Reliability of the spine adverse events severity system (SAVES) for individuals with traumatic spinal cord injury.

STUDY DESIGN: Test-retest analysis. OBJECTIVES: To determine the intra- and inter-rater reliability of the Spine Adverse Events Severity System for Spinal Cord Injury (SAVES-SCI) in patients with traumatic SCI. SETTING: Quaternary care spine program in Vancouver, Canada. METHODS: Ten hypothetical patient cases were developed. The cases were completed by 10 raters (seven physicians, one nurse, one physiotherapist and one researcher) who were asked to identify and grade the severity of adverse events using SAVES-SCI twice with 1-week interval. Intra- and inter-rater reliability were calculated using kappa statistics and intraclass correlation coefficients (ICC). RESULTS: Intra-rater reliability for both identifying and grading AEs were high with all AEs (kappa greater than 0.6) except for bone implant, diathermy burn, massive blood loss, myocardial infarction, neurological deterioration, pressure ulcer, return to operating room and tracheostomy requirement. The inter-rater reliability measured with ICC were all above 0.6 for identifying and grading intraoperative, pre and postoperative AEs and consequences of SCI. CONCLUSIONS: The SAVES-SCI demonstrated acceptable intra-and inter-rater reliability for a majority of the AEs. Further clarification and definition of some of the AEs as well as provision of sample training cases for clinicians would assist in reducing measurement errors. The SAVES-SCI is a useful tool to assess and capture AEs in patients with acute traumatic SCI.

Evaluation of a pilot Pressure Ulcer Prevention Initiative (PUPI) for patients with traumatic spinal cord injury.

OBJECTIVE: The purpose of this study was to determine whether implementation of a Pressure Ulcer Prevention Initiative (PUPI) changed the assessment and treatment of patients with a traumatic spinal cord injury (SCI) in an acute care setting, and improved patient outcomes. METHOD: The success of implementation was evaluated by examining the percentage of patients with completed occupational therapist (OT) skin care assessments and prescriptions for therapeutic support surfaces (TSS; i.e., mattresses) before implementation (historical, cohort 1) and after implementation (experimental, cohort 2). Patient outcomes were evaluated by examining changes in PU incidence, severity, timing and recurrence, as well as PU prevalence and satisfaction with life in the community. RESULTS: Final analysis included 70 patients in cohort 1 and 73 in cohort 2. OT skin care assessment documentation (31% to 60%; p<0.001) and TSS prescriptions (31% to 60%; p=0.02) significantly increased following the implementation. The PU incidence based on patient charts (both nursing and OT assessments) did not increase significantly (26% to 36%; p=0.2). However, documented PU incidence according to OT assessments showed a substantial increase (14% to 33%; p=0.002). No effect of the PUPI was seen on immediate or long-term patient outcomes during the study period. CONCLUSION: PUPI was successful in changing clinical practice in PU prevention but no statistically significant improvements in PU-related patient outcomes were demonstrated. Results from this study identified facilitators and barriers to implementation and highlighted the complexity and difficulty of instituting effective preventative or therapeutic interventions for this population in an acute care setting. This information will assist with refinements of the PUPI and inform similar future initiatives.

Use of the Spine Adverse Events Severity System (SAVES) in patients with traumatic spinal cord injury. A comparison with institutional ICD-10 coding for the identification of acute care adverse events.

STUDY DESIGN: Observational cohort comparison. OBJECTIVES: To compare the previously validated Spine Adverse Events Severity system (SAVES) with International Classification of Diseases, Tenth Revision codes (ICD-10) codes for identifying adverse events (AEs) in patients with traumatic spinal cord injury (TSCI). SETTING: Quaternary Care Spine Program. METHODS: Patients discharged between 2006 and 2010 were identified from our prospective registry. Two consecutive cohorts were created based on the system used to record acute care AEs; one used ICD-10 coding by hospital coders and the other used SAVES data prospectively collected by a multidisciplinary clinical team. The ICD-10 codes were appropriately mapped to the SAVES. There were 212 patients in the ICD-10 cohort and 173 patients in the SAVES cohort. Analyses were adjusted to account for the different sample sizes, and the two cohorts were comparable based on age, gender and motor score. RESULTS: The SAVES system identified twice as many AEs per person as ICD-10 coding. Fifteen unique AEs were more reliably identified using SAVES, including neuropathic pain (32 × more; P<0.001), urinary tract infections (1.4 × ; P<0.05), pressure sores (2.9 × ; P<0.001) and intra-operative AEs (2.3 × ; P<0.05). Eight of these 15 AEs more frequently identified by SAVES significantly impacted length of stay (P<0.05). Risk factors such as patient age and severity of paralysis were more reliably correlated to AEs collected through SAVES than ICD-10. CONCLUSION: Implementation of the SAVES system for patients with TSCI captured more individuals experiencing AEs and more AEs per person compared with ICD-10 codes. This study demonstrates the utility of prospectively collecting AE data using validated tools.

Mobilization of endothelial precursor cells: systemic vascular response to musculoskeletal trauma.

Postnatal vasculogenesis, the process by which vascular committed bone marrow stem cells or endothelial precursor cells (EPC) migrate, differentiate, and incorporate into the nacent endothelium contributing to physiological and pathological neovascularization, has stimulated much interest. Its contribution to tumor nonvascularization, wound healing, and revascularization associated with skeletal and cardiac muscles ischaemia is established. We evaluated the mobilization of EPCs in response to musculoskeletal trauma. Blood from patients (n = 15) following AO type 42a1 closed diaphyseal tibial fractures was analyzed for CD34 and AC133 cell surface marker expression. Immunomagnetically enriched CD34+ mononuclear cell (MNC(CD34+)) populations were cultured and examined for phenotypic and functional vascular endothelial differentiation. Circulating MNC(CD34+) levels increased sevenfold by day 3 postinjury. Circulating MNC(AC133+) increased 2.5-fold. Enriched MNC(CD34+) populations from day 3 samples in culture exhibited cell cluster formation with sprouting spindles. These cells bound UEA-1 and incorporated fluorescent DiI-Ac-LDL intracellularily. Our findings suggest a systemic provascular response is initiated in response to musculoskeletal trauma. Its therapeutic manipulation may have implications for the potential enhancement of fracture healing.

Activated protein C attenuates acute ischaemia reperfusion injury in skeletal muscle.

Activated protein C (APC) is an endogenous anti-coagulant with anti-inflammatory properties. The purpose of the present study was to evaluate the effects of activated protein C in the setting of skeletal muscle ischaemia reperfusion injury (IRI). IRI was induced in rats by applying rubber bands above the levels of the greater trochanters bilaterally for a period of 2h followed by 12h reperfusion. Treatment groups received either equal volumes of normal saline or activated protein C prior to tourniquet release. Following 12h reperfusion, muscle function was assessed electrophysiologically by electrical field stimulation. The animals were then sacrificed and skeletal muscle harvested for evaluation. Activated protein C significantly attenuated skeletal muscle reperfusion injury as shown by reduced myeloperoxidase content, wet to dry ratio and electrical properties of skeletal muscle. Further in vitro work was carried out on neutrophils isolated from healthy volunteers to determine the direct effect of APC on neutrophil function. The effects of APC on TNF-alpha stimulated neutrophils were examined by measuring CD18 expression as well as reactive oxygen species generation. The in vitro work demonstrated a reduction in CD18 expression and reactive oxygen species generation. We conclude that activated protein C may have a protective role in the setting of skeletal muscle ischaemia reperfusion injury and that this is in part mediated by a direct inhibitory effect on neutrophil activation.

Adenosine inhibits neutrophil vascular endothelial growth factor release and transendothelial migration via A2B receptor activation.

The effects of adenosine on neutrophil (polymorphonuclear neutrophils; PMN)-directed changes in vascular permeability are poorly characterized. This study investigated whether adenosine modulates activated PMN vascular endothelial growth factor (vascular permeability factor; VEGF) release and transendothelial migration. PMN activated with tumour necrosis factor-alpha (TNF-alpha, 10 ng/mL) were incubated with adenosine and its receptor-specific analogues. Culture supernatants were assayed for VEGF. PMN transendothelial migration across human umbilical vein endothelial cell (HUVEC) monolayers was assessed in vitro. Adhesion molecule receptor expression was assessed flow cytometrically. Adenosine and some of its receptor-specific analogues dose-dependently inhibited activated PMN VEGF release. The rank order of potency was consistent with the affinity profile of human A2B receptors. The inhibitory effect of adenosine was reversed by 3,7-dimethyl-1-propargylxanthine, an A2 receptor antagonist. Adenosine (100 microM) or the A2B receptor agonist 5'-N-ethylcarboxamidoadenosine (NECA, 100 microM) significantly reduced PMN transendothelial migration. However, expression of activated PMN beta2 integrins and HUVEC ICAM-1 were not significantly altered by adenosine or NECA. Adenosine attenuates human PMN VEGF release and transendothelial migration via the A2B receptor. This provides a novel target for the modulation of PMN-directed vascular hyperpermeability in conditions such as the capillary leak syndrome.

PCR in situ hybridisation detection of HPV 16 in fixed CaSki and fixed SiHa cell lines.

AIMS: To investigate the feasibility of using fixed cells with the polymerase chain reaction (PCR) in situ hybridisation and to investigate possible reasons for reaction failure. METHODS: Fixed SiHa and CaSki cells were used in an experimental model of PCR in situ hybridisation for the detection of low and intermediate copy number viral infection in fixed cells. RESULTS: PCR in situ hybridisation was able to detect one to two copies of human papillomavirus (HPV) 16 in SiHa cells, using small fragment amplicons (120 base pairs), confirming the high detection sensitivity and flexibility of the technique. Problems were encountered with localisation of PCR amplified product in CaSki cells (200-300 copies of HPV 16 per cell) owing to diffusion of product post amplification. Overall, 40% of reactions were successful, which confirms the current unreliability of the technique. Within cell preparations, about 50% of cells contained amplified product. CONCLUSION: PCR in situ hybridisation represents the marriage of two revolutionary molecular pathological techniques. However, it is currently unreliable, with reaction failure common. Standardised, dedicated equipment is urgently required if the technique is to achieve universal acceptance. In the future, the technique may be used to detect chromosomal translocations in human tumours and to study cellular gene expression.

The angiogenic response to skeletal injury is preserved in the elderly.

Angiogenesis is essential for normal bone formation and repair. Avascularity characterizes aberrant fracture union in the elderly, while angiogenic mechanisms during cutaneous wound repair are attenuated in aged humans. We hypothesized that skeletal injury results in local (circulating) and systemic (fracture site) 'angiogenic' responses and that these reparative mechanisms are attenuated with advanced patient age. This prospective study examined peripheral blood and fracture hematoma from 32 patients, 16 under 40 years and 16 over the age of 75, undergoing emergent surgery for isolated fracture. The angiogenic cytokines vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) were assayed. Endothelial cell cultures were supplemented with patient plasma and fracture hematoma and angiogenesis determined in vitro by measuring cell proliferation and blood vessel tube formation. Angiogenesis was determined in vivo using a murine dorsal wound pocket model and quantification of new blood vessel formation after 7 days. We found that all injured patients, irrespective of age, have elevated plasma and fracture hematoma levels of VEGF and PDGF. These elevated cytokine concentrations translate into biologically significant angiogenic effects, in vitro and in vivo. These effects are primarily VEGF mediated and are not dependent on patient age. The biological activity of these growth factors does not diminish with advanced age. Thus skeletal injury does result in local and systemic angiogenic responses whereby angiogenic cytokine availability and activity is preserved in the aged suggesting alternative mechanisms for the development of avascularity in delayed and fracture non-union in the elderly.

Pneumatic tourniquets in extremity surgery.

Pneumatic tourniquets maintain a relatively bloodless field during extremity surgery, minimize blood loss, aid identification of vital structures, and expedite the procedure. However, they may induce an ischemia-reperfusion injury with potentially harmful local and systemic consequences. Modern pneumatic tourniquets are designed with mechanisms to regulate and maintain pressure. Routine maintenance helps ensure that these systems are working properly. The complications of tourniquet use include postoperative swelling, delay of recovery of muscle power, compression neurapraxia, wound hematoma with the potential for infection, vascular injury, tissue necrosis, and compartment syndrome. Systemic complications can also occur. The incidence of complications can be minimized by use of wider tourniquets, careful preoperative patient evaluation, and adherence to accepted principles of tourniquet use.

The limping child: an algorithm to outrule musculoskeletal sepsis.

BACKGROUND: The acutely limping child presents a significant diagnostic challenge. AIM: The purpose of this study was to create a clinically useful algorithm to allow exclusion of 'musculoskeletal sepsis' as a differential diagnosis in the child presenting with limp. METHODS: Data were collected on all 286 limping children admitted to our centre over a 3-year-period. Using logistic regression analysis, the predictive model was constructed, to exclude infection. RESULTS: Duration of symptoms, constitutional symptoms, temperature, white cell count and ESR were significantly different in children with musculoskeletal infection (P < 0.05). Multivariate analysis demonstrated that when all three variables of duration of symptoms >1, <5 days; temperature >37.0 degrees C; and ESR >35 mm/h were present, the predicted probability of infection was 0.66, falling to 0.01 when none were present. CONCLUSION: This multivariate model enables us to rule out musculoskeletal infection with 99% certainty in limping children with none of these three presenting variables.

A systemic provascular response in bone marrow to musculoskeletal trauma in mice.

Post-natal vasculogenesis, the process by which vascular committed bone marrow stem cells or endothelial precursor cells migrate, differentiate and incorporate into the nacent endothelium and thereby contribute to physiological and pathological neurovascularisation, has stimulated much interest. Its contribution to neovascularisation of tumours, wound healing and revascularisation associated with ischaemia of skeletal and cardiac muscles is well established. We evaluated the responses of endothelial precursor cells in bone marrow to musculoskeletal trauma in mice. Bone marrow from six C57 Black 6 mice subjected to a standardised, closed fracture of the femur, was analysed for the combined expression of cell-surface markers stem cell antigen 1 (sca-1(+)) and stem cell factor receptor, CD117 (c-kit(+)) in order to identify the endothelial precursor cell population. Immunomagnetically-enriched sca-1(+) mononuclear cell (MNC(sca-1+)) populations were then cultured and examined for functional vascular endothelial differentiation. Bone marrow MNC(sca-1+,c-kit+) counts increased almost twofold within 48 hours of the event, compared with baseline levels, before decreasing by 72 hours. Sca-1(+) mononuclear cell populations in culture from samples of bone marrow at 48 hours bound together Ulex Europus-1, and incorporated fluorescent 1,1'-dioctadecyl- 3,3,3,'3'-tetramethylindocarbocyanine perchlorate-labelled acetylated low-density lipoprotein intracellularily, both characteristics of mature endothelium. Our findings suggest that a systemic provascular response of bone marrow is initiated by musculoskeletal trauma. Its therapeutic manipulation may have implications for the potential enhancement of neovascularisation and the healing of fractures.

Bacterial wall products induce downregulation of vascular endothelial growth factor receptors on endothelial cells via a CD14-dependent mechanism: implications for surgical wound healing.

INTRODUCTION: Vascular endothelial growth factor (VEGF) is a potent mitogenic cytokine which has been identified as the principal polypeptide growth factor influencing endothelial cell (EC) migration and proliferation. Ordered progression of these two processes is an absolute prerequisite for initiating and maintaining the proliferative phase of wound healing. The response of ECs to circulating VEGF is determined by, and directly proportional to, the functional expression of VEGF receptors (KDR/Flt-1) on the EC surface membrane. Systemic sepsis and wound contamination due to bacterial infection are associated with significant retardation of the proliferative phase of wound repair. The effects of the Gram-negative bacterial wall components lipopolysaccharide (LPS) and bacterial lipoprotein (BLP) on VEGF receptor function and expression are unknown and may represent an important biological mechanism predisposing to delayed wound healing in the presence of localized or systemic sepsis. MATERIALS AND METHODS: We designed a series of in vitro experiments investigating this phenomenon and its potential implications for infective wound repair. VEGF receptor density on ECs in the presence of LPS and BLP was assessed using flow cytometry. These parameters were assessed in hypoxic conditions as well as in normoxia. The contribution of CD14 was evaluated using recombinant human (rh) CD14. EC proliferation in response to VEGF was quantified in the presence and absence of LPS and BLP. RESULTS: Flow cytometric analysis revealed that LPS and BLP have profoundly repressive effects on VEGF receptor density in normoxic and, more pertinently, hypoxic conditions. The observed downregulation of constitutive and inducible VEGF receptor expression on ECs was not due to any directly cytotoxic effect of LPS and BLP on ECs, as measured by cell viability and apoptosis assays. We identified a pivotal role for soluble/serum CD14, a highly specific bacterial wall product receptor, in mediating these effects. The decreased VEGF receptor density on ECs accruing from the presence of bacterial wall products resulted in EC hyporesponsiveness to rhVEGF and significant abolition of VEGF-directed EC proliferation. CONCLUSION: These findings suggest that the well-recognized relationship between bacterial sepsis and attenuated wound healing may be due, in part, to the directly suppressive effects of bacterial wall components on EC VEGF receptor expression and, consequently, EC proliferation.

Trauma on rural roads: the role of a peripheral hospital.

Road accident trauma is a leading cause of death and serious morbidity among healthy young adults in the developed world. The Irish Republic has the third worst road safety record in the EU. In studying the unique demographics of rural road accidents, our aim was to provide information essential to the future development of trauma care in Ireland. Our figures highlight the inadequacies of data received by the National Roads Authority, illustrate the resource impact of road trauma on a peripheral hospital, and demonstrate the need for similar studies in the rationalisation of trauma care as we approach the next millennium.

Tourniquet-induced systemic inflammatory response in extremity surgery.

BACKGROUND: Tourniquet-induced reperfusion injury in animals produces significant systemic inflammatory effects. This study investigated whether a biologic response occurs in a clinically relevant model of tourniquet-induced reperfusion injury. METHODS: Patients undergoing elective knee arthroscopy were prospectively randomized into controls (no tourniquet) and subjects (tourniquet-controlled). The effects of tourniquet-induced reperfusion on monocyte activation state, neutrophil activation state, and transendothelial migration (TEM) were studied. Changes in the cytokines implicated in reperfusion injury, tumor necrosis factor-alpha, interleukin (IL)-1beta, and IL-10 were also determined. RESULTS: After 15 minutes of reperfusion, neutrophil and monocyte activation were significantly increased. Pretreatment of neutrophils with pooled subject (ischemia-primed) plasma significantly increased TEM. In contrast, TEM was not significantly altered by ischemia-primed plasma pretreatment of the endothelial monolayer. Significant elevation of tumor necrosis factor-alpha and IL-1beta were observed in subjects compared with controls after 15 minutes of reperfusion. There was no significant difference in serum IL-10 levels between the groups at all the time points studied. CONCLUSION: These results indicate a transient neutrophil and monocyte activation after tourniquet-ischemia that translates into enhanced neutrophil transendothelial migration with potential for tissue injury.

Thromboprophylaxis using a low molecular weight heparin delays fracture repair.

Low molecular weight heparins are significantly superior to unfractionated heparin or warfarin in the prevention of thromboembolic episodes associated with orthopaedic surgery. Therapeutic doses of heparin and warfarin have been shown to delay bone repair in a rabbit model. The current study investigated the effect of prophylactic administration of a low molecular weight heparin, enoxaparin, on the healing of a closed rabbit rib fracture. Fracture healing was assessed using histomorphometric, histologic, and immunohistochemical methods at 3, 7, and 14 days, and biomechanical testing with torsional loading was assessed after 21 days. Bone repair was significantly attenuated at all times in animals receiving subcutaneous enoxaparin compared with that of the control animals. Numerous putative mechanisms for this phenomenon are discussed, and additional studies are proposed to elucidate the effects of this pharmacologically diverse group of compounds on all aspects of bone physiology and repair.

Inosine attenuates tourniquet-induced skeletal muscle reperfusion injury.

BACKGROUND: Adenosine attenuates skeletal muscle reperfusion injury, but its short half-life in vivo limits potential therapeutic benefits. The aim of this study was to ascertain whether inosine, a stable adenosine metabolite, modulates skeletal muscle reperfusion injury. MATERIALS AND METHODS: C57BL/6 mice were randomized (8-10 per group) to six groups: time controls; inosine (100 mg/kg) before anesthesia; 2 h of bilateral tourniquet hindlimb ischemia; I/R (2 h of bilateral tourniquet hindlimb ischemia, 3 h of reperfusion); inosine (100 mg/kg) before I/R; drug vehicle before I/R. Serum tumor necrosis factor (TNF)-alpha and macrophage inflammatory protein (MIP)-2 were measured before ischemia and at the end of reperfusion. Tissue edema was determined by wet/dry weight ratios. Tissue leucosequestration was assessed by the myeloperoxidase (MPO) content. RESULTS: At the end of reperfusion, inosine pretreatment resulted in lower MPO levels in muscle (P = 0.02) and lung (P = 0.0002) than saline pretreatment. Similarly, muscle (P = 0.04) and lung (P = 0.02) wet/dry ratios were significantly reduced with inosine but not with saline pretreatment. At the end of reperfusion, serum proinflammatory cytokine levels (TNF-alpha and MIP-2) were significantly reduced (P < 0.05) compared to preischemia levels following inosine pretreatment but not saline pretreatment. Ischemia alone did not alter any of the parameters assessed. CONCLUSIONS: These findings demonstrate that pretreatment with inosine attenuates the local and systemic proinflammatory responses associated with skeletal muscle reperfusion injury.

The importance of fixation procedures on DNA template and its suitability for solution-phase polymerase chain reaction and PCR in situ hybridization.

Conventional solution-phase polymerase chain reaction (PCR) and in situ PCR/PCR in situ hybridization are powerful tools for retrospective analysis of fixed paraffin wax-embedded material. Amplification failure using these techniques is now encountered in some centres using archival fixed tissues. Such 'failures' may not only be due to absent target DNA sequences in the tissues, but may be a direct effect of the type of fixative, fixation time and/or fixation temperature used. The type of nucleic acid extraction procedure applied will also influence amplification results. This is particularly true with in situ PCR/PCR in situ hybridization. To examine these effects in solution-phase PCR, beta-globin gene was amplified in 100 mg pieces of tonsillar tissue fixed in Formal saline, 10% formalin, neutral buffered formaldehyde, Carnoy's Bouin's, buffered formaldehyde sublimate, Zenker's, Helly's and glutaraldehyde at 0 to 4 degrees C, room temperature and 37 degrees C fixation temperatures and for fixation periods of 6, 24, 48 and 72 hours and 1 week. DNA extraction procedures used were simple boiling and 5 days' proteinase K digestion at 37 degrees C. Amplified product was visible primarily yet variably from tissue fixed in neutral buffered formaldehyde and Carnoy's, whereas fixation in mercuric chloride-based fixatives produced consistently negative results. Room temperature and 37 degrees C fixation temperature appeared most conducive to yielding amplifiable DNA template. Fixation times of 24 and 48 hours in neutral buffered formaldehyde and Carnoy's again favoured amplification.(ABSTRACT TRUNCATED AT 250 WORDS)