Lung-Dependent Areas Collapse, Monitored by Electrical Impedance Tomography, May Predict the Oxygenation Response to Prone Ventilation in COVID-19 Acute Respiratory Distress Syndrome.

OBJECTIVES: ICUs have had to deal with a large number of patients with acute respiratory distress syndrome COVID-19, a significant number of whom received prone ventilation, which is a substantial consumer of care time. The selection of patients that we have to ventilate in prone position seems interesting. We evaluate the correlation between the percentage of collapsed dependent lung areas in the supine position, monitoring by electrical impedance tomography and the oxygenation response (change in Pao2/Fio2 ratio) to prone position. DESIGN: An observational prospective study. SETTING: From October 21, 2020, to 30 March 30, 2021. At the Sainte Anne military teaching Hospital and the Timone University Hospital. PATIENTS: Fifty consecutive patients admitted in our ICUs, with COVID-19 acute respiratory distress syndrome and required mechanical, were included. Twenty-four (48%) received prone ventilation. Fifty-eight prone sessions were investigated. INTERVENTIONS: An electrical impedance tomography recording was made in supine position, daily and repeated just before and just after the prone session. The daily dependent area collapse was calculated in relation to the previous electrical impedance tomography recording. Prone ventilation response was defined as a Pao2/Fio2 ratio improvement greater than 20%. MEASUREMENT AND MAIN RESULTS: The main outcome was the correlation between dependent area collapse and the oxygenation response to prone ventilation. Dependent area collapse was correlated with oxygenation response to prone ventilation (R2 = 0.49) and had a satisfactory prediction accuracy of prone response with an area under the curve of 0.94 (95% CI, 0.87-1.00; p < 0.001). Best Youden index was obtained for a dependent area collapse greater than 13.5 %. Sensitivity of 92% (95% CI, 78-97), a specificity of 91% (95% CI, 72-97), a positive predictive value of 94% (95% CI, 88-100), a negative predictive value of 87% (95% CI, 78-96), and a diagnostic accuracy of 91% (95% CI, 84-98). CONCLUSIONS: Dependent lung areas collapse (> 13.5%), monitored by electrical impedance tomography, has an excellent positive predictive value (94%) of improved oxygenation during prone ventilation.

Ability of Fibrin Monomers to Predict Progressive Hemorrhagic Injury in Patients with Severe Traumatic Brain Injury.

BACKGROUND: Progressive hemorrhagic injury (PHI) is common in patients with severe traumatic brain injury (TBI) and is associated with poor outcomes. TBI-associated coagulopathy is frequent and has been described as risk factor for PHI. This coagulopathy is a dynamic process involving hypercoagulable and hypocoagulable states either one after the other either concomitant. Fibrin monomers (FMs) are a direct marker of thrombin action and thus reflect coagulation activation. This study sought to determine the ability of FM to predict PHI after severe TBI. METHODS: We conducted a prospective, observational study including all severe TBI patients admitted in the trauma center. Between September 2011 and September 2016, we enrolled patients with severe TBI into the derivation cohort. Between October 2016 and December 2018, we recruited the validation cohort on the same basis. Study protocol included FM measurements and standard coagulation test at admission and two computed tomography (CT) scans (upon arrival and at least 6 h thereafter). A PHI was defined by an increment in size of initial lesion (25% or more) or the development of a new hemorrhage in the follow-up CT scan. Multivariate logistic regression analysis was applied to identify predictors of PHI. RESULTS: Overall, 106 patients were included in the derivation cohort. Fifty-four (50.9%) experienced PHI. FM values were higher in these patients (151 [136.8-151] vs. 120.5 [53.3-151], p < 0.0001). The ROC curve demonstrated that FM had a fair accuracy to predict the occurrence of PHI with an area under curve of 0.7 (95% CI [0.6-0.79]). The best threshold was determined at 131.7 µg/ml. In the validation cohort of 54 patients, this threshold had a negative predictive value of 94% (95% CI [71-100]) and a positive predictive value of 49% (95% CI [32-66]). The multivariate logistic regression analysis identified 2 parameters associated with PHI: FM ≥ 131.7 (OR 6.8; 95% CI [2.8-18.1]) and Marshall category (OR 1.7; 95% CI [1.3-2.2]). Coagulopathy was not associated with PHI (OR 1.3; 95% CI [0.5-3.0]). The proportion of patients with an unfavorable functional neurologic outcome at 6-months follow-up was higher in patients with positive FM: 59 (62.1%) versus 16 (29.1%), p < 0.0001. CONCLUSIONS: FM levels at admission had a fair accuracy to predict PHI in patients with severe TBI. FM values ≥ 131.7 µg/ml are independently associated with the occurrence of PHI.

Spontaneous Hyperventilation in Severe Traumatic Brain Injury: Incidence and Association with Poor Neurological Outcome.

BACKGROUND: Hypocapnia induces cerebral vasoconstriction leading to a decrease in cerebral blood flow, which might precipitate cerebral ischemia. Hypocapnia can be intentional to treat intracranial hypertension or unintentional due to a spontaneous hyperventilation (SHV). SHV is frequent after subarachnoid hemorrhage. However, it is understudied in patients with severe traumatic brain injury (TBI). The objective of this study was to describe the incidence and consequences on outcome of SHV after severe TBI. METHODS: We conducted a retrospective, observational study including all intubated TBI patients admitted in the trauma center and still comatose 24 h after the withdrawal of sedation. SHV was defined by the presence of at least one arterial blood gas (ABG) with both PaCO2 < 35 mmHg and pH > 7.45. Patient characteristics and outcome were extracted from a prospective registry of all intubated TBI admitted in the intensive care unit. ABG results were retrieved from patient files. A multivariable logistic regression model was developed to determine factors independently associated with unfavorable outcome (defined as a Glasgow Outcome Scale between 1 and 3) at 6-month follow-up. RESULTS: During 7 years, 110 patients fully respecting inclusion criteria were included. The overall incidence of SHV was 69.1% (95% CI [59.9-77]). Patients with SHV were more severely injured (median head AIS score (5 [4-5] vs. 4 [4-5]; p = 0.016)) and exhibited an elevated morbidity during their stay. The proportion of patients with an unfavorable functional neurologic outcome was significantly higher in patients with SHV: 40 (52.6%) versus 6 (17.6%), p = 0.0006. After adjusting for confounders, SHV remains an independent factor associated with unfavorable outcome at the 6-month follow-up (OR 4.1; 95% CI [1.2-14.4]). CONCLUSIONS: SHV is common in patients with a persistent coma after a severe TBI (overall rate: 69%) and was independently associated with unfavorable outcome at 6-month follow-up.

Causes and Characteristics of Death in Intensive Care Units: A Prospective Multicenter Study.

BACKGROUND: Different modes of death are described in selected populations, but few data report the characteristics of death in a general intensive care unit population. This study analyzed the causes and characteristics of death of critically ill patients and compared anticipated death patients to unexpected death counterparts. METHODS: An observational multicenter cohort study was performed in 96 intensive care units. During 1 yr, each intensive care unit was randomized to participate during a 1-month period. Demographic data, characteristics of organ failures (Sequential Organ Failure Assessment subscore greater than or equal to 3), and organ supports were collected on all patients who died in the intensive care unit. Modes of death were defined as anticipated (after withdrawal or withholding of treatment or brain death) or unexpected (despite engagement of full-level care or sudden refractory cardiac arrest). RESULTS: A total of 698 patients were included during the study period. At the time of death, 84% had one or more organ failures (mainly hemodynamic) and 89% required at least one organ support (mainly mechanical ventilation). Deaths were considered unexpected and anticipated in 225 and 473 cases, respectively. Compared to its anticipated counterpart, unexpected death occurred earlier (1 day vs. 5 days; P< 0.001) and had fewer organ failures (1 [1 to 2] vs. 1 [1 to 3]; P< 0.01) and more organ supports (2 [2 to 3] vs. 1 [1 to 2]; P< 0.01). Withdrawal or withholding of treatments accounted for half of the deaths. CONCLUSIONS: In a general intensive care unit population, the majority of patients present with at least one organ failure at the time of death. Anticipated and unexpected deaths represent two different modes of dying and exhibit profiles reflecting the different pathophysiologic underlying mechanisms.

Early-Onset Ventilator-Associated Pneumonia in Patients with Severe Traumatic Brain Injury: Incidence, Risk Factors, and Consequences in Cerebral Oxygenation and Outcome.

BACKGROUND: Early-onset ventilator-associated pneumonia (EOVAP) occurs frequently in severe traumatic brain-injured patients, but potential consequences on cerebral oxygenation and outcome have been poorly studied. The objective of this study was to describe the incidence, risk factors for, and consequences on cerebral oxygenation and outcome of EOVAP after severe traumatic brain injury (TBI). METHODS: We conducted a retrospective, observational study including all intubated TBI admitted in the trauma center. An EOVAP was defined as a clinical pulmonary infection score >6, and then confirmed by an invasive method. Patient characteristics, computed tomography (CT) scan results, and outcome were extracted from a prospective register of all intubated TBI admitted in the intensive care unit (ICU). Data concerning the cerebral oxygenation monitoring by PbtO2 and characteristics of EOVAP were retrieved from patient files. Multivariate logistic regression models were developed to determine the risk factors of EOVAP and to describe the factors independently associated with poor outcome at 1-year follow-up. RESULTS: During 7 years, 175 patients with severe TBI were included. The overall incidence of EOVAP was 60.6% (47.4/1000 days of ventilation). Significant risk factors of EOVAP were: therapeutic hypothermia (OR 3.4; 95% CI [1.2-10.0]), thoracic AIS score ≥3 (OR 2.4; 95% CI [1.1-5.7]), and gastric aspiration (OR 5.2, 95% CI [1.7-15.9]). Prophylactic antibiotics administration was a protective factor against EOVAP (OR 0.3, 95% CI [0.1-0.8]). EOVAP had negative consequences on cerebral oxygenation. The PbtO2 was lower during EOVAP: 23.5 versus 26.4 mmHg (p <0.0001), and there were more brain hypoxia episodes: 32 versus 27% (p = 0.03). Finally, after adjusting for confounders, an EOVAP was an independent factor associated with unfavorable neurologic functional outcome at the 1-year follow-up (OR 2.71; 95% CI [1.01-7.25]). CONCLUSIONS: EOVAP is frequent after a severe TBI (overall rate: 61%), with therapeutic hypothermia, severe thoracic lesion, and gastric aspiration as main risk factors. EOVAP had a negative impact on cerebral oxygenation measured by PbtO2 and was independently associated with unfavorable outcome at 1-year follow-up. This suggests that all precautions available should be taken to prevent EOVAP in this population.

Early neurological wake-up test in intubated brain-injured patients: A long-term, single-centre experience.

BACKGROUND: In prehospital setting, a severe traumatic brain injury (TBI) requires tracheal intubation, sedation and mechanical ventilation pending the initial imagery. An early neurological wake-up test (ENWT), soon after the initial imaging assessment, allows a rapid neurological reassessment. This strategy authorises an initial clinical examination of reference with which will be compared the later examinations. The main objective of this study was to describe the characteristics of the patients who underwent an ENWT, and to determine its causes of failure. METHODS: We conducted a retrospective, observational, single-centre study including all intubated TBI admitted in the trauma centre. An ENWT was defined as cessation of sedation within 24h after TBI. Data concerning patient characteristics, CT-scan results, and outcomes were extracted from a prospective register of all intubated TBI admitted in the ICU. Characteristic of ENWT and causes of failure were retrieved from patient files. A multivariate logistic regression model was developed to determine the risk factors of ENWT failure. RESULTS: During 7 years, 242 patients with intubated TBI were included. An ENWT was started in 96 patients, for an overall rate at 40%. The ENWT was stopped in 38 patients (39.5%), mostly due to neurological deterioration in 27 cases (71%) or respiratory distress in 10 cases (26%). Significant predictors of ENWT failure were: the presence of subdural hematoma with a thickness >5mm on first imagery (OR=3.2; 95%CI [1.01-10.28]), and an initial GCS score <5 (OR=7.4; 95%CI [1.92-28.43]). Prevalence of poor outcome at 1year was lesser in patients with successful ENWT compared to those with failure or absence of ENWT: 4% vs. 48% and 49% (p<0.0001). CONCLUSIONS: The ENWT is achieved in 40% of patients, with a success rate of 60.5%. In presence of a subdural hematoma with a thickness >5mm or an initial GCS score <5, an ENWT failure may be expected.

Impairment of cardiac metabolism and sympathetic innervation after aneurysmal subarachnoid hemorrhage: a nuclear medicine imaging study.

INTRODUCTION: Although aneurysmal subarachnoid hemorrhage (SAH) is often complicated by myocardial injury, whether this neurogenic cardiomyopathy is associated with the modification of cardiac metabolism is unknown. This study sought to explore, by positron emission tomography/computed tomography, the presence of altered cardiac glucose metabolism after SAH. METHODS: During a 16-month period, 30 SAH acute phase patients underwent myocardial (18)F- fluorodesoxyglucose positron emission tomography ((18)F-FDGPET), (99m)Tc-tetrofosmin and (123)I-meta-iodobenzylguanidine ((123)I-mIBG) scintigraphy, respectively, assessing glucose metabolism, cardiac perfusion, and sympathetic innervation. Patients with initial abnormalities were followed monthly for two months for (18)F-FDG, and six months later for (123)I-mIBG. RESULTS: In this SAH population, acute cardiac metabolic disturbance was observed in 83% of patients (n = 25), and sympathetic innervation disturbance affected 90% (n = 27). Myocardial perfusion was normal for all patients. The topography and extent of metabolic defects and innervation abnormalities largely overlapped. Follow-up showed rapid improvement of glucose metabolism in one or two months. Normalization of sympathetic innervation was slower; only 27% of patients (n = 8) exhibited normal (123)I-mIBG scintigraphy after six months. Presence of initial altered cardiac metabolism was not associated with more unfavorable cardiac or neurological outcomes. CONCLUSIONS: These findings support the hypothesis of neurogenic myocardial stunning after SAH. In hemodynamically stable acute phase SAH patients, cardiomyopathy is characterized by diffuse and heterogeneous (18)F-FDG and (123)I-mIBG uptake defect. TRIAL REGISTRATION: Clinicaltrials.gov NCT01218191. Registered 6 October 2010.

Tracheal intubation difficulties in the setting of face and neck burns: myth or reality?

INTRODUCTION: Face and/or neck burn (FNB) exposes patients to the double respiratory risk of obstruction and hypoxia, and these risks may require a tracheal intubation. This study aims to describe the incidence and the characteristics of difficult intubation in FNB patients. METHODS: We conducted a 5-year retrospective, single-center study including all patients meeting the following criteria: 18 years of age or older, an FNB at least 1% of burned surface area with a severity equal to or greater than the superficial second degree, and intubation and a burn center admission within the first 24 hours after the burn. Patients were compared according to the difficulty of their intubation. RESULTS: Between January 2007 and December 2011, we included 134 patients. The incidence of difficult intubation was 11.2% but was greater in the burn center than in the pre-burn center: 16.9% vs 3.5% (P = .02). The most important difference between patients with or without difficult intubation was the time between the burn injury and the intubation: 210 (105-290) vs 120 (60-180) minutes (P = .047). After multivariate analysis, an intubation performed at a burn center was independently associated with difficult intubation: odds ratio = 3.2; 95% confidence interval, 1.1-528. CONCLUSIONS: This study underlines the high incidence of difficult intubation in FNB patients, greater than 11.2%, and demonstrates that intubation is more difficult when realized at a burn center, probably because it is performed later, allowing for development of cervical and laryngeal edema.

FiO2 delivered by a turbine portable ventilator with an oxygen concentrator in an Austere environment.

BACKGROUND: Management of critically ill patients in austere environments is a logistic challenge. Availability of oxygen cylinders for the mechanically ventilated patient may be difficult in such a context. A solution is to use a ventilator able to function with an oxygen concentrator. OBJECTIVES: We tested the SeQual Integra™ (SeQual, San Diego, CA) 10-OM oxygen concentrator paired with the Pulmonetic System(®) LTV 1000 ventilator (Pulmonetic Systems, Minneapolis, MN) and evaluated the delivered fraction of inspired oxygen (FiO2) across a range of minute volumes and combinations of ventilator settings. METHODS: Two LTV 1000 ventilators were tested. The ventilators were attached to a test lung and FiO2 was measured by a gas analyzer. Continuous-flow oxygen was generated by the OC from 0.5 L/min to 10 L/min and injected into the oxygen inlet port of the LTV 1000. Several combinations of ventilator settings were evaluated to determine the factors affecting the delivered FiO2. RESULTS: The LTV 1000 ventilator is a turbine ventilator that is able to deliver high FiO2 when functioning with an oxygen concentrator. However, modifications of the ventilator settings such as increase in minute ventilation affect delivered FiO2 even if oxygen flow is constant on the oxygen concentrator. CONCLUSIONS: The ability of an oxygen concentrator to deliver high FiO2 when used with a turbine ventilator makes this method of oxygen delivery a viable alternative to cylinders in austere environments when used with a turbine ventilator. However, FiO2 has to be monitored continuously because delivered FiO2 decreases when minute ventilation is increased.

Evaluation of early mini-bronchoalveolar lavage in the diagnosis of health care-associated pneumonia: a prospective study.

INTRODUCTION: Health care-associated pneumonia (HCAP) has been proposed as a new category of respiratory infection to identify patients at risk of multidrug-resistant (MDR) pathogens. The American Thoracic Society's recommendation for HCAP treatment is to use broad-spectrum and multiple antibiotics. However, this strategy may be economically expensive and promote antimicrobial resistance when a multisensitive pathogen is not identified. METHODS: We prospectively included all patients presenting with HCAP in the emergency department. Blood cultures and fiberoptic bronchoscope-guided distal protected small volume bronchoalveolar lavage (FODP mini-BAL) were performed in each patient. Empirical antibiotic therapy was adapted when microbiological findings were available. The primary objective was to assess whether FODP mini-BAL is more efficient than blood cultures in identifying pathogens with the ratio of identification between both techniques as principal criteria. RESULTS: We included 54 patients with HCAP. Pathogens were identified in 46.3% of cases using mini-BAL and in 11.1% of cases using blood cultures (P <0.01). When the patient did not receive antibiotic therapy before the procedure, pathogens were identified in 72.6% of cases using mini-BAL and in 9.5% of cases using blood cultures (P <0.01). We noted multidrug-resistant pathogens in 16% of cases. All bronchoscopic procedures could be performed in patients without complications. CONCLUSIONS: FODP mini-BAL was more efficient than blood cultures for identifying pathogens in patients presenting with HCAP. When bacteriological identification was obtained, antibiotic therapy was adapted in 100% of cases.See related letter by Sircar et al.,http://ccforum.com/content/17/2/428.

Effect of statin therapy on mortality in patients with ventilator-associated pneumonia: a randomized clinical trial.

IMPORTANCE: Observational studies have reported that statin use may be associated with improved outcomes of various infections. Ventilator-associated pneumonia (VAP) is the most common infection in the intensive care unit (ICU) and is associated with substantial mortality. OBJECTIVE: To determine whether statin therapy can decrease day-28 mortality in patients with VAP. DESIGN, SETTING, AND PARTICIPANTS: Randomized, placebo-controlled, double-blind, parallel-group, multicenter trial performed in 26 intensive care units in France from January 2010 to March 2013. For power to detect an 8% absolute reduction in the day-28 mortality rate, we planned to enroll 1002 patients requiring invasive mechanical ventilation for more than 2 days and having suspected VAP, defined as a modified Clinical Pulmonary Infection Score of 5 or greater. The futility stopping rules were an absolute increase in day-28 mortality of at least 2.7% with simvastatin compared with placebo after enrollment of the first 251 patients. INTERVENTIONS: Participants were randomized to receive simvastatin (60 mg) or placebo, started on the same day as antibiotic therapy and given until ICU discharge, death, or day 28, whichever occurred first. MAIN OUTCOMES AND MEASURES: Primary outcome was day-28 mortality. Day-14, ICU, and hospital mortality rates were determined, as well as duration of mechanical ventilation and Sequential Organ Failure Assessment (SOFA) scores on days 3, 7, and 14. RESULTS: The study was stopped for futility at the first scheduled interim analysis after enrollment of 300 patients, of whom all but 7% in the simvastatin group and 11% in the placebo group were naive to statin therapy at ICU admission. Day-28 mortality was not lower in the simvastatin group (21.2% [95% CI, 15.4% to 28.6%) than in the placebo group (15.2% [95% CI, 10.2% to 22.1%]; P = .10; hazard ratio, 1.45 [95% CI, 0.83 to 2.51]); the between-group difference was 6.0% (95% CI, -3.0% to 14.9%). In statin-naive patients, day-28 mortality was 21.5% (95% CI, 15.4% to 29.1%) with simvastatin and 13.8% (95% CI, 8.8% to 21.0%) with placebo (P = .054) (between-group difference, 7.7% [95%CI, -1.8% to 16.8%). There were no significant differences regarding day-14, ICU, or hospital mortality rates; duration of mechanical ventilation; or changes in SOFA score. CONCLUSIONS AND RELEVANCE: In adults with suspected VAP, adjunctive simvastatin therapy compared with placebo did not improve day-28 survival. These findings do not support the use of statins with the goal of improving VAP outcomes. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01057758.

ABO blood type and functional neurological outcome in patients with severe traumatic brain injury.

BACKGROUND: The ABO blood system has been involved in the pathogenesis of several diseases, including coagulopathy and bleeding complications. In trauma patients, blood type A has been associated with acute respiratory distress syndrome, and recently, blood type O has been associated with all-cause mortality. The purpose of this study was to assess the association between ABO blood types and long-term functional outcomes in critically ill patients with severe traumatic brain injury (TBI). METHODS: We conducted a single-center, retrospective, observational study including all patients admitted to the intensive care unit with severe TBI (defined as a Glasgow Coma Scale score of ≤8) between January 2007 and December 2018. Patient characteristics and outcomes were extracted from a prospective registry of all intubated patients admitted to the intensive care unit for TBI. ABO blood types were retrospectively retrieved from patient medical records. The association between ABO blood type (A, B, AB, and O) and unfavorable functional outcome (defined by a Glasgow Outcome Scale score between 1 and 3) 6 months after injury was assessed in univariate and multivariate analysis. RESULTS: A total of 333 patients meeting the inclusion criteria were included. There were 151 type O (46%), 131 type A (39%), 37 type B (11%), and 12 type AB patients (4%). No significant differences in baseline demographic, clinical, or biological characteristics were observed between blood types. The prevalence of unfavorable outcome was significantly different between the four groups. After adjustment for confounders, blood type O was significantly associated with unfavorable outcome at 6 months (odds ratio, 1.97; confidence interval [1.03-3.80]; p = 0.042). The prevalence of coagulopathy or progressive hemorrhagic injury was not statistically different between blood types ( p = 0.575 and p = 0.813, respectively). CONCLUSION: Blood type O appears to be associated with unfavorable long-term functional outcome in critically ill patients with severe TBI. Further studies are needed to detail the mechanism underlying this relationship. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level IV.

Intestinal Necrosis Associated with Orally Administered Calcium Polystyrene Sulfonate Without Sorbitol.

OBJECTIVE: To describe a case of extensive intestinal necrosis with oral intake of calcium polystyrene sulfonate without sorbitol. CASE SUMMARY: A 73-year-old woman was admitted to the emergency department with abdominal pain. Abdominal computed tomography (CT) scan showed widespread dilatation of the bowel. The diagnosis of acute colonic pseudoobstruction was made. On day 3, her serum potassium level rose to 5.6 mEq/L. It was treated with hydrocortisone 100 mg/day and calcium polystyrene sulfonate 15 g/day via nasogastric tube from day 3 to day 6. On day 6, the severe abdominal pain recurred, with abdominal tenderness. CT scan showed pneumoperitoneum and peritoneal effusion. At surgery, 2 lenticular jejunal perforations and an ischemic cecum were found. Microscopic findings indicated that the transmural abscess contained massive inflammatory infiltrate and the cecal mucosa showed ulceration and inflammation with a fibrinous and purulent coating. Small gray-purple or blue angulated crystals were embedded in the cecal and most of the jejunal mucosal ulcers. On day 19, the patient died of multiple organ failure after her third laparotomy. DISCUSSION: Ion-exchanging resins are given orally or by retention enema for the treatment of hyperkalemia. The most commonly used and best-established resin is sodium polystyrene sulfonate. However, it is known to promote colonic necrosis when sorbitol is also given or especially in patients with renal failure or postoperative ileus. Calcium polystyrene sulfonate is another ion-exchange resin. There are few reports of adverse effects in the literature. Our case is interesting for 2 reasons: the resin given was calcium polystyrene sulfonate and sorbitol was not used. CONCLUSIONS: Like sodium polystyrene sulfonate, calcium polystyrene sulfonate is an ion-exchanging resin that can promote bowel necrosis. We believe that it should not be used with sorbitol or when bowel transit time is slowed.

Acute respiratory distress syndrome in the forward environment. Retrospective analysis of acute respiratory distress syndrome cases among French Army war casualties.

BACKGROUND: According to the Joint Theater Trauma Registry, 26% to 33% of war casualties develop acute respiratory distress syndrome (ARDS), with high mortality. Here, we aimed to describe ARDS incidence and severity among patients evacuated from war zones and admitted to French intensive care units (ICUs). METHODS: We performed an observational retrospective multicentric review of all patients evacuated from war zones and admitted to French ICUs between 2003 and 2018. Our analysis included all medical and trauma patients developing ARDS according to the Berlin definition. We evaluated ARDS incidence, and determined ARDS severity from arterial blood gas analysis. Analyzed parameters included invasive ventilation duration, ARDS treatments, ICU stay length, and 30-day and 90-day mortalities. RESULTS: Among 141 included patients (84% military; median age, 30 years), 57 (42%) developed ARDS. Acute respiratory distress syndrome was mild in 13 (22%) patients, moderate in 24 (42%) patients, and severe in 20 (36%) patients. Evacuation occurred in less than 26 hours for 32 war casualties, 17 non-war-related trauma patients, and 8 medical patients. Among severe trauma patients, median Injury Severity Score was 34, and Abbreviated Injury Scale thorax was 3. Upon French ICU admission, median partial pressure of oxygen in arterial blood/inspirated fraction of oxygen ratio was 241 [144-296]. Administered ARDS treatments included intubation (98%, n = 56), protective ventilation (87%, n = 49), neuromuscular blockade (76%, n = 43), prone position (16%, n = 9), inhaled nitric oxide (10%, n = 6), almitrine (7%, n = 7), and extracorporeal life support (4%, n = 2). Median duration of invasive ventilation was 13 days, ICU stay was 18 days, 30-day mortality was 14%, and 90-day mortality was 21%. CONCLUSION: Acute respiratory distress syndrome was frequent and severe among French patients evacuated from war theaters. Improved treatment capacities are needed in the forward environment-for example, a specialized US team can provide extracorporeal life support for highly hypoxemic war casualties. LEVEL OF EVIDENCE: Prognostic and epidemiological study, level III.

The Site of Oxygen Delivery Into a Home Ventilator Affects Recorded Volumes.

BACKGROUND: Long-term home mechanical ventilation is increasingly used by patients with chronic respiratory failure. Storage of medical data in the cloud is expanding, and ventilation can be monitored remotely. The aim of this bench study was to determine whether tidal volume (VT) can be affected by the location of supplemental oxygen placement. METHODS: We tested 4 home ventilators in a bench test using a dual-chamber test lung to test the addition of supplemental oxygen placement via a connector in the circuit (ie, front intake port) versus via the manufacturer's rear intake port, with different oxygen supply flows of 2, 4, 6, and 8 L/min. We compared the effectively delivered VT as measured with a pneumotachograph (ie, measured VT) versus the VT reported by each home ventilator (ie, monitored VT). RESULTS: For all of the home ventilators, the monitored VT and measured VT were comparable when the rear oxygen intake was used, regardless of oxygen flow. However, when the front oxygen intake was used, the monitored VT as measured by the ventilators was significantly lower than the measured VT, with the greatest difference reaching 29% for the highest oxygen flow tested (8 L/min). CONCLUSIONS: The monitored VT may be inaccurate if oxygen is added with a connector in the circuit, which may have consequences on both the individual level and collective level (ie, big data analysis). Physicians who analyze data from home ventilators should be aware of the site of oxygen supplementation and promote use of only the rear oxygen intake.

Fibrin monomers and association with significant hemorrhage or mortality in severely injured trauma patients.

BACKGROUND: Post-traumatic hemorrhage is still the leading cause of potentially preventable death in patients with severe trauma. Traumatic-induced coagulopathy has been described as a risk factor for significant hemorrhage and mortality in this population. Fibrin monomers (FMs) are a direct marker of thrombin action, and thus reflect coagulation activation. This study sought to determine the association of FMs levels at admission with significant hemorrhage and 28-day mortality after a severe trauma. METHODS: We conducted a retrospective, observational study including all severe trauma patients admitted in a level-1 trauma center between January 2012 and December 2017. Patients with severe traumatic brain injury or previous anticoagulant / antiaggregant therapies were excluded. FMs measurements and standard coagulation test were taken at admission. Significant hemorrhage was defined as a hemorrhage requiring the transfusion of ≥ 4 Red Blood Cells units during the first 6 h. Multivariable analysis was applied to identify predictors of significant hemorrhage and a simple logistic regression analysis was applied to identify an association between FMs and 28-day mortality. RESULTS: Overall, 299 patients were included. A total of 47 (16%) experienced a significant hemorrhage. The ROC curve demonstrated that FMs had a poor accuracy to predict the occurrence of significant hemorrhage with an AUC of 0.65 (0.57-0.74). The best threshold at 92.45 µg/ml had excellent sensitivity (87%) and negative predictive value (95%), but was not independently associated with significant hemorrhage (OR = 1.5; 95%CI (0.5-4.2)). The 28-day mortality rate was 5%. In simple logistic regression analysis, FMs values ≥109.5 µg/ml were significantly associated with 28-day mortality (unadjusted OR = 13.2; 95%CI (1.7-102)). CONCLUSIONS: FMs levels at admission are not associated with the occurrence of a significant hemorrhage in patients with severe trauma. However, the excellent sensitivity and NPV of FMs could help to identify patients with a low risk of severe bleeding during hospital care. In addition, FMs levels ≥109.5 µg/ml might be predictive of 28-day mortality.

In COPD, Nocturnal Noninvasive Ventilation Reduces the FIO2 Delivered Compared With Long-Term Oxygen Therapy at the Same Flow.

BACKGROUND: Nocturnal noninvasive ventilation is recommended for patients with hypercapnic COPD. Long-term oxygen therapy improves survival in patients with hypoxemic disease. However, leaks during noninvasive ventilation are likely to reduce the fraction of inspired oxygen. OBJECTIVES: To compare nocturnal inspired O2 fractions during noninvasive ventilation with daytime pharyngeal inspired O2 fractions during nasal cannula oxygen therapy (with the same O2 flow) in patients with COPD at home (ie, real-life conditions). METHODS: This single-center prospective observational study included 14 subjects with COPD who received long-term O2 therapy. We analyzed pharyngeal inspired O2 fractions in the evening, with a nasopharyngeal probe (sidestream gas analyzer). The O2 flow was measured with a precision flow meter, at the usual flow. Then, the same O2 flow was implemented for noninvasive ventilation with a study's home ventilator. The all-night noninvasive ventilation parameters were delivered in pressure mode with a single-limb leaking circuit. Daytime and nighttime inspired O2 fractions were compared. RESULTS: The mean ± SD daytime pharyngeal inspired O2 fraction, measured with normobaric basal O2 flow, 0.308 ± 0.026%, was significantly higher than the mean ± SD nighttime inspired O2 fraction, measured during noninvasive ventilation (0.251 ± 0.011; P < .001). CONCLUSIONS: The nighttime inspired O2 fraction decreased with a modern noninvasive ventilation pattern, pressure target, and intentional leaks. This partial lack of O2 therapy is likely to be harmful. It might explain the poor results in all but 2 randomized controlled trials on long-term noninvasive ventilation in COPD. (ClinicalTrials.gov registration NCT02599246.).