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Biomedical subjects

G Redl

Publications and source records attributed to G Redl.

At least 19 recordsLinked to original sources
PubMed2006

[Preoperative psychoeducation for a severely traumatized child].

N., an 8-year-old girl with a long term history of severe sexual abuse and maltreatment with consecutive mental disorders, was scheduled for surgery of clubfeet. The team consisting of an anesthesiologist, a psychologist and a pediatrician decided to prepare the girl for surgery without time pressure. In a first step we applied psychoeducation to obtain a certain degree of confidence. Psychoeducation is a special form of psychological treatment aiming to define cause and goal of surgery together with the patient and relatives. In a further step the anesthesiologist familiarized her with the surgical procedure and the operating theatre. Finally a careful anesthesia with a pain-free postoperative period was applied. Even extremely traumatized children can be prepared for surgery by the help of psychoeducative methods, without time pressure, a careful and pain-free anesthesia and an experienced team of doctors.

Anesthesia↗
PubMed2001

[Do baseline haemoglobin-rates point to the efficacy of blood saving techniques?].

OBJECTIVE: We tested the hypothesis that blood saving techniques are more effective in patients with a low baseline haemoglobin. METHODS: We analysed retrospectively 1665 total hip replacements and 848 total knee replacements. Patients were divided in three groups according to the baseline haemoglobin (Hb): Group A were patients with a Hb of more than 15 g/dl, group B between 15 g/dl and 13 g/dl and group C with a Hb of less than 13 g/dl. The blood saving techniques applied (Preoperative blood donation, isovolemic haemodilution, and mechanical autotransfusion) aimed to a high patient population which underwent surgery without transfusion of homologous blood. RESULTS: The higher the baseline value of haemoglobin the higher was the patient population without homologous blood transfusion. The lower the Hb the higher was the effectiveness of blood saving techniques. In case of total hip replacement preoperative blood donation increased the patient population without homologous blood transfusion in all three groups significantly. However, in case of total knee replacement preoperative blood donation increased the patient population without homologous blood transfusion only in group B and C significantly. In both surgical procedures the combination of preoperative blood donation with other blood saving techniques did not further increase the patient population without homologous blood transfusion. In total hip replacement mechanical autotransfusion as well as isovolemic haemodilution reduced homologous transfusion in patients with low baseline haemoglobin. However, the increase was more pronounced when both techniques were combined. CONCLUSION: From our data is derived that the likelihood of homologous blood transfusion is greater in patients with a low baseline haemoglobin. However, in case of hip arthroplasty patients with a high baseline haemoglobin also profit from blood saving techniques while in case of knee arthroplasty the efficiency of blood saving techniques in a patient population with a high baseline haemoglobin is negligible. It seems to make sense to evaluate for the different kinds of surgery those patients who profit most from the different blood saving techniques.

Arthroplasty, Replacement, Hip↗
PubMed2000

[Analysis of a blood use list for orthopedic operations].

OBJECTIVE: Is the documentation of blood utilisation, as demanded in the guidelines of serology and transfusion medicine, a proper instrument of quality control for the use of homologous blood saving techniques? PATIENTS AND METHODS: We analysed retrospectively a list of blood utilisation based on 12,482 surgical procedures in orthopaedic surgery. This list included the type of operation, the number of transfused packed red cell units and, if applicable, the type of homologous blood saving technique (preoperative blood donation, mechanical autotransfusion and isovolaemic haemodilution). Total hip and knee replacement patients were divided in two groups according to base line haemoglobin (A: Hb > 13 mg%, B: hB < or = 13 mg%). RESULTS: The increase of the percentage of patients not receiving homologous blood achieved by blood saving techniques is more pronounced in group B. Preoperative blood donation seems to be the most effective technique with a percentage of patients not receiving homologous blood of 93% in group A and 80% in group B of total hip replacement. This high percentage cannot be improved when preoperative blood donation is combined with mechanical autotransfusion or isovolaemic haemodilution. The efficiency of mechanical autotransfusion and isovolaemic haemodilution can be improved by combination of the two techniques. CONCLUSIONS: A list of blood utilisation as presented can serve as a basis for guidelines regarding the use of homologous blood saving techniques. Moreover such a simple statistic provides a means of quality control and provides information about the likelihood of transfusion.

Adult↗
PubMed1993

Right ventricular function in early septic shock states.

OBJECTIVES: To define a variable which could reliably predict when fluid resuscitation as monotherapy is not expected to improve organ perfusion pressure, owing to limitations in cardiac output responsiveness in patients with severe sepsis. DESIGN: Prospective controlled trial. SETTING: Anesthesiological ICU in a university hospital. PATIENTS: Twenty seven patients in early septic shock states (MAP < 60 mmHg). INTERVENTIONS: Infusion therapy was titrated until no further increase in cardiac index and mean arterial pressure could be achieved. Fluid resuscitation as monotherapy was deemed unsuccessful at the end of 2 h if inotropic or vasoactive pharmacologic support was required to maintain a mean arterial pressure > 60 mmHg. MEASUREMENTS AND RESULTS: We investigated the hemodynamic course during fluid resuscitation (2850 +/- 210 ml crystalloids) with special emphasis on right heart function using the thermodilution technique. Eleven patients (group A) had a right ventricular (RV) ejection fraction below 45%. In this group positive inotropic and/or vasoactive drugs were obligatory to achieve and maintain a sufficient perfusion pressure (MAP > 60 mmHg) after fluid challenge. CONCLUSIONS: In 27 septic shock patients investigated, we diagnosed right ventricular dysfunction in 41%. In this specific patient population fluid replacement alone did not succeed in stabilizing hemodynamic variables, therefore necessitating catecholamine therapy.

Adult↗
PubMed1993

The threshold for thermoregulatory vasoconstriction during nitrous oxide/isoflurane anesthesia is lower in elderly than in young patients.

BACKGROUND: Thermoregulatory vasoconstriction minimizes further core hypothermia during anesthesia. Elderly patients become more hypothermic during surgery than do younger patients, and take longer to rewarm postoperatively. These data indicate that perianesthetic thermoregulatory responses may be especially impaired in the elderly. Accordingly, the authors tested the hypothesis that the thermoregulatory threshold for vasoconstriction during nitrous oxide/isoflurane anesthesia is reduced more in elderly than in young patients. METHODS: The authors studied 12 young patients aged 30-50 yr and 12 elderly patients aged 60-80 yr. All were undergoing major orthopedic or open abdominal surgery. Anesthesia was induced with thiopental and fentanyl, and maintained only with nitrous oxide (70%) and isoflurane (0.6-0.8%). Core temperature was measured in the distal esophagus. Fingertip vasoconstriction was evaluated using forearm minus fingertip, skin-temperature gradients. A gradient of 4 degrees C identified significant vasoconstriction, and the core temperature triggering vasoconstriction identified the thermoregulatory threshold. RESULTS: The vasoconstriction threshold was significantly less in the elderly patients (33.9 +/- 0.6 degree C) than in the younger ones (35.1 +/- 0.3 degrees C) (P < 0.01). The gender distribution, weight, and height of the elderly and young patients did not differ significantly. The end-tidal isoflurane concentration at the time of vasoconstriction did not differ significantly in the two groups. CONCLUSIONS: These data indicate that thermoregulatory responses in the elderly are initiated at temperatures approximately 1.2 degrees C less than that in younger patients. Thus, it is likely that elderly surgical patients become more hypothermic than do younger patients, at least in part, because they fail to trigger protective thermoregulatory responses.

Adult↗
PubMed1993

Forced-air warming maintains intraoperative normothermia better than circulating-water mattresses.

The hypothesis that forced-air warming preserves core temperature better than circulating-water mattresses was tested in: (a) 16 adults undergoing major maxillofacial surgery, including radical node resection and flap reconstruction; (b) 53 adults undergoing hip arthroplasty, having approximately 25% of their body surface area available for warming; (c) 20 infants undergoing minor maxillofacial surgery; and (d) 10 young children undergoing pelvic or femoral osteotomies. Patients having each type of surgery were randomly assigned to forced-air warming (approximately 40 degrees C) or conductive warming using a full-length circulating-water mattress at 40 degrees C. Forced-air warming was applied to the legs of the adults undergoing maxillofacial surgery and to one arm, the shoulders, and the neck in the adults undergoing hip arthroplasty; a U-shaped, tubular forced-air cover was positioned around the pediatric patients. Core temperatures increased in all patients given forced-air warming and decreased or remained constant in those without active warming. Furthermore, we needed to decrease the temperature of the warmer from high to medium (approximately 37 degrees C) in most patients assigned to forced-air warming to prevent hyperthermia. After 15 h of anesthesia, rectal temperatures in the adults undergoing maxillofacial surgery were 3.4 degrees C higher in the forced-air group (P < 0.01). After 4 h of anesthesia, esophageal temperatures had increased 0.8 +/- 0.5 degrees C in the patients warmed with forced-air and decreased 0.8 +/- 0.3 degrees C in those warmed by circulating-water mattresses (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Mechanism of immunoreactive atrial natriuretic factor release in an ovine model of endotoxemia.

We have previously reported an increase in plasma levels of atrial natriuretic factor (ANF) in an ovine model of endotoxemia. The purpose of this study was to determine if this IR-ANF release was mediated by the increase of right atrial pressure (RAP) and right heart volumes concomitantly observed following endotoxin (LPS) administration. We studied right ventricular function, renal blood flow (RBF), urinary output (UO), urinary clearance of free water (CH20), urinary osmolality (UOSM), sodium excretion (UENA), and the plasma IR-ANF concentration (radioimmunoassay), following the administration of an E. coli LPS bolus (1 microgram/kg) with (group O, n = 8) and without (group E, n = 10) pretreatment with OKY-046, a selective thromboxane synthetase inhibitor. LPS induced early increases in RAP, right ventricular end-systolic (RVESV) and end-diastolic (RVEDV) volumes, heart rate (HR), and IR-ANF, and delayed increases in RBF, UO, and CH20. OKY-046 prevented the elevation of RAP, RVEDV, and RVESV; however, both groups showed virtually identical increases in IR-ANF (E: 20.03 +/- 3.8 to 192.33 +/- 35.47 pg/ml, O: 17.9 +/- 4.1 to 159.5 +/- 23 pg/ml) as well as an increase of HR, RBF, UO, and CH20. The increase in IR-ANF release noted following the administration of LPS in an ovine model does not appear to be related to the early elevations in right heart volumes or atrial distension.

Animals↗
PubMed1991

Inhibition of thromboxane synthesis reduces endotoxin-induced right ventricular failure in sheep.

BACKGROUND AND METHODS: There is a marked decrease of the right ventricular ejection fraction after the administration of a bolus of endotoxin to sheep. This hemodynamic response may be the result of thromboxane-mediated pulmonary hypertension. Right ventricular function was studied in an ovine model after the administration of endotoxin (1 microgram/kg Escherichia coli) with and without pretreatment with OKY-046, a selective thromboxane synthetase inhibitor. RESULTS: OKY-046 attenuated the endotoxin-induced increase in pulmonary arterial pressure and prevented the early decreases in right ventricular ejection fraction and cardiac output. However, thromboxane synthetase inhibition failed to prevent endotoxin-induced hypoxemia. The marked increase in plasma thromboxane concentrations, which is usually seen after the administration of endotoxin, was prevented by pretreating the animals with OKY-046. On the other hand, increased plasma prostacyclin concentrations were observed in sheep treated with the thromboxane synthetase inhibitor. CONCLUSION: This series of experiments shows that the early endotoxin-induced decrease in right ventricular ejection fraction can be alleviated by the application of OKY-046.

Animals↗
PubMed1991

Cardiac function in an ovine model of endotoxemia.

Eight awake sheep were monitored with ultrasonic crystals, positioned at the anterior and posterior left ventricular wall. A left-sided intraventricular pressure transducer and a right ventricular ejection fraction catheter were positioned in the right and left hearts, respectively. After administration of endotoxin (Escherichia coli, LPS 1.5 micrograms/kg in 30 min), the hemodynamic variables showed a triphasic course. Phase I, (0-1 hr post LPS) was characterized by an increased pulmonary artery pressure and a decreased right ventricular ejection fraction. The inability of the right ventricle to compensate for the increased preload resulted in a fall of the left ventricular preload, stroke volume, and cardiac output. Three hours after LPS administration a second drop of the cardiac output was noted (phase II). This occurred as a result of a fall in preload. Eight hours post LPS a hyperdynamic phase (phase III) was distinguished, with a high cardiac output and a low systemic vascular resistance. During this time there was evidence of probable reduced myocardial contractility.

Animals↗
PubMed1991

[Right heart function and endotoxemia in animals].

We used a chronic instrumented ovine model to investigate right heart function following an endotoxin bolus. Primary aim of the experiments was to elucidate the influence of the right heart on the cardiopulmonary system. Furthermore, we tried a thromboxane synthetase inhibitor as a therapeutical approach. At least we investigated the IR-ANF release, as the endocrinal function of the right heart, in this model. Following the endotoxin administration we observed a massive increase of the pulmonary arterial pressure. As a result of the increased right ventricular afterload right ventricular ejection fraction decreased and end-systolic volume increased. Impaired right heart function could not be compensated sufficiently using Frank Starling mechanism. Consequently, decreased left ventricular preload, stroke volume and cardiac output followed. Pretreatment with OKY-046, a selective thromboxane synthase inhibitor, attenuated the increase in pulmonary arterial pressure and prevented the early right heart failure including the drop of cardiac output. Furthermore, OKY-046 changed the thromboxane-prostacyclin relationship. Therefore we consider the cardiopulmonary reactions following pretreatment with OKY-046 as a result of the attenuated right ventricular afterload as well as of the increased prostacyclin concentration. Endotoxin induced hypoxaemia could not be prevented by pretreatment with OKY-046 and might be caused by interstitial edema following endothelial leakage. IR-ANF release in our model, accompanied by polyuria and natriuresis, seemed to be independent of right heart dysfunction and increase of right atrial pressure. We suggest endotoxin or a endotoxin induced mediator as a trigger of IR-ANF release.

Animals↗
PubMed1990

Serum vasopressin (AVP) levels in polyuric brain-dead organ donors.

Hydromineral metabolism and serum arginine-vasopressin (AVP) levels were investigated in 11 patients who sustained brain death. They showed various degrees of polyuria with low osmolality and low fractional sodium excretion. Urine osmolality was always below that of serum, and AVP levels were between 1.3 and 50.0 pg/ml vs 0.7-8.0 pg/ml in ten normal subjects. Thus central diabetes insipidus was excluded. A renal mechanism inducing water diuresis has to be assumed. The type of renal lesion, however, remains unclear.

Adolescent↗
PubMed1990

Bronchial blood flow reduction with positive end-expiratory pressure after acute lung injury in sheep.

Smoke inhalation increases bronchial blood flow (Qbr) and produces edema of the airway system. This study investigates whether the increased Qbr seen 24 h after inhalation injury can be affected by mechanical ventilation with PEEP (5, 10, 15 cm H2O). Sheep (n = 8) previously prepared with cardiopulmonary catheters and ultrasonic transit time flow probes mounted around their bronchial arteries were insufflated with four sets of 12 breaths each of cotton smoke. Different levels of PEEP were added to the mechanical ventilation 24 h after injury; each PEEP level was applied for 45 min. There were significant increases in Qbr and lung lymph flow (QL) associated with a marked decrease in bronchial vascular resistance (BVR) 24 h after injury. However, no change was observed in mean arterial pressure (MAP) or cardiac index (CI). There was a substantial reduction in PaO2/FIO2 (P/F), which indicated a deterioration in arterial oxygenation. The application of varying levels of PEEP decreased Qbr (p less than .05) while BVR increased (p less than .05), but QL and P/F did not. CI and MAP were recorded. After removal of PEEP, none of the cardiopulmonary variables were significantly different from their postsmoke control values. These findings suggest that mechanical ventilation with PEEP markedly decreases the smoke-induced hyperemia edema frequently seen after inhalation injury without any significant alterations in MAP or CI.

Animals↗
PubMed1989

Control of the total artificial heart: new aspects in human versus animal experience.

Control strategies for total artificial heart application have generally been based on experience with healthy animals. Human patients in a bad state of health who have impaired organ functions and who are subjected to intensive care procedures can develop atypical hemodynamic behavior. In these patients, both unstable and hyperstable behavior of the vascular resistance were observed. Therefore, regulation of cardiac output (CO) by pressure parameters only was avoided and CO was adjusted to obtain an appropriate O2-utilization (O2U). Intending to keep the O2U within ranges of 20-25%, we obtained cardiac indexes between 3.3 and 4.4 L/m2/min (CO 6-8 L/min), which is higher than other cardiac indexes reported. A CO of 10.5 L/min was even necessary to obtain an O2U of 30% in a septic patient. This strategy caused a stable driving management and led to a rapid hemodynamic stabilization and general improvement of the patients' condition. Results indicate that it is also very important to monitor metabolic parameters for appropriate driver adjustment as well, especially in the early postoperative phase, and that O2-U is a sensitive and useful parameter for this purpose.

Animals↗