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Biomedical subjects

M Bengtsson

Publications and source records attributed to M Bengtsson.

At least 73 records · Page 4Linked to original sources
PubMed1994

Spinal anaesthesia for caesarean section following epidural analgesia in labour: a relative contraindication.

Three cases are described in which epidural analgesia was performed during labour using an infusion of bupivacaine 0.125-0.25%. When, in all 3 cases, caesarean section was required for failure to progress, hyperbaric bupivacaine was given in doses of 10 mg, 12.5 mg and 15 mg respectively. Within 2-4 min all 3 patients had a high block, complained of difficulty in breathing and subsequently developed apnoea. The trachea was intubated after administration of thiopentone and succinylcholine and the operation continued. Cardiovascular support was provided by the administration of ephedrine injected intermittently intravenously. The spinal block receded and the patients were able to return to the ward without any further complications. All three mothers remain in good health and do not regret having had spinal anaesthesia for caesarean section. In contrast to previously reported cases of high spinal anaesthesia following unsuccessful epidural anaesthesia for caesarean section, this report describes 3 cases of high spinal following the administration of spinal anaesthesia upon an ongoing epidural infusion of local anaesthetic during labour. As no guidelines are available as to the recommended dose of spinal anaesthetic under such circumstances and, in view of the several case reports describing a similar complication under different circumstances, we suggest that spinal anaesthesia is contraindicated upon ongoing epidural analgesia or following a failed epidural.

Journal Article↗
PubMed1994

Implantable devices for venous access: nurses' and patients' evaluation of three different port systems.

Implantable injection port systems are safe and convenient for long-term venous access. The present investigation comprises nurses' and patients' evaluation of three different types of devices; Port-A-Cath (16.0 g), Cordis Miniport (3.8 g) for implantation in the chest wall and the PAS Port system (5.6 g) for implantation in the forearm. The devices were implanted for chemotherapy. Eighty patients and 17 nurses answered a questionnaire regarding their experience with the devices. Overall, the systems functioned well and were helpful for both patients and nurses. In the patient study few significant differences emerged. Nurses noted that the PAS Port system was more difficult to withdraw blood from (P < 0.001) and its infusion flow capacity was inferior to the two ports in the chest wall (P < 0.001). Port-A-Cath was judged to be the easiest system for needle insertion and the needle position was felt to be more secure (P < 0.001). Fourteen of the 17 nurses preferred Cordis Miniport for cosmetic reasons (P < 0.001). All devices functioned well. The differences in shape, size and site of implantation allow an optimum port selection for each patient. The replies in this study expressed the need for educational programmes in order to spread the injection port concept further.

Adolescent↗
PubMed1993

Cardiac arrest during caesarean section.

A case is described of a previously healthy obese woman in her fourth pregnancy who presented for caesarean section due to cephalopelvic disproportion (CPD). Forty minutes after a spinal anaesthetic a healthy child was delivered. Shortly after the injection of ergometrine and Syntocinon into the uterus, the patient described a general feeling of discomfort which was followed by convulsions and cardiac arrest. Resuscitation was successful and the circulation was restored. However, it was difficult to maintain oxygenation and the patient was mechanically ventilated for 24 hours and subsequently supplementary oxygen therapy was given for three days. A pulmonary scintigram on the fourth day after delivery showed large uptake defects indicative of pulmonary embolism. The patient recovered completely and was discharged home after two weeks. Differential diagnosis and measures to reduce the risk of deep vein thrombosis (DVT) are discussed.

Journal Article↗
PubMed1993

Comparison of portable emergency ventilators using a lung model.

A lung model was used to test the performance of five emergency ventilators (MEDUMAT Elektronik, MEDUMAT Variabel, OSIRIS, OXYLOG and rescuPAC 2DM). The model comprised two glass jars filled with water to suitable compliances and connecting tubes. A resistance (obstruction) was added to one of the "bronchial" tubes in order to simulate a patient with obstructive lung disease. Preset minute volume was compared with measured minute volume and the gas distribution produced by the different ventilators. Acceptable performance was found with the MEDUMAT Elektronik, MEDUMAT Variabel, OSIRIS and OXYLOG ventilators.

Critical Care↗
PubMed1993

Halothane-diethyl ether azeotrope anesthesia under primitive conditions: guidelines for neuromuscular blockade with vecuronium.

The dose-response relationship for vecuronium during anesthesia with the azeotropic mixture of halothane and diethyl ether (HE) (66 ml of halothane mixed with 34 ml of ether in the same bottle)/oxygen was compared with halothane/nitrous oxide/oxygen anesthesia. The HE is not explosive and has preserved many of the advantageous properties of diethyl ether, making it an attractive anesthetic drug under difficult circumstances such as war or civil disaster. If muscular relaxation is needed in military anesthesia, it is essential to use a short- to medium-acting compound that can be stored without refrigeration. Vecuronium bromide fulfills these criteria. The study was conducted on 20 young (mean 24 years, range 18-31), ASA I patients. Using adductor pollicis mechanomyography and a cumulative dose technique, individual dose-response curves for vecuronium were constructed. Care was taken to keep peripheral and core temperatures normal and the times of exposure to inhalational gases equal. The results were analyzed by the log-probit method. During HE anesthesia, ED50 for vecuronium was 22 +/- 2 micrograms kg-1 (mean +/- SE) and ED90 was 49 +/- 8 micrograms kg-1. During halothane/nitrous oxide anesthesia, ED50 for vecuronium was 18 +/- 2 micrograms kg-1 (mean +/- SE) and ED90 was 39 +/- 7 micrograms kg-1. The dose-response relationships for vecuronium were similar during HE anesthesia and halothane/nitrous oxide anesthesia.

Adolescent↗
PubMed1992

Is repeated mismatching at regrafting deleterious?

We reviewed our clinical experience of allowing kidney regrafting with a repeated HLA mismatch. We also permitted a weakly positive B-cell cross-match. All patients who received a second or subsequent renal graft (n = 92) between January 1985 and June 1990 were analysed for graft survival. The overall 1-year graft survival was 70%. A repeated mismatch occurred in 29 of the patients at at least one HLA locus and their 1-year graft survival was 66%. The balance of the regrafts (63) were performed without a repeated mismatch, and their 1-year graft survival was 70%. Even a weakly positive B-cell cross-match was deleterious; when a grafting with a repeated mismatch was performed only one out of five grafts survived. Our results indicate that retransplantation of renal grafts with a repeated mismatch in the HLA A or B locus can be performed without a negative influence on transplant outcome provided that both the T- and B-cell cross-matches are negative.

Graft Survival↗
PubMed1992

Cellular localization and hormonal regulation of 7,12-dimethylbenz[a]anthracene mono-oxygenase activity in the rat ovary.

To identify the ovarian cell type(s) responsible for the metabolism of 7,12-dimethylbenz[a]anthracene (DMBA) and their dependence on hormonal influences, DMBA mono-oxygenase activity was determined in primary cultures of cells dispersed from rat ovaries and separated by centrifugation on discontinuous Percoll density gradients. The contents of progesterone and oestradiol in the different cell cultures were characterized. Moreover, the morphological appearance of ovarian cells obtained from untreated and pregnant mare's serum gonadotropin (PMSG)-treated rats was examined. It is concluded from experiments with immature PMSG-treated rats, that DMBA mono-oxygenase activity is localized in follicular granulosa (and/or theca) cells. This activity decreases during luteinization, and is recovered in a population of cells harvested at a higher density on the Percoll gradient. The xenobiotic-metabolizing activity was not correlated to the rate of biosynthesis of progesterone or oestradiol in isolated cells, measured in the presence or absence of human chorionic gonadotropin and/or testosterone. However, a certain dependence of DMBA metabolism on steroids and/or steroid-synthesizing enzymes could not be excluded. For example, DMBA mono-oxygenase activity was markedly increased in a cell population, tentatively identified as granulosa cells, obtained from untreated mature rat ovaries upon addition of testosterone, which is the substrate for oestrogen synthesis, to the cell culture.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1992

Stimulation of NK cell, T cell, and monocyte functions by the novel immunomodulator Linomide after autologous bone marrow transplantation. A pilot study in patients with acute myeloid leukemia.

Immunostimulatory therapy is at present considered after autologous bone marrow transplantation (ABMT) in order to mimic the allogeneic graft-versus-leukemia effect and thereby reduce the relapse rate. In a pilot study, five adults with acute myeloid leukemia were treated with the new immunomodulator Linomide post-ABMT. Linomide (0.3 mg/kg/week orally) was given in cycles of three weeks followed by three weeks of rest for up to six months. During treatment periods cyclic increases of CD56+CD3- and CD16+ NK cells were observed in parallel with enhanced cytotoxic activity of patient cells against both the NK-sensitive K562 and NK-resistant Daudi cell lines. A cyclic increase of CD14+ monocytic cells was also recorded. The proliferative responses of patient cells to PHA and allogeneic cells (MLC) were enhanced during Linomide therapy. The in vitro production of TNF alpha, IFN gamma, and IL-1 followed the same cyclic increase during treatment periods. Side effects were generally mild, and no harmful effects on engraftment were seen. Linomide therapy after ABMT thus induces a broad immunostimulation that offers a potential benefit with regard to leukemia-free survival.

Adjuvants, Immunologic↗
PubMed1992

A new ventilator converter with the Siemens Servo Ventilator--evaluation in a lung model.

A ventilator converter device (Anmedic) for connecting a non-rebreathing ventilator (Servo Ventilator 900 B; Siemens-Elema) to a circle anaesthesia system was evaluated in a lung model. Recorded minute ventilation was slightly lower than dialled in most cases. We furthermore found inadequate expiratory expansion of the ventilator converter bellows, with progressive loss of tidal volume and consequently recorded minute volume, when fresh gas flow to the circle system was low (1 l.min-1), expiratory time was short (less than 40%) and respiratory obstruction was present.

Airway Obstruction↗
PubMed1992

Influence of intrathecal morphine and naloxone intervention on postoperative ventilatory regulation in elderly patients.

Thirty elderly patients undergoing major hip surgery under spinal analgesia were randomly allocated in a double-blind manner into three groups. The aim was to evaluate the influence of intrathecal morphine and postoperative naloxone infusion on the regulation of ventilation. The Bupivacaine Group received spinal analgesia with 20 mg bupivacaine intrathecally. The Morphine Group received spinal analgesia with 20 mg bupivacaine + 0.3 mg morphine intrathecally. The Naloxone Group received spinal analgesia with 20 mg bupivacaine + 0.3 mg morphine intrathecally + postoperative naloxone infusion intravenously (1 microgram/kg/h over 12 h, 0.25 micrograms/kg/h over the next 12 h). Evaluation of resting ventilation and the ventilatory responses to hypercarbia and hypoxaemia was made on three occasions: before surgery, and 8, and 24 h after the intrathecal injection. Intrathecal morphine had no significant effect on ventilatory regulation in elderly patients undergoing major hip surgery performed under bupivacaine spinal analgesia. Postoperative administration of opioids or sedatives after intrathecal morphine as well as postoperative blood loss associated with a fall in blood pressure appeared to increase the risk of developing respiratory depression. Naloxone infusion seemed to reduce the risk of developing respiratory depression. Furthermore, one third of the elderly had a poor response to hypoxaemia before surgery.

Aged↗
PubMed1992

Autologous bone marrow transplantation in children with acute lymphoblastic leukemia.

We report 25 children with acute lymphoblastic leukemia (ALL) treated with purged autologous bone marrow transplantation (ABMT) at a single center. Two children with high-risk ALL were transplanted in first remission and 23 with relapsing ALL were transplanted in second (n = 21) or third (n = 2) remission. There was no procedure-related mortality. The median time to engraftment (i.e. to reach a polymorphonuclear cell count of 0.5 x 10(9)/l) was 25 days (range 16-45 days). Seven children relapsed, four within five months after ABMT: 18 of 25 children (72%) are in continuous complete remission after a median follow-up period of 50 months (range 5-71 months). The predicted long-term disease-free survival is 65% in the whole group and 61% in those transplanted after relapse. Relapse-free children returned to normal activities within three months after ABMT. The major side effects were development of cataract and gonadal insufficiency. We consider the results promising, but our data do not allow comparison with results reported from treatment with chemotherapy alone, since some of our patients were referred from other centers and represent a selected patient group. Long-term follow-up of well-defined patient populations is necessary to evaluate the effect of ABMT.

Adolescent↗
PubMed1992

Fibrin sleeve formation after long term brachial catheterisation with an implantable port device. A prospective venographic study.

OBJECTIVE: To evaluate the risk of thrombosis after long term venous access with an implantable port device (PAS-Port system). DESIGN: Open study. SETTING: University Hospital, Linköping, Sweden. SUBJECTS: Sixteen patients who required central venous catheters for long term chemotherapy were prospectively followed for 218 patient months (median 12.5 months/patient, range 3-34). INTERVENTIONS: Venogram taken while the catheters were being withdrawn. Venography was also done in 10 patients 1-29 months after the catheter had been removed. RESULTS: The venograms showed that fibrin sleeves had developed along the route of the catheter in all cases (cubital vein to the superior vena cava n = 7; to subclavian vein alone n = 8; and basilic vein alone n = 1). One of the 10 patients who underwent venography 1-29 months later had developed an occlusive subclavian vein thrombosis with well developed collateral vessels 10 months after the catheter had been removed. CONCLUSION: Because of the high incidence of formation of extensive fibrin sleeves, implantable port devices should be removed as soon as they have served their purpose. If catheters malfunction they should be evaluated radiographically.

Arm↗
PubMed1991

Minimum alveolar concentration of halothane-diethyl-ether azeotrope.

The azeotropic mixture of halothane and diethyl ether (HE) may be a valuable alternative to other anaesthetic agents under circumstances such as war, civil disaster, and primitive conditions. In the present study the minimum alveolar concentrations (MACs) for HE in man (n = 25) and in pigs (n = 6) were determined. For comparison with results of other studies, the MAC for halothane in man (n = 14) was also determined. A Normac gas analyser and a Varian 3700 gas chromatograph were calibrated against known standards of HE. The performance of two vaporizers (Fluotec Mark III, Servo vaporizer for halothane) was studied. The Fluotec Mark III vaporizer and the Servo halothane vaporizer filled with HE gave a linear performance with increasing dial settings. The Normac gas analyser set for methoxyflurane was linearly sensitive to the ether component of the azeotrope. The MAC for HE in man was 0.71 vol.% +/- 0.03 (s.e.mean) (ether 0.21 vol.%, halothane 0.50 vol.%) in the age group 19-42 years. MAC for halothane in man was 0.65 +/- 0.03 in the age group 19-32 years. The MAC for HE in pigs between 20-24 kg was 0.99 vol.% +/- 0.07. The ether component seems to act synergistically with halothane in the azeotropic mixture. The present study provides an opportunity to compare HE with other volatile anaesthetic agents.

Adult↗
PubMed1991

Regeneration of CALLA (CD10+), TdT+ and double-positive cells in the bone marrow and blood after autologous bone marrow transplantation.

In this prospective study we investigated the frequency of CD10+, TdT+ and CD10+TdT+ mononuclear cells in the bone marrow (BM) and peripheral blood (PB) before and after autologous bone marrow transplantation (ABMT). 49 patients treated for acute lymphoblastic or myeloblastic leukaemia, malignant lymphoma or multiple myeloma were included. A significant increase in CD10+ cells occurred in BM in both children and adults after ABMT. In children, we also found a significant increase in CD10+ cells in PB. In individual patients remaining in remission, up to 34% CD10+ cells having a normal Ig kappa/lambda light chain ratio were recorded after ABMT. In children, the percentage of TdT+ and CD10+ TdT+ cells increased significantly in BM. In most cases the CD10/TdT-ratio was greater than 1.0, but during early regeneration after ABMT this ratio was less than 1.0 in several patients remaining in complete remission. In patients remaining in remission, CD10+TdT+ cells were detected in the blood in only 2 out of 140 samples tested, and the proportion of these cells never exceeded 0.03%. We conclude that quantitation of CD10+TdT+ cells in peripheral blood is helpful in the evaluation of complete remission in patients treated for pre-B-ALL.

Adult↗