Cell-based Therapies for Acute Respiratory Distress Syndrome: Where Are We Now?

There is considerable interest in the potential for cell-based therapies, particularly mesenchymal stromal cells (MSCs) and their products, as a therapy for acute respiratory distress syndrome (ARDS). MSCs exert effects via diverse mechanisms including reducing excessive inflammation by modulating neutrophil, macrophage and T-cell function, decreasing pulmonary permeability and lung edema, and promoting tissue repair. Clinical studies indicate that MSCs are safe and well tolerated, with promising therapeutic benefits in specific clinical settings, leading to regulatory approvals of MSCs for specific indications in some countries.This perspective reassesses the therapeutic potential of MSC-based therapies for ARDS given insights from recent cell therapy trials in both COVID-19 and in 'classic' ARDS, and discusses studies in graft-vs.-host disease, one of the few licensed indications for MSC therapies. We identify important unknowns in the current literature, address challenges to clinical translation, and propose an approach to facilitate assessment of the therapeutic promise of MSC-based therapies for ARDS.

Repair of Acute Respiratory Distress Syndrome in COVID-19 by Stromal Cells (REALIST-COVID Trial): A Multicenter, Randomized, Controlled Clinical Trial.

Rationale: Mesenchymal stromal cells (MSCs) may modulate inflammation, promoting repair in coronavirus disease (COVID-19)-related acute respiratory distress syndrome (ARDS). Objectives: We investigated the safety and efficacy of ORBCEL-C (CD362 [cluster of differentiation 362]-enriched, umbilical cord-derived MSCs) in COVID-19-related ARDS. Methods: In this multicenter, randomized, double-blind, allocation-concealed, placebo-controlled trial (NCT03042143), patients with moderate to severe COVID-19-related ARDS were randomized to receive ORBCEL-C (400 million cells) or placebo (Plasma-Lyte 148). The primary safety and efficacy outcomes were the incidence of serious adverse events and oxygenation index at Day 7, respectively. Secondary outcomes included respiratory compliance, driving pressure, PaO2:FiO2 ratio, and Sequential Organ Failure Assessment score. Clinical outcomes relating to duration of ventilation, lengths of ICU and hospital stays, and mortality were collected. Long-term follow-up included diagnosis of interstitial lung disease at 1 year and significant medical events and mortality at 2 years. Transcriptomic analysis was performed on whole blood at Days 0, 4, and 7. Measurements and Main Results: Sixty participants were recruited (final analysis: n = 30 received ORBCEL-C, n = 29 received placebo; 1 participant in the placebo group withdrew consent). Six serious adverse events occurred in the ORBCEL-C group and three in the placebo group (risk ratio, 2.9 [95% confidence interval, 0.6-13.2]; P = 0.25). Day 7 mean (SD) oxygenation index did not differ (ORBCEL-C, 98.3 [57.2] cm H2O/kPa; placebo, 96.6 [67.3] cm H2O/kPa). There were no differences in secondary surrogate outcomes or in mortality at Day 28, Day 90, 1 year, or 2 years. There was no difference in the prevalence of interstitial lung disease at 1 year or significant medical events up to 2 years. ORBCEL-C modulated the peripheral blood transcriptome. Conclusion: ORBCEL-C MSCs were safe in subjects with moderate to severe COVID-19-related ARDS but did not improve surrogates of pulmonary organ dysfunction.

Twelve tips for developing and implementing an effective critical care simulation programme.

Simulation training in healthcare settings has become a valuable training tool. It provides an ideal formative assessment for interdisciplinary teaching. It provides a high fidelity and highly immersive environment where healthcare staff and students can practice developing their skills in a safe and controlled manner. Simulation training allows staff to practice skills that better prepare them for clinical emergencies, therefore possibly optimising clinical care. While the benefits of simulation education are well understood, establishing a programme for use by critical care staff is complex. Complexities include the highly specialised scenarios that are not typically encountered in non-critical care areas, as well as the need for advanced monitoring equipment, ventilation equipment etc. These 12 tips are intended to assist healthcare educators in navigating the complexities in the establishment of a critical care simulation programme, providing advice on selecting target audiences, learning outcomes, creating a critical care simulation environment and recommendations on evaluation and development of the programme.

Evaluation of severe traumatic brain injury referrals to the National Tertiary Neurosurgical Centre in the Republic of Ireland.

BACKGROUND: Transfer of all severe TBI patients to a neurosurgical unit (NSU) has been advocated irrespective of levels of complexity and prognostic factors. Previous publications have suggested that only 50% of severe TBI patients in Ireland were managed in NSUs. AIMS: This study aims to audit severe TBI referrals to the National Neurosurgical Centre, to evaluate reasons for nonacceptance, assess for differences in the transferred and not transferred cohorts and to analyse observed and expected mortality rates. METHODS: Data on all patients with TBI referred in 2021 were prospectively collected using an electronic referral system. Patients with severe TBI (GCS ≤ 8 and AIS ≥ 3) were included and dichotomised into transferred and not transferred cohorts. RESULTS: Of 118 patients referred with severe TBI, 45 patients (38.1%) were transferred to the neurosurgical centre. Patients in the transferred cohort were significantly younger (p < 0.001), had a higher GCS score (p < 0.001) and a lower proportion of bilaterally unreactive pupils (p < 0.001) compared to the not transferred cohort. 93% (68/73) of those not transferred were either >65 years old, or had bilaterally unreactive pupils, or both. Based on the IMPACT model, the observed to expected mortality ratios in the transferred and not transferred cohorts were 0.65 (95% CI 0.25-1.05) and 0.88 (95% CI 0.65-1.11) respectively. CONCLUSION: The observed mortality rate for severe TBI in Ireland was similar to or better than expected mortality rates when adjusted for important prognostic factors. 93% of severe TBI patients not transferred to a neurosurgical centre were either elderly or had bilaterally unreactive pupils or both. These patients have an extremely poor prognosis and recommendation for transfer cannot be made based on current available evidence.

Amplitude Integrated Electroencephalography: Simulated Assessment of Neonatal Seizure Detection in PICU Patients.

OBJECTIVES: Amplitude integrated electroencephalography (aEEG) is a mainstay of care in neonatal ICUs; however, knowledge gaps exist in relation to its accuracy for identifying seizures in older children. We aimed to review the diagnostic accuracy of existing neonatal seizure detection criteria for seizure detection in older children in hospital. DESIGN: Retrospective study. SETTING: PICU/Neurophysiology Department in Dublin. PATIENTS: One hundred twenty patients (2 mo to 16 yr old) were chosen from a database of formal 10-20 system, 21-lead electroencephalography recordings (2012-2020), comprising 30 studies with seizures, 90 without. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Electroencephalography studies containing electrographic seizures (ESzs) were annotated to describe number, duration, distribution, and spread. Two-channel aEEG (using leads C3-P3, C4-P4) recordings were generated and independently reviewed by a professional specialist in clinical neurophysiology blinded to outcome and without reference to the raw electroencephalography trace. Logistic regression was used to identify factors associated with correct seizure identification on aEEG. Median patient age was 6.1 years. Abnormal recordings featured 123 seizures. Status epilepticus (SE) was evident by electroencephalography in 10 cases. Using neonatal criteria, aEEG had a sensitivity of 70% and negative predictive value of 90% for identifying any ESz. Accurate detection of individual seizures was diminished when seizures were very short or occurred during waking. Sensitivity for individual seizures was 81% when seizures less than 1 minute were excluded. aEEG correctly identified SE in 70% of the 10 cases, although ESz were confirmed to be present in 80% of this subpopulation. CONCLUSIONS: aEEG criteria for neonatal seizure identification can be applied with caution to older children and should be supplemented by formal electroencephalography. Seizure identification is better for longer seizures and those arising from sleep. SE is not always recognized by aEEG among older children.

Pressure ulcers in patients with COVID-19 acute respiratory distress syndrome undergoing prone positioning in the intensive care unit: A pre- and post-intervention study.

BACKGROUND: Prone positioning has been widely used to improve oxygenation and reduce ventilator-induced lung injury in patients with severe COVID-19 acute respiratory distress syndrome (ARDS). One major complication associated with prone positioning is the development of pressure ulcers (PUs). AIM: This study aimed to determine the impact of a prevention care bundle on the incidence of PUs in patients with COVID-19 ARDS undergoing prone positioning in the intensive care unit. STUDY DESIGN: This was a single-centre pre and post-test intervention study which adheres to the Standards for Reporting Implementation Studies (StaRI) guidelines. The intervention included a care bundle addressing the following: increasing frequency of head turns, use of an open gel head ring, application of prophylactic dressings to bony prominences, use of a pressure redistribution air mattress, education of staff in the early identification of evolving PUs through regular and rigorous skin inspection and engaging in bedside training sessions with nursing and medical staff. The primary outcome of interest was the incidence of PU development. The secondary outcomes of interest were severity of PU development and the anatomical location of the PUs. RESULTS: In the pre-intervention study, 20 patients were included and 80% (n = 16) of these patients developed PUs, comprising 34 ulcers in total. In the post-intervention study, a further 20 patients were included and 60% (n = 12) of these patients developed PUs, comprising 32 ulcers in total. This marks a 25% reduction in the number of patients developing a PU, and a 6% decrease in the total number of PUs observed. Grade II PUs were the most prevalent in both study groups (65%, n = 22; 88%, n = 28, respectively). In the post-intervention study, there was a reduction in the incidence of grade III and deep tissue injuries (pre-intervention 6%, n = 2 grade III, 6% n = 2 deep tissue injuries; post-intervention no grade III ulcers, grade IV ulcers, or deep tissues injuries were recorded). However, there was an increase in the number of unstageable PUs in the post-intervention group with 6% (n = 2) of PUs being classified as unstageable, meanwhile there were no unstageable PUs in the pre-intervention group. This is an important finding to consider as unstageable PUs can indicate deep tissue damage and therefore need to be considered alongside PUs of a more severe grade (grade III, grade IV, and deep tissue injuries). CONCLUSION: The use of a new evidence-based care bundle for the prevention of PUs in the management of patients in the prone position has the potential to reduce the incidence of PU development. Although improvements were observed following alterations to standard practice, further research is needed to validate these findings. RELEVANCE TO CLINICAL PRACTICE: The use of a new, evidence-based care bundle in the management of patients in the prone position has the potential to reduce the incidence of PUs.

Amplitude integrated electroencephalography - Reference values in children aged 2 months to 16 years.

AIM: Amplitude integrated electroencephalography (aEEG) is a bedside neuromonitoring tool, standard within neonatal critical care provision. Its application in children is increasing but normative data underpinning such use are lacking. We present a dataset of normative aEEG values for children aged 2 months to 16 years. METHODS: This retrospective observational cohort study derives aEEG normative amplitude characteristics from electroencephalograms (EEGs) recorded in Children's Health Ireland at Crumlin. aEEG was derived from 350 normal EEGs, recorded in children aged 2 months to 16 years. Supplementary aEEGs were derived from children with abnormal EEG traces. Median upper and lower margin amplitudes and bandwidth were calculated from 5 min waking and sleeping EEG epochs. RESULTS: aEEG amplitudes vary with age and state, increasing over the first 2 years of life before diminishing. Upper and lower margin amplitudes and bandwidth are greater during sleep for children <6 years. Reference ranges may be cohorted into two groups (upper and lower reference limits; <6 years - 38 µV/7 µV awake, 54 µV/10 µV asleep; >6 years - 33 µV/5 µV awake, 36 µV/6 µV asleep). CONCLUSION: aEEG traces evolve with age in childhood and differ from neonatal values. We provide a comprehensive set of aEEG normatives to facilitate clinical interpretation in older children.

S100B, GFAP, UCH-L1 and NSE as predictors of abnormalities on CT imaging following mild traumatic brain injury: a systematic review and meta-analysis of diagnostic test accuracy.

Biomarkers such as calcium channel binding protein S100 subunit beta (S100B), glial fibrillary acidic protein (GFAP), ubiquitin c-terminal hydrolase L1 (UCH-L1) and neuron-specific enolase (NSE) have been proposed to aid in screening patients presenting with mild traumatic brain injury (mTBI). As such, we aimed to characterise their accuracy at various thresholds. MEDLINE, SCOPUS and EMBASE were searched, and articles reporting the diagnostic performance of included biomarkers were eligible for inclusion. Risk of bias was assessed using the QUADAS-II criteria. A meta-analysis was performed to assess the predictive value of biomarkers for imaging abnormalities on CT. A total of 2939 citations were identified, and 38 studies were included. Thirty-two studies reported data for S100B. At its conventional threshold of 0.1 µg/L, S100B had a pooled sensitivity of 91% (95%CI 87-94) and a specificity of 30% (95%CI 26-34). The optimal threshold for S100B was 0.72 µg/L, with a sensitivity of 61% (95% CI 50-72) and a specificity of 69% (95% CI 64-74). Nine studies reported data for GFAP. The optimal threshold for GFAP was 626 pg/mL, at which the sensitivity was 71% (95%CI 41-91) and specificity was 71% (95%CI 43-90). Sensitivity of GFAP was maximised at a threshold of 22 pg/mL, which had a sensitivity of 93% (95%CI 73-99) and a specificity of 36% (95%CI 12-68%). Three studies reported data for NSE and two studies for UCH-L1, which precluded meta-analysis. There is evidence to support the use of S100B as a screening tool in mild TBI, and potential advantages to the use of GFAP, which requires further investigation.

Measuring subepidermal moisture to detect early pressure ulcer development: a systematic review.

OBJECTIVE: The aim was to assess evidence related to the measuring of subepidermal moisture (SEM) to detect early, nonvisible development of pressure ulcers (PUs). METHOD: Using systematic review methodology, all quantitative animal and human research studies written in English were considered. In January 2021, PubMed, CINAHL, SCOPUS, Cochrane and EMBASE databases were searched. The primary outcome of interest was the validity of SEM measurement to detect early PU development. The secondary outcome was time to PU detection, sensitivity and specificity of SEM measurement, and the impact of SEM measurements on PU prevention. Data analysis was undertaken using RevMan and narrative synthesis. RESULTS: A total of 17 articles met the inclusion criteria. In all studies, a consistent abnormal deviation in SEM measurements corresponded with evidence of visual PU development. Time to PU development, explored in four studies, showed earlier detection of PU development using SEM measurement. RevMan analysis identified the mean difference in time to PU development (SEM measurement versus visual skin assessment, VSA) was 4.61 days (95% confidence interval: 3.94-5.28; p=0.0001) in favour of SEM measurements. The sensitivity of SEM measurements was reported in four studies, and scores varied from 48.3% to 100.0%. Specificity was also reported in four studies and scores ranged from 24.4% to 83.0%. The impact of the detection of abnormal SEM measurements on PU prevention was explored by one study. Results showed a 93% decrease in PU rates when staff acted on the results of the SEM readings. CONCLUSION: The findings of this review identified that SEM measurement detects PU development earlier than VSA. Furthermore, when staff responded to abnormal SEM measurements, prevention strategies were enhanced, with a subsequent reduction in visible PU development. SEM measurement may therefore be a useful addition to PU prevention strategies. DECLARATION OF INTEREST: The School of Nursing & Midwifery, RCSI has a research agreement with Bruin Biometrics. Funding for the study was through an Irish Research Council PhD Enterprise Partnership Scheme with Bruin Biometrics. The authors have no other conflicts of interest.

Preventing facial pressure injuries among health care staff working in diverse COVID-19 care environments.

The aim of this study was to determine the impact of a specially designed care bundle on the development of facial pressure injuries among frontline health care workers wearing personal protective equipment (PPE) during the COVID-19 pandemic. This was a mixed methods study. First, a pre-posttest observational design was employed to evaluate the impact of the pre-piloted intervention, a care bundle including skin cleansing and hydration, protective material use, facemask selection and skin inspection, developed in line with international best practice guidelines. Data were collected using survey methodology. Frontline COVID-19 staff working in acute, community and ambulance services were invited to participate. Then, judgemental and volunteer sampling was used to select participants to undertake semi-structured interviews to elicit feedback on their perceptions of the care bundle. The sample included 120 acute hospital staff, 60 Ambulance staff, 24 Community Hub staff and 20 COVID-19 testing centre staff. A survey response rate of 61% was realised (n = 135/224). Of the participants, 32% (n = 43) had a facial pressure ulcer (FPI) pre-intervention and 13% (n = 18) developed an FPI while using the care bundle. The odds ratio (OR) was 0.33 (95% CI: 0.18 to 0.61; P = .0004), indicating a 77% reduction in the odds of FPI development with use of the care bundle. Analysis of the qualitative data from 22 interviews identified three key themes, the context for the care bundle, the ease of use of the care bundle and the care bundle as a solution to FPI development. The care bundle reduced the incidence of FPI among the participants and was found to be easy to use. Implementation of skin protection for frontline staff continues to be important given the persistently high incidence of COVID-19 and the ongoing need to wear PPE for protracted durations.

Von Willebrand factor propeptide in severe coronavirus disease 2019 (COVID-19): evidence of acute and sustained endothelial cell activation.

Endothelial cell (EC) activation plays a key role in the pathogenesis of pulmonary microvascular occlusion, which is a hallmark of severe coronavirus disease 2019 (COVID-19). Consistent with EC activation, increased plasma von Willebrand factor antigen (VWF:Ag) levels have been reported in COVID-19. Importantly however, studies in other microangiopathies have shown that plasma VWF propeptide (VWFpp) is a more sensitive and specific measure of acute EC activation. In the present study, we further investigated the nature of EC activation in severe COVID-19. Markedly increased plasma VWF:Ag [median (interquatile range, IQR) 608·8 (531-830)iu/dl] and pro-coagulant factor VIII (FVIII) levels [median (IQR) 261·9 (170-315) iu/dl] were seen in patients with severe severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Sequential testing showed that these elevated VWF-FVIII complex levels remained high for up to 3 weeks. Similarly, plasma VWFpp levels were also markedly elevated [median (IQR) 324·6 (267-524) iu/dl]. Interestingly however, the VWFpp/VWF:Ag ratio was reduced, demonstrating that decreased VWF clearance contributes to the elevated plasma VWF:Ag levels in severe COVID-19. Importantly, plasma VWFpp levels also correlated with clinical severity indices including the Sequential Organ Failure Assessment (SOFA) score, Sepsis-Induced Coagulopathy (SIC) score and the ratio of arterial oxygen partial pressure to fractional inspired oxygen (P/F ratio). Collectively, these findings support the hypothesis that sustained fulminant EC activation is occurring in severe COVID-19, and further suggest that VWFpp may have a role as a biomarker in this setting.

α1-Antitrypsin: Key Player or Bystander in Acute Respiratory Distress Syndrome?

Acute respiratory distress syndrome is characterized by hypoxemia, altered alveolar-capillary permeability, and neutrophil-dominated inflammatory pulmonary edema. Despite decades of research, an effective drug therapy for acute respiratory distress syndrome remains elusive. The ideal pharmacotherapy for acute respiratory distress syndrome should demonstrate antiprotease activity and target injurious inflammatory pathways while maintaining host defense against infection. Furthermore, a drug with a reputable safety profile, low possibility of off-target effects, and well-known pharmacokinetics would be desirable. The endogenous 52-kd serine protease α1-antitrypsin has the potential to be a novel treatment option for acute respiratory distress syndrome. The main function of α1-antitrypsin is as an antiprotease, targeting neutrophil elastase in particular. However, studies have also highlighted the role of α1-antitrypsin in the modulation of inflammation and bacterial clearance. In light of the current SARS-CoV-2 pandemic, the identification of a treatment for acute respiratory distress syndrome is even more pertinent, and α1-antitrypsin has been implicated in the inflammatory response to SARS-CoV-2 infection.

Characterization of the Inflammatory Response to Severe COVID-19 Illness.

Rationale: Coronavirus disease (COVID-19) is a global threat to health. Its inflammatory characteristics are incompletely understood.Objectives: To define the cytokine profile of COVID-19 and to identify evidence of immunometabolic alterations in those with severe illness.Methods: Levels of IL-1ß, IL-6, IL-8, IL-10, and sTNFR1 (soluble tumor necrosis factor receptor 1) were assessed in plasma from healthy volunteers, hospitalized but stable patients with COVID-19 (COVIDstable patients), patients with COVID-19 requiring ICU admission (COVIDICU patients), and patients with severe community-acquired pneumonia requiring ICU support (CAPICU patients). Immunometabolic markers were measured in circulating neutrophils from patients with severe COVID-19. The acute phase response of AAT (alpha-1 antitrypsin) to COVID-19 was also evaluated.Measurements and Main Results: IL-1ß, IL-6, IL-8, and sTNFR1 were all increased in patients with COVID-19. COVIDICU patients could be clearly differentiated from COVIDstable patients, and demonstrated higher levels of IL-1ß, IL-6, and sTNFR1 but lower IL-10 than CAPICU patients. COVID-19 neutrophils displayed altered immunometabolism, with increased cytosolic PKM2 (pyruvate kinase M2), phosphorylated PKM2, HIF-1α (hypoxia-inducible factor-1α), and lactate. The production and sialylation of AAT increased in COVID-19, but this antiinflammatory response was overwhelmed in severe illness, with the IL-6:AAT ratio markedly higher in patients requiring ICU admission (P < 0.0001). In critically unwell patients with COVID-19, increases in IL-6:AAT predicted prolonged ICU stay and mortality, whereas improvement in IL-6:AAT was associated with clinical resolution (P < 0.0001).Conclusions: The COVID-19 cytokinemia is distinct from that of other types of pneumonia, leading to organ failure and ICU need. Neutrophils undergo immunometabolic reprogramming in severe COVID-19 illness. Cytokine ratios may predict outcomes in this population.

The Royal College of surgeons multidisciplinary guidelines on elective tracheostomy insertion in COVID-19 ventilated patients.

BACKGROUND: The current COVID-19 pandemic has placed enormous strain on healthcare systems worldwide. Understanding of COVID-19 is rapidly evolving. Pneumonia associated with COVID-19 may lead to respiratory failure requiring mechanical ventilation. The rise in patients requiring mechanical ventilation may lead to an increase in tracheostomies being performed in patients with COVID-19. Performing tracheostomy in patients with active SARS-CoV-2 infection poses a number of challenges. METHODS: These guidelines were written following multidisciplinary agreement between Otolaryngology, Head and Neck Surgery, Respiratory Medicine and the Department of Anaesthetics and Critical Care Medicine in the Royal College of Surgeons in Ireland. A literature review was performed and a guideline for elective tracheostomy insertion in patients with COVID-19 proposed. CONCLUSION: The decision to perform tracheostomy in patients with COVID-19 should be undertaken by senior members of the multidisciplinary team. Steps should be taken to minimise risks to healthcare workers.

Facial pressure injuries and the COVID-19 pandemic: skin protection care to enhance staff safety in an acute hospital setting.

OBJECTIVES: The aim of this study was to determine the impact of a specially designed care bundle on the development of facial pressure injuries (PI) among frontline healthcare workers wearing personal protective equipment (PPE) during the COVID-19 pandemic. The primary outcome of interest was the incidence of facial PIs. The secondary outcomes of interest were facial pain while wearing PPE and ease of use of the care bundle. METHODS: This study used a voluntary survey by questionnaire, supplemented by a qualitative analysis of interviews from a small purposive sample that took place in one large Irish hospital over a two-month period in 2020. The hospital was a city-based public university teaching hospital with 800 inpatient beds. The intervention was a care bundle consisting of skin protection, face mask selection, material use, skin inspection, cleansing and hydration developed in line with international best practice guidelines. All staff working in COVID-19 wards, intensive care units and the emergency department in the hospital were given a kitbag containing the elements of the care bundle plus an information pamphlet. Data were collected via a survey and interviews. RESULTS: A total of 114 staff provided feedback on the use of the care bundle. Before using the care bundle 29% (n=33) of the respondents reported developing a facial PI, whereas after using the care bundle only 8% (n=9) of the respondents reported developing a facial PI. The odds ratio (OR) of skin injury development was 4.75 (95% confidence interval (CI): 2.15-10.49; p=0.0001), suggesting that after the care bundle was issued, those who responded to the survey were almost five times less likely to develop a skin injury. Interviews with 14 staff determined that the bundle was easy to use and safe. CONCLUSION: Among those who responded to the survey, the use of the bundle was associated with a reduction in the incidence of skin injury from 29% to 8%, and respondents found the bundle easy to use, safe and effective. As with evidence from the international literature, this study has identified that when skincare is prioritised, and a systematic preventative care bundle approach is adopted, there are clear benefits for the individuals involved.

The economic impact of pressure ulcers among patients in intensive care units. A systematic review.

BACKGROUND: The incidence and prevalence of pressure ulcers in critically ill patients in intensive care units (ICUs) remain high, despite the wealth of knowledge on appropriate prevention strategies currently available. METHODS: The primary objective of this systematic review was to examine the economic impact of pressure ulcers (PU) among adult intensive care patients. A systematic review was undertaken, and the following databases were searched; Medline, Embase, CINAHL, and The Cochrane Library. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was used to formulate the review. Quality appraisal was undertaken using the Consensus on Health Economic Criteria (CHEC)-list. Data were extracted using a pre-designed extraction tool, and a narrative analysis was undertaken. RESULTS: Seven studies met the inclusion criteria. Five reported costs associated with the prevention of pressure ulcers and three explored costs of treatment strategies. Four main PU prevention cost items were identified: support surfaces, dressing materials, staff costs, and costs associated with mobilisation. Seven main PU treatment cost items were reported: dressing materials, support surfaces, drugs, surgery, lab tests, imaging, additional stays and nursing care. The overall validities of the studies varied between 37 and 79%, meaning that there is potential for bias within all the included studies. CONCLUSION: There was a significant difference in the cost of PU prevention and treatment strategies between studies. This is problematic as it becomes difficult to accurately evaluate costs from the existing literature, thereby inhibiting the usefulness of the data to inform practice. Given the methodological heterogeneity among studies, future studies in this area are needed and these should use specific methodological guidelines to generate high-quality health economic studies.

Initial Assessment of the Percutaneous Electrical Phrenic Nerve Stimulation System in Patients on Mechanical Ventilation.

OBJECTIVES: Maintaining diaphragm work using electrical stimulation during mechanical ventilation has been proposed to attenuate ventilator-induced diaphragm dysfunction. This study assessed the safety and feasibility of temporary percutaneous electrical phrenic nerve stimulation on user-specified inspiratory breaths while on mechanical ventilation. DESIGN: Two-center, nonblinded, nonrandomized study. SETTING: Hospital ICU. PATIENTS: Twelve patients mechanically ventilated from 48 hours to an expected 7 days. INTERVENTIONS: Leads were inserted to lie close to the phrenic nerve in the neck region using ultrasound guidance. Two initial patients had left-sided placement only with remaining patients undergoing bilateral lead placement. Percutaneous electrical phrenic nerve stimulation was used for six 2-hour sessions at 8-hour intervals over 48 hours. MEASUREMENTS AND MAIN RESULTS: Data collected included lead deployment success, nerve conduction, ventilation variables, work of breathing, electrical stimulation variables, stimulation breath synchrony, and diaphragm thickness measured by ultrasound at baseline, 24, and 48 hours. Primary endpoints included ability to capture the left and/or right phrenic nerves and maintenance of work of breathing within defined limits for 80% of stimulated breaths. Lead insertion was successful in 21 of 22 attempts (95.5%). Analysis of 36,059 stimulated breaths from 10 patients with attempted bilateral lead placement demonstrated a mean inspiratory lag for phrenic nerve stimulation of 23.7 ms (p < 0.001 vs null hypothesis of <88ms). Work of breathing was maintained between 0.2 and 2.0 joules/L 96.8% of the time, exceeding the 80% target. Mean diaphragm thickness increased from baseline by 7.8% at 24 hours (p = 0.022) and 15.0% at 48 hours (p = 0.0001) for patients receiving bilateral stimulation after excluding one patient with pleural effusion. No serious device/procedure-related adverse events were reported. CONCLUSIONS: The present study demonstrated the ability to safely and successfully place percutaneous electrical phrenic nerve stimulation leads in patients on mechanical ventilation and the feasibility of using this approach to synchronize electrical stimulation with inspiration while maintaining work of breathing within defined limits.

Human Umbilical Cord Mesenchymal Stromal Cells Attenuate Systemic Sepsis in Part by Enhancing Peritoneal Macrophage Bacterial Killing via Heme Oxygenase-1 Induction in Rats.

BACKGROUND: Mesenchymal stromal cells have therapeutic potential in sepsis, but the mechanism of action is unclear. We tested the effects, dose-response, and mechanisms of action of cryopreserved, xenogeneic-free human umbilical cord mesenchymal stromal cells in a rat model of fecal peritonitis, and examined the role of heme oxygenase-1 in protection. METHODS: Separate in vivo experiments evaluated mesenchymal stromal cells in fecal sepsis, established dose response (2, 5, and 10 million cells/kg), and the role of heme oxygenase-1 in mediating human umbilical cord-derived mesenchymal stromal/stem cell effects. Ex vivo studies utilized pharmacologic blockers and small inhibitory RNAs to evaluate mechanisms of mesenchymal stromal cell enhanced function in (rodent, healthy and septic human) macrophages. RESULTS: Human umbilical cord mesenchymal stromal cells reduced injury and increased survival (from 48%, 12 of 25 to 88%, 14 of 16, P = 0.0033) in fecal sepsis, with dose response studies demonstrating that 10 million cells/kg was the most effective dose. Mesenchymal stromal cells reduced bacterial load and peritoneal leukocyte infiltration (from 9.9 ± 3.1 × 10/ml to 6.2 ± 1.8 × 10/ml, N = 8 to 10 per group, P < 0.0001), and increased heme oxygenase-1 expression in peritoneal macrophages, liver, and spleen. Heme oxygenase-1 blockade abolished the effects of mesenchymal stromal cells (N = 7 or 8 per group). Mesenchymal stromal cells also increased heme oxygenase-1 expression in macrophages from healthy donors and septic patients. Direct ex vivo upregulation of macrophage heme oxygenase-1 enhanced macrophage function (phagocytosis, reactive oxygen species production, bacterial killing). Blockade of lipoxin A4 production in mesenchymal stromal cells, and of prostaglandin E2 synthesis in mesenchymal stromal cell/macrophage cocultures, prevented upregulation of heme oxygenase-1 in macrophages (from 9.6 ± 5.5-fold to 2.3 ± 1.3 and 2.4 ± 2.3 respectively, P = 0.004). Knockdown of heme oxygenase-1 production in macrophages ablated mesenchymal stromal cell enhancement of macrophage phagocytosis. CONCLUSIONS: Human umbilical cord mesenchymal stromal cells attenuate systemic sepsis by enhancing peritoneal macrophage bacterial killing, mediated partly via upregulation of peritoneal macrophage heme oxygenase-1. Lipoxin A4 and prostaglandin E2 play key roles in the mesenchymal stromal cell and macrophage interaction.

Restrictive compared with liberal red cell transfusion strategies in cardiac surgery: a meta-analysis.

AIMS: To determine whether a restrictive strategy of red blood cell (RBC) transfusion at lower haemoglobin concentrations is inferior to a liberal strategy of RBC transfusion at higher haemoglobin concentrations in patients undergoing cardiac surgery. METHODS AND RESULTS: We conducted a systematic review, meta-analysis, and trial sequential analysis of randomized controlled trials of the effect of restrictive and liberal RBC transfusion strategies on mortality within 30 days of surgery as the primary outcome. Secondary outcomes were those potentially resulting from anaemia-induced tissue hypoxia and transfusion outcomes. We searched the electronic databases MEDLINE, EMBASE, and the Cochrane Library until 17 November 2017. Thirteen trials were included. The risk ratio (RR) of mortality derived from 4545 patients assigned to a restrictive strategy when compared with 4547 transfused according to a liberal strategy was 0.96 [95% confidence interval (CI) 0.76-1.21, I2 = 0]. A restrictive strategy did not have a statistically significant effect on the risk of myocardial infarction (RR 1.01, 95% CI 0.81-1.26; I2=0), stroke (RR 0.93, 95% CI 0.68-1.27, I2 = 0), renal failure (RR 0.96, 95% CI 0.76-1.20, I2 = 0), or infection (RR 1.12, 95% CI 0.98-1.29, I2 = 0). Subgroup analysis of adult and paediatric trials did not show a significant interaction. At approximately 70% of the critical information size, the meta-analysis of mortality crossed the futility boundary for inferiority of the restrictive strategy. CONCLUSION: The current evidence does not support the notion that restrictive RBC transfusion strategies are inferior to liberal RBC strategies in patients undergoing cardiac surgery.