Anders Sondén

Laser‐induced shock wave endothelial cell injury

Several laser procedures, extracorporeal lithotripsies (ESWL), and high‐velocity missile trauma generate pressure transients that are transmitted through the tissues. Despite several publications demonstrating shock wave−induced tissue injury, little is known about its pathophysiology. This study introduces an in vitro model for studying shock wave effects on endothelial cell (EC) monolayers.

Impact of surgeon-performed ultrasound on diagnosis of abdominal pain

Background: A randomised study was performed to evaluate the diagnostic accuracy of surgeon-performed ultrasound in the emergency department for patients presenting with abdominal pain. Methods: Surgeons responsible for the examination of study patients underwent 4 weeks of ultrasound training. 800 patients who were attending the emergency department for abdominal pain were randomised to undergo or not undergo surgeon-performed ultrasound as a complement to standard examination. The preliminary diagnosis made by the surgeon, with or without ultrasound, was compared with the final diagnosis made by a senior surgeon 6–8 weeks later. Results: Diagnostic accuracy was significantly higher in the group examined with ultrasound (64.7% vs 56.8%, p = 0.027). Ultrasound proved to be helpful in making or confirming a correct diagnosis in 24.1% of cases receiving ultrasound and to contribute in 2.9%. In 22.3% of patients the diagnosis of non-specific pain was confirmed by normal findings. Ultrasound was misleading in 10.2% of cases and had no influence on the diagnosis in 40.0%. Conclusion: For patients with acute abdominal pain, higher diagnostic accuracy is achieved when surgeons use ultrasound as a diagnostic complement to standard examination. The use of bedside ultrasound should be considered in emergency departments.

Hydrogen peroxide induces endothelial cell atypia and cytoskeleton depolymerization

Reactive oxygen intermediates induce cell injury in a variety of pathophysiological conditions. Human umbilical cord vein endothelial cell (HUVEC) cultures were exposed to 1 or 200 microM H2O2 for 15 min, and observed after 15 min, or 1, 4, 24, or 120 h. Factor VIII and the cytoskeletal proteins vimentin and tubulin were visualized immunocytochemically. Release of lactate dehydrogenase (indices of cell membrane injury) did not increase after H2O2 exposure; nor was cellular expression of factor VIII affected. 200 microM H2O2 induced cell contraction after 15 min which disappeared after 1 and 4 h, but was evident again after 24 h. Immediately after exposure, the filamentous structure of vimentin and tubulin disappeared, but normalized after 1 h. After 120 h, the cytoskeleton filaments were coarsened and disorganized, and an abundance of multinucleated giant cells were observed. Catalase (150 U/ml) abolished all effects of H2O2. One microM H2O2 did not induce any changes in HUVEC. Thus, the present concentrations of H2O2 did not induce cell necrosis or altered expression of factor VIII. Early, reversible cell contraction and depolymerization of cytoskeletal proteins were observed, followed by a delayed contraction and cell atypia after 200 microM H2O2.

Bilateral vagotomy inhibits apnea and attenuates other physiological responses after blunt chest trauma.

BACKGROUND Behind armor blunt trauma (BABT) is defined as the nonpenetrating injury resulting from a ballistic impact on body armor. Some of the kinetic energy is transferred to the body, causing internal injuries and, occasionally, death. The aim of this study was to investigate if apnea and other pathophysiological effects after BABT is a vagally mediated reflex. METHODS Sixteen anesthetized pigs wearing body armor, of which five were vagotomized, were shot with a standard 7.62 mm assault rifle. These animals were compared with control animals (n = 8), shot with blank ammunition. We performed bilateral vagotomy before the shot and assessed the outcome on the apnea period, respiration, circulation, and brain function. Animals were monitored during a 2-hour period after the shot. RESULTS Nonvagotomized animals had a mean apnea period of 22 (6-44) seconds. This group also showed a significant decrease in oxygen saturation compared with control animals. Furthermore, electroencephalogram-changes were more pronounced in nonvagotomized animals. In contrast, vagotomized animals were protected from apnea and showed only a minor decrease in oxygen saturation. All exposed animals showed impaired circulation, and postmortem examination revealed a pulmonary contusion. CONCLUSION This study shows that apnea after BABT is a vagally mediated reflex that can be inhibited by bilateral vagotomy. Our results indicate that the initial apnea period is an important factor for hypoxia after BABT. Supported ventilation should begin immediately if the affected person is unconscious and suffers from apnea. It should continue until the neurologic paralysis disappears and sufficient spontaneous breathing begins.

Cyanoacrylate in nerve repair: transient cytotoxic effect

Cyanoacrylate adhesive has been suggested as an alternative to suturing when repairing severed peripheral nerves. The authors examined the cytotoxic effect of ethyl-cyanoacrylate on the human neuroblastoma cell line SH-SY5Y and compared it with the effects of butyl-cyanoacrylate (Histoacryl), an adhesive approved for skin closure. Ethyl-cyanoacrylate or butyl-cyanoacrylate was applied in confluent SH-SY5Y cultures. Immediately, at 24h and at 7, 14, 21 and 28 days, cultures were photographed and analysed digitally. At corresponding intervals, cell death was quantified using a (51)Cr release assay. In cultures exposed to ethyl-cyanoacrylate or butyl-cyanoacrylate, cell death was observed predominantly in conjunction with the adhesive, causing a halo devoid of cells. Surviving cells showed neurodegenerative properties with loss of neuritis and reduction of body size up to 3 days post exposure. The inhibition halo diminished over time in both groups and at 28 days cells reached the margin of the adhesive in the ethyl-cyanoacrylate group. (51)Cr assay indicated significant cell death in exposed cultures, which rapidly decreased during the first 14 days. No significant differences were found between the adhesives. This study demonstrates that ethyl-cyanoacrylate and butyl-cyanoacrylate have a transient cytotoxic effect, which may explain the promising results when using cyanoacrylate for nerve repair.

Proinflammatory Reaction and Cytoskeletal Alterations in Endothelial Cells after Shock Wave Exposure

Background Although the effects on human organs by shock waves (SWs) induced by medical treatments or high-energy trauma are well recognized, little is known about the effects on the cellular level. Since blood vessel injury is a common finding after SW exposure, we assessed the in vitro effects of SWs on human umbilical vein endothelial cells (HUVECs). Methods An in vitro trauma model was used to expose HUVEC monolayers to focused SWs or to shock waves plus cavitation (SWC), a subsequent phenomenon that is often considered the main cause of SW vascular injury. Results SWs alone did not cause any changes in the studied variables. In contrast, HUVEC monolayers exposed to SWC exhibited discrete central lesions with extensive cell death. Cells peripheral to the main lesion area displayed disassembly of dense peripheral bands and formation of actin stress fibers, indicating increased intercellular gaps. Expression of P-selectin was enhanced 11-fold compared with controls, whereas expression of E-selectin and intercellular adhesion molecule 1 was enhanced 8-fold (p < .05) and 1.5-fold (p < .01), respectively. The latter responses were preceded by nuclear translocation of nuclear factor κB subunit p65 by 16% (p < .01). When compared with mechanically produced lesions used as controls, SWC lesions exhibited an impaired regeneration rate of the endothelial cell layer (p < .001). Redistribution of centrosomes toward the lesion borders was less effective in the SWC samples compared with the mechanically produced lesions (p < .01). Conclusions SWC lesions were associated with a switch to an endothelial proinflammatory phenotype, with an impaired regeneration rate and changes in cytoskeletal functions.

Impact of postoperative complications on the risk for chronic groin pain after open inguinal hernia repair

BACKGROUND Chronic pain is common after inguinal hernia repair and has become one of the most important outcome measures for this procedure. The purpose of this study was to determine whether or not there is a relationship between specific postoperative complications and risk for chronic pain after open inguinal hernia repair. METHODS A prospective cohort study was designed in which participants responded to the Inguinal Pain Questionnaire regarding postoperative groin pain 8 years after inguinal hernia repair. Responses to the questionnaire were matched with data from a previous study regarding reported postoperative complications after open inguinal hernia repair. Participants were recruited originally from the Swedish Hernia Register. Response rate was 82.4% (952/1,155). The primary outcome was chronic pain in the operated groin at follow‐up. Grading of pain was performed using the Inguinal Pain Questionnaire. RESULTS A total of 170 patients (17.9%) reported groin pain and 29 patients (3.0%) reported severe groin pain. The risk for developing chronic groin pain was greater in patients with severe pain in the preoperative or immediate postoperative period (odds ratio 2.09; 95% confidence interval 1.28–3.41). Risk for chronic pain decreased for every 1‐year increase in age at the time of operation (odds ratio 0.99, 95% confidence interval 0.98–1.00). CONCLUSION Both preoperative pain and pain in the immediate postoperative period are strong risk factors for chronic groin pain. Risk factor patterns should be considered before operative repair of presumed symptomatic inguinal hernias. The problem of postoperative pain must be addressed regarding both pre‐emptive and postoperative analgesia.

Cellular High-Energy Cavitation Trauma - Description of a Novel In Vitro Trauma Model in Three Different Cell Types

The mechanisms involved in traumatic brain injury have yet to be fully characterized. One mechanism that, especially in high-energy trauma, could be of importance is cavitation. Cavitation can be described as a process of vaporization, bubble generation, and bubble implosion as a result of a decrease and subsequent increase in pressure. Cavitation as an injury mechanism is difficult to visualize and model due to its short duration and limited spatial distribution. One strategy to analyze the cellular response of cavitation is to employ suitable in vitro models. The flyer-plate model is an in vitro high-energy trauma model that includes cavitation as a trauma mechanism. A copper fragment is accelerated by means of a laser, hits the bottom of a cell culture well causing cavitation, and shock waves inside the well and cell medium. We have found the flyer-plate model to be efficient, reproducible, and easy to control. In this study, we have used the model to analyze the cellular response to microcavitation in SH-SY5Y neuroblastoma, Caco-2, and C6 glioma cell lines. Mitotic activity in neuroblastoma and glioma was investigated with BrdU staining, and cell numbers were calculated using automated time-lapse imaging. We found variations between cell types and between different zones surrounding the lesion with these methods. It was also shown that the injured cell cultures released S-100B in a dose-dependent manner. Using gene expression microarray, a number of gene families of potential interest were found to be strongly, but differently regulated in neuroblastoma and glioma at 24 h post trauma. The data from the gene expression arrays may be used to identify new candidates for biomarkers in cavitation trauma. We conclude that our model is useful for studies of trauma in vitro and that it could be applied in future treatment studies.

Surgeon-Performed Ultrasound in Diagnosing Acute Cholecystitis and Appendicitis

BackgroundThe use of ultrasound (US) outside the radiology department has increased the last decades, but large studies assessing the quality of bedside US are still lacking. This study evaluates surgeon-performed US (SPUS) and radiologist-performed US (RPUS) with respect to biliary disease and appendicitis.MethodsBetween October 2011 and November 2012, 300 adult patients, with a referral for an abdominal US, were prospectively enrolled in the study and examined by a radiologist as well as a surgeon. The surgeons had undergone a 4-week-long US education. US findings of the surgeon and of the radiologist were compared to final diagnosis, set by an independent external observer going through each patient’s chart.ResultsAmong 183 patients with suspected biliary disease, 74 had gallstones and 21 had acute cholecystitis. SPUS and RPUS diagnosed gallstones with a sensitivity of 87.1 versus 97.3%. Specificity was 96.0 versus 98.9%, and the accuracy 92.3 versus 98.2%. The sensitivity, specificity and accuracy for acute cholecystitis by SPUS and RPUS were: 60.0 versus 80.0%, 98.6 versus 97.8% and 93.9 versus 95.6%, respectively. Among 58 patients with suspected appendicitis, 15 had the disease. The sensitivity, specificity and accuracy for appendicitis by SPUS and RPUS were: 53.3 versus 73.3%, 89.7 versus 93.3% and 77.3 versus 86.7%, respectively.ConclusionSPUS is reliable in diagnosing gallstones. Diagnosing cholecystitis and appendicitis with US is more challenging for both surgeons and radiologists.Trial registration numberThe study was registered at clinicaltrials.gov. Registration number: NCT02469935.

An interprofessional initiative aimed at creating a common learning resource for the operating room ward

ABSTRACT Every semester, the operating room (OR) ward receives students from different educational programmes. Although interprofessional knowledge is essential for OR teamwork, students have traditionally been prepared in an uniprofessional manner, with no focus on interprofessional learning outcomes. This report describes the work process of an interprofessional initiative undertaken to create a common learning resource aimed at preparing students for OR practice. With a focus on interprofessional learning, shared and profession-specific learning outcomes, which are needed to prepare for practice, were identified by an interprofessional faculty. To avoid timetabling and geographic barriers, learning outcomes and constructed learning activities were packaged into an e-module and delivered on-line as an adjunct to existing lectures and workshops. A survey was administered to 4th year medical (n = 42) and 1st year OR nurse students (n = 4) to evaluate their perceptions of the e-module. We found that most learning outcomes from the different syllabuses were common for all professions. The overall response rate of the survey was 59% (27 of 46 students). Eighteen of the 27 responding students had used the learning resource, of which 15 students considered it to be of ‘high’ or ‘very high’ value. In summary, this interprofessional initiative resulted in a new common learning resource for the OR, which was used and perceived valuable by a majority of the students. The learning outcomes needed to prepare students from different educational programmes for OR practice are, to a great extent, generic and interprofessional and we thus argue that the interprofessional nature of the faculty was essential for the success of the initiative.