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Biomedical subjects

B Lisander

Publications and source records attributed to B Lisander.

At least 37 records · Page 2Linked to original sources
PubMed1996

Giving both enoxaparin and dextran increases the need for transfusion in revision hip arthroplasty.

OBJECTIVE: To find out if the need for transfusion was increased by volume substitution with dextran 70 in patients receiving prophylaxis against thrombosis with low molecular weight heparin. DESIGN: Open randomised controlled trial. SETTING: University hospital, Sweden. SUBJECTS: 40 patients undergoing revision hip arthroplasty. INTERVENTIONS: Enoxaparin 40 mg was given daily. Intraoperative normovolaemia was maintained with albumin (n = 20) or dextran 70 (n = 20). Intraoperative autotransfusion was used. Packed cell volume was kept above 0.29, if necessary with homologous blood. MAIN OUTCOME MEASURES: External blood loss, red cell balance. RESULTS: Dextran patients received 0.64 (0.2) g/kg of dextran (mean (SD)) and required more (p < 0.05) homologous blood (3.8 (2.4) units) than those receiving albumin (2.3 (1.6) units). The initial and final packed cell volumes were similar (0.40 and 0.32 compared with 0.41 and 0.32, respectively). The calculated loss of red cells was larger in the dextran group (1401 (511) compared with 1077 (374); p < 0.05). CONCLUSION: The combination of enoxaparin and dextran appreciably increased the need for transfusion compared with enoxaparin alone.

Aged↗
PubMed1995

Release of inflammatory mediators in association with collection of wound drainage blood during orthopaedic surgery.

Ten patients undergoing hip replacement surgery were studied regarding activation of complement and leukocytes in association with collection of wound drainage blood. The blood was collected postoperatively but not reinfused due to the possible risks with reinfusion of blood containing inflammatory mediators. Blood samples for analysis of complement activation (TCC), leukocyte activation (PMN elastase) and cytokines (Interleukin-6) were drawn preoperatively from the patients. Blood samples were also drawn intraoperatively from the wound. Samples were also drawn from the collected wound drainage blood, before and after blood was passed through a microporous filter. There were elevated concentrations of TCC, PMN elastase and IL-6 in the collected wound drainage blood before and after the filter. The filtration did not significantly reduce the concentrations of these factors. In the wound blood the concentrations were higher compared to those found in the systemic blood preoperatively, but lower compared to concentrations found in the collected drainage blood. The study demonstrates that the collection of wound drainage whole blood is associated with activation of complement, release of PMN elastase and cytokines.

Aged↗
PubMed1994

Antihistaminergic pretreatment prevents tissue extravasation of albumin from intra-abdominal trauma in rats.

Intra-abdominal surgery causes a loss of plasma into tissues within and around the abdomen, endangering tissue viability. Mast cells, containing histamine, are abundant in the abdominal cavity. In a model of mechanical intra-abdominal trauma, we investigated whether pretreatment with histaminergic H1 and H2 receptor blockers counteracts this extravasation. In Wistar rats under chloralose anaesthesia, tissue clearances of labelled albumin were determined by a double isotope technique. Four groups were studied: Traumatized rats, pretreated (n = 10) and non-pretreated (n = 9): non-traumatized rats; pretreated (n = 10) and non-pretreated (n = 9). In the traumatized rats, given pyrilamine 10 mg kg-1 (H1) plus cimetidine 25 mg kg-1 (H2) just before the trauma, the blockers prevented the haemoconcentration from loss of plasma and the drop in arterial pressure during the very trauma procedure, observed among non-pretreated rats. Furthermore, they significantly decreased the clearance of albumin in the abdominal wall and the pancreas. In the non-traumatized animals, the blockers lowered arterial pressure and heart rate. In conclusion, the anti-histaminergic pretreatment decreased the trauma induced leakage of albumin, by mechanisms which may involve readjustments of pressures and flows in capillaries as well as a prevention of histamine effects on capillary permeability.

Abdominal Injuries↗
PubMed1993

Evaluation of the analgesic effect of metoclopramide after opioid-free analgesia.

Metoclopramide may enhance opioid analgesia, but it is not known if the drug is analgesic itself. This question was examined in a double-blind, randomized study of 38 patients undergoing knee arthroscopy with opioid-free anaesthesia comprising propofol, isoflurane and nitrous oxide in oxygen. At the end of surgery, patients received either metoclopramide 0.5 mg kg-1 or placebo i.v. After operation, they received patient-controlled analgesia with pethidine for 3 h, during which period, pain score was assessed on a visual analogue scale (VAS). There were no significant differences between the groups in the patterns of pethidine consumption. However, the VAS-pain scores tended to be smaller in the metoclopramide group; this difference was significant 30 min after operation. These results do not demonstrate conclusively a clinically relevant analgesic action of metoclopramide.

Adult↗
PubMed1993

Analgesic action of metoclopramide in prosthetic hip surgery.

Prosthetic hip surgery was performed under subarachnoidal anaesthesia with bupivacaine 16-20 mg and morphine 0.2 mg. Preoperatively, metoclopramide 1 mg.kg-1 was given i.v., followed by an infusion of 1.5 mg.kg-1 over 9 h (n = 17). Control patients received corresponding volumes of solvent (n = 23. The design of the study was double blind. The characteristics of the spinal block (level of analgesia to pinprick and muscular block) and postoperative VAS pain scores were similar in both groups. During the 24 h following the start of the infusion, four patients receiving metoclopramide required i.v. opioids, compared to 15 in the control group (P < 0.05). The pain-free period was longer (P < 0.05) in the metoclopramide group. Arterial PCO2-levels were increased, reaching a maximum within 6 h of infusion, with no significant difference between the groups. The study suggests an analgesic action of metoclopramide.

Aged↗
PubMed1992

Capsaicin pretreatment of rats does not prevent tissue extravasation of albumin from intra-abdominal trauma.

Intra-abdominal surgery causes a loss of plasma into tissues within and around the abdomen, predisposing to a decreased tissue viability and postoperative complications. In a rat model of intra-abdominal trauma, we investigated whether neuropeptides released from thin afferent nerve endings may contribute to this extravasation. Newborn male Wistar rats were pretreated with capsaicin 50 mg/kg s.c., leading to a lifelong degeneration of thin afferents. The same animals, when adult, were subjected to experiments under chloralose anesthesia in which tissue clearances of radiolabelled albumin were determined by a double isotope technique. Non-pretreated animals served as controls. In non-traumatized animals, pretreated rats had a higher loss of labelled albumin in calf muscle. In animals subjected to the standardized intra-abdominal trauma, the pretreatment did not decrease the trauma-induced loss of albumin. In neck skin, the loss of protein was higher in pretreated animals, possibly due to a decreased trauma-induced sympathetic activation. In conclusion, degeneration of thin afferent fibers may alter the autonomic reflex response to intra-abdominal trauma, but neuropeptide release from afferents apparently plays no role in the relocation of albumin.

Abdominal Injuries↗
PubMed1991

Tissue extravasation of albumin from intraabdominal trauma in rats.

Intraabdominal surgery tends to lower circulating plasma volume by mechanisms unrelated to bleeding and evaporation. In chloralose-anesthetized rats, the tissue clearance of radiolabelled albumin was determined by a double isotope method. Animals were subjected to a standardized abdominal trauma, eliciting minimal bleeding and evaporation, and others served as controls. The trauma significantly increased tissue albumin extravasation in abdominal skin, abdominal wall, pancreas, small intestine, colon, mesentery and diaphragm. Considering the mass of the respective tissues, a substantial portion of the albumin extravasation took place in the abdominal wall. No increased albumin clearance was found in extra-abdominal tissues. It is suggested that abdominal surgery decreases plasma volume by extravasation in the operation field.

Abdominal Injuries↗
PubMed1990

Anaphylatoxin and terminal complement complexes in red cell salvage.

Thirteen patients undergoing elective orthopedic surgery were studied regarding anaphylatoxin (C3a and C5a) and terminal complement complex (TCC) formation in association with red cell salvage. The auto-transfusion equipment gave a centrifuged and washed erythrocyte fraction. The concentrations of C5a and TCC were not increased but elevated C3a levels were found in the suspension. After infusion of the erythrocyte fraction to the patient, no signs of systemic complement activation were observed. Thus, plasma levels of C3a, C5a and TCC were within the normal range in all the patients before and after autotransfusion. This study indicates that the complement system is activated in the cellsaver equipment. The washing procedure, however, seems to eliminate most of the anaphylatoxins and terminal complement complexes. No extensive systemic activation of complement seems to occur in association with autotransfusion to patients undergoing elective surgery.

Aged↗
PubMed1989

Gamma 2-MSH immunoreactivity in the human heart.

In patients undergoing aorto-coronary by-pass surgery, we found a 26% arterial-venous difference of immunoreactive gamma 2-melanocytostimulating hormone (MSH), a proopiomelanocortin (POMC) derived peptide known to possess profound hemodynamic effects. These results prompted an investigation of the presence of gamma 2-MSH in the human heart. Using a two-step extraction procedure, regions of human hearts were examined by sensitive and specific radioimmunoassays to determine their gamma 2-MSH content. Mean (+/- SEM) concentrations of 0.14 +/- 0.023 pmol/g and 0.12 +/- 0.017 were found in right atrium and right ventricle, respectively. High performance liquid chromatography indicated that 80-90% of the total immunoreactivity eluted in a single sharp peak in a position identical to that of synthetic gamma 2-MSH.

Chromatography, High Pressure Liquid↗
PubMed1989

Decrease in plasma volume from intraabdominal trauma in rats.

Intraabdominal surgery tends to lower circulating blood volume by mechanisms unrelated to bleeding. This phenomenon was investigated in chloralose anesthetized rats. Plasma volume was determined with radiolabelled albumin. Animals were subjected to a standardized abdominal trauma, eliciting minimal bleeding and evaporation, and others served as controls. The trauma decreased plasma volume and increased hematocrit significantly, whereas the plasma concentration of labelled albumin followed a similar time course in traumatized animals and in controls. It is concluded that experimental abdominal trauma may decrease blood volume by a loss of fluid with virtually the same albumin concentration as that of plasma.

Abdomen↗
PubMed1989

Hypothalamic inhibition of duodenal alkaline secretion via a sympatho-adrenergic mechanism in the rat.

Experiments were performed on rats anaesthetized with chloralose. A duodenal segment was perfused with recirculating isotonic saline, and alkalinization of this perfusate (HCO3- secretion) was measured by continuous pH-stat titration. Stereotaxic electric unipolar stimulations were performed in the perifornical region of the hypothalamus. Stimulation points eliciting an increased arterial pressure were stimulated for a period of 15 min. Duodenal HCO3- secretion decreased in 19 out of 25 experiments and increased in four out of 25 experiments. Inhibitory responses to hypothalamic stimulation were blocked either by thoracic epidural anaesthesia or by the adrenolytic agent guanethidine, suggesting a spinal pathway to the duodenum, presumably in the thoracic splanchnic nerves, and involvement of adrenergic neurons.

Anesthesia, Epidural↗
PubMed1988

Preoperative haemodilution.

In preoperative haemodilution, blood is withdrawn before surgery while normovolaemia is maintained by infusion of cell free fluid. A surgical bleeding then entails a smaller loss of red cells. Reinfusion of the saved blood maintains normovolaemia, raises hematocrit and decreases the need for donor blood. Dilutional anaemia may endanger the oxygenation of the tissues. Tissue oxygenation can be upheld by an augmented and redistributed cardiac output and by a raised oxygen extraction. These compensatory mechanisms are less efficient in the presence of vascular stenosis, in particular in the myocardium which relies virtually exclusively on coronary vasodilatation. Major contraindications to preoperative haemodilution are, apart from coronary insufficiency, ventricular failure and valvular disease. Deleterious increases in cardiac oxygen consumption and/or heart rate may result from e.g. hypovolaemia, arterial desaturation and painful stimuli. The haemodilution procedure requires knowledge and vigilance in all involved personnel and gives best results if combined with other blood saving measures, like blood predeposit and intraoperative red blood cell salvage.

Animals↗
PubMed1987

Hypothalamic stimulation counteracts sympathetically mediated gastrointestinal inhibition in chloralose-anaesthetised cats.

The inhibitory motor effect of the sympathetic gastrointestino-gastrointestinal (GI-GI) reflex was studied in cats with isolated innervated ileal (Thiry-Vella) loops. They were subjected to acute experiments under chloralose-gallamine anaesthesia where gastric volume, arterial blood pressure and heart rate were continuously monitored. The cervical vagi were sectioned and used for efferent stimulation. The hypothalamus was systematically explored by means of stereotaxically guided electrodes. When the abdomen was undisturbed, gastric contractile responses to central stimulation were virtually absent, regardless of whether a vagally induced tone was present or not. Distension of the isolated intestinal loop induced marked inhibition of vagally induced gastric tone, indicating activation of the GI-GI reflex. Under these conditions, about 17% of the hypothalamic points induced gastric excitation, due to withdrawal of sympathetic tone. The GI-GI reflex can thus be inhibited from diencephalic levels. This inhibition is not linked to any distinct cardiovascular 'pattern'.

Animals↗
PubMed1986

Bradykinin-induced atropine-sensitive gastric contractions. Activation of an intramural axon reflex?

Gastric motor responses, recorded as volume changes of an intragastric balloon, were induced by the close i.a. administration of bradykinin (0.75-4 micrograms) in chloralose-anaesthetized cats. The animals were vagotomized and the adrenals were ligated at the outset of the experiments. Prior to autonomic blocking agents bradykinin elicited relaxatory or biphasic motor responses. Following nicotinic ganglionic receptor blockade bradykinin caused predominantly gastric contractions. Such excitatory responses were antagonized by 80-100% by atropine, suggesting a dominant neurogenic component. An hypothesis is put forward that the observed gastric contractions result from a bradykinin-induced activation of an axon reflex arrangement confined to thin sensory nerve fibres which, by substance P release from intramural collaterals, excite postganglionic cholinergic motor neurones.

Animals↗
PubMed1985

Epidural fentanyl counteracts sympathetic gastric inhibition.

Postoperative paralytic ileus is in part mediated by the sympathetic gastrointestino-gastrointestinal (GI-GI) reflex. The modulation of this reflex by epidural fentanyl (50 micrograms) was studied in chloralose-anesthetized, ventilated cats. The vagi were cut in the neck but could be efferently stimulated. Gastric volume, arterial pressure and heart rate were followed and the GI-GI reflex was elicited by intestinal distension, mesenteric afferent nerve stimulation or heating or capsaicin administered intra-arterially to an intestinal loop. Epidural fentanyl enhanced the gastric contraction response to efferent vagal stimulation and considerably counter-acted the GI-GI reflex inhibition of vagally induced tone. These effects were reversed by epidural naloxone (10 micrograms). In contrast, 50 micrograms of fentanyl i.v. only enhanced the effect of vagal stimulation but had no influence on the inhibitory GI-GI reflex responses. Apparently, epidural fentanyl may inhibit the GI-GI reflex by a spinal point of action.

Animals↗
PubMed1984

Atropine-sensitive gastric smooth muscle excitation by mucosal nociceptive stimulation--the involvement of an axon reflex?

Experiments were performed in chloralosed cats where gastric motility was recorded by the "volume method". Mucosal and serosal nociceptive stimulations were accomplished by local heating to 45-52 degrees C. Heating generally elicited gastric relaxations, mainly due to activation of extrinsic inhibitory reflexes, but mucosal heating sometimes caused contractile responses which were resistant to nicotinic and adrenergic blockade. The contractions were, however, blocked by atropine and, further, could not be demonstrated after degeneration of splanchnic afferents. On the basis of these and earlier results it is suggested that the gastric contractions induced by mucosal nociceptive stimulation are due to axon reflexes, conveyed by splanchnic afferents that, possibly via release of substance P, make non-nicotinic reflex contacts with intramural excitatory cholinergic neurons.

Animals↗