PubMed Health⌕ Search

Biomedical subjects

A Brinkmann

Publications and source records attributed to A Brinkmann.

At least 37 records · Page 2Linked to original sources
PubMed1999

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.

Adult↗
PubMed1999

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.

Adult↗
PubMed1998

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.

Aged↗
PubMed1998

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.

Adolescent↗
PubMed1998

[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.

Gastric Mucosa↗
PubMed1998

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.

Abdomen↗
PubMed1997

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.

6-Ketoprostaglandin F1 alpha↗
PubMed1996

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.

Adult↗
PubMed1996

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.

Amino Acid Sequence↗
PubMed1996

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.

APACHE↗
PubMed1995

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)

Animals↗
PubMed1995

[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.

Adolescent↗
PubMed1995

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.

Analgesia, Epidural↗
PubMed1995

Localisation of androgen receptors in dermal fibroblasts, grown in vitro, from normal subjects and from patients with androgen insensitivity syndrome.

Human genital skin fibroblasts show the androgen receptor (AR) as bright red granules (0.5 micron in diameter) after treatment with one (of 3) primary polyclonal antibody and a secondary antibody linked to alkaline phosphatase. Almost all AR were cytoplasmic in 12 normal strains and in 8 strains from patients with partial (PAIS) and 6 with complete androgen insensitivity syndrome (CAIS). When 25.8 nM 5-alpha-dihydrotestosterone (DHT) or methyltrienolone was added to the medium, some AR were translocated into the nucleus in 13 experiments with 8 strains of normal fibroblasts; of 8 strains of patients with PAIS 3 failed to translocate to a detectable extent in the presence of androgen in the medium and none of the 6 strains from patients with CAIS translocated.

Androgens↗
PubMed1995

Economic aspects of the use of impregnated mosquito nets for malaria control.

The use of pyrethroids to impregnate mosquito nets has had a good impact on the incidence of morbidity and mortality from malaria. These nets are therefore likely to be used on a large scale as an important strategy of malaria control in the future. Published information on the cost and effectiveness of mosquito nets is presented and analysed. In two examples, from Malawi and Cameroon, the per household expenditure to purchase and use impregnated mosquito nets compares favourably with the costs of malaria. Thus, we expect that the economic losses from malaria would be reduced by 37.3% over a 3-year period in Malawi. Even if the impact of malaria on productivity is not taken into account, the introduction of nets will result in gains, as shown in Cameroon; savings of 9.3% and 11.2% in two places resulted as a consequence of a diminished need for case treatment. The role of government programmes in the promotion of bednets is indirect and concerned mainly with facilitation and the dissemination of information. Much depends on the capability of the private sector and the willingness of the target population to buy the nets for a programme to be effective. Specific studies by health economists on this subject are lacking.

Bedding and Linens↗
PubMed1994

[The effect of thoracic epidural anesthesia on the pathophysiology of the eventration syndrome].

Abdominal mesenteric traction (MT) results in decreased mean arterial pressure (MAP), systemic vascular resistance (SVR) and increased cardiac output (CO). This response is induced by a considerable release of prostacyclin (PGI2). Precipitous falls in systemic arterial pressure related to central and/or autonomic nervous reflex arcs also have been described during operations on the upper abdominal viscera. Those hypotensive responses to visceral traction appear to be transmitted along afferent fibres contained within the splanchnic nerves. We investigated the influence of supplementary thoracic epidural anaesthesia on mesenteric traction response during major abdominal surgery. METHODS. With the approval of the Human Investigation Review Board we studied 40 patients scheduled for major abdominal surgery (infrarenal aortic, gastrointestinal and pancreatic surgery) according to a prospective, randomized double-blinded protocol. Patients were randomized to two different anaesthetic regimens. Patients in group 1 received general anaesthesia (GA n = 20) with 0.1-0.15 mg/kg midazolam and 10 micrograms/kg fentanyl prior to skin incision. Maintenance included 65% nitric oxide in oxygen and 0.1 mg increments of fentanyl as required. Group 2 patients (EA n = 20) underwent a combined technique of dose-reduced general anaesthesia and supplementary continuous, thoracic epidural anaesthesia (bupivacaine 0.25%, sensory blockade T4 to L1-3). In both anaesthesia groups ibuprofen (400 mg i.v.) or a placebo equivalent was administered 15 min before the induction of anaesthesia. MT was applied in a uniform fashion. Baseline values preceded the incision of the peritoneum. Further assessments followed 5, 15 and 30 min after MT. The plasma concentrations of 6-keto-PGF1 alpha (stable metabolite of PGI2), TXB2 (stable metabolite of thromboxane), PGF2 alpha, KH2-PGF2 alpha (stable metabolite of PGF2 alpha) were determined by radioimmunoassay. At all assessments we recorded systolic and diastolic blood pressure, heart rate and measured arterial blood gases. Statistical analyses were performed using three-factor ANOVA for repeated measurements after log(x) transformation. A P-value of less than 0.05 was considered significant when the Bonferroni-Holm adjustment was applied. RESULTS. Patients with supplementary epidural anaesthesia demonstrated lower systolic (P = 0.0001) and diastolic (P = 0.006) blood pressure than those in the GA group. Nevertheless, in untreated patients in the EA and GA group there was a significant decrease of about 20-30% in systolic and diastolic blood pressure (P = 0.0001) after mesenteric traction. Irrespective of the anaesthetic procedure, paO2 (P = 0.0001) decreased after mesenteric traction in the placebo group. The control patients in the GA group exhibited a more pronounced increase in heart rate after MT. After traction on the mesentery a significant 20- to 30-fold increase in 6-keto-PGF1 alpha plasma concentrations occurred in the placebo group: GA group 1950/58 (5 min), 1574/59 (15 min) 858/66 (30 min) ng/l, P < 0.0001; EA group: 2002/106 (5 min), 2955/107 (15 min) 1807/70 (30 min) ng/l, P < 0.0001, for placebo vs ibuprofen. There was no statistically significant difference between the two anaesthetic procedures used. In ibuprofen-pretreated patients haemodynamics and paO2 values were stable, while 6-keto-PGF1 alpha plasma concentrations remained within the normal range. CONCLUSION. Our data clearly indicate that the mesenteric traction response consists in relevant haemodynamic alterations and a significant decrease of paO2. Stable haemodynamics and paO2 following cyclooxygenase inhibition signify an action mediated by prostacyclin. Deafferentation of the splanchnic nerves by supplementary thoracic epidural anaesthesia did not influence either prostacyclin release or the decrease in blood pressure and paO2 after traction on the mesentery root...

Abdomen↗