16C. Gaarder et al. the prehospital careprovider with amoreorless obvious mechanismo fi njury,c omplaintsa nd symptoms, and with many uncontrolled factors making both diagnosis and triage achallenge.Vo lume loading results in adecrease in haemoglobin and clotting factors. Furthermore, the relative expansion with 500 ml of isotonic crystalloid is greater in as hocked person than in ah ealthy individual. The optimal volume of intravenous fluid to administer is abalance between avoiding hypovolaemia and not increasing systolic blood pressure(SBP) causing disruption of clots and further bleeding. To what extent this is moret han at heoretical worry in patients with blunt trauma, is not well documented. Several animal models of penetrating injury,h owever,h ave documented the relationship between increasing blood pressure, increased bleeding and fatal outcome.AS BP <90m mH gi su sed extensively to assess volume status in trauma patients, both for triage, treatment and study protocols. How well aSBP <90 mm Hg defines the presence of uncontrolled bleeding, the need for intravenous fluid resuscitation and later surgical interventions is still not clear.T herei s also some evidence to support the use of only manual SBP for pre-hospital, or hospital, triage decisions (1).In EMS (Emergency Medical Services) systems wherep re-hospital fluid therapy is used, the incidence of hypotension at hospital admission is lower than 10% and the need for immediate haemostatic surgery is low (5). Recent publications have reinforced the impression that fluid resuscitation and blood transfusion in the Emergency Department still aree ssential elements of early management in most critically injured patients. Hence, providing the same therapy earlier,i fn ot exaggerated, seems logical. A major concern with prehospital fluid therapy is that infusing cold fluids will cause hypothermia in the patients, afactor known to reduce clotting activity.Patients with severeT BI (traumatic brain injury) do not tolerate even short periods of hypotension. Hence, theu se of volume therapy to counteract hypovolaemia and hypotension is considered standard treatment by most authors. The discussion has been focused moreonwhat systolic blood pressuretoaim for and what fluid to use. RECOMMENDATIONS

BackgroundEarly intramedullary nailing (IMN) of long bone fractures in severely injured patients has been evaluated as beneficial, but has also been associated with increased inflammation, multi organ failure (MOF) and morbidity. This study was initiated to evaluate the impact of primary femoral IMN on coagulation-, fibrinolysis-, inflammatory- and cardiopulmonary responses in polytraumatized patients.MethodsTwelve adult polytraumatized patients with femoral shaft fractures were included. Serial blood samples were collected to evaluate coagulation-, fibrinolytic-, and cytokine activation in arterial blood. A flow-directed pulmonary artery (PA) catheter was inserted prior to IMN. Cardiopulmonary function parameters were recorded peri- and postoperatively. The clinical course of the patients and complications were monitored and recorded daily.ResultsMean Injury Severity Score (ISS) was 31 ± 2.6. No procedure-related effect of the primary IMN on coagulation- and fibrinolysis activation was evident. Tumor necrosis factor alpha (TNF-α) increased significantly from 6 hours post procedure to peak levels on the third postoperative day. Interleukin-6 (IL-6) increased from the first to the third postoperative day. Interleukin-10 (IL-10) peaked on the first postoperative day. A procedure-related transient hemodynamic response was observed on indexed pulmonary vascular resistance (PVRI) two hours post procedure. 11/12 patients developed systemic inflammatory response syndrome (SIRS), 7/12 pneumonia, 3/12 acute lung injury (ALI), 3/12 adult respiratory distress syndrome (ARDS), 3/12 sepsis, 0/12 wound infection.ConclusionIn the polytraumatized patients with femoral shaft fractures operated with primary IMN we observed a substantial response related to the initial trauma. We could not demonstrate any major additional IMN-related impact on the inflammatory responses or on the cardiopulmonary function parameters. These results have to be interpreted carefully due to the relatively few patients included.Trial RegistrationClinicalTrials.gov: NCT00981877

The pattern of the procedure-related hemodynamic and pulmonary effects did not differ significantly between the RIA and the TR groups. The RIA group had lower numbers (ns) of embolisms per square centimeter lung area than the TR group. After reaming with the TR device, two animals died of PEs, the first postoperative day. The patients with femoral shaft fracture and additional cardiopulmonary injury or preexisting reduced cardiopulmonary function, however, need special attention, and the use of RIA may, in these cases, represent a better operative alternative with a lesser operative burden.

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The acidemia-induced rightward shift of the oxyhemoglobin dissociation curve does not increase further at a pH < 6.4, and is, at such extreme acidemia, less pronounced than calculated by the commonly used equations. To obtain optimal tissue oxygenation in patients with severe circulatory failure and extreme metabolic acidosis, Pao2 should be > 250 torr (> 33.3 kPa).

Background and objectives. In fresh blood, tissue hypoxia increases microcirculatory acidosis, which enhances erythrocyte O2 unloading and increases the amount of available O2. Storage of eryfhrocytes increases the HbO2 affinity and reduces O2 unloading. We examined the development of the affinity change during a period of 5 weeks of storage by present blood bank standards, and investigated to what extent acidosis offsets the affinity change. Materials and methods. Blood from volunteer donors was processed and stored as erythrocyte concentrates (EC). At 2–5 day intervals, EC were drawn from the bags and suspended in plasma and crystalloids to an Hb ≈ 10 g/dL. The suspensions were adjusted to give a pH of 7.40, 7.10, 6.80 or 6.30 and equilibrated with different gas mixtures to SO2 0, 25, 50, 75 and 100%. Measurements of the PO2/SO2 pairs at each pH were used to calculate the position of the HbO2 curve and its P50 value. Results. A significant leftward shift in the HbO2 curve was established after 1 week of storage; after 2.5 weeks only minor further changes were observed. Acidification right-shifted the HbO2 curve, after 2.5 weeks of storage the curve at pH 7.10 was similar to that for fresh blood at pH 7.40. Calculations of extractable O2 showed that the left-shifted HbO2 curve of stored EC could be advantageous at a low arterial PO2. Conclusions. The rightward shift of the HbO2 curve due to acidosis is well maintained in stored eryfhrocytes, a moderate pH decrease offsets the storage-induced increased HbO2 affinity.

The amount of reactive oxygen intermediates (ROI) generated by activated polymorphonuclear neutrophils (PMN), as well as the closeness of contact between PMN and vessel wall, may determine whether PMN activators will induce the adult respiratory distress syndrome. We examined the ROI-generating and aggregating effects of zymosan activated plasma (ZAP), phorbol myristate acetate (PMA) and n-formyl-methionyl-leucyl-phenylalanine (FMLP), on isolated human and rabbit PMN. PMA, after a short lag phase, induced a large and long-lasting increase in ROI generation. The initial peak response was higher and more rapid in human than in rabbit cells. The reaction to FMLP occurred almost instantaneously, but was much weaker than that to PMA, and ROI generation returned to near baseline in less than 10 min. No species difference was seen. ZAP caused an FMLP-like ROI response in human cells, whereas no response was observed in rabbit PMN. PMN aggregation was induced by all three activators, most markedly by PMA. No species difference was detected for PMA; FMLP gave a stronger aggregation of rabbit than of human PMN, however, while the opposite was true for ZAP. In conclusion, ZAP was a potent stimulus for PMN aggregation, but had modest (or no) effects on the production of ROI. Marked differences between human and rabbit PMN responses were observed.

The immune system, defending our organism against infections, can also cause disease. Anaesthetics may impair immunological defence by modifying the number and functions of immunocompetent cells, including the polymorphonuclear leucocytes (PMN). We have studied the effects of thiopentone, ketamine and morphine on some stimulated PMN responses that presumably reflect their microbicidal activity, i.e. oxygen consumption, aggregation, and volume increase. Stimulators were N-formyl-methionyl-leucyl-phenylalanine (FMLP, affecting cells via specific membrane receptors) and phorbol-myristate-acetate (PMA, activating protein kinase C, thereby short-cutting intramembraneous steps in normal signal transmission, and presumably provoking near-maximal cell responses with the dose applied). Preincubation of PMN with low doses of thiopentone enhanced oxygen consumption in unstimulated cells as well as in response to FMLP, but not PMA. FMLP-stimulated volume and aggregation responses were not detectably affected. The highest concentration of thiopentone depressed both oxygen uptake and volume/aggregation responses in FMLP-stimulated PMN. The amount of oxygen consumed after PMA stimulation was not affected, but both the onset of increased consumption and the maximal response were delayed. The two other drugs investigated, ketamine and morphine, did not appreciably affect oxygen consumption or aggregation by PMN: neither the baseline values nor those obtained after FMLP or PMA stimulation.