Usage of RePlay as a Take-Home System to Support High-Repetition Motor Rehabilitation After Neurological Injury.

Stroke is a leading cause of chronic motor disability. While physical rehabilitation can promote functional recovery, several barriers prevent patients from receiving optimal rehabilitative care. Easy access to at-home rehabilitative tools could increase patients' ability to participate in rehabilitative exercises, which may lead to improved outcomes. Toward achieving this goal, we developed RePlay: a novel system that facilitates unsupervised rehabilitative exercises at home. RePlay leverages available consumer technology to provide a simple tool that allows users to perform common rehabilitative exercises in a gameplay environment. RePlay collects quantitative time series force and movement data from handheld devices, which provide therapists the ability to quantify gains and individualize rehabilitative regimens. RePlay was developed in C# using Visual Studio. In this feasibility study, we assessed whether participants with neurological injury are capable of using the RePlay system in both a supervised in-office setting and an unsupervised at-home setting, and we assessed their adherence to the unsupervised at-home rehabilitation assignment. All participants were assigned a set of 18 games and exercises to play each day. Participants produced on average 698 ± 36 discrete movements during the initial 1 hour in-office visit. A subset of participants who used the system at home produced 1593 ± 197 discrete movements per day. Participants demonstrated a high degree of engagement while using the system at home, typically completing nearly double the number of assigned exercises per day. These findings indicate that the open-source RePlay system may be a feasible tool to facilitate access to rehabilitative exercises and potentially improve overall patient outcomes.

A "hot Spot"-Enhanced paper lateral flow assay for ultrasensitive detection of traumatic brain injury biomarker S-100ß in blood plasma.

Currently colorimetric paper lateral flow strips (PLFS) encounter two major limitations, that is, low sensitivity and severe interference from complex sample matrices such as blood. These shortcomings limit their application in detection of low-concentration analytes in complex samples. To solve these problems, a PLFS has been developed by utilizing surface-enhanced Raman scattering (SERS) for sensing signal transduction. In particular, a hierarchical three-dimensional nanostructure has been designed to create "hot spots", which can significantly amplify the SERS sensing signal, leading to high sensitivity. As a result, this PLFS has demonstrated a limit of detection (LOD) of 5.0 pg mL-1 toward detection of S-100ß, a traumatic brain injury (TBI) protein biomarker in blood plasma. The PLFS has been successfully used for rapid measurement of S-100ß in clinical TBI patient samples taken in the emergency department. Availability of PLFS for blood testing would shift the paradigm of TBI patient management and clinical outcome in emergency departments. It is expected that this type of PLFS can be adapted for rapid detection of various human diseases due to its capability of measuring a low level of protein blood biomarkers in complex human fluids.

Correction to: A suite of automated tools to quantify hand and wrist motor function after cervical spinal cord injury.

The original article [1] contains several errors which the authors would like to rectify.

A suite of automated tools to quantify hand and wrist motor function after cervical spinal cord injury.

BACKGROUND: Cervical spinal cord injury (cSCI) often causes chronic upper extremity disability. Reliable measurement of arm function is critical for development of therapies to improve recovery after cSCI. In this study, we report a suite of automated rehabilitative tools to allow simple, quantitative assessment of hand and wrist motor function. METHODS: We measured range of motion and force production using these devices in cSCI participants with a range of upper limb disability and in neurologically intact participants at two time points separated by approximately 4 months. Additionally, we determined whether measures collected with the rehabilitative tools correlated with standard upper limb assessments, including the Graded Redefined Assessment of Strength, Sensibility, and Prehension (GRASSP) and the Jebsen Hand Function Test (JHFT). RESULTS: We find that the rehabilitative devices are useful to provide assessment of upper limb function in physical units over time in SCI participants and are well-correlated with standard assessments. CONCLUSIONS: These results indicate that these tools represent a reliable system for longitudinal evaluation of upper extremity function after cSCI and may provide a framework to assess the efficacy of strategies aimed at improving recovery of upper limb function.

Vagus Nerve Stimulation Paired With Upper Limb Rehabilitation After Chronic Stroke.

Background and Purpose- We assessed safety, feasibility, and potential effects of vagus nerve stimulation (VNS) paired with rehabilitation for improving arm function after chronic stroke. Methods- We performed a randomized, multisite, double-blinded, sham-controlled pilot study. All participants were implanted with a VNS device and received 6-week in-clinic rehabilitation followed by a home exercise program. Randomization was to active VNS (n=8) or control VNS (n=9) paired with rehabilitation. Outcomes were assessed at days 1, 30, and 90 post-completion of in-clinic therapy. Results- All participants completed the course of therapy. There were 3 serious adverse events related to surgery. Average FMA-UE scores increased 7.6 with active VNS and 5.3 points with control at day 1 post-in-clinic therapy (difference, 2.3 points; CI, -1.8 to 6.4; P=0.20). At day 90, mean scores increased 9.5 points from baseline with active VNS, and the control scores improved by 3.8 (difference, 5.7 points; CI, -1.4 to 11.5; P=0.055). The clinically meaningful response rate of FMA-UE at day 90 was 88% with active VNS and 33% with control VNS ( P<0.05). Conclusions- VNS paired with rehabilitation was acceptably safe and feasible in participants with upper limb motor deficit after chronic ischemic stroke. A pivotal study of this therapy is justified. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT02243020.

Paper-Based Surface-Enhanced Raman Scattering Lateral Flow Strip for Detection of Neuron-Specific Enolase in Blood Plasma.

An inexpensive and disposable paper-based lateral flow strip (PLFS) has been developed as an immunoassay, in which surface-enhanced Raman scattering (SERS) is utilized for sensing signal transduction. The Au nanostar@Raman Reporter@silica sandwich nanoparticles are developed as the SERS probes, which is the key to the high sensitivity of the device. Compared with a colorimetric PLFS, the SERS-PLFS exhibits superior performance in terms of sensitivity and limit of detection (LOD) in a blood plasma-containing sample matrix. In addition, the SERS-PLFS has been successfully used for detection of neuron-specific enolase (NSE), a traumatic brain injury (TBI) protein biomarker, in diluted blood plasma samples, achieving a LOD of 0.86 ng/mL. Moreover, the SERS-PLFS was successfully employed to measure the NSE level in clinical blood plasma samples taken from deidentified TBI patients. This work demonstrates that the SERS-PLFS has great potential in assisting screening of TBI patients in the point-of-care setting.

The association of maximum Troponin values post out-of-hospital cardiac arrest with electrocardiographic findings, cardiac reperfusion procedures and survival to discharge: A sub-study of ROC PRIMED.

BACKGROUND: The role of Troponin (Tn) levels in the management of patients post out-of-hospital cardiac arrest (OHCA) is unclear. METHODS: All OHCA patients enrolled in the Resuscitation Outcomes Consortium Prehospital Resuscitation using an IMpedance valve and Early versus Delayed analysis trial and admitted to hospital with a Tn level and a 12-lead electrocardiogram were stratified by ST elevation (STE) or no STE in a regression model for survival to discharge adjusted for Utstein predictors and site. RESULTS: Of the 15,617 enrolled OHCA patients, 4118 (26%) survived to admission to hospital; 17% (693) were STE and 77% (3188) were no STE with 6% unknown; 83% (3460) had at least one Tn level. Reperfusion rates were higher when Tn level >2ng/ml (p>0.1ng/ml) improved with a diagnostic cardiac catheterization (p<0.001). CONCLUSIONS: Elevated Tn levels >2ng/ml were associated with improved survival to discharge in patients post OHCA with STE. Survival in patients with no STE and Tn values >0.1ng/ml was higher when associated with diagnostic cardiac catheterization or treated with reperfusion or revascularization.

Sex- and gender-specific research priorities in cardiovascular resuscitation: proceedings from the 2014 Academic Emergency Medicine Consensus Conference Cardiovascular Resuscitation Research Workgroup.

Significant sex and gender differences in both physiology and psychology are readily acknowledged between men and women; however, data are lacking regarding differences in their responses to injury and treatment and in their ultimate recovery and survival. These variations remain particularly poorly defined within the field of cardiovascular resuscitation. A better understanding of the interaction between these important factors may soon allow us to dramatically improve outcomes in disease processes that currently carry a dismal prognosis, such as sudden cardiac arrest. As part of the 2014 Academic Emergency Medicine consensus conference "Gender-Specific Research in Emergency Medicine: Investigate, Understand, and Translate How Gender Affects Patient Outcomes," our group sought to identify key research questions and knowledge gaps pertaining to both sex and gender in cardiac resuscitation that could be answered in the near future to inform our understanding of these important issues. We combined a monthly teleconference meeting of interdisciplinary stakeholders from largely academic institutions with a focused interest in cardiovascular outcomes research, an extensive review of the existing literature, and an open breakout session discussion on the recommendations at the consensus conference to establish a prioritization of the knowledge gaps and relevant research questions in this area. We identified six priority research areas: 1) out-of-hospital cardiac arrest epidemiology and outcome, 2) customized resuscitation drugs, 3) treatment role for sex steroids, 4) targeted temperature management and hypothermia, 5) withdrawal of care after cardiac arrest, and 6) cardiopulmonary resuscitation training and implementation. We believe that exploring these key topics and identifying relevant questions may directly lead to improved understanding of sex- and gender-specific issues seen in cardiac resuscitation and ultimately improved patient outcomes.

Bulk derivatization and direct injection of human cerebrospinal fluid for trace-level quantification of endogenous estrogens using trap-and-elute liquid chromatography with tandem mass spectrometry.

Although there are existing methods for determining estrogen in human bodily fluids including blood plasma and serum, very little information is available regarding estrogen levels in human cerebrospinal fluid (CSF), which is critical to assess in studies of neuroprotective functions and diffusion of neuroprotective estrogens across the blood-brain barrier. To address this problem, a liquid chromatography with tandem mass spectrometry method for the simultaneous quantification of four endogenous estrogens (estrone, 17α-estradiol, 17ß-estradiol, and estriol) in human CSF was developed. An aliquot (300 µL) of human CSF was bulk derivatized using dansyl chloride in the sample and 10 µL was directly injected onto a restricted-access media trap column for protein removal. No off-line sample extraction or cleanup was needed. The limits of detection of estrone, 17α-estradiol, 17ß-estradiol, and estriol were 17, 28, 13, and 30 pg/mL, respectively, which is in the parts-per-trillion regime. The method was then applied to human CSF collected from ischemic trauma patients. Endogenous estrogens were detected and quantified, demonstrating the effectiveness of this method.

Estrogen-provided cardiac protection following burn trauma is mediated through a reduction in mitochondria-derived DAMPs.

Mitochondria-derived danger-associated molecular patterns (DAMPs) play important roles in sterile inflammation after acute injuries. This study was designed to test the hypothesis that 17ß-estradiol protects the heart via suppressing myocardial mitochondrial DAMPs after burn injury using an animal model. Sprague-Dawley rats were given a third-degree scald burn comprising 40% total body surface area (TBSA). 17ß-Estradiol, 0.5 mg/kg, or control vehicle was administered subcutaneously 15 min following burn. The heart was harvested 24 h postburn. Estradiol showed significant inhibition on the productivity of H2O2 and oxidation of lipid molecules in the mitochondria. Estradiol increased mitochondrial antioxidant defense via enhancing the activities and expression of superoxide dismutase (SOD) and glutathione peroxidase (GPx). Estradiol also protected mitochondrial respiratory function and structural integrity. In parallel, estradiol remarkably decreased burn-induced release of mitochondrial cytochrome c and mitochondrial DNA (mtDNA) into cytoplasm. Further, estradiol inhibited myocardial apoptosis, shown by its suppression on DNA laddering and downregulation of caspase 1 and caspase 3. Estradiol's anti-inflammatory effect was demonstrated by reduction in systemic and cardiac cytokines (TNF-α, IL-1ß, and IL-6), decrease in NF-κB activation, and attenuation of the expression of inflammasome component ASC in the heart of burned rats. Estradiol-provided cardiac protection was shown by reduction in myocardial injury marker troponin-I, amendment of heart morphology, and improvement of cardiac contractility after burn injury. Together, these data suggest that postburn administration of 17ß-estradiol protects the heart via an effective control over the generation of mitochondrial DAMPs (mtROS, cytochrome c, and mtDNA) that incite cardiac apoptosis and inflammation.

Detection of ß-amyloid oligomers as a predictor of neurological outcome after brain injury.

OBJECT: Traumatic brain injury (TBI) is known to be a risk factor for Alzheimer-like dementia. In previous studies, an increase in ß-amyloid (Aß) monomers, such as ß-amyloid 42 (Aß42), in the CSF of patients with TBI has been shown to correlate with a decrease in amyloid plaques in the brain and improved neurological outcomes. In this study, the authors hypothesized that the levels of toxic high-molecular-weight ß-amyloid oligomers are increased in the brain and are detectable within the CSF of TBI patients with poor neurological outcomes. METHODS: Samples of CSF were collected from 18 patients with severe TBI (Glasgow Coma Scale Scores 3-8) and a ventriculostomy. In all cases the CSF was collected within 72 hours of injury. The CSF levels of neuron-specific enolase (NSE) and Aß42 were measured using enzyme-linked immunosorbent assay. The levels of high-molecular-weight ß-amyloid oligomers were measured using Western blot analysis. RESULTS: Patients with good outcomes showed an increase in the levels of CSF Aß42 (p = 0.003). Those with bad outcomes exhibited an increase in CSF levels of ß-amyloid oligomers (p = 0.009) and NSE (p = 0.001). In addition, the CSF oligomer levels correlated with the scores on the extended Glasgow Outcome Scale (r = -0.89, p = 0.0001), disability rating scale scores (r = 0.77, p = 0.005), CSF Aß42 levels (r = -0.42, p = 0.12), and CSF NSE levels (r = 0.70, p = 0.004). Additionally, the receiver operating characteristic curve yielded an area under the curve for ß-amyloid oligomers of 0.8750 ± 0.09. CONCLUSIONS: Detection of ß-amyloid oligomers may someday become a useful clinical tool for determining injury severity and neurological outcomes in patients with TBI.

Resveratrol decreases inflammation in the brain of mice with mild traumatic brain injury.

BACKGROUND: Following a mild traumatic brain injury (TBI) event, the secondary brain injury that persists after the initial blow to the head consists of excitotoxicity, decreased cerebral glucose levels, oxidant injury, mitochondrial dysfunction, inflammation, and neuronal cell death. To date, there are no effective interventions used at decreasing secondary brain injury after mild TBI. METHODS: In this study, male mice were treated with either placebo or resveratrol (100 mg/kg) at 5 minutes and 12 hours after mild TBI. The mice were injured using the controlled cortical impact device. In this closed-head model, a midline incision was made to access the skull and the impactor tip was aligned on the sagittal suture midway between the bregma and lambda sutures. The mice were injured at a depth of 2.0 mm, velocity of 4 m/s, and a delay time of 100 milliseconds. At 72 hours following injury, the animals were intracardially perfused with 0.9% saline followed by 10% phosphate-buffered formalin. The whole brain was removed, sliced, and stained for microglial activation (Iba1). In addition, using the enzyme-linked immunosorbent assay, tissue levels of interleukin 6 (IL-6) and IL-12 were measured in the cerebral cortex and hippocampus. RESULTS: In this study, we found that in the placebo treatment group, there was a significant increase in Iba1 staining in the brain. The levels of microglial activation was reduced by resveratrol in the cerebral cortex (p < 0.001), corpus callosum (p < 0.001), and dentate gyrus (p < 0.005) brain regions after mild TBI. In addition to Iba1, resveratrol decreased the brain levels of IL-6 (p < 0.0001) and IL-12 (p < 0.004), which were observed in the hippocampus of the placebo group. In our model, no increase of IL-6 or IL-12 was observed in the cerebral cortex following TBI. CONCLUSION: Resveratrol given acutely after TBI results in a decrease in neuroinflammation. These results suggest that resveratrol may be beneficial in reducing secondary brain injury after experiencing a mild TBI.

17ß-Estradiol reappropriates mass lost to the hypermetabolic state in thermally injured rats.

BACKGROUND: The hypermetabolic response to severe thermal injury is unlike any physiologic response seen in medicine. While some parallels can be drawn to shock and sepsis states, this response is typified by its intensity and duration. Our group has been interested in the myriad effects of estrogens after injury, specifically the ability of estrogens to reduce inflammatory responses. Given this, and the known link between severe inflammation and the hypermetabolic response, we examined the effects of a single dose of 17ß estradiol administered after a severe thermal injury in rats. METHODS: Twelve male Sprague-Dawley rats were subject to either a sham burn or a 40% total body surface area burn, followed by fluid resuscitation. Burned animals were divided into a vehicle and treatment group, with injections given 15 min after the injury. Animals were monitored for a period of 45 d, with markers of hypermetabolism (weight, fecal output, food intake, and serum insulin and glucose) measured daily. RESULTS: We identified a significant difference in daily measured weights between the burned groups. We observed a sparing of body mass during the acute phase lasting 2 wk after the injury and an improved recovery phase during the remainder of the study. Glucose and insulin levels during the first week of the study did not differ between the treatment groups. CONCLUSION: Estrogen may have a role in preserving body mass after severe thermal injury. Further studies are required to determine if this spared body mass composition.

Specific inhibition of mitochondrial oxidative stress suppresses inflammation and improves cardiac function in a rat pneumonia-related sepsis model.

Using a mitochondria-targeted vitamin E (Mito-Vit-E) in a rat pneumonia-related sepsis model, we examined the role of mitochondrial reactive oxygen species in sepsis-mediated myocardial inflammation and subsequent cardiac contractile dysfunction. Sepsis was produced in adult male Sprague-Dawley rats via intratracheal injection of S. pneumonia (4 × 10(6) colony formation units per rat). A single dose of Mito-Vit-E, vitamin E, or control vehicle, at 21.5 µmol/kg, was administered 30 min postinoculation. Blood was collected, and heart tissue was harvested at various time points. Mito-Vit-E in vivo distribution was confirmed by mass spectrometry. In cardiac mitochondria, Mito-Vit-E improved total antioxidant capacity and suppressed H(2)O(2) generation, whereas vitamin E offered little effect. In cytosol, both antioxidants decreased H(2)O(2) levels, but only vitamin E strengthened antioxidant capacity. Mito-Vit-E protected mitochondrial structure and function in the heart during sepsis, demonstrated by reduction in lipid and protein oxidation, preservation of mitochondrial membrane integrity, and recovery of respiratory function. While both Mito-Vit-E and vitamin E suppressed sepsis-induced peripheral and myocardial production of proinflammatory cytokines (tumor necrosis factor-α, interleukin-1ß, and interleukin-6), Mito-Vit-E exhibited significantly higher efficacy (P < 0.05). Stronger anti-inflammatory action of Mito-Vit-E was further shown by its near-complete inhibition of sepsis-induced myeloperoxidase accumulation in myocardium, suggesting its effect on neutrophil infiltration. Echocardiography analysis indicated that Mito-Vit-E ameliorated cardiac contractility of sepsis animals, shown by improved fractional shortening and ejection fraction. Together, our data suggest that targeted scavenging of mitochondrial reactive oxygen species protects mitochondrial function, attenuates tissue-level inflammation, and improves whole organ activities in the heart during sepsis.

Estrone is neuroprotective in rats after traumatic brain injury.

In various animal and human studies, early administration of 17ß-estradiol, a strong antioxidant, anti-inflammatory, and anti-apoptotic agent, significantly decreases the severity of injury in the brain associated with cell death. Estrone, the predominant estrogen in postmenopausal women, has been shown to be a promising neuroprotective agent. The overall goal of this project was to determine if estrone mitigates secondary injury following traumatic brain injury (TBI) in rats. Male rats were given either placebo (corn oil) or estrone (0.5 mg/kg) at 30 min after severe TBI. Using a controlled cortical impact device in rats that underwent a craniotomy, the right parietal cortex was injured using the impactor tip. Non-injured control and sham animals were also included. At 72 h following injury, the animals were perfused intracardially with 0.9% saline followed by 10% phosphate-buffered formalin. The whole brain was removed, sliced, and stained for TUNEL-positive cells. Estrone decreased cortical lesion volume (p<0.01) and neuronal injury (p<0.001), and it reduced cerebral cortical levels of TUNEL-positive staining (p<0.0001), and decreased numbers of TUNEL-positive cells in the corpus callosum (p<0.03). We assessed the levels of ß-amyloid in the injured animals and found that estrone significantly decreased the cortical levels of ß-amyloid after brain injury. Cortical levels of phospho-ERK1/2 were significantly (p<0.01) increased by estrone. This increase was associated with an increase in phospho-CREB levels (p<0.021), and brain-derived neurotrophic factor (BDNF) expression (p<0.0006). In conclusion, estrone given acutely after injury increases the signaling of protective pathways such as the ERK1/2 and BDNF pathways, decreases ischemic secondary injury, and decreases apoptotic-mediated cell death. These results suggest that estrone may afford protection to those suffering from TBI.

Investigation of the temperature stability of premarin intravenous using liquid chromatography-mass spectrometry.

Stability of Premarin(®)Intravenous was investigated in dry and reconstituted forms by monitoring major components in samples for a period of six months, using liquid chromatography-mass spectrometry. The components, largely comprising a series of estrogen and steroid hormone sulfates, were considered to be fairly stable (variation≤10%) for dry samples stored at room temperature and at 38°C (100°F) during the experimental time frame. However, significant variation, especially after 2 months of storage, was observed in reconstituted solutions. This variation was significantly larger for samples stored at elevated vs. room temperature. It was interesting to note that the concentration of equilenin sulfate increased over time, whereas that of other major components were seen to fluctuate and decrease. This phenomenon was partially explained by the conversion of equilin compounds into their corresponding equilenin forms, a phenomenon which was further investigated through a storage study with pure standard solutions and by tandem mass spectrometry.

Simultaneous quantification of four native estrogen hormones at trace levels in human cerebrospinal fluid using liquid chromatography-tandem mass spectrometry.

Estrogens are known to exhibit neuroprotective effects on the brain. Their importance in this regard and in others has been emphasized in many recent studies, which increases the need to develop reliable analytical methods for the measurement of estrogen hormones. A heart-cutting two-dimensional liquid chromatography separation method coupled with electrospray ionization-tandem mass spectrometry (ESI-MS/MS) has been developed for simultaneous measurement of four estrogens, including estriol (E3), estrone (E1), 17ß-estradiol (17ß-E2), and 17α-estradiol (17α-E2), in human cerebrospinal fluid (CSF). The method was based on liquid-liquid extraction and derivatization of estrogens with dansyl chloride to enhance the sensitivity of ESI-based detection in conjunction with tandem mass spectrometry. Dansylated estriol and estrone were separated in the first dimension by an amide-C18 column, while dansylated 17ß- and 17α-estradiol were resolved on the second dimension by two C18 columns (175 mm total length) connected in series. This is the first report of a method for simultaneous quantification of all four endogenous estrogen compounds in their dansylated form. The detection limits for E1, 17α-E2, 17ß-E2, and E3 were 19, 35, 26, and 61pg/mL, respectively. Due to matrix effects, validation and calibration was carried out in charcoal-stripped CSF. The precision and accuracy were more than 86% for the two E2 compounds and 79% for E1 and E3 while the extraction recovery ranged from 91% to 104%. The method was applied to measure estrogens obtained in a clinical setting, from the CSF of ischemic trauma patients. While 17ß-estradiol was present at a significant level in the CSF of some samples, other estrogens were present at lower levels or were undetectable.

Rationale for routine and immediate administration of intravenous estrogen for all critically ill and injured patients.

In addition to a number of very compelling clinical observations, an extensive body of extremely supportive experimental data has generated a very persuasive argument that intravenous estrogen should be routinely administered, as soon as possible, to all persons identified as having a critical illness or injury. Although, to date, definitive gold-standard clinical trials are lacking, what has made this provocative argument even more convincing is the longstanding, documented safety of intravenous estrogen for various illnesses and conditions as well as the relative ease and inexpensive cost of treatment. As such, even routine prehospital administration becomes extremely feasible for a myriad of conditions. More importantly, the worldwide magnitude of potential patients who could benefit is profound. Even if estrogen only changes the outcome in a relatively small percentage of applicable cases, the potential impact may still be of dramatic proportions in terms of the absolute number of lives saved and the resources spared worldwide. Resources may be spared not only in terms of diminishing the economic impact of death and long-term disability, but also in terms of preventing extended intensive care unit stays and treatment of preventable complications that result in longer recovery.

Preventing severe hypoxia during emergent intubation: is nasopharyngeal oxygenation the answer?

Critically ill patients requiring emergent endotracheal intubation are at risk for life-threatening hypoxemia during the intubation procedure, particularly when the patient is apneic and not receiving any supplemental oxygen. In a current study, Engström and colleagues investigated the effect of nasopharyngeal oxygenation in eight anesthetized pigs with induced acute lung injury. The investigators confirmed, even in this model, that pharyngeal oxygenation significantly prolonged the time to desaturation during periods of apnea. Recognizing the limitations of directly extrapolating these experimental results to critically ill human subjects, the findings do support the contention that, until proven otherwise, nasopharyngeal oxygenation should at least be considered as one technique to diminish hypoxemic complications in very sick patients, particularly those with underlying pulmonary impairment.

Intravenous fluid resuscitation for the trauma patient.

PURPOSE OF REVIEW: Although longstanding practice in trauma care has been to provide immediate, aggressive intravenous fluid resuscitation to injured patients with presumed internal hemorrhage, recent experimental and clinical data suggest a more discriminating approach that first considers concurrent head injury, hemodynamic stability, and the presence of potentially uncontrollable hemorrhage (e.g., deep truncal injury) versus a controllable source (e.g., distal extremity wound). RECENT FINDINGS: The data suggest that rapid intravenous fluid infusions could be used for patients with isolated extremity, thermal or head injury. However, intravenous fluids should be limited in conditions with potentially uncontrollable internal hemorrhage, and particularly in patients with penetrating truncal injury being transported immediately to a trauma center. Likewise, positive pressure ventilatory support should be limited with severe hemorrhage due to the secondary reductions in venous return off-setting the effects of the fluids. For trauma patients with severe bleeding, there is growing evidence for the increased use of plasma and factor VIIa, as well as tourniquets, intra-osseus devices, and evolving monitoring techniques. SUMMARY: Future research efforts in trauma should focus on the timing and rate of infusions as well as the concept of infusing alternative intravenous resuscitative fluids such as hemoglobin-based oxygen carriers (HBOCs) and the use of hemostatic agents and special blood products.