ß-Blocker after severe traumatic brain injury is associated with better long-term functional outcome: a matched case control study.

PURPOSE: Severe traumatic brain injury (TBI) is the predominant cause of death and disability following trauma. Several studies have observed improved survival in TBI patients exposed to ß-blockers, however, the effect on functional outcome is poorly documented. METHODS: Adult patients with severe TBI (head AIS ≥ 3) were identified from a prospectively collected TBI database over a 5-year period. Patients with neurosurgical ICU length of stay <48 h and those dying within 48 h of admission were excluded. Patients exposed to ß-blockers ≤ 48 h after admission and who continued with treatment until discharge constituted ß-blocked cases and were matched to non ß-blocked controls using propensity score matching. The outcome of interest was Glasgow Outcome Scores (GOS), as a measure of functional outcome up to 12 months after injury. GOS ≤ 3 was considered a poor outcome. Bivariate analysis was deployed to determine differences between groups. Odds ratio and 95% CI were used to assess the effect of ß-blockers on GOS. RESULTS: 362 patients met the inclusion criteria with 21% receiving ß-blockers during admission. After propensity matching, 76 matched pairs were available for analysis. There were no statistical differences in any variables included in the analysis. Mean hospital length of stay was shorter in the ß-blocked cases (18.0 vs. 26.8 days, p < 0.01). The risk of poor long-term functional outcome was more than doubled in non-ß-blocked controls (OR 2.44, 95% CI 1.01-6.03, p = 0.03). CONCLUSION: Exposure to ß-blockers in patients with severe TBI appears to improve functional outcome. Further prospective randomized trials are warranted.

Assessment of hospital surge capacity using the MACSIM simulation system: a pilot study.

AIM: The aim of this study was to use a simulation model developed for the scientific evaluation of methodology in disaster medicine to test surge capacity (SC) in a major hospital responding to a simulated major incident with a scenario copied from a real incident. METHODS: The tested hospital was illustrated on a system of magnetic boards, where available resources, staff, and patients treated in the hospital at the time of the test were illustrated. Casualties were illustrated with simulation cards supplying all data required to determine procedures for diagnosis and treatment, which all were connected to real consumption of time and resources. RESULTS: The first capacity-limiting factor was the number of resuscitation teams that could work parallel in the emergency department (ED). This made it necessary to refer severely injured to other hospitals. At this time, surgery (OR) and intensive care (ICU) had considerable remaining capacity. Thus, the reception of casualties could be restarted when the ED had been cleared. The next limiting factor was lack of ventilators in the ICU, which permanently set the limit for SC. At this time, there was still residual OR capacity. With access to more ventilators, the full surgical capacity of the hospital could have been utilized. CONCLUSIONS: The tested model was evaluated as an accurate tool to determine SC. The results illustrate that SC cannot be determined by testing one single function in the hospital, since all functions interact with each other and different functions can be identified as limiting factors at different times during the response.

Extracorporeal membrane oxygenation improves coagulopathy in an experimental traumatic hemorrhagic model.

PURPOSE: Hemorrhage is the most common cause of preventable death after trauma. Coagulopathy plays a central role in uncontrolled bleeding and is caused by multiple factors. Extracorporeal Membrane Oxygenation (ECMO) is an established treatment for patients with respiratory failure and has in recent years also been used in severely injured trauma patients with cardiopulmonary failure and coexisting bleeding shock. The aim of this study was to evaluate the effect of ECMO on hypothermia, acidosis, and coagulopathy in a traumatic hemorrhagic rabbit model. METHODS: After anesthesia and tracheostomy, ten New Zealand White rabbits sustained laparotomy, bilateral femur fractures and were hemorrhaged 45% of their estimated blood volume. After 90 min of hemorrhagic shock they were resuscitated with a standard transfusion protocol together with venoarterial ECMO (n = 5) or with a standard transfusion protocol only (n = 5) for 60 min. No systemic heparin was administered. RESULTS: ECMO during 60 min of resuscitation significantly increased heart rate (p = 0.01), mean arterial pressure (p = 0.01), body temperature (p = 0.01) and improved the metabolic acidosis, pH (p = 0.01), and lactate (p = 0.01). ECMO also improved the coagulation capacity measured in vitro by Rotational Thromboelastometry with a significant decrease in clot formation time (p < 0.01). This finding was confirmed in vivo with a significant reduction in the animals' ear bleeding time (p < 0.01) and cuticle bleeding time (p < 0.01); 5/5 animals survived in the ECMO group and 3/5 animals survived in the control group. CONCLUSIONS: Heparin-free ECMO stabilizes circulation, improves coagulation, and may impact short-time survival, during the first 60 min, in an experimental traumatic model with severe hemorrhagic shock.

Assessing bicycle-related trauma using the biomarker S100B reveals a correlation with total injury severity.

PURPOSE: Worldwide, the use of bicycles, for both recreation and commuting, is increasing. S100B, a suggested protein biomarker for cerebral injury, has been shown to correlate to extracranial injury as well. Using serum levels of S100B, we aimed to investigate how S100B could be used when assessing injuries in patients suffering from bicycle trauma injury. As a secondary aim, we investigated how hospital length of stay and injury severity score (ISS) were correlated to S100B levels. METHODS: We performed a retrospective, database study including all patients admitted for bicycle trauma to a level 1 trauma center over a four-year period with admission samples of S100B (n = 127). Computerized tomography (CT) scans were reviewed and remaining data were collected from case records. Univariate- and multivariate regression analyses, linear regressions and comparative statistics (Mann-Whitney) were used where appropriate. RESULTS: Both intra- and extracranial injuries were correlated with S100B levels. Stockholm CT score presented the best correlation of an intracranial parameter with S100B levels (p < 0.0001), while the presences of extremity injury, thoracic injury, and non-cervical spinal injury were also significantly correlated (all p < 0.0001, respectively). A multivariate linear regression revealed that Stockholm CT score, non-cervical spinal injury, and abdominal injury all independently correlated with levels of S100B. Patients with a ISS > 15 had higher S100 levels than patients with ISS < 16 (p < 0.0001). Patients with extracranial, as well as intracranial- and extracranial injuries, had significantly higher levels of S100B than patients without injuries (p < 0.05 and p < 0.01, respectively). The admission serum levels of S100B (log, µg/L) were correlated with ISS (log) (r = 0.53) and length of stay (log, days) (r = 0.45). CONCLUSIONS: S100B levels were independently correlated with intracranial pathology, but also with the extent of extracranial injury. Length of stay and ISS were both correlated with the admission levels of S100B in bicycle trauma, suggesting S100B to be a good marker of aggregated injury severity. Further studies are warranted to confirm our findings.

Helmet use in bicycle trauma patients: a population-based study.

INTRODUCTION: In recent years, the increasing number of bicyclists has evoked the debate on use of bicycle helmet. The aim of this study was to investigate the association between helmet use and injury pattern in bicycle trauma patients. PATIENTS AND METHODS: We performed a retrospective population-based study of 186 patients treated for bicycle-related injuries at a Level 1 Trauma Centre in Sweden during a 3-year period. Data were collected from case records. Unconditional logistic regression was used to calculate odds ratios (ORs), and 95% confidence intervals (CIs). RESULTS: 43.5% of the 186 patients used a bicycle helmet at the time of the crash. Helmet users were less likely to get head and facial injuries in collisions than non-helmet users (OR, 0.3; 95% CI, 0.07-0.8, and OR, 0.07; 95% CI, 0.02-0.3), whereas no difference was seen in single-vehicle accidents. The risk of limb injuries was higher among helmet users. CONCLUSIONS: Non-helmet use is associated with an increased risk of injury to head and face in collisions, whereas helmet use is associated with an increased risk of limb injuries in all types of crashes.

Wounds of war in the civilian sector: principles of treatment and pitfalls to avoid.

INTRODUCTION: Terror attacks with explosive devices or mass shootings have introduced a new pattern of injuries into the civilian sector. The aim of this short review on the treatment principles for so-called penetrating war wounds is to remind surgeons who are not normally confronted with them of some basic rules to follow and pitfalls to avoid. MATERIALS AND METHODS: This review article is based on literature research of the National Library of Medicine and the National Institutes of Health MEDLINE database using PubMed, as well as updated books on war surgery and the author's own experience of war zones. RESULTS AND DISCUSSION: Principles of treatment of penetrating war injuries to the head, neck, and torso are all based on damage control surgery focusing on hemorrhage and contamination control and early restoration of the deranged physiology. For injuries to the extremities, differences in treatment principles between low- and high-energy wounds are more important, although initial treatment is also focused on hemorrhage control. The surgical treatment should be based on thorough wound examination and debridement as well as fracture stabilization when required. CONCLUSION: Certain knowledge of the treatment of war wounds is necessary in all civilian hospitals that receive patients injured in terror attacks.

Beneficial effects of hypertonic saline/dextran on early survival in porcine endotoxin shock.

BACKGROUND: Hypertonic saline/dextran (HSD) has been shown to have beneficial effects in haemorrhagic shock. These effects, with improved haemodynamics and organ perfusion, would in theory also be of benefit in septic shock. However, this is less studied. We have therefore further evaluated the effect of additional treatment with HSD in a porcine endotoxin shock model. METHODS: Sixteen anaesthetized pigs were used. A continuous infusion of endotoxin (LPS EC) was increased stepwise during 30 min to a rate of 5 microg/kg/h. The infusion was discontinued after 3 h and the animals were observed for another 2 h. The animals received continuous basal fluid resuscitation with isotonic Ringer's glucose 2.5% at a rate of 20 ml/kg/h throughout the experiment. After 1 h of endotoxin infusion, the animals were randomized to additional treatment with HSD, 4 ml/kg over 5 min, or the same volume of isotonic saline. Every 30 min, haemodynamics and mixed venous saturation (SvO2) were measured via a pulmonary artery catheter. Regional blood flow rates were measured continuously by perivascular ultrasonic flow probes. The metabolic response was measured by arterial blood gas analysis. RESULTS: The endotoxin put all animals into a progressive hypodynamic circulatory shock during the experiment. Treatment with HSD improved survival rate to 8/8 compared with controls 3/8. There was a transient circulatory recovery with improved central and regional haemodynamics, accompanied by stabilized metabolic response. CONCLUSION: Treatment with additional HSD improves survival in an early phase of endotoxin shock. Generally improved haemodynamics and oxygenation of peripheral tissues are suggested as possible mechanisms.

Early resuscitation with hypertonic saline/dextran in uncontrolled intra-abdominal bleeding in swine combined with a soft tissue gunshot wound.

The effects of hypertonic saline/dextran (HSD) on hemodynamics and on rebleeding were studied during an uncontrolled intra-abdominal hemorrhage combined with a high-energy gunshot wound (GSW) in the hind limb of anesthetized swine. The GSW had instant effects on the central hemodynamics, which were aggravated when the internal hemorrhage was induced. Compared with baseline, cardiac output decreased to about 42%, mean arterial pressure decreased to 52 +/- 4%, and mean flow rates in the splanchnic region, in the upper aorta, and in the kidney decreased to 51 to 15%. The injection of HSD at 10 minutes was followed by a prompt increase in blood flow rates, but rebleeding occurred in five of eight animals, although only two died. In conclusion, GSW induced instant changes in hemodynamics at distance from the injury. When HSD treatment was given in a bolus injection, rebleeding occurred in five of eight animals, although the second hemorrhage became fatal in only one animal.

High-dose intravenous infusion of irrigating fluids containing glycine and mannitol in the pig.

BACKGROUND: Large-scale absorption of electrolyte-free irrigating fluid during endoscopic surgery may result in a "transurethral resection syndrome." The severity of the syndrome can probably be modified by using mannitol 5% instead of the most widely used glycine 1.5%. METHODS: Seventeen pigs with a mean body weight of 22 (range 19-26) kg received an intravenous infusion of 100 mL kg(-1) h(-1) of either glycine 1.5% or mannitol 5% over 90 min. Central hemodynamics, whole-body and brain oxygen consumption, intracranial pressure, blood hemoglobin, and the sodium concentrations in serum and urine were monitored for 120 min. Selected measurements were made on 6 other pigs given mannitol 3% and in 2 controls not given any fluid. Morphological examinations of the hearts were conducted. RESULTS: Both glycine 1.5% and mannitol 5% transiently increased cardiac output, the aortic blood flow rate, and arterial pressures, but all of these parameters fell to below baseline after the infusions were ended. The intracranial pressure was lower (P < 0.05) and the oxygen consumption in the brain decreased (P < 0.001) during the infusion of mannitol 5%. Glycine 1.5% expanded the intracellular volume more than mannitol did (P < 0.002). Signs of myocardial damage were graded glycine 1.5% > mannitol 5% > mannitol 3%. CONCLUSIONS: Massive infusion of glycine 1.5% and mannitol 5% left the pigs in a hypokinetic hypotensive state. Glycine 1.5% increased the intracranial pressure and injured the myocardium more than mannitol 5%, which then seems to be a more appropriate irrigating fluid to use during endoscopic surgery.

Short-term crystalloid fluid resuscitation in uncontrolled intra-abdominal bleeding in swine.

INTRODUCTION: Fluid therapy in uncontrolled bleeding is controversial. In a previously used experimental animal model of aortic injury, the outcome often was impaired by re-bleeding that began at least 20 minutes after crystalloid fluid resuscitation was initiated. Therefore, it was hypothesized that re-bleeding might be avoided if volume loading is carried out for 20 minutes and then discontinued. METHODS: Ten minutes after a 5 mm laceration was produced in the infra-renal aorta on eight anesthetized pigs, they received a 20-minute intravenous infusion of Ringer's solution in the ratio of 1:1 to the expected blood loss. Hemodynamics were studied for 120 minutes using arterial and pulmonary artery catheters and blood flow probes placed proximal and distal to the aortic lesion and around the left renal artery and portal vein. RESULTS: The bleeding stopped between three and four minutes after the onset of bleeding. The blood flow rate dropped to 38% (mean) of baseline in the splanchnic region, to 31% in the upper aorta, and to 13% in the kidney. The flow rates and the oxygen consumption increased transiently during fluid resuscitation, but never reached baseline levels. Re-bleeding amounted to about 15% of the initial bleeding and occurred in only three of the animals. Four of the pigs died of shock within 90 minutes (range 47-85 minutes) after the aortic injury. CONCLUSION: Short-term crystalloid fluid therapy in uncontrolled aortic hemorrhage transiently improved the hemodynamic status and the oxygen consumption following the initial bleeding. Furthermore, the infusion did not cause re-bleeding of more than 100 ml, which occurred in previously conducted experiments when the infusion was continued for more than 20 minutes.

[Aggravated uncontrolled hemorrhage induced by intravenous fluid administration]. / Okontrollerad blödning förvärras av intravenös vätsketillförsel.

A model of uncontrolled haemorrhage where a 0.5 mm laceration is made in the porcine abdominal aorta has shown outcome to be impaired by conventional fluid therapy given to restore blood volume. Findings in recent studies where the difference in blood flow rates, proximal vs. distal to the site of vascular lesion, was used as a measure of bleeding suggest the adverse effect of fluid therapy to be strongly associated with re-bleeding after primary haemostasis has occurred. Optimal survival is dependent on a fluid infusion rate ensuring balance between the risk of re-bleeding and the beneficial effects of fluid therapy on oxygen consumption.

[More precise indications for fluid therapy during transportation to hospital are required]. / Tydliga indikationer krävs för att ge vätska under transport till sjukhus.

Although early intravenous fluid therapy for haemorrhage and shock is usually given before arrival at the hospital, its value is unclear and more precise indications are needed. The indications will take into account such factors as transport time, volume and type of bleeding, and the presence or absence of concomitant head injury. Fluid resuscitation can be omitted if transport time is less than 30 min, but may be beneficial if it is more than 30 min. Choice of infusion rate should be guided by the estimated risk of re-bleeding when haemorrhage is uncontrolled, and by cerebral perfusion where severe head injury is present.

Early hemodynamic changes during uncontrolled intra-abdominal bleeding.

Central hemodynamics was studied in 32 pigs during the first 10 min after making a 5-mm laceration in the infrarenal aorta. Blood flow probes were placed proximally and distally to the site of the bleeding and also over the portal vein and renal artery. We found that the bleeding, which was indicated by a difference in the rate of blood flow between the two aortic probes, stopped spontaneously after about 3 min. The short-term changes in blood flow rates closely followed simple monoexponential functions with mean half-times of 34 (proximal aorta), approximately 10 (lower aorta), 27 (splanchnic) and 21 s (kidney) to reach steady-state levels amounting to 20, 20, 27 and 8% of the baseline flow rates, respectively.

Central and regional hemodynamics during uncontrolled bleeding using hypertonic saline dextran for resuscitation.

The effects of hypertonic (7.5%) saline/6% dextran 70 (HSD) on central and regional hemodynamics were studied during uncontrolled intra-abdominal bleeding in 16 anesthetized pigs. Ultrasonic flow probes were placed proximally and distally to an aortic injury to indicate the incidence and extent of rebleeding after injecting 4 mL kg(-1) (N = 8) and 2.65 mL kg(-1) (N = 8) of HSD 10 min after the vascular injury was induced. The initial aortic bleeding reduced the blood flow rates to 71% of baseline in the skin, 53% in the splanchnic region, 42% in the upper aorta, and 15% in the kidney. Cardiac output dropped to 46% and the mean arterial pressure to 57% of baseline. The injection of HSD was followed by a prompt increase in all blood flow rates, but rebleeding started within 2 min in 13 of the pigs (81%). A second period of rebleeding occurred in six of them. The rebleeding averaged 300 mL, which is 62% of the blood lost when the aortic injury was induced. There was no significant difference between the treatment groups with respect to these blood losses or to the oxygen consumption, which was not restored by HSD. Five animals in each treatment group died after about 70 min, while the remaining six pigs (38%) survived the 120 min study period. These results suggest that HSD in the recommended dose, and even two-thirds thereof, promotes rebleeding when given shortly after a low energy intra-abdominal aortic injury. The fluid seems to have no beneficial effect on this type of uncontrolled hemorrhage.

Central and regional hemodynamics during crystalloid fluid therapy after uncontrolled intra-abdominal bleeding.

OBJECTIVE: To study the effect of graded crystalloid fluid resuscitation on central hemodynamics and outcome after intra-abdominal hemorrhage. METHODS: Ten minutes after a 5-mm long laceration was produced in the infrarenal aorta, 32 pigs were randomized to receive either no fluid or Ringer's solution in the proportion 1:1, 2:1, or 3:1 to the expected amount of blood lost per hour (26 mL kg[-1]) over 2 hours. The hemodynamics were studied using arterial and pulmonary artery catheters and four blood flow probes placed over major blood vessels. RESULTS: During the first 40 minutes after the injury, the respective blood flow rates in the distal aorta were 39% (no fluid), 41% (1:1), 56% (2:1), and 56% (3:1) of the baseline flow. Fluid resuscitation increased cardiac output but had no effect on arterial pressure, oxygen consumption, pH, or base excess. Rebleeding occurred only with the 2:1 and 3:1 fluid programs. Survival was highest with the 1:1 and 2:1 programs. CONCLUSIONS: Crystalloid fluid therapy improved the hemodynamic status but increased the risk of rebleeding. Therefore, a moderate fluid program offered the best chance of survival.

Haemodynamics during inhalation of a 50% nitrous-oxide-in-oxygen mixture with and without hypovolaemia.

BACKGROUND: Inhalation of a gas mixture containing 50% nitrous oxide in oxygen (N2O/O2) is widely used for pain relief in emergency situations, which may also be associated with blood loss. The aim of this study was to evaluate the haemodynamic effects of this gas mixture in normo- and hypovolaemic subjects. METHODS: Six healthy males were studied during inhalation of N2O/O2 before and after withdrawal of 900 ml of blood. On each occasion, we measured systemic and pulmonary arterial pressures, cardiac output, blood gases, extravascular lung water, and the blood flow and oxygen consumption in the whole body, liver and kidneys. RESULTS: Inhalation of N2O/O2 reduced the stroke volume and increased peripheral resistance. Oxygen uptake decreased in the liver (-30%) and in the whole body (-23%). Blood withdrawal reduced the pulmonary arterial and central venous pressures (-30 to -50%) and further decreased stroke volume and the blood flows to the liver and the kidney (-15%). The extravascular lung water tended to increase both during inhalation of N2O/O2 and during hypovolaemia. CONCLUSION: N2O/O2 aggravated the hypokinetic circulation induced by hypovolaemia. However, the oxygen consumption decreased only during inhalation of N2O/O2. This opens up the possibility that the cardiodepression associated with N2O/O2 is caused by a change in metabolic demands.

Central and regional hemodynamics during acute hypovolemia and volume substitution in volunteers.

OBJECTIVES: To study the central and regional hemodynamics and oxygen consumption during acute hypovolemia and volume replacement with crystalloid and colloid solutions. DESIGN: Prospective, randomized, laboratory investigation. SETTING: Clinical physiology department at a university hospital. SUBJECTS: Eighteen healthy male volunteers, between 21 and 35 yrs of age (mean 26). INTERVENTIONS: Catheters were inserted in the cubital vein, brachial artery, pulmonary artery, thoracic aorta, right hepatic vein, and left renal vein for measurements of systemic arterial and pulmonary arterial pressures, total and central blood volumes, extravascular lung water, and the splanchnic (liver) and renal blood flow rates. The exchange of respiratory gases was measured, using the Douglas bag technique. Measurements were made before and after a venesection of 900 mL and again after the subjects had been randomized and received volume replacement with either 900 mL of Ringer's acetate solution 900 mL of albumin 5%, or 900 plus 900 mL of Ringer's solution. MEASUREMENTS AND MAIN RESULTS: Withdrawal of 900 mL of blood decreased cardiac output and the splanchnic and renal blood flow rates by between -16% and -20%. The oxygen uptake decreased by 13% in the whole body, while it remained unchanged in the liver and kidney. The systemic and pulmonary vascular resistances increased, while the extravascular lung water decreased. Autotransfusion of fluid from tissue to blood was indicated by hemodilution, which was most apparent in subjects showing only a minor change in peripheral resistance. Cardiac output, blood volume, and systemic vascular resistance were significantly more increased by infusion of 900 mL of albumin 5% than by 900 mL of Ringer's solution. However, infusion of 1800 mL of Ringer's solution increased the extravascular lung water and the pulmonary arterial pressures to significantly above baseline, while no significant difference from baseline was found after 900 mL of Ringer's acetate solution. CONCLUSIONS: Withdrawal of 900 mL of blood induces similar reductions in cardiac output as in the splanchnic and renal blood flow rates. A fluid shift from the extravascular to the intravascular fluid compartment might restore up to 50% of the blood loss. Optimal volume substitution with Ringer's solution can be effectuated by infusing between 100% and 200% of the amount of blood lost.

Breast conserving surgery for invasive breast cancer: risk factors for ipsilateral breast tumor recurrences.

To identify risk factors associated with an increased risk for ipsilateral breast tumor recurrence following breast-conserving surgery, a cohort of 759 women with T1-T2 tumors were studied. The majority of the patients (88%) had received postoperative radiation therapy to the breast. Median follow-up time was 10 (range: 6-17) years. There was a 1-1.5% yearly increase in ipsilateral breast tumor recurrences. For women < 50 ys the cumulative recurrence rate at 10 years was 18% and for women > or = 50 ys, 9%. Node positive women had a cumulative breast recurrence rate of 25% versus 10% for node negative women. Ten years postoperatively, irradiated patients had a cumulative recurrence rate of 11% versus 26% when no irradiation was given. The beneficial effect of radiotherapy was substantial during the first four postoperative years. The relative risk for an ipsilateral breast tumor recurrence during this period was 4.5 times higher than for non-irradiated patients. However, the protective effect of radiotherapy decreased with time. After ten years the relative risk of ipsilateral breast tumor recurrence was the same among irradiated and non-irradiated patients although the number of events during this period was low. Univariate analysis showed that seven factors were significantly associated with an increased risk of ipsilateral breast tumor recurrence, namely age < 50 ys, increasing tumor size, uncertain microscopic margins, axillary lymph node metastases, no postoperative tamoxifen treatment, premenopausal status, and no postoperative radiotherapy. Three factors remained independently significant after multivariate analysis: age < 50 ys, no postoperative radiation therapy, and positive lymph nodes. In conclusion, radiotherapy reduced the breast recurrence rate, but the effect decreased with time. Node-negative women > or = 50 were a low risk-group for ipsilateral breast tumor recurrence, with a cumulative risk at 10 years of 9% without radiation therapy and 5% with breast irradiation.