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Biomedical subjects

D Selander

Publications and source records attributed to D Selander.

30 records · Page 2Linked to original sources
PubMed1978

Longitudinal spread of intraneurally injected local anesthetics. An experimental study of the initial neural distribution following intraneural injections.

Unexpected spinal anesthesia, occurring after peripheral nerve blocks close to the spine, may be caused by a centripetal spread of the local anesthetic along the injected nerve to the spinal cord. In order to analyze the pathway of such a spread, a radioactive local anesthetic mixed with a fluorescent dye was injected into difrerent compartments of the rabbit sciatic nerve, and the early distribution of these tracers was studied by scintillation counting and fluorescence microscopy. Epineurial (extrafascicular) injections were of low injection pressure (25-60 mmHg) (3.3-7.9 kPa) and limited spread, while endoneurial (intrafascicular) injections reached higher pressures (300-750 mmHg) (39.9-99.7 kPa) and caused a rapid spread over long distances within the fascicle. The sacral plexus seemed difficult to pass. However, 20% of endoneurial injections reached the spinal cord, where the injectate primarily spread in the thin subpial space. Our experimental findings suggest that intraneural injections of local anesthetics are responsible for the reported cases of unexpected spinal anesthesia due to inadvertent intrafascicular spread. Although intrafascicular injections are rarely made, we recommend that intraneural injections of local anesthetics or other solutions close to the spine should be avoided, as they may cause unexpected spinal anesthesia or lesion of the cord.

Anesthesia, Spinal↗
PubMed1977

Hepatitis B immune globulin in prevention of hepatitis B among hospital staff members.

In a double-blind trial of hospital staff members at risk of contracting hepatitis B, 110 subjects received hepatitis B immune globulin or immune serum globulin prophylactically. An additional 125 individuals working in the same locations were unwilling to participate in the trial and received no prophylaxis. During the study period of 28 months, 13 cases of clinical hepatitis B occurred in the untreated group, whereas only three cases occurred among the subjects who received prophylaxis.

Adult↗
PubMed1977

Peripheral nerve injury due to injection needles used for regional anesthesia. An experimental study of the acute effects of needle point trauma.

Nerve injury can arise as a complication peripheral nerve block anesthesia. Of the various factors involved, the trauma caused by the injection needle may be of significance. In this experimental study the frequency of fascicular injury was investigated immediately after needling isolated rabbit sciatic nerve preparations, and after intraneural injection with the nerve in situ. Two different injection needles were used, one with a bevel angle of 14 degrees and the other with a 45 degrees bevel angle. Fascicular injury was indicated by a fluorescence microscopy technique, tracing locally applied Evans Blue Albumin, The results show that a 45 degrees-beveled needle less frequently produces fascicular damage and should therefore be recommended for use in clinical anesthesia. It is also concluded that paresthesiae, when necessary, should be elicited gently, and that intraneural injections should be avoided.

Anesthesia, Conduction↗
PubMed1977

Catheter technique in axillary plexus block. Presentation of a new method.

A flexible, disposable intravenous catheter can be introduced into the neuro-vascular sheath in the axilla and used for injection of local anesthetic solution to block the axillary brachial plexus. The technique is described and the results of the first 137 consecutive catheter blocks are reported and compared to a similarly evaluated series of conventional axillary blocks. The catheter method constitutes an interesting alternative to needle techniques and offers the possibility of a continuous axillary block.

Adult↗
PubMed1976

Vascular and extravascular spaces in a transplantable rat tumour after local X-ray irradiation.

Local X-ray irradiation of a transplantable rat tumour in a single dose of 3000 R increased significantly the extracellular space of this tumor as estimated by the plasma-tissue equilibration of 51Cr-EDTA, while the plasma and red blood cell volume as estimated with 125I-labeled albumin and 59Fe-labelled erythrocytes after sacrifice by bleeding under ether anaesthesia were unchanged. These results combined signified a decreased cell volume of cells, excluding red blood cells.

Animals↗
PubMed1975

Supraclavicular brachial plexus block with etidocaine without vasoconstrictor. Preliminary report.

When used for supraclavicular brachial plexus blocks, etidocaine 1% gave a quick and sufficient onset. Its duration was longer than that of mepivacaine 2%, and equal to that of bupivacaine 0.5%. Onset times for etidocaine 0.5% and bupivacaine 0.5% were about equal, but the former seemed to give a more profound motor block. The duration of etidocaine 0.5% was shorter than that of bupivacaine 0.5%. The long-acting agents showed great variations in duration, and they all had longer regression times than mepivacaine. No serious pharmacological side-effects were observed during this study, and so far there are no reports on neurological sequelae.

Acetanilides↗
PubMed1975

Hepatitis B immune serum globulin in prevention of hepatitis B among hospital personnel. Preliminary report from a controlled trial.

At Sahlgren Hospital, Göteborg, hepatitis B has been a serious problem for several years among the personnel in the hemodialysis and renal transplantation wards as well as in the chemical laboratories. For this reason a randomized controlled clinical study with conventional gammaglobulin and hepatitis B immune globulin was started in May 1973. The titer of anitbodies against HBsAg by passive hemagglutination was 1:100 and approximately 1:350,000, respectively. Newly employed staff without a history of jaundice and without demonstratable HBsAg (RIA) or HBsAb (RIP) in serum were enrolled in the trial. Assignment of the two preparations was performed by random numbers and the ampoules were labelled only with the serial number of the participant. Three cc of either preparation was administered i.m. within seven days after admission and was repeated three months later. After that no further injections were given. Each participating employee was followed up with liver function tests, IEOP, RIA and RIP tests for at least six months after the last injection. Preliminary results from this double-blind study, which is still going on, are presented.

Clinical Trials as Topic↗
PubMedDate not supplied

Pharmacokinetics and efficacy of 40 ml ropivacaine 7.5 mg/ml (300 mg), for axillary brachial plexus block--an open pilot study.

In this study, the pharmacokinetics, tolerability and efficacy of 40 ml of ropivacaine 7.5 mg/ml (300 mg) for axillary brachial plexus block were investigated. With institutional review board approval, 10 patients presenting for surgery of the upper limb were enrolled in this open study. The axillary plexus was identified with a nerve stimulator and the study drug was injected into the neurovascular sheath. Fifteen venous blood samples were obtained from each patient for pharmacokinetic measurements over a 24-h period. All blocks were sufficient for surgery after 45 min without any need for supplemental analgesia or general anesthesia. The mean (SD) peak plasma concentration was 2.3 (0.8) mg/l at median tmax 54 min (range 16-92 min). The mean (SD) maximum free plasma concentration was calculated to be 0.12 (0.06) mg/l (range 0.07-0.29 mg/l). The t 1/2 was about 6 h. There were no clinical signs or symptoms of central nervous system and/or cardiac toxicity in any patient. Ropivacaine 7.5 mg/ml, used in a dose of 300 mg, was effective and well tolerated for axillary brachial plexus block.

Adolescent↗
PubMedDate not supplied

Hepatitis B immune serum globulin and standard gamma globulin in prevention of hepatitis B infection among hospital staff: a preliminary report.

In May 1973 a controlled double-blind clinical trail with prophylactic injects of hepatitis B immune serum globulin (antibody titer by passive hemagglutination 1:355,000) and standard gamma globulin (1:100) was started in Sahlgren's Hospital, Göteborg, Sweden. The annual attack rate of clinical hepatitis B in the three departments studied had been 5 to 8 per cent during recent years. A total of 118 members of the hospital staff were prophylactically treated while 125 staff members were unwilling to participate and received no prophylactic treatment. During the first 20 months of study nine cases of clinical hepatitis B with jaundice occurred within the untreated group (7.2 per cent) while three cases (2.5 per cent) were observed in prophylactically treated individuals. After decoding it was found that 60 individuals had received specific hepatitis B immune serum globulin while 58 had received standard gamma globulin. Two of the three clinical cases of hepatitis B occurred within the standard gamma globulin group. Both groups included two individuals with transient antigenemia only and the standard gamma globulin group also included four individuals with antibody seroconversion.

Antibody Formation↗
PubMedDate not supplied

Neurotoxicity of local anesthetics: animal data.

OBJECTIVE: To extract experimental data of importance for the understanding of neurotoxicity of local anesthetics, with special reference to continuous spinal anesthesia. METHODS: Literature on clinical experience of and experimental studies on neurotoxic complications of local anesthetics, especially concerning spinal and continuous spinal anesthesia and long-term peripheral nerve block, was reviewed. The overall incidence of neural complications of central and peripheral nerve blocks was extracted, and the results of animal experimental studies on neurotoxicity of local anesthetics were used to characterize the possible mechanisms behind such complications. RESULTS: Persistent neurologic complications of regional anesthesia varied from 0 to 0.09% for central blockades and from 0 to more than 5% for brachial plexus blocks, depending on the technique used. All local anesthetics seem to be involved in clinical reports of neural complications. Experimental studies indicate that all local anesthetics are potentially neurotoxic and that the neurotoxicity parallels their anesthetic potency. In fact, the nerve conduction block may be an expression of a reversible toxic effect of the local anesthetic (LA). The mechanism is not completely understood, but factors of importance are the concentration of the LA and time of exposure of the neural tissue to the LA. Contributing factors are neural trauma and ischemia, both of which may be deleterious by themselves. CONCLUSIONS: Correctly administered LAs of clinical concentration are safe, but animal data indicate that all LAs are potentially neurotoxic. The neurotoxicity seems to be a function of the concentration of the LA and the time of exposure of the nervous tissue to the LA. Concomitant neural trauma, ischemia, or both, may potentiate the neurotoxic effect of the LA.

Anesthetics, Local↗