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Biomedical subjects

M Torrens

Publications and source records attributed to M Torrens.

At least 37 records · Page 2Linked to original sources
PubMed1994

Facial and acoustic nerve preservation during excision of extracanalicular acoustic neuromas using the suboccipital approach.

The results are presented from a consecutive operative series of 62 acoustic neuromas in 60 patients following the introduction of improved neurophysiological monitoring techniques. Twenty-two patients had usable preoperative hearing. Thirty tumours were less than 2.5 cm diameter and 32 greater in size. Operation was via a 3-4-cm diameter retromastoid craniectomy. The internal auditory meatus was opened by an ENT surgeon (RM) using a drill and the facial nerve identified by stimulation. The tumour was then centrally evacuated by a neurosurgeon (MT/HC) using an ultrasonic aspirator, and the thin exterior part of the tumour carefully dissected off the nerves in or around the capsule with constant stimulation and monitoring of facial EMG, BSAEP and electrocochleography. A new type of stimulation probe has been designed and coupled to a stimulator/integrator/tone burst generator (SB) so that continuous immediate direct feedback to the surgeon is possible. A variable amplitude discriminator rejects baseline EMG (> 50 microV) and a gating circuit prevents stimulus artefact (during monopolar stimulation) from causing interference. By these means the VII nerve could be identified even when translucent and undefinable as a nerve bundle. Anatomical preservation was possible in 98% of VII nerves. Full facial function was present in 20 cases immediately postoperatively. Full delayed recovery occurred in 23 cases giving an eventual total in House Grade I of 69%. Seven other cases recovered to House Grade II. There was therefore 81% satisfactory facial nerve function. This percentage is exactly the same for larger and for smaller tumours. Anatomical preservation of the VIII nerve was achieved in 24/62 (39%) of the whole series and 11/16 (69%) of those with a hearing loss of < 50 dB. Functional preservation of hearing described as usable by the patient (< 65 dB) was achieved in 7/22 cases (32%), 3/13 (23%) in tumours < 2.5 cm and 4/9 (44%) in those > 2.5 cm diameter. Hearing preservation of < 50 dB in patients with preoperative hearing threshold < 50 dB and tumours of < 2.5 cm was 3/11 (27%). Monitoring by BSAEP and ECochG was technically unsatisfactory because the responses were affected by drilling and stimulation. Acoustic nerve preservation should be attempted in all cases with measurable hearing, regardless of tumour size.

Ear Neoplasms↗
PubMed1993

Flunitrazepam consumption among heroin addicts admitted for in-patient detoxification.

The use of benzodiazepines among 973 heroin addicts admitted for inpatient detoxification over a 10-year period was assessed in a cross-sectional study. A total of 780 (80.2%) patients had a history of benzodiazepine use; 666 (68.5%) were consuming benzodiazepines at the time of admission and 419 (43.1%) on an almost daily basis. Seventy-five (7.7%) patients fulfilled criteria for sedative-hypnotic abuse or dependence. Consumption of benzodiazepines began after subjects had become addicted to heroin. Flunitrazepam was ranked first by 68.4% of patients, followed by clorazepate (13%), and diazepam (12.4%). The prevalence of benzodiazepine use, in particular flunitrazepam, among heroin addicts is very high. Specific abuse liability studies are needed to determine whether pharmacologic reasons exist to explain heroin addicts' preference for this compound.

Anti-Anxiety Agents↗
PubMed1993

Consumption of buprenorphine and other drugs among heroin addicts under ambulatory treatment: results from cross-sectional studies in 1988 and 1990.

We assessed the prevalence of consumption of buprenorphine and other drugs among heroin addicts under ambulatory treatment in two cross-sectional studies conducted in 1988 (188 subjects) and in 1990 (197 subjects). Patients were enrolled in one of three different programmes: methadone maintenance programme (MMP), antagonist maintenance programme (AMP) and drug-free programme (DFP). Information given by participants was compared with results of urine screening for drugs. Urine samples were tested using enzyme immunoassay for the detection of heroin, cocaine, dextropropoxyphene, cannabis and benzodiazepines, and radioimmunoassay for buprenorphine. Sixty-six percent of patients in 1988 and 71% of patients in 1990 reported having consumed buprenorphine at some time during their history of drug dependence (period prevalence) and 5.9% and 6.1%, respectively, tested positive to the drug (point prevalence). In over 70% of these patients consumption was by the intravenous route. Consumption of cannabis, cocaine and benzodiazepines was also very high in the study population. Overall, patients in the DFP group consumed the largest number of the drugs tested, while those in the AMP group consumed the smallest number. Abuse of buprenorphine could be more widespread than previously reported.

Adult↗
PubMed1992

Assessment and management of opioid withdrawal symptoms in buprenorphine-dependent subjects.

The spontaneous physical dependence of buprenorphine was assessed in opioid addicts who switched from heroin to sublingual or intravenous buprenorphine. Twenty-two patients were randomly assigned to double-blind administration of methadone (n = 11) or placebo (n = 11) for 13 days after abrupt withdrawal of buprenorphine. Methadone was administered according to four pre-established dosing schedules depending on the previous amount of daily consumed buprenorphine. No methadone-treated patient required modification of the therapeutic regimen, whereas eight of eleven placebo-treated patients needed treatment with methadone. Buprenorphine withdrawal syndrome was of opioid type, began somewhat more slowly, and showed a peak until day 5. The occurrence, time-course and characteristics of buprenorphine withdrawal syndrome make it necessary to reconsider the abuse potential of this analgesic.

Adult↗
PubMed1991

Cocaine abuse among heroin addicts in Spain.

Abuse of cocaine is becoming a major problem among heroin addicts in Spain. Between 1987 and 1988, 75% of patients admitted as inpatients for detoxification from opiate dependence had consumed cocaine during the 6 months prior to admission and 25% had abused cocaine daily or several times/week. These cocaine abusers showed more toxicologic and psychopathologic problems than opiate addicts who did not abuse cocaine. The opiate addicts who also abused cocaine had begun using illicit drugs earlier and showed a higher frequency of anti-HIV antibodies. They also had more antisocial personality disorders and persistence of depressive symptoms during opiate detoxification than heroin addicts who did not abuse cocaine. Based on these findings, we insist on the need to develop different treatments for detoxifying patients with this dual addiction.

Adolescent↗
PubMed1990

[Treatment of acute leukemia: usefulness of an immunodepressed unit].

A special unit for immune-depressed patients was used in the treatment of acute leukemia in 33 patients. Results of therapy were compared to those in 30 historical controls treated in a general ward. Both groups were comparable regarding age, sex, type of leukemia and severity of bone marrow depression. The incidence of fever and the percentage of complete remission were higher in patients treated in the unit, including patients with acute lymphoblastic leukemia. The remission rate in the subgroup of patients with acute myeloid leukemia was not improved. Mortality rates were also not different. We recommend the use of this unit for treatment of patients with acute leukemia, given the lower infection rate and the higher probability of remission.

Acute Disease↗
PubMed1989

CT-guided thalamotomy in the treatment of movement disorders.

CT-guided thalamotomy has been used in Frenchay Hospital since 1985 in the treatment of movement disorders. This technique avoids intraventricular contrast injections and therefore simplifies the placement of thalamic lesions, decreases patient morbidity and shortens inpatient stay. Our experience with this technique is presented.

Humans↗
PubMed1989

[Cytogenetic study of acute and chronic leukemias].

From 1983 to 1987 we studied 30 patients with leukemia searching for chromosomal alterations. Cytogenetic studies of bone marrow showed an abnormal karyotype in 19 (67%). Seven out of 14 cases of acute leukemia presented different chromosomic alterations. The Philadelphia chromosome was found in 11 patients with chronic myeloid leukemia and 3 patients with chronic lymphatic leukemia; a Pseudo-Philadelphia chromosome was present in one patient, this being the first such finding in Chile. Thus, the karyotype is a valuable complementary study not only in chronic myeloid leukemia but also in chronic lymphatic leukemia and the acute lymphoblastic and non-lymphoblastic varieties.

Adolescent↗
PubMed1989

[Infection in severe neutropenia: analysis of 140 episodes].

We analyzed infections complicating 140 episodes of severe neutropenia in 86 patients. The underlying diagnosis was acute leukemia in 64, lymphoma in 12 and isolated cases of bone marrow aplasia, agranulocytosis, dysmyelopoiesis and solid tumors. No fever developed in 35 (25%) episodes. No cause for the fever was identified in 40% of the remaining episodes. Clinical evidence of an infection was present in 20%, with positive bacteriologic findings in 27%. Respiratory infection (16%), pneumonia (11%) and sepsis (10%) were the most common infectious processes. Infectious agents isolated were gram negative bacilli (72%), gram positive cocci (19%) and fungi (9%). The association of amikacin and carbenicillin or cephalosporins proved to be superior to gentamycin-penicillin (p less than 0.01). 16 patients died for an overall mortality of 11%. Pneumonia and infection by K pneumoniae or C albicans were associated to a poorer prognosis.

Anti-Bacterial Agents↗