance for catheter-associated urinary tract infection (CAUTI), ventilator-associated event (VAE), and central line-associated bloodstream infection (CLABSI) was done by trained infection control nurses (ICNs) along with quality champion nurses with HAI surveillance forms with bundle care auditing, which was attached to the case sheets of all patients on devices. The surveillance definitions of DA-HAIs were adapted from the Centers for Disease Control and Prevention (CDC)’s National Healthcare Safety Network (CDC-NHSN) 2017 surveillance criteria. Data were analyzed at the end of every month to generate the cumulative device-associated infection (DAI) rates and device utilization ratio (DUR). These data were compared with NHSN and International Nosocomial Infection Control Consortium (INICC) - India HAI rates and communicated to corresponding ICUs and also presented at the hospital infection control committee (HICC) meeting.

Results

The surveillance data were reported over 71,877 patient days during the study period. The DUR of urinary catheters, ventilator, and central line were 0.53, 0.16, and 0.22, respectively. CAUTI, VAE, and CLABSI rates were 0.97, 10.5, and 0.43 per 1,000 device days, respectively. Among 166 DA-HAIs reported, 182 pathogens were identified. Klebsiella pneumoniae was the most common organism isolated, accounting for 37.4% of all DA-HAI cases, followed by Acinetobacter baumanii (30.8%). Most of the Gram-negative organisms were carbapenem-resistant (153/175; 87.4%). Vancomycin resistance rate in Enterococcus was 28.5% (2/7).

Conclusion

DUR and CAUTI, VAE, CLABSI rates were less/on par with the benchmarks of INICC and CDC-NHSN in almost all ICUs of our tertiary care unit. Gram-negative pathogen with 87.4% carbapenem resistance worsened the scenario. Proper active surveillance with bundle care and training by ICNs made a significant difference in all DA-HAI rates, especially VAE, which decreased to 10.5 from 23.6 per 1,000 ventilator days. Sustained active surveillance of HAI and bundle care auditing by a trained infection prevention team with a stringent antibiotic policy are the need of the hour to combat DAIs.

The COSMIC Bubble Helmet: A Non-Invasive Positive Pressure Ventilation System for COVID-19

Goal: COSMIC Medical, a Vancouver-based open-source volunteer initiative, has designed an accessible, affordable, and aerosol-confining non-invasive positive-pressure ventilator (NIPPV) device, known as the COSMIC Bubble Helmet (CBH). This device is intended for COVID-19 patients with mild-to-moderate acute respiratory distress syndrome. System Design: CBH is composed of thermoplastic polyurethane, which creates a flexible neck seal and transparent hood. This device can be connected to wall oxygen, NIPPVs including Continuous Positive Airway Pressure and Bi-level Positive Airway Pressure, and mechanical ventilators. Discussion: Justification of CBH design components relied on several factors, predominantly the safety and comfort of patients and healthcare providers. Conclusion: CBH has implications within and outside of the pandemic, as an alternative to invasive mechanical ventilation methods. We have experimentally verified that CBH is effective in minimizing aerosolization risks and performs at specified clinical requirements.

The physics of human breathing: flow, timing, volume, and pressure parameters for normal, on-demand, and ventilator respiration

Normal breathing for healthy humans is taken for granted; it occurs without conscious effort using ambient (1-atmosphere) pressure with 21% oxygen (O2) concentration. The body automatically adjusts for stress, exercise, altitude, and mild disease by increasing the volume and frequency of breathing. Longer term adaptations for exercise and altitude include increases in red blood cell counts and higher concentrations of capillaries in muscle tissue. When more challenging external environmental conditions or pulmonary illnesses exceed the capability for these adaptations, the human system requires technology to maintain sufficient ventilation to preserve life. On the environmental side there are two conditions to be addressed: toxicity of the surrounding atmosphere and changes in external pressure and O2concentration. On the medical side, mechanisms for assisting breathing include O2supplementation at ambient pressure, positive pressure/flow without additional O2, or a combination of both. This overview describes the various technologies applied to maintaining a safe breathing environment. Topics for environmental intervention include filter-based and flowing air-supply masks for toxic environments (occupational and laboratory protection), and on-demand gas supply systems for firefighters, self-contained underwater breathing apparatus divers, and altitude (high performance aircraft, spacecraft) applications. The topics for medical intervention include nasal cannula, continuous positive airway pressure, and medical ventilators. The primary purpose of this article is to provide a basic understanding of normal human breathing and the adaptation of breathing in different environments using available technologies.

Heated Humidifiers for Noninvasive Respiratory Support and the Risk of Burns in Neonates: A Bench Evaluation

BACKGROUND

User errors in managing heated humidifiers (HHs) have been suggested to be a source of nasal burns in newborns treated with nasal CPAP. This study evaluated the risk of burns by reproducing 3 typical errors concerning the use of HHs.

METHODS

Six HHs were tested on a bench in a traditional nasal CPAP setup: PMH5000, Aircon (Wilamed); MR730, MR850, MR950 (Fisher & Paykel); and H900 (Hamilton). Temperature was measured at the end of the inspiratory tubing limb. Errors tested were (1) misconnection of the HH thermal probes (NoProbe), (2) absence of gas flow while the HH is on (NoFlow), and (3) unsuitable repeated acknowledgment of the HH alarm (NoAlarm). These errors were combined in 3 standardized scenarios: (1) NoProbe + NoFlow + NoAlarm; (2) NoProbe + NoAlarm, and (3) NoFlow + NoAlarm. The NoProbe + NoFlow + NoAlarm and NoProbe + NoAlarm scenarios were not tested in the H900 and MR950 because the proprietary circuits of these HHs are equipped with embedded probes.

RESULTS

For each HH, the highest inspiratory gas temperature (HIGT) and the rating on a self-designed risk-of-burn scale (ie, no risk, moderate risk, or severe risk) were reported. In the NoProbe + NoFlow + NoAlarm scenario, the risk was severe for the MR730, PMH5000, MR850, and Aircon, with HIGTs of > 65°C, 58°C, 56°C, and > 65°C, respectively. In the NoProbe + NoAlarm scenario, the risk was also severe for the same 4 HHs, with HIGTs of 56°C, 47°C, 56°C, and 48°C, respectively. In the NoFlow + NoAlarm scenario, the risk was severe for the PMH5000, Aircon, and H900, with HIGTs of 52°C, > 65°C, and 49°C, respectively, and moderate for the MR730, MR850, and MR950, with HIGTs of 45°C, 47°C, and 44°C, respectively).

CONCLUSIONS

In case of misuse, 5 of the 6 tested devices presented a severe risk of inducing skin burns, whereas the MR950 presented a moderate risk.

A Simple Ventilator Designed To Be Used in Shortage Crises: Construction and Verification Testing

Background

The COVID-19 pandemic has demonstrated the possibility of severe ventilator shortages in the near future.

Objective

We aimed to develop an acute shortage ventilator.

Methods

The ventilator was designed to mechanically compress a self-inflating bag resuscitator, using a modified ventilator patient circuit, which is controlled by a microcontroller and an optional laptop. It was designed to operate in both volume-controlled mode and pressure-controlled assist modes. We tested the ventilator in 4 modes using an artificial lung while measuring the volume, flow, and pressure delivered over time by the ventilator.

Results

The ventilator was successful in reaching the desired tidal volume and respiratory rates specified in national emergency use resuscitator system guidelines. The ventilator responded to simulated spontaneous breathing.

Conclusions

The key design goals were achieved. We developed a simple device with high performance for short-term use, made primarily from common hospital parts and generally available nonmedical components to avoid any compatibility or safety issues with the patient, and at low cost, with a unit cost per ventilator is less than $400 US excluding the patient circuit parts, that can be easily manufactured.

Annual Respiratory Evaluations in Congenital Central Hypoventilation Syndrome and Changes in Ventilatory Management

Background: Annual in-hospital respiratory evaluations (AREs) during wakefulness and sleep are recommended to assess ventilatory requirements in patients with congenital central hypoventilation syndrome (CCHS) aged ≥2-3 years based on expert consensus. This study aimed to determine if AREs in patients with CCHS led to changes in ventilatory management. Methods: Retrospective review of patients with CCHS who underwent AREs with or without polysomnography between 2017 and 2019 was conducted. Clinical symptoms, results of AREs, and subsequent changes in ventilatory management were analyzed. Results: We identified 10 patients with CCHS aged 4-20 years. All patients required assisted ventilation (AV) only during sleep delivered by positive pressure ventilation via tracheostomy (n = 7) or diaphragm pacing (n = 3). In total, 7 (70%) patients had abnormal oxygenation and/or ventilation requiring changes in ventilator settings or duration of AV. Six patients required an increase in settings and/or duration of AV, and only 1 patient required a decrease in ventilator settings. Two patients had awake hypercapnia during a routine outpatient visit that improved following increase in ventilator settings and a period of continuous AV. One patient who was previously ventilator-dependent only during sleep was identified to require 16 h per day of AV. All patients (n = 3) who reported symptoms such as headache or oxygen desaturations during sleep required an increase in ventilator settings. Conclusion: We report a high prevalence of changes in AV management following an ARE. Our results demonstrate the importance of regular AREs in patients with CCHS to assess their ventilatory requirements and optimize AV.

ATENA-A Novel Rapidly Manufactured Medical Invasive Ventilator Designed as a Response to the COVID-19 Pandemic: Testing Protocol, Safety, and Performance Validation

Background: The urgent need for mechanical ventilators to support respiratory insufficiency due to SARS-CoV-2 led to a worldwide effort to develop low-cost, easily assembled, and locally manufactured ventilators. The ATENA ventilator project was developed in a community-based approach targeting the development, prototyping, testing, and decentralized manufacturing of a new mechanical ventilator. Objective: This article aims to demonstrate ATENA's adequate performance and safety for clinical use. Material: ATENA is a low-cost ventilator that can be rapidly manufactured, easily assembled, and locally produced anywhere in the world. It was developed following the guidelines and requirements provided by European and International Regulatory Authorities (MHRA, ISO 86201) and National Authorities (INFARMED). The device was thoroughly tested using laboratory lung simulators and animal models. Results: The device meets all the regulatory requirements for pandemic ventilators. Additionally, the pre-clinical experiences demonstrated security and adequate ventilation and oxygenation, in vivo. Conclusion: The ATENA ventilator had a good performance in required tests in laboratory scenarios and pre-clinical studies. In a pandemic context, ATENA is perfectly suited for safely treating patients in need of mechanical ventilation.

[Development Progress of Ventilator]

Ventilator is an indispensable emergency medical equipment in hospitals. The global outbreak of the coronavirus disease 2019 (COVID-19) has highlighted the importance of the ventilator, which has attracted the attention and research on ventilators of all countries in the world. This article reviews the development history of the ventilator, briefly introduces the main air circuit structure and working principle of the ventilator, and then deeply analyzes the key technologies of this device. In addition, it compares some major brands of ventilators from several aspects in the market. Finally, the development trend and perspective of ventilators are presented.

Miniaturization of Respiratory Measurement System in Artificial Ventilator for Small Animal Experiments to Reduce Dead Space and Its Application to Lung Elasticity Evaluation

A respiratory measurement system composed of pressure and airflow sensors was introduced to precisely control the respiratory condition during animal experiments. The flow sensor was a hot-wire thermal airflow meter with a directional detection and airflow temperature change compensation function based on MEMS technology, and the pressure sensor was a commercially available one also produced by MEMS. The artificial dead space in the system was minimized to the value of 0.11 mL by integrating the two sensors on the same plate (26.0 mm × 15.0 mm). A balloon made of a silicone resin with a hardness of A30 was utilized as the simulated lung system and applied to the elasticity evaluation of the respiratory system in a living rat. The inside of the respiratory system was normally pressurized without damage, and we confirmed that the developed system was able to evaluate the elasticity of the lung tissue in the rat by using the pressure value obtained at the quasi-static conditions in the case of the ventilation in the animal experiments.

Gut Microbiota and Probiotics/Synbiotics for Modulation of Immunity in Critically Ill Patients

Patients suffering from critical illness have host inflammatory responses against injuries, such as infection and trauma, that can lead to tissue damage, organ failure, and death. Modulation of host immune response as well as infection and damage control are detrimental factors in the management of systemic inflammation. The gut is the motor of multiple organ failure following injury, and it is recognized that gut dysfunction is one of the causative factors of disease progression. The gut microbiota has a role in maintaining host immunity, and disruption of the gut microbiota might induce an immunosuppressive condition in critically ill patients. Treatment with probiotics and synbiotics has been reported to attenuate systemic inflammation by maintaining gut microbiota and to reduce postoperative infectious complications and ventilator-associated pneumonia. The administration of prophylactic probiotics/synbiotics could be an important treatment option for preventing infectious complications and modulating immunity. Further basic and clinical research is needed to promote intestinal therapies for critically ill patients.

COVID-19 Efforts at the Institute of Image Guided Surgery (IHU-Strasbourg): 2020

We submit a summary of some of the activities of the IHU-Strasbourg during the initial period of the COVID-19 pandemic. These were presented as part of the coronnavation effort coordinated by Dr Adrian Park. Three initiatives are presented as follows: Protect-Est App, healthcare worker stress, and converted diving mask for ventilation. Two of the 3 projects are still ongoing, and one (Predoict-Est) has been adopted nationally.

Asynchrony During Pediatric Noninvasive Ventilation With a Nasal Cannula Interface: A Lung Model Study

BACKGROUND

Pediatric noninvasive ventilation (NIV) is used commonly in the acute care setting and is associated with high incidence of patient ventilator asynchrony.

METHODS

An ASL 5000 breathing simulator was used to model pediatric patients with varying patient efforts and lung conditions. For delivery of NIV, a commonly used acute care ventilator was used by connecting a nasal cannula interface to model nares produced with a 3-dimensional printer. The modes of ventilation were NIV pressure control continuous mandatory ventilation and NIV pressure control continuous spontaneous ventilation. Patient and ventilator waveforms were analyzed using the ASL 5000 software to assess for asynchrony events and determine the asynchrony index (AI).

RESULTS

Significant asynchrony (AI > 0.1) existed in the majority of scenarios for both pressure control continuous mandatory ventilation and pressure control continuous spontaneous ventilation (79% and 93%, respectively). The most common asynchrony event was ineffective trigger, accounting for 81.9% of events in pressure control continuous mandatory ventilation and 79.3% in pressure control continuous spontaneous ventilation. There were no statistically significant differences in the AI when comparing simulated patient effort or lung condition.

CONCLUSIONS

Significant asynchrony exists during NIV with a commonly used acute care ventilator and nasal cannula interface, which raises questions regarding its utility in clinical practice in the pediatric population.