Femoral nerve blockade administered preclinically for pain relief in severe knee trauma is more feasible and effective than intravenous metamizole: a randomized controlled trial.

BACKGROUND: Before clinical treatment and during transportation, the analgesic therapy offered to patients with painful knee trauma may be quite insufficient. We hypothesize that a femoral nerve blockade for analgesia can be administered in a preclinical setting at the injury site and provides better pain relief than intravenous metamizole, whose analgesic effect is comparable with that of opioids. METHODS: After an initial clinical investigation, 52 patients were randomized according to computer-generated codes; 26 patients received a femoral nerve blockade and 26 received metamizole. The treatment was started at the injury site and the level of pain on the 100-mm visual analog scale was assessed at the beginning and the end of treatment. RESULTS: Pain and anxiety scores were significantly reduced by half in the femoral nerve blockade group; peripheral vasoconstriction was noted in 26 patients at the injury site and dropped to six at the time of arrival at the hospital. Two of 26 patients in the blockade group did not benefit from the treatment. In the metamizole group, pain and anxiety did not decrease significantly; vasoconstriction persisted in all patients. CONCLUSION: Patients with painful knee trauma benefited from femoral nerve blockade administered before hospitalization. The treatment can be administered safely in the preclinical setting and provides effective analgesia.

A randomized controlled trial of femoral nerve blockade administered preclinically for pain relief in femoral trauma.

BACKGROUND: Analgesia at the location of the accident and on transport for femoral trauma is often delayed or insufficient. In this prospective, randomized, controlled study, we evaluated the preclinical use of femoral nerve blockade for reducing pain and anxiety compared with IV analgesia using metamizol. METHODS: Patients with painful femoral trauma, such as fracture or severe contusion, were randomized to receive at the site of the accident a femoral nerve blockade (n = 31) or IV analgesia with metamizol (n = 31). A visual analog scale (VAS) was used to assess pain and anxiety. Variables were assessed at baseline, during transport and upon arrival at the hospital. RESULTS: In patients receiving the femoral nerve blockade, pain values decreased by half from VAS 86 +/- 6 mm at the site of the accident to VAS 41 +/- 15 mm during transport. Anxiety decreased by half from VAS 84 +/- 11 mm to VAS 39 +/- 14 mm. Heart rate decreased by 20 +/- 5 bpm. In the metamizol group, pain, anxiety, and heart rate did not decrease (P < 0.001). Time of treatment was 7.4 +/- 3.5 min longer in the femoral nerve blockade group. CONCLUSION: Preclinically administered femoral nerve blockade effectively decreases pain, anxiety, and heart rate after femoral trauma. Regional blockade is an option for out-of-hospital analgesia administered by a trained physician.

The influence of stellate ganglion transcutaneous electrical nerve stimulation on signal quality of pulse oximetry in prehospital trauma care.

BACKGROUND: Accurate monitoring of the peripheral arterial oxygen saturation has become an important tool in the prehospital emergency medicine. This monitoring requires an adequate plethysmographic pulsation. Signal quality is diminished by cold ambient temperature due to vasoconstriction. Blockade of the stellate ganglion can improve peripheral vascular perfusion and can be achieved by direct injection or transcutaneous electrical nerve stimulation (TENS) stimulation. We evaluated whether TENS on the stellate ganglion would reduce vasoconstriction and thereby improve signal detection quality of peripheral pulse oximetry. METHODS: In our study, 53 patients with minor trauma who required transport to the hospital were enrolled. We recorded vital signs, including core and skin temperature before and after transport to the hospital. Pulse oximetry sensors were attached to the patient's second finger on both hands. TENS of the stellate ganglion was started on one side after the beginning of the transport. Pulse oximeter alerts, due to poor signal detection, were recorded for each side separately. RESULTS: On the hand treated with TENS we detected a significant reduction of alerts compared to the other side (mean alerts TENS 3.1 [1-15] versus control side 8.8 [1-28] P < 0.05). The duration of dropouts was shorter as well (mean duration TENS 77 [16-239] s versus control side 333 [78-1002] s). CONCLUSION: The data indicate that blockade of the stellate ganglion with TENS improves signal quality of pulse oximeters in the prehospital setting.

Dynamic CT measurement of pulmonary enhancement in piglets with experimental acute respiratory distress syndrome.

PURPOSE: To investigate whether analysis of a washout curve of contrast material obtained with serial computed tomography (CT) enables differentiation between hydrostatic pulmonary edema and pulmonary edema caused by increased capillary permeability. MATERIALS AND METHODS: The institutional committee on animal experiments approved this study, which was performed in accordance with designated guidelines. Chest CT was performed in 12 piglets after induction of anesthesia and start of mechanical ventilation. Dynamic CT was performed before and after induction of hydrostatic edema (n = 5) or oleic acid-induced increased vascular permeability edema (n = 7). Scans were obtained over 240 seconds during inspiratory breath holding at a single representative subcarinal level in the lungs. This anatomic level was kept constant and included areas of normal ventilation before and after induction of pulmonary edema and areas of ground-glass opacity and consolidation after induction of pulmonary edema. Measured lung attenuation in the regions of interest was normalized to that before contrast material injection and plotted as a function of time. Statistical analysis was performed by using two-way analysis of variance with repeated measures. RESULTS: In general, before induction of pulmonary edema, attenuation of normally aerated lung areas did not increase after the initial peak of enhancement during the first pass of contrast material. In animals with hydrostatic edema, no attenuation changes in areas of ground-glass opacity were observed after the initial peak. Conversely, lung attenuation increased continuously in animals with oleic acid-induced high-permeability pulmonary edema (P = .002). After induction of lung edema, pulmonary enhancement measured in lung regions with normal ventilation or consolidation did not change in either group. Pulmonary fluid accumulation 90 minutes after induction of edema did not significantly differ between groups. CONCLUSION: Dynamic contrast-material enhanced CT can help differentiate between permeability and hydrostatic lung edema in an animal model.

Transcutaneous electrical nerve stimulation as prehospital emergency interventional care: treating acute pelvic pain in young women.

Objectives. In Europe, patients with acute pelvic pain are transported to the hospital in an ambulance without an emergency physician. We hypothesized that transcutaneous electrical nerve stimulation (TENS) would be an effective noninvasive procedure for pain treatment. Methods. We conducted a prospective, randomized, blinded study where 100 women were randomly assigned into a real- or a sham-TENS group. TENS began before the transport to the ambulance and was left in place until the arrival at the hospital. Each patient rated her pain on paper using a visual analog scale. Results. Compared to sham TENS, patients with active TENS felt that their pain was reduced by half after treatment (p < 0.01), anxiety scores significantly decreased (p < 0.01), heart rate and arteriolar vasoconstriction decreased significantly (p < 0.01), and nausea (p < 0.01) was lessened. Overall satisfaction with the received care was significantly higher (p < 0.01). Conclusion. TENS is a safe, rapid, and effective analgesic treatment for acute pelvic pain.

Heparinase-modified thrombelastography in term and preterm neonates.

UNLABELLED: Thrombelastography (TEG) appears to be a promising test to assess coagulation in infants and children. TEG enables a rapid assessment of hemostatic function with only 300 microL of whole blood and provides information about plasmatic coagulation, platelet function, and fibrinolysis. In this study, we used TEG to assess the coagulation system of preterm and term neonates to determine the effects of their deficient coagulation factor levels on global hemostatic function. Heparinase-modified TEG, platelet and red blood cell count, plasma fibrinogen, and prothrombin time were assessed in four groups of clinically stable infants: severely preterm (gestational age [GA], 27-31 wk), moderately preterm (GA, 32-36 wk), term (GA, 36-40 wk), and former preterm (corrected GA, 34-40 wk). Healthy adult volunteers served as a control group. When compared with the adult group, thromboelastography revealed no defects in coagulation from groups of clinically stable infants, documenting the functional integrity of coagulation despite, in part, decreased conventional coagulation variables. Because clinically stable preterm and term infants show a relatively small incidence of bleeding, despite prolonged conventional coagulation tests, TEG may better reflect the hemostatic potential of these patients compared with conventional coagulation tests. IMPLICATIONS: This study assessed the coagulation of preterm and term infants by thrombelastography and found functional integrity of coagulation despite, in part, decreased conventional coagulation variables.

Acetylsalicylic acid, diclofenac, and lornoxicam, but not rofecoxib, affect platelet CD 62 expression.

UNLABELLED: Nonsteroidal antiinflammatory drugs are routinely administered in the perioperative period. Because of the absence of cyclooxygenase-2 in platelets, cyclooxygenase-2-selective drugs are thought not to cause platelet inhibition. Because platelets play an important role in the coagulation process, the absence of platelet function inhibition may lead to fewer bleeding complications after surgery. We studied the influence of aspirin, diclofenac, lornoxicam, and rofecoxib on arachidonic acid and collagen-induced CD 62 P (P selectin) expression by using flow cytometry. Blood from 68 volunteers was obtained before and 1, 3, and 12 h after the oral ingestion of 1 of the randomly assigned study medications. Aspirin, diclofenac, and lornoxicam had a significant effect on arachidonic acid and collagen-induced CD 62 P expression in platelets, whereas rofecoxib did not show this effect. We conclude that rofecoxib is safe to use perioperatively with respect to inhibition of platelet function. IMPLICATIONS: We compared the effect of rofecoxib and three nonselective nonsteroidal antiinflammatory drugs on platelet function, measured by CD 62 P expression. Platelet function was not altered by rofecoxib, but it was inhibited by aspirin, diclofenac, and lornoxicam. Rofecoxib may be safer than classic NSAIDs with respect to platelet function during the perioperative period.

The influence of VIP and epoprostenol on platelet CD62P expression and primary haemostasis in vitro.

Human vasoactive intestinal peptide (VIP) and epoprostenol (prostacyclin) have vasodilatative effects in the pulmonary circulation. Both VIP and epoprostenol are successfully used to treat pulmonary hypertension in humans and experimental animal models. The positive effects of epoprostenol on the course of this disease are achieved through vasodilatation and inhibitory effects on platelet activity. Since VIP also binds specifically to platelets, we compared the in vitro effects of VIP and epoprostenol on platelet P-Selectin (CD62P) expression and primary haemostasis. Anti-aggregative effects of VIP (10(-6) mol and 10(-8) mol) and epoprostenol (50, 5 and 0.5 ng/ml) on platelets were determined by agonist-induced CD62P expression and in vitro bleeding time (PFA-100 trade mark system). Blood from healthy individuals was either incubated with epoprostenol, VIP or saline control and was analysed by whole blood flow cytometry and the PFA-100 trade mark. Prior to flow cytometric analysis, the platelets were stimulated with either arachidonic acid (AA) or adenosine diphosphate (ADP). Whole blood flow cytometry analysis showed that epoprostenol inhibited dose-dependently agonist-induced CD62P expression, whereas VIP did not inhibit CD62P expression. PFA analysis revealed substantial closure time prolongation by epoprostenol and again no effects of VIP. These results indicate that VIP, in contrast to epoprostenol, has no effect on platelet CD62P expression and primary haemostasis.

Educational or organizational approach: which is more effective in changing blood-sampling habits?

UNLABELLED: Diagnostic blood loss is a recognized issue during the delivery of intensive care services. We designed this study to compare the effects of educational versus organizational approaches to reduce daily diagnostic blood loss in intensive care patients. First, as an educational approach, physicians on two wards were repeatedly informed about the importance of diagnostic blood loss and that 1.0-1.5 mL is sufficient for blood gas analysis. Second, as an organizational approach, 3-mL syringes were replaced by 2-mL syringes. Measurements after both periods were compared with a control group. The amount of drawn/discarded blood of 320 samples was measured in each group after the 2 interventions. Compared with the control group, the educational program reduced the amount of drawn/discarded blood in one ward, but not the other. After the organizational change, the amount of drawn/discarded blood was reduced in both wards. Additionally, because of the smaller costs of 2-mL syringes, implementation of 2-mL syringes saved US dollars 30800/yr in our hospital. In conclusion, our study shows that an educational program seems less effective in influencing physician behavior than organizational changes. Therefore, organizational changes should be favored over educational approaches whenever possible. IMPLICATIONS: Organizational change is more effective than educational programs to reduce diagnostic blood loss. Organizational implementation of smaller syringes reduces the amount of discarded blood and can save money.

Nutrition and anabolic agents in burned patients.

PURPOSE OF REVIEW: Much of the morbidity and mortality of severely burned patients is connected with hypermetabolism and catabolism with its accompanying impairment of wound healing and increased infection risks. In order to prevent the erosion of body mass, nutritional support and other strategies to prevent catabolism have become a major focus in the care of severely burned patients. RECENT FINDINGS: Major themes discussed in recent literature are dealing with enteral versus parenteral nutrition and gastric versus duodenal feeding. The possibility of overfeeding is another important aspect of high calorie nutrition as commonly used in burned patients. Specific formulas for enteral nutrition for specific metabolic abnormalities are under evaluation as well as the role of anabolic and anticatabolic agents. SUMMARY: From the clinical literature, total enteral nutrition starting as early as possible without any supplemental parenteral nutrition is the preferred feeding method for burned patients. Using a duodenal approach, especially in the early postburn phase, seems to be superior to gastric feeding. Administration of high calorie total enteral nutrition in any later septic phase should be critically reviewed due to possible impairment of splanchnic oxygen balance. Therefore, measurement of CO(2)-gap should be considered as a monitoring method during small bowel nutrition. The impact on the course of disease of supplements such as arginine, glutamine and vitamins as well as the impact of the use of anabolic and anticatabolic agents is not yet evident. Furthermore, the effect of insulin administration and low blood sugar regimes on wound healing and outcome in burned patients should be evaluated in future studies.

Onset time, quality of blockade, and duration of three-in-one blocks with levobupivacaine and bupivacaine.

Levobupivacaine is the isolated S(-)-stereoisomer of racemic bupivacaine. Important pharmacodynamic properties of levobupivacaine have not been determined for the femoral three-in-one block. In this randomized, controlled, double-blinded trial, we studied 60 ASA physical status I-III patients scheduled for surgery of the lower limb. A nerve-stimulator-guided three-in-one block was performed as supplemental analgesic therapy with 20 mL of bupivacaine 0.5% (n = 20), levobupivacaine 0.5% (n = 20), or levobupivacaine 0.25% (n = 20). Sensory onset time, quality of blockade, and duration of blockade were assessed by pinprick test in the central sensory innervation region of the femoral nerve (distribution of the anterior femoral cutaneous nerve). A rating scale from 100% (normal sensation) to 0% (no sensation at all) as compared with the contralateral leg was used. No significant difference in sensory onset time among the three local anesthetic solutions was observed (mean [95% confidence interval]): bupivacaine 0.5%, 27 min (20-33 min); levobupivacaine 0.5%, 24 min (18-30 min); and levobupivacaine 0.25%, 30 min (23-36 min) (P = 0.49). The analgesic quality of the blockade was also not significantly different among the three groups, whereas a complete sensory block was achieved in significantly fewer patients in the levobupivacaine 0.25% group (P = 0.02). The duration of blockade was significantly shorter with levobupivacaine 0.25% compared with the other groups: bupivacaine 0.5%, 1053 min (802-1304 min); levobupivacaine 0.5%, 1001 min (844-1158 min); and levobupivacaine 0.25%, 707 min (551-863 min) (P = 0.01). Levobupivacaine 0.5% is recommended instead of bupivacaine 0.5% for the three-in-one block.

Awake nasotracheal fiberoptic intubation: patient comfort, intubating conditions, and hemodynamic stability during conscious sedation with remifentanil.

Awake nasotracheal fiberoptic intubation requires an anesthetic management that provides sufficient patient comfort, adequate intubating conditions, and stable hemodynamics. Short-acting and easily titratable analgesics are excellent choices for this maneuver. In this study, our aim was to determine an appropriate dosage regimen of remifentanil for awake nasotracheal fiberoptic intubation. For that reason, we compared two different dosage regimens. Twenty-four patients were randomly assigned to receive remifentanil 0.75 micro g/kg in bolus, followed by a continuous infusion of 0.075 micro g x kg(-1) x min(-1) (Group L), or remifentanil 1.5 micro g/kg in bolus, followed by a continuous infusion of 0.15 micro g x kg(-1) x min(-1) (Group H). All patients were premedicated with midazolam 0.05 mg/kg IV and glycopyrrolate 0.2 mg IV. Both dosage regimens ensured patient comfort and sedation. Discomfort did not differ between groups. Patients in Group H were sedated more profoundly. Hemodynamic stability was maintained with both remifentanil doses. Intubating conditions were adequate in all patients and comparable between the groups. The large dosage regimen did not result in any additional benefit compared with the small dosage. For awake nasotracheal fiberoptic intubation, we therefore recommend remifentanil 0.75 micro g/kg in bolus followed by continuous infusion of 0.075 micro g x kg(-1) x min(-1), supplemented with midazolam 0.05 mg/kg.

Effect of prostacyclin on platelets, polymorphonuclear cells, and heterotypic cell aggregation during hemofiltration.

OBJECTIVES: Hemodialysis activates both platelets and leukocytes, which play a role in the development of multiple organ dysfunctions in critically ill patients. Prostacyclin inhibits both cell types. To examine the hypothesis that prostacyclin prevents cellular activation during clinical hemofiltration, we investigated the expression of activation markers on platelets and leukocytes using whole blood flow cytometry. DESIGN: Prospective, randomized, double-blind, controlled trial. SETTING: Intensive care unit. PATIENTS: A total of 24 consecutive, critically ill, mechanically ventilated patients with acute renal failure secondary to sepsis or major surgery. INTERVENTIONS: For anticoagulation during hemofiltration, patients received either unfractionated heparin or unfractionated heparin and prostacyclin (5 ng x kg(-1) x min(-1)). Anticoagulants were administered into the extracorporeal circuit before the hemofilter. Blood samples were obtained from an arterial catheter before hemofiltration and from the inlet and outlet lines of the extracorporeal circuit at 1 and 24 hrs during hemofiltration. MEASUREMENTS AND MAIN RESULTS: Expression of GP IIb-IIIa and P-selectin on adenosine diphosphate-activated platelets and platelet-leukocyte aggregation were significantly lower after the passage of blood through the hemofilter in patients receiving an extracorporeal infusion of prostacyclin plus heparin when compared with control patients receiving heparin only. There were no statistically significant differences in the expression of CD11b on leukocytes between the two groups. CONCLUSIONS: These findings suggest that prostacyclin reversibly inhibits platelet function by diminishing the expression of platelet fibrinogen receptors and P-selectin and reduces heterotypic platelet-leukocyte aggregation during clinical hemofiltration. However, prostacyclin fails to inhibit leukocyte activation at clinically relevant doses.

Preoperative orthostatic dysfunction is associated with an increased incidence of postoperative nausea and vomiting.

BACKGROUND: Postoperative nausea and vomiting (PONV) occurs frequently after gynecologic surgery. Because hemodynamic condition seems to be influential, women presenting with preoperative orthostatic dysregulation may have an increased risk for PONV. The aim of the present study was to assess the relationship between preoperative orthostatic dysregulation and the incidence of PONV. METHODS: In a prospective observer-blinded clinical trial, 200 women who were scheduled for elective gynecologic surgery underwent an orthostatic test on the day before surgery. Based on the orthostatic test results, women were stratified into orthostatic dysregulation (OR; systolic blood pressure decrease > 20 mmHg on standing up) and nonorthostatic dysregulation (NOR; systolic blood pressure decrease < 20 mmHg) groups. RESULTS: Forty-nine women were stratified to the OR group and 151 to the NOR group. Frequencies of PONV and vomiting during the study period were higher in the OR group compared with the NOR group (77.6% vs. 31.1% and 55.1 vs. 18.5%, respectively; all P < 0.001). Women with hypotension in their history showed a significantly higher frequency of PONV within 24 h (P < 0.05). CONCLUSION: Women presenting with orthostatic dysregulation and arterial hypotension in their history exhibit an increased risk of PONV.

Anticoagulation with prostaglandins and unfractionated heparin during continuous venovenous haemofiltration: a randomized controlled trial.

BACKGROUND: The objective of this prospective, randomized, controlled clinical study was to compare efficacy, safety, and costs of fixed-dose prostaglandins with adjusted-dose unfractionated heparin as anticoagulants for continuous venovenous haemofiltration. PATIENTS AND METHODS: Perioperative critically ill patients requiring continuous haemofiltration for acute renal failure received unfractionated heparin anticoagulation titrated to achieve an activated clotting time in the extracorporeal system of > 120 s. Patients were randomly assigned to receive a test infusion containing either prostaglandin I2 (5 ng/kg/min; group I; n = 15; 75 filters), prostaglandin E1 (5 ng/kg/min; group E; n = 18; 72 filters), or placebo (group H; n = 17; 63 filters). Heparin and test solutions were infused into the extracorporeal circuit before the haemofilter. All AN69-surface hollow fiber filters were primed with normal saline containing 5.000 IU heparin. RESULTS: The primary outcome measure--adequate haemofilter life span > 24 h--was compared by using Cochran's Q test. There was a significant difference in the frequencies of adequate haemofilter life span between the groups (36% group H, 65% group I, 59% group E; P < 0.05 versus group H). There were 6 bleeding episodes in group H, 2 in group E, and only 1 trivial bleeding episode in group I (P < 0.05 versus group H). Daily costs of haemofiltration were 61% higher in group I and 23% higher in group E than in group H (P < 0.05 versus group H). A heparin-sparing effect of prostaglandins was observed. CONCLUSIONS: Fixed-dose prostaglandins I2 and E1 reduced the incidence of haemofilter failure and bleeding when compared with adjusted-dose unfractionated heparin. There was no significant difference between the two prostaglandin groups. The increase in daily costs for haemofiltration treatment under prostaglandins is not clinically relevant.

Impact of duodenal feeding on the oxygen balance of the splanchnic region during different phases of severe burn injury.

Enteral nutrition is recommended in burned patients. Depending on the amount administered, enteral feeding causes an increase of intestinal oxygen-demand. Since intestinal perfusion is decreased after major burns the aim of this study was to evaluate, whether duodenal feeding might be a cofactor for the development of a splanchnic O(2)-imbalance. In 15 severely burned patients during duodenal feeding starting within 6 h after injury the assessment of the CO(2)-gap between arterial and gastric CO(2), as a parameter for the measurement of intestinal O(2)-balance was performed. Beginning prior to enteral nutrition CO(2)-gap measurements were carried out to show when the CO(2)-gap increased above 30 mmHg during the whole critical illness phase of the patients. When the CO(2)-gap increased above 30 mmHg enteral nutrition was reduced by 50% and the CO(2)-gap was measured 1 h later. In none of the patients the CO(2)-gap increased during increase of enteral nutrition. In seven patients, the CO(2)-gap increased between the 6th and 13th day above 30 mmHg and fell significantly 1 h after reduction of enteral nutrition. Contrary to the early postburn phase, enteral feeding might have adverse effects on the oxygen balance of the intestine in the later stages of the critical illness phase.