Quantitative CT imaging of the spatio-temporal distribution patterns of vasa vasorum in aortas of apoE-/-/LDL-/- double knockout mice

OBJECTIVE

To investigate the distribution of vasa vasorum (VV) relative to advanced atherosclerotic lesions (calcified, fibrotic or hemorrhaged) along the aortic wall of apoE-/-/LDL-/- mice at the age of 25 and 80 weeks using high-resolution nano-CT.

METHODS

Aortas from male apoE-/-/LDL-/- mice at the age of 25 weeks (n=4) and 80 weeks (n=7) were infused in situ with contrast agent and harvested for scanning with nano-CT. The spatial distribution of vasa vasorum [number and area/cross-section (mm2)] was compared to aortic luminal cross-sectional area and plaque cross-sectional area in the ascending aorta, aortic arch and descending aorta. Results were complemented with co-localized histology.

RESULTS

The number and total luminal cross-sectional area of VV showed a significant decrease in the ascending aorta and aortic arch from 25 to 80 weeks but not in the descending aorta. The number and cross-sectional area of VV showed significant local differences depending on whether it was near a fibrotic, and hemorrhaged or calcified plaque in animals at the age of 80 weeks. Area of VV progressively increased along the aorta from least in the ascending aorta<aortic arch<descending aorta in animals at the age of 80 weeks and is inverse in animals aged 25 weeks.

CONCLUSION

Atherosclerotic lesion type is correlated to the number and cross-sectional area of VV in different aortic segments in apoE-/-/LDL-/- mice. The chronological development of VV along the aorta proceeds distally from the ascending aorta and aortic arch.

[Patient surveys as an element of quality management in outpatient care: development and assessment of a questionnaire]

OBJECTIVE

The present study was designed to develop and assess a questionnaire measuring all relevant quality dimensions of general practice care from the patients' perspective. Furthermore, the study aimed to evaluate the implementation of a patient survey in outpatient care.

METHODS

Based on the Kölner Patientenfragebogen (KPF) and by developing some additional new items, we created the new questionnaire KPF-A (Kölner Patientenfragebogen-ambulant) which covers all relevant aspects of outpatient care. The questionnaire was distributed to the patients of 41 GP's and specialists in ambulatory care from different regions of Germany. N=3188 patients were included in the sample. We used these data to assess some selected psychometric characteristics of the KPF-A. Factor analysis was used to examine the underlying factor structure. A qualitative study was conducted to evaluate the implementation of the patient survey. Therefore, all N=41 doctors involved were asked to complete five open questions concerning their experience.

RESULTS

Most scales of the KPF-A showed good psychometric characteristics in the present study. Factor analysis revealed a two-factors solution for the new items representing the dimensions "professional competence" and "medical equipment". We have not yet been able to find a sound factor solution for those items representing the dimension "Staff and Organisation". The results of the qualitative study revealed a satisfying implementation of the patient survey in daily routine from the doctors' perspective. The length of the questionnaire was criticised by some participants. In the design of the study patients were supposed to fill in the questionnaires after consultation. This turned out to be difficult. We therefore modified the KPF-A so that patients can fill it in either before or after consultation.

Antikörperkontrollierte zytostatische Therapie des malignen Thymoms bei begleitender Myasthenia gravis

In a 46-year-old female patient with malignant thymoma and concomitant myasthenia gravis relapse with gravitational metastases occurred 6 1/2 years after the first operation. Metastases could be removed surgically only partially and were subsequently irradiated with 50 Gy. After 3 1/2 years renewed metastatic growth occurred. Until then the concomitant myasthenia had been stable during treatment with pyridostigmine and azathioprin and intermittent prednisone; acetylcholine receptor antibody titres had remained largely stable. Combined cytostatic treatment with vincristine, cyclophosphamide, prednisone and doxorubicin or cisplatin led to regression of metastases during the observation period of 1 1/2 years and at the same time to stabilisation of the myasthenia. Acetylcholine receptor antibody titres decreased and this was roughly paralleled by clinical improvement. Whereas there is no obvious correlation of antibodies against acetylcholine-receptor protein and tendency of tumour growth there is good agreement with the course of the accompanying myasthenia.

[Management of the operation room in an university hospital]

The heart of any surgical department is the operation room area. Any disturbances in the daily routine will affect the work flow of the whole hospital. As an example the major complaints of a university surgical department regarding workflow and communication are outlined. To solve these problems a team "OR organization" was established, which started the work based on a new developed OR statute. Within a short period the contentment of the employees as well as the workflow improved. But as a matter of fact, even in the following years of central OR management there is still the need to further stabilize the system and carefully improve the controlling system.

An unusual case of early fulminant post-traumatic fat embolism syndrome

A multiple-injured patient developed a very early onset fulminant fat embolism syndrome that was partially masked by haemorrhagic shock. Despite early diagnosis by transoesophageal echocardiography and aggressive symptomatic treatment, there was a rapid evolution to death. Post mortem examination revealed the presence of both pulmonary and systemic fat emboli. This case highlights the ever present risk of masked fat embolism syndrome shortly after trauma.

Laterale Ischiadikusblockaden

In the present study we examined 41 volunteers using magnetic resonance imaging to obtain biometric data of the thigh used for a planned blockade of the sciatic nerve via the lateral approach. At a needle entry point 12 cm proximal to the gap of the knee joint at the posterior border of the M. vastus lateralis, the sciatic nerve lies on average at a depth of 5.2 cm (39% of the femoral diameter at this site) with an angle of 10.9 degrees to the horizontal in a dorsal direction. Here the popliteal artery lies on average at a depth of 6.4 cm (48% of the femoral diameter) with an angle of 4.7 degrees to the horizontal in a ventral direction. At the marked point in the middle between the gap of the knee joint and the trochanter major at the posterior border of the M. vastus lateralis, the sciatic nerve is at an average depth of 6.2 cm (40% of the femoral diameter at this site) with an angle of 8.2 degrees in a dorsal direction. At a marked point 5 cm distal of the trochanter major at the posterior border of the M. vastus lateralis, the sciatic nerve is at a depth of 9.1 cm at a dorsal angle of 15.5 degrees (49% of the femoral diameter). The lateral blockade of the sciatic nerve at different sites of the thigh is a technique which is easy to plan with the presented biometric data. The popliteal artery could be reached only at the distal puncture point using a deep puncture and an angle in the ventral direction.

[Possibilities in improving patients's turn-over coordination in the OR of an University Hospital]

An efficient Operating Room (OR) management might increase the cost-effectiveness of an OR. For this purpose, we have evaluated the coordination and the times of the solitary processes that are involved in the patient turnover. The mean time between skin suture of the preceding patient and incision of the following patient (SI-time) was, depending on the type of operation, between 44 and 78 minutes. Mean empty-room time (ERT) was 7 minutes. SI-times depended on various factors, including the times necessary to discharge the preceding patient from the OR and the times necessary for induction of anesthesia or for preparation of the OR. Altogether, our data provide evidence for the fact, that optimisation of the patients turnover can decrease SI-times between 10-15 minutes. Although this period appears too short to reliably allow an additional scheduled operation during regular working hours, an improved coordination may result in reduced overtimes of the OR-staff and thus should increase staff satisfaction.

[Fatal outcome after multiple trauma. The thoracic injury as the decisive factor]

In patients suffering from multiple injury, chest trauma is often the main cause of fatality. A case report is given and the literature reviewed.A 49 years old motorcyclist hit a car frontally in a road accident. After primary stabilization and first clinical care, he was transferred to our trauma centre because of severe chest injury, suspected pericardial effusion and lesion of the thoracic aorta. Initial diagnostics (plain radiographs, CT scan of thorax, abdominal ultrasound, echocardiography) showed left-sided serial rib fractures, a fracture of the left scapula, a hematopneumothorax left-sided, bilateral lung contusion, a small pneumothorax of the right side, a minimal pericardial effusion and a small splenic hematoma. The patient was treated in the intensive care unit, and the situation was initially stable. After 12 h, respiration deteriorated and a bronchoscopy showed filling of the airways with mucous fluid. The CT scan showed a worsening of the pulmonary damage and increasing pericardial fluid compression. A pericardiotomy was carried out, but the situation remained unstable. The patient was treated with invasive ventilation (PEEP>10, FiO2>0,5). Sudden severe bleeding out of left lower lobe was managed by thoracotomy and lobectomy. The patient remained unstable and died 95 h after the accident. This case shows that the severity of chest trauma does not necessarily correlate with the initial clinical and radiological findings. Even with all diagnostic and therapeutic procedures, a fatal outcome could not be prevented. This demonstrates the role of chest injury as a major and unforeseeable cause of death in multiple trauma patients.

Balanced Scorecard

The change in hospital funding with diagnosis related groups (DRG), medical advances as well as demographic changes will call for new quantitative and qualitative standards imposed on German hospitals. Increasing costs and competition in the health care sector requires new and innovative strategies for resource management. Today's policy is mainly defined by rationing and intensified workload. The introduction of DRGs will presumably further constrict management perspectives on pure financial aspects. However, to ensure future development, compassionate services and continued existence of hospitals, a balance of seemingly conflicting perspectives, such as finance, customer, process, learning and growth are of utmost importance. Herein doctors and nurses in leading positions should play a key role in changing management practice. For several years the balanced scorecard has been successfully used as a strategic management concept in non-profit organizations, even in the health care sector. This concept complies with the multidimensional purposes of hospitals and focuses on policy deployment. Finally it gives the opportunity to involve all employees in the original development, communication and execution of a balanced scorecard approach.

[OR-manager: surgeon or anaesthetist?]

The heart of any surgical department is the operating room (OR) area. Any disturbances in the daily routine will affect the work flow of the whole hospital. On account of its central function, with numerous connections to other departments, the OR is the crystallisation point for deficiencies in various events and processes. As an example, the major complaints made by a surgical department regarding workflow and communication are outlined. To solve these problems, an "OR organization" team was established, which worked on the basis of a newly developed OR statute. Within 1 year the employees were more contentment and the workflow had improved. However, even in the second year of central OR management there is still the need to further stabilize the system as mismanagement still occurs.

Stress response during weaning after cardiac surgery

We compared the effects of weaning using synchronized intermittent mandatory ventilation (SIMV) with the use of biphasic positive airway pressure (BIPAP) on the stress response, oxygen uptake (VO2) and work of breathing (WOB) in 10 patients after aortocoronary bypass surgery. All three ventilatory settings were investigated in each patient, for example, volume-controlled mechanical ventilation immediately before weaning was followed, in randomized order, by both SIMV and BIPAP. In addition to routine monitoring of continuous and respiratory state, we measured VO2, WOB, and pressure-time product (PTP) as well as the plasma concentrations of epinephrine, norepinephrine, ACTH, cortisol, vasopressin, and prolactin. Although respiratory rate (f), WOB and PTP were greater with both SIMV and BIPAP when compared with control, other variables did not change with the ventilatory mode. In conclusion, weaning from mechanical ventilation using partial support modes does not affect the postoperative stress response in patients who have had uncomplicated cardiac surgery.

Does gastric juice pH influence tonometric PCO2 measured by automated air tonometry?

To determine the influence of changes in gastric juice pH due to intravenous administration of pentagastrin and omeprazole on intramucosal regional PCO2 (Pr(CO2)), we investigated 17 healthy human volunteers. Gastric juice pH was obtained from a glass pH electrode for continuous gastric juice pH measurement and Pr(CO2))was measured by using automated air tonometry. After baseline (8:00 A.M.-9:00 A.M.) the subjects received 0.6 microg/kg/h pentagastrin intravenously for 1 h (9:00 A.M.-10:00 A.M., after stimulation 10:00 A.M.-11:00 A.M.) and 40 mg omeprazole intravenously (after omeprazole 11:00 A.M.-3:00 P.M.). Following pentagastrin administration gastric juice pH significantly decreased from 1.2 +/- 0.4 to 0.6 +/- 0.4 (mean +/- SD, p < 0.007, versus baseline), whereas omeprazole transiently increased luminal pH up to 4.4 +/- 1.7 (p < 0.007 versus baseline). These subsequent changes in gastric juice pH were accompanied by a significant increase in Pr(CO2) from 48 +/- 12 to 61 +/- 17 mm Hg (p < 0.007 versus baseline) and a decrease to 44 +/- 5 mm Hg (p < 0.002 versus pentagastrin), respectively. A gastric juice pH > 4 considerably reduces mean gastric Pr(CO2) and interindividual variability. Thus omeprazole may improve the validity of gastric tonometry data.

Gastrointestinal tract resuscitation in critically ill patients

Particular research interest is currently focusing on the resuscitation of the gastrointestinal tract, because the gut is regarded to be both the "canary of the body", i.e. a sentinel organ during situations of compromised oxygen or substrate supply, as well as the "motor of multiple organ failure". Several therapeutic strategies have recently been proposed for the resuscitation of this organ system, aimed primarily at the augmentation of blood flow and oxygenation but also integrating nutritional or metabolic support and antioxidant administration.

Hepatic oxygen exchange and energy metabolism in hyperdynamic porcine endotoxemia: effects of the combined thromboxane receptor antagonist and synthase inhibitor DTTX30

OBJECTIVE

We compared the effects of thromboxane receptor antagonist and synthase inhibitor DTTX30 on systemic and liver blood flow, oxygen (O2) exchange and energy metabolism during 24 h of hyperdynamic endotoxemia with untreated endotoxemia.

DESIGN

Prospective, randomized, experimental study with repeated measures.

SETTING

Investigational animal laboratory.

SUBJECTS

Twenty-seven domestic pigs: 16 during endotoxemia with volume resuscitation alone; 11 with endotoxemia, volume resuscitation and treatment with DTTX30.

INTERVENTIONS

Continuous infusion of Escherichia coli lipopolysaccharide (LPS) for 24 h together with volume resuscitation. After 12 h of endotoxemia, DTTX30 was administered as a bolus of 0.12 mg kg-1 followed by 12 h continuous infusion of 0.29 mg kg-1 per h.

MEASUREMENTS AND RESULTS

DTTX30 effectively counteracted the endotoxin-associated increase in TXB2 levels and increased 6-keto-PGF1 alpha with a significant shift of the thromboxane/prostacyclin ratio towards predominance of prostacyclin. DTTX30 prevented the significant progressive endotoxin-induced decrease of mean arterial pressure (MAP) below baseline while maintaining cardiac output (CO), and increased the fractional contribution of liver blood flow to CO without an effect on either hepatic O2 delivery or O2 uptake. The mean capillary hemoglobin O2 saturation (HbO2) on the liver surface and HbO2 frequency distributions remained unchanged as well.

CONCLUSIONS

DTTX30 significantly attenuated the endotoxin-induced derangements of cellular energy metabolism as reflected by the diminished progressive decrease in hepatic lactate uptake rate and a blunted increase in hepatic venous lactate/pyruvate ratios. While endotoxin significantly increased the endogenous glucose production (EGP) rate, EGP returned towards baseline levels in the DTTX30-treated group. Thus, in our model DTTX30 resulted in hemodynamic stabilization concomitant with improved hepatic metabolic performance.

Hepatic O2 exchange and liver energy metabolism in hyperdynamic porcine endotoxemia: effects of iloprost

OBJECTIVE

To compare the effects of a 12 h continuous infusion of iloprost, a stable prostacyclin analogue, on hepatic blood flow (Qliv), O2 exchange, and energy metabolism during a 24 h hyperdynamic, porcine endotoxemia with volume resuscitation alone.

DESIGN

Prospective, randomized, experimental study with repeated measures.

SETTING

Investigational animal laboratory.

SUBJECTS

Twenty-eight domestic pigs: 16 animals during endotoxemia with volume resuscitation alone (ETX), 12 with endotoxemia, volume resuscitation, and treatment with iloprost (ILO).

INTERVENTIONS

Endotoxemia was initiated by continuous infusion of E. coli lipopolysaccharide. Animals were resuscitated with hetastarch, aimed at maintaining a MAP of > 60 mmHg. After 12 h of endotoxemia, iloprost was administered for 12 h in the treatment group, titrated to avoid pharmacologically induced hypotension (MAP < 60 mmHg).

MEASUREMENTS AND RESULTS

Iloprost significantly increased Qliv, with no effect on hepatic O2 delivery. Mean capillary hemoglobin O2 saturation (HbScO2) on the liver surface, as well as HbScO2 frequency distributions--a measure of microcirculatory O2 availability--remained unchanged. Treatment with iloprost, however, significantly attenuated the endotoxin-induced derangements of cellular energy metabolism as reflected by the diminished progressive decrease in hepatic lactate uptake rate and a blunted increase in hepatic venous lactate/pyruvate ratios. While endotoxin significantly increased endogenous glucose production (EGP) rate, iloprost restored EGP to normal at the end of the experiment.

CONCLUSIONS

Thus, in a clinically relevant model of human sepsis, iloprost did not produce potential adverse effects but rather ameliorated hepatic metabolic disturbances and, thereby, hepatic energy balance.

Effects of the combined thromboxane receptor antagonist and synthase inhibitor DTTX-30 on intestinal O2-exchange and energy metabolism during hyperdynamic porcine endotoxemia

Sepsis may lead to deranged thromboxane-prostacyclin ratio with consecutive organ dysfunction. Because of the suggested role of the gut in the pathogenesis of septic shock and multiple organ failure, we investigated the effects of the novel dual thromboxane synthase inhibitor and receptor antagonist DTTX-30 (TRASI) on intestinal tissue perfusion, O2 kinetics, and energy metabolism over 24 h of hyperdynamic, normotensive porcine endotoxemia. Before, 12, 18, and 24 h after starting continuous i.v. endotoxin (LPS), we measured portal venous (PV) blood flow, intestinal oxygen extraction (iO2ER), intracapillary hemoglobin O2 saturation (HbO2%) of the ileal wall, intramucosal ileal PCO2, PV lactate-pyruvate (L-P) ratio, and plasma levels of thromboxane and prostacyclin. Treatment with TRASI (0.12 mg/kg i.v. bolus injection followed by an infusion of 0.29 mg/kg/h) initiated after 12 h of LPS infusion markedly reduced the plasma thromboxane levels and attenuated the LPS-induced fall in systemic vascular resistance, resulting in hemodynamic stabilization. TRASI did not influence the LPS-induced increase in PV blood flow nor intracapillary HbO2%, thus reflecting unchanged microcirculatory O2 availability and decreased iO2ER, possibly because of reduced O2 requirements. Nevertheless, TRASI prevented the LPS-induced increase in the PV L-P ratio, attenuated the progression of the ileal mucosal-arterial PCO2 gap, and tended to attenuate the gradual fall of PV pH. Hence, compounds like TRASI may beneficially influence LPS-related derangements of gut energy metabolism.

Determination of molecular geometry by high-order multiple-quantum evolution in solid-state NMR

The principles of molecular geometry determination by high-quantum heteronuclear local field spectroscopy in solid-state NMR are discussed. The extreme multiple-quantum coherences in a cluster of nuclear spins are allowed to evolve in the presence of heteronuclear through-space couplings to two spins of a different type. The multiple-quantum dephasing curve is independent of the homonuclear spin-spin couplings and may be described in terms of geometric parameters. The triple-quantum version of the experiment is demonstrated by determining the psi torsion angle in a [(15)N(2), (13)C(3)]-labeled sample of the peptide ala-ala-gly. Two regions of torsion angle space fit the experimental data, one in the neighborhood of -152 degrees and one in the neighborhood of +161 degrees. The latter determination is in excellent agreement with the X-ray estimate of +160.5 degrees.

Mechanistic aspects of dihydrogen activation and transfer during asymmetric hydrogenation in supercritical carbon dioxide

A new "CO2-philic" chiral rhodium diphosphinite complex was synthesized and applied as catalyst precursor in the asymmetric hydrogenation of dimethyl itaconate in scCO2, scC2H6 and various liquid organic solvents. Deuterium labeling studies and parahydrogen-induced polarization (PHIP) NMR experiments were used to provide the first detailed mechanistic insight into the activation and transfer of the dihydrogen molecule during hydrogenation in scCO2. Chemical interactions between CO2 and reactive intermediates of the catalytic pathway could be excluded as possible explanations for the experimentally verified difference in the catalytic behavior in scCO2 and hexane.

[Expression of AC133 vs. CD34 in acute childhood leukemias]

AC133, a newly discovered antigen on human progenitor cells, demonstrating 5-transmembranous domains is expressed by 30-60% out of all CD34+ cells. Our aim therefore was to investigate the extent of human stem-/progenitor cells expressing AC133 antigen in umbilical cord blood, peripheral blood without or following an application of granulocyte-colony stimulating factor (rhG-CSF). The main task was the investigation of bone marrow aspirates derived from children suffering from newly diagnosed acute leukemias, as well as from patients with a relapse or during a complete remission. The determination of antigen expression was done by application of flow cytometry (FACScan analysis) and the usage of newly developed monoclonal antibodies (AC133/1 and AC133/2; Miltenyi Biotec GmbH) in combination with monoclonal antibody directed against CD34-antigens (HPCA-2; BD). Our studies till now show average percentages in umbilical cord blood derived from 43 newborns about 0.294 +/- 0.165% AC133+ vs. 0.327 +/- 0.156% CD34+ hematopoietic stem-/progenitor cells (HSPC). In peripheral blood from 11 healthy donors we verified up to 0.15% CD34+ as well as AC133+ HSPC's. The concentration of progenitor cells was found to be obviously higher in peripheral blood from children with various diseases (neuroblastoma, rhabdomyosarcoma, ALL/AML) and undergoing application with rhG-CSF in order to be prepared for PBSC-transplantation. In those cases we found up to 3.51% AC133+ cells as well as slightly higher values (3.94%) for CD34 antigens. Additionally we quantified 128 bone marrow (BM) samples for AC133+ and CD34+ cells. In 10 BM samples, derived from patients without any neoplasia, the CD34+ cells were about 0.03% and 1.49%, whereas AC133 values were up to 0.64%. Bone marrow aspirates from 53 children with acute leukemias at time of diagnosis (ALL: n = 41/AML: n = 12) have been immunophenotyped and leukemic blast cells have been proved for AC133- and CD34 antigen expression. 32/41 (78%) of lymphoblastic leukemic cells showed to be positive for CD34 antigen and 24/41 (58%) demonstrated AC133 antigens. Interestingly there were 2 ALL-patients with pathological blast cells positive for AC133 but lacking of any CD34 antigens. 42% (5/12) of investigated AML patients showed CD34+ phenotype, on the other hand there were only 25% (3/12) with AC133+ phenotype. Similar values were found in relapsed patients (n = 18). In BM samples from patients during complete remission (n = 47) we could detect percentages up to 5.55% for CD34 and up to 1.25% for AC133 positive stem-/progenitor cells. Such quite high data may be explained by occasionally application of rhG-CSF therapy. Our results till now lead to the conclusion, that it seems to be useful, to recruit quantification of CD34+ HPSC by additionally detecting AC133 antigens. This new stem cell marker (AC133) may be of great value in case of autologous peripheral blood stem cell transplantation (PBSCT) because it could be an alternative to the usual CD34+ MACS selection system.

[The effect of hepatosplanchnic circulation in treatment of trauma and sepsis. Beyond O2-supply O2-uptake relationship?]

Sepsis and SIRS are characterised by increased hepatosplanchnic blood flow and oxygen transport due to sepsis-associated hypermetabolism with enhanced oxygen uptake. Regional hypermetabolism may be linked with a mismatch of oxygen availability and demand potentially resulting in a pathological splanchnic oxygen uptake/supply dependency. Splanchnic hypermetabolism has been hypothesised to be due to increased hepatic gluconeogenesis caused by accelerated glucose precursor uptake resulting from increased release from the peripheral tissues. This increased precursor efflux is triggered by cytokines. The response of splanchnic haemodynamics and oxygen kinetics, however, to therapeutic interventions does not necessarily parallel the different metabolic pathways. Therefore, understanding of both tissue perfusion and oxygenation as well as metabolism is pivotal for evaluating the effects of different therapeutic strategies in intensive care medicine.

Multiple-quantum relaxation in the magic-angle-spinning NMR of 13C spin pairs

We determine the decay rate constants of zero-, double- and single-quantum coherence for 13C spin pairs in magic-angle-spinning solid-state NMR. The double-quantum coherence is excited by a C7 pulse sequence and converted into zero-quantum coherence by a frequency-selective pair of pi/2 pulses. The zero-quantum coherence is reconverted into observable magnetization by a second pair of pi/2 pulses followed by a second C7 sequence. In a magnetically dilute system where the 13C-13C distance is 0.296 nm, the relaxation rate constants are consistent with a model of uncorrelated random fields at the two labeled 13C sites. In a fully-labelled system with a short 13C-13C distance of 0.153 nm, the measured rate constants are inconsistent with the uncorrelated random field model.

Changes in gastric intramucosal pH following mesenteric traction in patients undergoing pancreas surgery

BACKGROUND/AIM

During major abdominal surgery, mesenteric traction (MT) may result in hemodynamic instability mainly due to endogenous prostacyclin release. Gastric intramucosal pH (pHi) and PiCO2 are indicators of splanchnic tissue perfusion with a predictive value for the postoperative outcome. We investigated the influence of MT on gastric pHi and on postoperative outcome in patients undergoing pancreas surgery.

METHODS

Forty-six consecutive patients scheduled for pancreas surgery were investigated. We registered hemodynamics and pHi by gastric tonometry and documented postoperative outcome (complications, hospital stay). Baseline data (T0) were recorded after skin incision. Further assessments followed 30, 60 and 120 min after intentional MT (T1-3) and at the end of surgery (T4).

RESULTS

Thirty-three patients demonstrated a decrease in mean arterial pressure (MAP) following MT, whereas 13 patients showed entirely stable hemodynamics. The significant reduction in MAP in patients with an MT response was not associated with changes in pHi as compared to patients with no response (stable MAP) (T0 7.34 +/- 0.08 vs. 7.35 +/- 0.06; T1 7.34 +/- 0.05 vs. 7.32 +/- 0.07; T2 7.32 +/- 0. 05 vs. 7.31 +/- 0.08; T3 7.32 +/- 0.05 vs. 7.32 +/- 0.07; T4 7.26 +/- 0.1 vs. 7.27 +/- 0.08; mean +/- SD, MT response vs. no response). Neither MT response nor gastric intramucosal acidosis as evidenced by a pHi <7.32 at the end of surgery predicted postoperative complications or longer hospital stay.

CONCLUSION

No deterioration of gastric pHi was found, which could reflect acceptable splanchnic perfusion and oxygenation despite systemic blood pressure reactions in patients experiencing an MT response.

Peri-operative tolerance to large-dose 6% HES 200/0.5 in major urological procedures compared with 5% human albumin

We studied the long-term efficacy and safety of medium-molecular-weight hydroxyethyl starch (HES) administered in doses above 20 ml.kg-1 during major blood replacement therapy. Blood replacement for 50 patients used 6% HES 200/0.5 (HES group) or 5% albumin (ALB group) and additional blood components according to a defined protocol. We compared safety, efficacy and costs in 4 peri-operative days. Colloid administration on the day of surgery was 38.4 ml.kg-1 (HES group) and 35.1 ml.kg-1 (ALB group). Haemodynamic, coagulation and renal function parameters were similar. Although total serum protein was still different on the third postoperative day (53.45 gl-1 (HES group) and 60.6 gl-1 (ALB group) (p < 0.01)) the colloid osmotic pressure always remained above 19.5 (2.5) mmHg (HES group). Blood loss (3810 (1632) ml (HES group) and 3455 (1733) ml (ALB group)) and the requirement for blood components was comparable. Costs were reduced by 35% (p < 0.05) in the HES group. We conclude that using 6% HES 200/0.5 as the only colloid for treatment even of large blood loss is a safe and economic alternative to albumin.

Vasopressor hormone response following mesenteric traction during major abdominal surgery

BACKGROUND

We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI2) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia.

METHODS

In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGF1 alpha (stabile metabolite of PGI2), TXB2 (stabile metabolite of thromboxane A2) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection.

RESULTS

Following MT, arterial hypotension occurred along with a substantial PGI2 release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF1 alpha (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P = 0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB2 (164 (87) vs. 58 (1) ng/L, P = 0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P = 0.001), AVP (41 +/- (18) vs. 12 (7) ng/L, P = 0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients.

CONCLUSION

Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI2 release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A2, presumably contributing to hemodynamic stability within 30 min after MT.

[Gastric mucosal tonometry: more than splanchnic circulation and oxygenics]

The tonometric measurement of the arterial-intramucosal PCO2-difference and the calculation of the intramucosal pH is currently the only parameter which is available in the clinical routine for the assessment of perfusion, oxygen kinetics and metabolic activity of the patho-splanchnic region. Since this region with its unique both parallel and serial blood supply net comprises several organs with different metabolic performance, among which moreover the synthetic activity of the liver has to be taken into account, tonometric data have to be interpreted independently from blood flow and oxygen transport and uptake in this region. In fact, tonometry is an integrative parameter for perfusion, oxygenation and cellular energy balance. Therefore, it more completely reflects the complex anatomical and physiological conditions.

A cross-validated multifactorial index of perioperative risks in adults undergoing anaesthesia for non-cardiac surgery. Analysis of perioperative events in 26907 anaesthetic procedures

OBJECTIVE

To develop a severity index of anaesthetic risk that predicts relevant perioperative adverse events in adults.

DESIGN

Prospective cross-sectional study.

SETTING

Department of anaesthesiology at one university hospital.

PATIENTS

26907 consecutive anaesthetic procedures in patients over 15 years of age and a complete preoperative evaluation. Patients undergoing cardiac and obstetric surgery were excluded.

MEASUREMENTS AND MAIN RESULTS

Demographic data, preoperative health status, type of anaesthesia, operative procedures, and perioperative incidents (standardised on a national basis) were acquired by means of a computerised anaesthetic record system. Occurrence of at least one perioperative event with impact on postanaesthetic care was computed by a multivariate logistic regression model against 17 variables with different characteristics representing possible risk factors. Fourteen variables proved to be independent risk factors. The weighting of the variables was expressed in scores which added up to form a simple index for each patient. Patients without major risk factors (0-10 points) had a 0.3% risk of suffering from a relevant incident. Patients with more than 60 points had a 28.6% risk. The results were well demonstrated by cross-validation.

CONCLUSIONS

The index seems to reflect the risk of relevant perioperative incidents. It can be used for audit purposes. In daily routine, the index could focus our attention on patients with increased perioperative risk. However, it is limited in detecting particular constellations of factors which interact on each other with regard to perioperative risk.

Ibuprofen does not impair renal function in patients undergoing infrarenal aortic surgery with epidural anaesthesia

OBJECTIVE

To investigate the effect of preoperative ibuprofen administration on renal function during and after infrarenal aortic surgery under thoracolumbar epidural anaesthesia (EPA).

DESIGN

A prospective randomised, double-blinded clinical study.

SETTING

Operation room and intensive care unit in a university hospital.

PATIENTS

Twenty-six consecutive patients scheduled for elective infrarenal aortic surgery.

INTERVENTIONS

The patients were prospectively randomised to receive 400 mg ibuprofen intravenously (i.v.) or a placebo aliquot before surgery.

MEASUREMENTS AND RESULTS

We assessed renal function by calculating creatinine clearance, and fractional sodium excretion before surgery (baseline), 1 h after cross-clamping (intraoperative), 6 h after cross-clamping (postoperative) and 24 h after cross-clamping (on the 1 st postoperative day). At each point in time, we additionally registered haemodynamics and determined the plasma concentration of 6-keto-PGF1alpha (stable metabolite of prostacyclin, PGI2), bicyclic PGE2 (stable metabolite of PGE1 E2), active renin, aldosterone and vasopressin by radioimmunoassays. Throughout the observation period the renal function parameters mostly remained within the normal range without a significant difference between ibuprofen- and placebo-treated patients (creatinine clearance: baseline 41 +/- 3 vs 38 +/- 6, intraoperative 57 +/- 8 vs 64 +/- 11, postoperative 64 +/- 9 vs 56 +/- 9, first postoperative day 43 +/- 5 vs 47 +/- 6 ml x min x m(-2), means +/- SEM). The plasma levels of 6-keto-PGF1alpha (68 +/- 8 vs 380 +/- 71* ng x l(-1)), bicyclic PGE2 (57 +/- 5 vs 88 +/- 9* ng x l(-1)) and vasopressin (14 +/- 7 vs 45 +/- 10* ng x l(-1), p < 0.0125), however, were significantly higher during the intraoperative period in the placebo-treated patients.

CONCLUSION

The inhibition of endogenous prostaglandin release by ibuprofen does not substantially impair renal function during infrarenal aortic surgery under EPA.

The impact of prostanoids on pulmonary gas exchange during abdominal surgery with mesenteric traction

We investigated the effect of intravenous (iv) ibuprofen on prostanoid release and on pulmonary gas exchange after abdominal mesenteric traction (MT) during either abdominal aortic surgery or pancreas resection. In a prospective, randomized, double-blind study, 400 mg ibuprofen (pancreas n = 13, aorta n = 13) or a placebo (pancreas n = 13, aorta n = 13) was administered iv before skin incision. MT was applied uniformly. The prostanoid plasma concentrations, venous admixture (Q(va)/Q(t)), and PaO2/FIO2 ratio were determined at baseline (before MT) and 5, 15, 45, and 90 min after MT. Patients who underwent aortic surgery were older and exhibited a lower preoperative PaO2 than those who underwent pancreas resection. Placebo-treated patients revealed a 30-fold peak increase in 6-keto-prostaglandin F1alpha (stable metabolite of prostacyclin) levels after intentional MT during aortic as well as pancreatic operations. This response was accompanied by an increase in Q(va)/Q(t) (ibuprofen: pancreas 7% +/- 1%, aorta 14% +/- 2%; placebo: pancreas 16% +/- 3%, aorta 26% +/- 3%/15 min after MT [mean +/- SEM, P < 0.05, placebo vs ibuprofen]), which resulted in decreased PaO2/ FIO2 ratio only in the aortic surgery patients (ibuprofen: 310 +/- 19; placebo: 237 +/- 24 15 min after MT, [mean +/- SEM, P < 0.05]). The authors conclude that ibuprofen-pretreated patients demonstrated almost constant prostanoid levels without changes in pulmonary gas exchange after MT.

Perioperative endotoxemia and bacterial translocation during major abdominal surgery: evidence for the protective effect of endogenous prostacyclin?

OBJECTIVE

To investigate the potential role of endogenous prostacyclin (PGI2) released after mesenteric traction during major abdominal surgery on perioperative endotoxemia and bacterial translocation.

DESIGN

Prospective, randomized, double-blind clinical study.

SETTING

Operating room and surgical intensive care unit in a university hospital.

PATIENTS

Fifty consecutive patients scheduled for major abdominal surgery (pancreas resection, abdominal aortic surgery).

INTERVENTIONS

Fifteen minutes before skin incision, either 400 mg of ibuprofen or a placebo equivalent were administered intravenously. Immediately after peritoneal incision, eventration and action of the small bowel was intentionally performed in a uniform fashion.

MEASUREMENTS AND MAIN RESULTS

Baseline values were obtained before induction of anesthesia. Additional measurements, along with assessments of hemodynamics and gas exchange, were performed before incision of the peritoneum and at 5, 30, and 45 mins and 3, 6, and 24 hrs after mesenteric traction. Arterial plasma concentrations of 6-keto-prostaglandin F1 alpha and thromboxane B2 (stable metabolites of PGI2 and thromboxane A2) were determined by radioimmunoassay. Endotoxin was measured by limulus amebocyte lysate test. Mesenteric lymph nodes were sampled in 31 patients (ibuprofen n = 14, placebo n = 17) and sent for culture under sterile conditions. Transient hypotension and a marked increase of plasma 6-keto-prostaglandin F1 alpha concentrations occurred up to 6 hrs after mesenteric traction in untreated patients with median peak concentrations (2243 vs. 72 ng/L [p < .0001, placebo vs. ibuprofen], observed 5 mins after mesenteric traction). Endotoxemia occurred in both study groups. However, after mesenteric traction, plasma endotoxin concentrations were significantly higher in the ibuprofen group. Median peak concentrations (0.12 vs. 0.27 EU/mL [p < .001, placebo vs. ibuprofen]) were observed 3 hrs after mesenteric traction. Gram-negative bacteria in mesenteric lymph nodes were detected exclusively in the ibuprofen group (n = 5, p < .01).

CONCLUSIONS

In ibuprofen-pretreated patients, significantly higher endotoxin concentrations as well as bacterial translocation to mesenteric lymph nodes occurred, despite the absence of a transient decrease in mean arterial pressure that had been associated with PGI2 release. Therefore, we hypothesized that during major abdominal surgery, endogenous PGI2 released in response to mesenteric traction may play a crucial role in maintaining splanchnic microcirculation and thus preserving gut mucosal barrier function.

Vasopressin administration in refractory cardiac arrest

BACKGROUND

Successful outcomes after cardiopulmonary resuscitation remain disappointingly infrequent, in animal studies, administration of exogenous vasopressin during closed- and open-chest cardiopulmonary resuscitation has recently been shown to be more effective than optimal doses of epinephrine in improving vital organ blood flow.

OBJECTIVE

To describe the clinical effects and outcomes of administering vasopressin to patients in cardiac arrest refractory to current medical therapies.

DESIGN

Case reports.

SETTING

University hospital.

PATIENTS

8 adults with in-hospital cardiac arrest.

INTERVENTIONS

After intravenous epinephrine (administered according to American Heart Association guidelines) and defibrillation efforts had failed, patients in cardiac arrest who were having cardiopulmonary resuscitation received 40 U of vasopressin intravenously and then defibrillation.

MEASUREMENTS

Return of spontaneous circulation and hospital discharge rates.

RESULTS

After administration of vasopressin, spontaneous circulation was promptly restored in all patients. Three patients were discharged from the hospital with intact neurologic function; the other five lived for between 30 minutes and 82 hours.

CONCLUSION

In the presence of ventricular fibrillation with severe hypoxia and acidosis, vasopressin seems to be more potent and effective than adrenergic vasopressors for restoring spontaneous cardiovascular function. These results do not justify the widespread use of vasopressin for refractory cardiac arrest. However, on the basis of these cases, further studies comparing vasopressin with epinephrine are warranted in an effort to improve the currently dismal prognosis of patients after cardiac arrest.

Molecular basis of androgen insensitivity

Male sexual differentiation and development proceed under direct control of androgens. Androgen action is mediated by the intracellular androgen receptor, which belongs to the superfamily of ligand-dependent transcription factors. In the X-linked androgen insensitivity syndrome, defects in the androgen receptor gene have prevented the normal development of both internal and external male structures in 46, XY individuals. The complete form of androgen insensitivity syndrome is characterized by 46, XY karyotype, external female phenotype, intra-abdominal testes, absence of uterus and ovaries, blindly ending vagina, and gynecomastia. There is also a group of disorders of androgen action that result from partial impairment of androgen receptor function. Clinical indications can be abnormal sexual development of individuals with a predominant male phenotype with severe hypospadias and micropenis or of individuals with a predominantly female phenotype with cliteromegaly, ambiguous genitalia, and gynecomastia. Complete or gross deletions of the androgen receptor gene have not been frequently found in persons with the complete androgen insensitivity syndrome, whereas point mutations at several different sites in exons 2-8 encoding the DNA- and androgen-binding domain have been reported in both partial and complete forms of androgen insensitivity, with a relatively high number of mutations in two clusters in exons 5 and 7. The number of mutations in exon 1 is extremely low, and no mutations have been reported in the hinge region, located between the DNA-binding domain and the ligand-binding domain. The X-linked condition of spinal and bulbar muscle atrophy (Kennedy's disease) is characterized by a progressive motor neuron degeneration associated with signs of androgen insensitivity and infertility. The molecular cause of spinal and bulbar muscle atrophy is an expanded length (> 40 residues) of one of the polyglutamine stretches in the N-terminal domain of the androgen receptor.

Analgesic and hemodynamic effects of epidural clonidine, clonidine/morphine, and morphine after pancreatic surgery--a double-blind study

This study characterizes analgesia an hemodynamics after epidural clonidine 8 micrograms/kg (Group C) or clonidine 4 micrograms/kg+morphine 2 mg (Group CM) in comparison to epidural morphine 50 micrograms/kg (Group M). Forty-five patients scheduled for pancreatectomy in combined general/epidural anesthesia were studied. The study drugs were administered 75 min postoperatively and for 10 h pain intensity (visual analog scale [VAS]), heart rate (HR), mean arterial pressure (MAP), and cardiac output (CO) were measured; filling pressures were kept > 5 mm Hg. Adequate analgesia could be achieved within 1 h in all patients of Groups C and CM, but only in six patients of Group M (P < 0.001). Quality of analgesia was comparable in all groups (VAS reduction 82% +/- 20%, mean +/- SD) but duration of analgesic action was longer in Groups CM (586 +/- 217 min) and M (775 +/- 378 min) compared to Group C (336 +/- 119 min) (P < 0.001). In Group M, no hemodynamic alterations occurred. In Groups C and CM, HR, CO, and MAP were reduced significantly compared to baseline within the first 15-90 min, while stroke volume and systemic vascular resistance remained stable. We conclude, that hemodynamic alteration after epidural clonidine under conditions of stable filling pressures is caused mainly by a decrease in HR. It is not an effect of analgesia but of the intrinsic antihypertensive action of clonidine.

Analgesic and hemodynamic effects of epidural clonidine, clonidine/morphine, and morphine after pancreatic surgery--a double-blind study

This study characterizes analgesia an hemodynamics after epidural clonidine 8 micrograms/kg (Group C) or clonidine 4 micrograms/kg+morphine 2 mg (Group CM) in comparison to epidural morphine 50 micrograms/kg (Group M). Forty-five patients scheduled for pancreatectomy in combined general/epidural anesthesia were studied. The study drugs were administered 75 min postoperatively and for 10 h pain intensity (visual analog scale [VAS]), heart rate (HR), mean arterial pressure (MAP), and cardiac output (CO) were measured; filling pressures were kept > 5 mm Hg. Adequate analgesia could be achieved within 1 h in all patients of Groups C and CM, but only in six patients of Group M (P < 0.001). Quality of analgesia was comparable in all groups (VAS reduction 82% +/- 20%, mean +/- SD) but duration of analgesic action was longer in Groups CM (586 +/- 217 min) and M (775 +/- 378 min) compared to Group C (336 +/- 119 min) (P < 0.001). In Group M, no hemodynamic alterations occurred. In Groups C and CM, HR, CO, and MAP were reduced significantly compared to baseline within the first 15-90 min, while stroke volume and systemic vascular resistance remained stable. We conclude, that hemodynamic alteration after epidural clonidine under conditions of stable filling pressures is caused mainly by a decrease in HR. It is not an effect of analgesia but of the intrinsic antihypertensive action of clonidine.

[Incidents, events and complications in the perioperative period in normal and malnurished patients--results of 23,056 patients]

AIM

Prevalence of cardiovascular risk factors in anaesthetic patients and perioperative pitfalls, events and complications (PECs) in different nutritional states were examined. The results should contribute to a current project of the German Society of Anaesthesiology and Intensive Care, established for quality assurance.

METHOD

Preoperative data (age, sex, defined preexisting diseases, nutritional state, grade of urgency and ASA-class) were integrated in an automatically readable paper record, as well as the perioperative interventions and events, type of anaesthesia, and kind of operation. The records were routinely in use for every patient. After control and correction the data were stored in a modern data base. Data of patients under 16 years of age and incomplete sets of data were excluded from analysis.

MAIN RESULTS

From July 1, 1992 to December 31, 1993 23,056 anaesthesias were recorded, 5,852 (25.4%) of them with a total of 8,107 PECs. 17,255 patients had normal body weight and 23% of them PECs. 4,484 obese (but not extremely) patients had a PEC rate of 31.2%, 330 extremely obese patients had a PEC rate of 38.2%, 966 patients with underweight (but not extremely) had a PEC rate of 36.1% and 21 with extreme underweight had a PEC rate of 38.1%. Obese patients had a higher prevalence of preexisting cardiovascular disturbances (angina pectoris, myocardial infarction and hypertension) and tended to a higher incidence of perioperative hypertensive, bronchospastic and hypoxic events as well as more difficulties in application of regional anaesthesia. Young adult patients (16-39 years) had a PEC rate of 14% in case of normal nutritional state but of 20% in case of obesity. The incidence of respiratory PECs and of PECs of higher severity was almost double in obese young patients compared to normal weight patients of the same age. When preoperative cardiovascular disease was known there was little difference between the different states of nutrition in respect of perioperative PECs.

CONCLUSIONS

Nutritional disorder is an important epidemiological factor in anaesthesia. Particularly in younger patients without defined preoperative cardiovascular disturbance but with obesity the anaesthesist may be surprised by a remarkable incidence of relevant problems during and immediately after anaesthesia. We should consider the possible phenomenon that we are underestimating the anaesthetic challenge in young obese patients in a "healthy" cardiovascular state.

Unchanged 5'-deiodinating activity during the induction of a nonthyroidal illness

We investigated the formation of a "nonthyroidal illness" (NTI) in pigs undergoing ventricular fibrillation (VF) and resuscitation. Seven minutes after VF twenty-one pigs received either Epinephrine (E: 45 micrograms/kg B.W.; n = 7), Norepinephrine (NE: 45 micrograms/kg B.W.; n = 7), or Vasopressin (VP: 0.8 U/kg B.W.; n = 7). We determined the serum concentrations (sc) of total T4 (TT4), FT4, total T3 (TT3) and rT3 120 min before, during (t0), and 5, 15, 60 and 120 min after VF. At the end of the observation period we figured out the in-vitro T3-generation (kM, Vmax), the in-vitro rT3-generation, the in-vitro rT3-decomposition (kM, Vmax) and the content of cytosolic sulfhydryls (total sulfhydryls, non-protein bound sulfhydryls) in liver and kidney specimen. Animals not undergoing VF served as controls (C) for parameters measured in the intracellular compartment. TT4- and TT3-sc decreased to 3.3 +/- 0.6 micrograms/dl (p < 0.05, vs. t0) and 15.2 +/- 4.1 ng/dl (p < 0.05, vs t0), resp. FT4-sc remained stable for five minutes (2.63 +/- 0.41 ng/dl) before declining to 1.8 +/- 0.39 ng/dl (p < 0.05, vs. t0). The rT3-sc raised finally to 46.9 +/- 7.3 ng/dl (p < 0.05, vs t0). Iodothyronine sc did not exhibit differences between E-, NE- and VP-treatment. Neither in-vitro T3-generation, nor in-vitro rT3-generation, nor in-vitro rT3-decomposition nor intracellular sulfhydryl content were affected by the events of VF and resuscitation as compared to the controls.(ABSTRACT TRUNCATED AT 250 WORDS)