High levels of soluble VEGF receptor 1 early after trauma are associated with shock, sympathoadrenal activation, glycocalyx degradation and inflammation in severely injured patients: a prospective study

Background

The level of soluble vascular endothelial growth factor receptor 1 (sVEGFR1) is increased in sepsis and strongly associated with disease severity and mortality. Endothelial activation and damage contribute to both sepsis and trauma pathology. Therefore, this study measured sVEGFR1 levels in trauma patients upon hospital admission hypothesizing that sVEGFR1 would increase with higher injury severity and predict a poor outcome.

Methods

Prospective observational study of 80 trauma patients admitted to a Level I Trauma Centre. Data on demography, biochemistry, Injury Severity Score (ISS), transfusions and 30-day mortality were recorded and plasma/serum (sampled a median of 68 min (IQR 48-88) post-injury) was analyzed for sVEGFR1 and biomarkers reflecting sympathoadrenal activation (adrenaline, noradrenaline), tissue injury (histone-complexed DNA fragments, hcDNA), endothelial activation and damage (von Willebrand Factor Antigen, Angiopoietin-2, soluble endothelial protein C receptor, syndecan-1, soluble thrombomodulin (sTM)), coagulation activation/inhibition and fibrinolysis (prothrombinfragment 1 + 2, protein C, activated Protein C, tissue-type plasminogen activator, plasminogen activator inhibitor-1, D-dimer) and inflammation (interleukin-6). Spearman correlations and regression analyses to identify variables associated with sVEGFR1 and its predictive value.

Results

Circulating sVEGFR1 correlated with injury severity (ISS, rho = 0.46), shock (SBE, rho = -0.38; adrenaline, rho = 0.47), tissue injury (hcDNA, rho = 0.44) and inflammation (IL-6, rho = 0.54) (all p < 0.01) but by multivariate linear regression analysis only lower SBE and higher adrenaline and IL-6 were independent predictors of higher sVEGFR1. sVEGFR1 also correlated with biomarkers indicative of endothelial glycocalyx degradation (syndecan-1, rho = 0.67), endothelial cell damage (sTM, rho = 0.66) and activation (Ang-2, rho = 0.31) and hyperfibrinolysis (tPA, rho = 0.39; D-dimer, rho = 0.58) and with activated protein C (rho = 0.31) (all p < 0.01). High circulating sVEGFR1 correlated with high early and late transfusion requirements (number of packed red blood cells (RBC) at 1 h (rho = 0.27, p = 0.016), 6 h (rho = 0.27, p = 0.017) and 24 h (rho = 0.31, p = 0.004) but was not associated with mortality.

Conclusions

sVEGFR1 increased with increasing injury severity, shock and inflammation early after trauma but only sympathoadrenal activation, hypoperfusion, and inflammation were independent predictors of sVEGFR1 levels. sVEGFR1 correlated strongly with other biomarkers of endothelial activation and damage and with RBC transfusion requirements. Sympathoadrenal activation, shock and inflammation may be critical drivers of endothelial activation and damage early after trauma.

Effect of an analgo-sedation protocol for neurointensive patients: a two-phase interventional non-randomized pilot study

Introduction

Sedation protocols are needed for neurointensive patients. The aim of this pilot study was to describe sedation practice at a neurointensive care unit and to assess the feasibility and efficacy of a new sedation protocol. The primary outcomes were a shift from sedation-based to analgesia-based sedation and improved pain management. The secondary outcomes were a reduction in unplanned extubations and duration of sedation.

Methods

This was a two-phase (before-after), prospective controlled study at a university-affiliated, 14-bed neurointensive care unit in Denmark. The sample included patients requiring mechanical ventilation for at least 48 hours treated with continuous sedative and analgesic infusions or both. During the observation phase the participants (n = 106) were sedated as usual (non-protocolized), and during the intervention phase the participants (n = 109) were managed according to a new sedation protocol.

Results

Our study showed a shift toward analgo-sedation, suggesting feasibility of the protocol. We found a significant reduction in the use of propofol (P < .001) and midazolam (P = .001) and an increase in fentanyl (P < .001) and remifentanil (P = .003). Patients selected for daily sedation interruption woke up faster, and estimates of pain free patients increased from 56.8% to 82.7% (P < .001), suggesting efficacy of the protocol. The duration of sedation and unplanned extubations were unchanged.

Conclusions

Our pilot study showed feasibility and partial efficacy of our protocol. Some neurointensive patients might not benefit from protocolized practice. We recommend an interdisciplinary effort to target patients requiring less sedation, as issues of oversedation and inadequate pain management still need more attention.

Trial registration

ISRCTN80999859.

Cardiac arrhythmias the first month after acute traumatic spinal cord injury

OBJECTIVE

Cardiovascular complications including cardiac arrest and arrhythmias remain a clinical challenge in the management of acute traumatic spinal cord injury (SCI). Still, there is a lack of knowledge regarding the characteristics of arrhythmias in patients with acute traumatic SCI. The aim of this prospective observational study was to investigate the occurrence of cardiac arrhythmias and cardiac arrests in patients with acute traumatic SCI.

METHODS

As early as possible after SCI 24-hour Holter monitoring was performed. Additional Holter recordings were performed 1, 2, 3, and 4 weeks after SCI. Furthermore, 12-lead electrocardiograms (ECGs) were obtained shortly after SCI and at 4 weeks.

RESULTS

Thirty patients were included. Bradycardia (heart rate (HR) <50 b.p.m.) was present in 17-35% of the patients with cervical (C1-C8) SCI (n = 24) within the first 14 days. In the following 14 days, the occurrence was 22-32%. Bradycardia in the thoracic (Th1-Th12) SCI group (n = 6) was present in 17-33% during the observation period. The differences between the two groups were not statistically significant. The mean minimum HR was significantly lower in the cervical group compared with the thoracic group both on 12-lead ECGs obtained shortly after SCI (P = 0.030) and at 4 weeks (P = 0.041).

CONCLUSION

Many patients with cervical SCI experience arrhythmias such as bradycardia, sinus node arrest, supraventricular tachycardia, and more rarely cardiac arrest the first month after SCI. Apart from sinus node arrests and limited bradycardia, no arrhythmias were seen in patients with thoracic SCI. Standard 12-lead ECGs will often miss the high prevalence these arrhythmias have.

Depression, anxiety and quality-of-life among relatives of patients with severe brain injury: the acute phase

PRIMARY OBJECTIVE

To investigate the emotional well-being of relatives of patients with a severe brain injury in the acute setting, as well as risk factors associated with high anxiety and depression scores and impaired quality-of-life.

RESEARCH DESIGN

Clinical convenience sample.

METHODS AND PROCEDURES

Participants included 45 relatives of patients with severe brain injury recruited at a NICU. All relatives completed selected scales from the SCL-90-R and SF-36 ∼ 14 days after injury. Data concerning the condition of the patient were also collected.

MAIN OUTCOME AND RESULTS

Of the relatives, 51% and 69% reported anxiety and depression, respectively, as well as significantly impaired quality-of-life compared to normal reference populations. Regression analysis revealed that up to 20% of the variance in depression and anxiety scores could be explained by the CRASH 2 Mortality prediction.

CONCLUSIONS

The majority of the relatives had severely impaired quality-of-life and symptoms of anxiety and depression during the patient's NICU stay. Future research is required to explore stressors and evaluate effects of psychological intervention in the acute setting.

Effect of prolonged alveolar hypoxia on pulmonary arterial pressure and segmental vascular resistance

The time course of hypoxic pulmonary vasoconstriction and its segmental distribution were studied during prolonged (150 min) alveolar hypoxia in in vivo dog lungs at constant-flow perfusion. With the pulmonary and the systemic circulations separated by two extracorporeal circuits, adequate systemic oxygenation was achieved throughout the experiments. The pulmonary circulation exhibited a time-related biphasic hypoxic vasoconstrictor response: an initial rapid contraction [79 +/- 11% (SE) above control level] was followed by a partial relaxation when a second slow and sustained vasoconstriction (92 +/- 13% above control level) superseded. We partitioned the pulmonary circulation into two segments by arterial occlusion: an upstream arterial segment and a downstream segment consisting of a middle and a venous segment. Measurements were performed at baseline and during the late sustained vasoconstrictor response. Prolonged alveolar hypoxia increased pulmonary capillary pressure by 90 +/- 18%, the site of pulmonary vasomotion being the arterial upstream and downstream middle and venous segments.

Effect of alveolar hypoxia on segmental pulmonary vascular resistance and lung fluid balance in dogs

In a biventricular bypass preparation with constant-flow perfusion, pulmonary arterial pressure (Ppa), average pulmonary capillary pressure (Ppc), venous pressure (Pv), extravascular lung water volume (EVWd) and capillary permeability-surface area product for urea (PS) were determined in control animals and in animals subjected to alveolar hypoxia. During hypoxia, Ppa increased in a biphasic manner, the site of hypoxic pulmonary vasoconstriction being located in the arterial upstream segment. At baseline, Ppc values were identical in control and experimental animals (3.4 +/- 0.4 vs. 3.6 +/- 0.2 mmHg). During 150 min of airway hypoxia, the rise in Ppc (5.1 +/- 0.3 mmHg) did not exceed the rise in Ppc (4.9 +/- 0.5 mmHg) recorded in control animals at same time interval during normoxic ventilation. EVWd increased during hypoxia to values significantly higher than those obtained in control animals (0.559 +/- 0.036 vs. 0.466 +/- 0.027 mL water g-1 lung). PS remained unchanged at baseline level throughout experiments in both groups of animals. Present data suggest that lung oedema formation during alveolar hypoxia may be caused by increased transcapillary fluid loss preferentially through transcellular hydraulic pathways in capillary endothelial cells.

Post-transfusion purpura (PTP) and disseminated intravascular coagulation (DIC)

A 47-yr-old female with acute pancreatitis received four units of fresh frozen plasma because of subtle signs of disseminated intravascular coagulation (DIC). Seven days later, she developed severe thrombocytopenia. Serological studies demonstrated antibodies against HPA-1a together with pan-reactive antibodies against platelet glycoproteins (GPIIb-IIIa, GPIb-IX and GPIa-IIa), which was consistent with the diagnosis of PTP. The patient was treated with platelet transfusions, corticosteroids and intravenous immunoglobulin (IVIG) without permanent beneficial effect. After treatment with plasma exchange the platelet count increased to normal values.

Cardiac arrhythmias six months following traumatic spinal cord injury

OBJECTIVE

To investigate the incidence of cardiac arrhythmias at six months following traumatic spinal cord injury (SCI) and to compare the prevalence of arrhythmias between participants with cervical and thoracic SCI.

DESIGN

A prospective observational study using continuous twenty-four-hour Holter monitoring.

SETTING

Inpatient rehabilitation unit of a university research hospital and patient home setting.

PARTICIPANTS

Fifty-five participants with acute traumatic SCI were prospectively included. For each participant, the SCI was characterized according to the International Standards for Neurological Classification of SCI by the neurological level and severity according to the American Spinal Injury Association Impairment Scale.

OUTCOME MEASURES

Comparisons between demographic characteristics and arrhythmogenic occurrences as early as possible after SCI (4 ± 2 days) followed by 1, 2, 3, 4 weeks and 6 month time points of Holter monitoring.

RESULTS

Bradycardia (heart rate [HR] <50 bpm) was present in 29% and 33% of the participants with cervical (C1-C8) and thoracic (T1-T12) SCI six months after SCI, respectively. The differences in episodes of bradycardia between the two groups were not significant (P < 0.54). The mean maximum HR increased significantly from 4 weeks to 6 months post-SCI (P < 0.001), however mean minimum and maximum HR were not significantly different between the groups at the six-month time point. There were no differences in many arrhythmias between recording periods or between groups at six months.

CONCLUSIONS

At the six-month timepoint following traumatic SCI, there were no significant differences in occurrences of arrhythmias between participants with cervical and thoracic SCI compared to the findings observed in the first month following SCI.

[Acute respiratory distress syndrome. Pathogenesis and therapy of acute pulmonary failure]

Adult respiratory distress syndrome (ARDS) is the pulmonary response to systemic inflammation precipitated by local or systemic tissue hypoxia, or ischaemia and reperfusion. ARDS is a dynamic, pathological process with a multifactorial etiology. The main clinical manifestations of ARDS are dyspnoea, non-cardiogenic pulmonary oedema, and hypoxia due to increased pulmonary capillary permeability, pulmonary vasoconstriction and diminished pulmonary vascular reactivity. Eventually this pulmonary pathology results in first, oedema, pulmonary hypertension, and increased ventilation-perfusion inequality and later, pulmonary remodelling and irreversible pulmonary hypertension. The inflammatory mechanisms involved in acute lung injury are complex and include activation of polymorphonuclear neutrophils, endothelial cells, and synthesis of free radicals, predominantly derived from oxygen. Cytokines synthesized by macrophages maintain and regulate the inflammatory host response. Immune-modulating therapy in ARDS is yet experimental. Accordingly, treatment in ARDS is supportive, directed towards pulmonary oedema, pulmonary hypertension and hypoxaemia. The use of low tidal volumes and low inspiratory pressures in mechanical ventilation is established therapy. The goal in haemodynamic monitoring by applying a Swan-Ganz catheter is to obtain a low pulmonary capillary wedge pressure (< 12-15 mmHg) without compromising adequate delivery of oxygen to vital organs. For treatment of pulmonary hypertension nitric oxide is useful. Change of position and inhalation with beta2-agonists are therapeutic possibilities. Steroids may be of benefit in the late proliferative phase of ARDS.

[Actively induced hypothermia following severe traumatic brain injury]

A Cochrane metaanalysis and a study performed on children have recently confirmed that therapeutic hypothermia does not improve outcome after severe traumatic brain injury (TBI). TBI is not comparable to a short episode of global ischemia, where therapeutic hypothermia has been shown to improve outcome. The difference may be explained by the fact that hypothermia-induced stress after a traumatic brain injury reduces cerebral perfusion in the penumbra zone, where local circulation is already reduced. Thus, to date there is no indication for therapeutic hypothermia in TBI patients.