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Biomedical subjects

M Rosen

Publications and source records attributed to M Rosen.

At least 163 records · Page 9Linked to original sources
PubMed1988

Maximum FIO2 during caesarean section.

Forty patients undergoing elective and emergency Caesarean section (excluding severe fetal distress) were divided into four groups to receive 50% oxygen, 50% nitrous oxide, and 0.5% halothane (group 1, controls) or 100% oxygen supplemented by 1.5 x MAC of halothane, enflurane or isoflurane (groups 2,3,4, respectively) reducing to 1.0 x MAC 5 min after induction. The umbilical venous PO2 in the oxygen-only groups was higher than in the oxygen-nitrous oxide groups, this difference reaching statistical significance when the patients in the oxygen-only groups were combined. Blood loss and uterine contractility were unaffected by the increased concentrations of volatile agents, and awareness did not occur. Improved cardiovascular stability was demonstrated in the elective high-oxygen groups. The technique is safe and warrants further study, since there are no important ethical objections.

Anesthesia, Inhalation↗
PubMed1988

Effects of sodium bicarbonate in canine hemorrhagic shock.

We studied the use of sodium bicarbonate administration in a canine model of hemorrhagic shock to determine its effect on hemodynamics, arterial and venous blood gases, respiratory gases, and blood lactate levels. Thirteen dogs were anesthetized, paralyzed, mechanically ventilated, and hemodynamically monitored. Hypotension was induced and maintained at a mean arterial pressure of 40 to 45 mm Hg using controlled hemorrhage and reinfusion. After 2.5 h of shock, the dogs were randomized into two groups: one group (n = 6) received NaCl infusion; the other (n = 7) received sodium bicarbonate (1 mEq/kg followed by a continuous infusion of 2.5 mEq/kg.h for 2.5 h). CO2 production was increased in the alkali group, but there was no statistically significant difference between groups in any measured hemodynamic, blood gas, or respiratory gas variable. These included heart rate, BP, cardiac output, arterial and venous pH, CO2 production, and bicarbonate levels. Blood lactate levels, however, in the bicarbonate treated animals were significantly (p less than .01) higher than in the group treated with NaCl alone (10.1 +/- 3.2 vs. 5.1 +/- 1.2 mEq/L). These results are similar to the effects of bicarbonate found in other models of lactic acidosis, and suggest that bicarbonate therapy may have limited usefulness in the treatment of lactic acidosis.

Acidosis, Lactic↗
PubMed1988

Propofol induction and maintenance with nitrous oxide in paediatric outpatient dental anaesthesia. A comparison with thiopentone-nitrous oxide-halothane.

Intravenous induction of anaesthesia with propofol (3.5 mg/kg) and maintenance boluses (1 mg/kg), with 30% oxygen and 70% nitrous oxide, were compared with intravenous thiopentone induction (5 mg/kg) followed by 30% oxygen and 70% nitrous oxide, supplemented with 2 to 3% halothane in children aged 2-11 years who underwent dental extractions. Both techniques were found to be acceptable in clinical practice. Recovery from anaesthesia was assessed by the time taken to reach clinically-defined milestones. Times to open eyes, give name, stand unaided, and time to discharge were all 3 to 7 minutes shorter in those who had the propofol technique compared with those who had thiopentone-halothane (p less than 0.05). These indices of recovery were more sensitive than the Steward score.

Ambulatory Surgical Procedures↗
PubMed1988

Patient-controlled analgesia with a mixture of pethidine and doxapram hydrochloride. A comparison of the incidence of respiratory dysrhythmias with pethidine alone.

Twenty-four patients who underwent elective cholecystectomy received double-blind increments of either pethidine 30 mg or a mixture of pethidine 30 mg and doxapram 45 mg delivered on a patient-controlled basis. A loading dose of doxapram 100 mg or saline was administered. There was no difference in respiratory depression as indicated by respiratory frequency and end tidal carbon dioxide concentration. The incidence of respiratory apnoea was similar in the two groups but apnoea was of shorter duration in patients who received doxapram, although the difference was not significant. Patients who received doxapram assessed overall pain as worse on a linear analogue scale (p less than 0.05) but demanded similar amounts of pethidine. There was no difference in pain on movement.

Adult↗
PubMed1988

Midwive's assessment of the upper sensory level after epidural blockade.

The ability of midwives to assess accurately the level of epidural blockade after a short period of instruction was examined. Seventy-two midwives estimated the upper level bilaterally in 100 patients, by detection of the loss of sensation to a cold stimulus. The midwife and anaesthetist were in complete agreement over the level of block in 71.5% of cases; the midwife overestimated the height of the block in 9.5% of cases, and underestimated in 19%. The midwife underestimated by three spinal segments in 1.5% of cases, and never by more. The technique was acceptable to patients and midwives alike. This procedure should enable safe management of obstetric analgesia, whoever administers top-ups; accurate detection of a block that recedes below therapeutic levels should facilitate earlier top-ups and thus reduce pain for the patient in labour.

Anesthesia, Epidural↗
PubMed1988

Cerebral metabolism and patterned visual stimulation: a positron emission tomographic study of the human visual cortex.

We studied the impact of visual stimulation upon cerebral metabolism in normal young men using FDG-PET. Results obtained from subjects receiving patterned visual stimulation while performing an ocular fixation task were compared with results from ocular fixation alone. Visual stimulation in the macular region of either hemifield produced significant increases in metabolism of the contralateral posterior striate cortex. Visual stimulation induced highly significant asymmetries in metabolism of the prefrontal and inferior parietal cortices. Metabolic activation in extrastriate areas tended to be right-sided. These findings support the classic notion of retinotopic organization within the primary visual sensory cortex. They also indicate that the patterns of cerebral metabolism are not equivalent between the two cerebral hemispheres. This latter finding suggests that in humans the right cerebral hemisphere may be specialized for visual processing.

Adolescent↗
PubMed1988

Resolving metabolic abnormalities in a case of pure alexia.

We report resolving metabolic abnormalities corresponding to clinical improvement in a patient with pure alexia secondary to acute cerebral infarction. Local cerebral glucose metabolism (lCMRgl) was measured with positron emission tomography (PET) using 18F-fluorodeoxyglucose (18F-FDG) close to ictus and 4 1/2 months later. Serial CTs and a subsequent MRI demonstrated small, unchanging left-hemispheric lesions involving the area of the lateral geniculate body and the splenium of the corpus callosum. PET demonstrated the evolution of the metabolic abnormality resulting from intrahemispheric (lateral geniculate) and interhemispheric (splenium) disconnection in the absence of occipital lobe infarction. This case illustrates that cerebral disconnection can result in the syndrome of pure alexia. The factors accounting for focal hypometabolism in the absence of cerebral infarction are discussed.

Brain↗
PubMed1988

A double-blind comparison between nitrazepam, lorazepam, lormetazepam and placebo as preoperative night sedatives.

Benzodiazepines are used as hypnotics to reduce anxiety and give a good night's sleep on the night prior to surgery. In a double-blind procedure, patients were given either lorazepam (2 mg or 4 mg), lormetazepam (1 mg or 2 mg), nitrazepam 10 mg or placebo. Measures were taken of sleep, anxiety, memory and after-effects. There was no evidence that the drugs reduced anxiety, nor evidence of amnesia. Quality and length of sleep was shown to be better for nitrazepam (P less than 0.05), lorazepam 2 mg (P less than 0.05) and lorazepam 4 mg (P less than 0.01), compared with placebo. However, significantly higher ratings of clumsiness and confusion as after-effects were found with nitrazepam (P less than 0.05), and clumsiness (P less than 0.005), slurred speech and blurred vision (P less than 0.01), sleepiness, nausea, weakness and confusion (P less than 0.05) with lorazepam 4 mg. It was concluded that lorazepam 2 mg produced the greatest net benefit.

Adult↗
PubMed1987

Induction of differentiation of human myeloid cell lines by tumor necrosis factor in cooperation with 1 alpha,25-dihydroxyvitamin D3.

We analyzed the combined effect of tumor necrosis factor and 1 alpha,25-dihydroxyvitamin D3 on the differentiation of human myeloid cell lines HL-60, ML3, and U937. The two compounds synergize in inducing the morphological, phenotypic, enzymatic, and functional characteristics of cells of the monocytic lineage. Immune gamma-interferon synergizes with each compound to induce differentiation. However, recombinant tumor necrosis factor is much more effective than recombinant gamma-interferon in potentiating the effect of 1 alpha,25-dihydroxyvitamin D3 and, alone, is also more effective than recombinant gamma-interferon in inducing expression of the high-affinity Fc receptor on ML3 cells. The possible physiological or pathological relevance of the synergistic effect of tumor necrosis factor and 1 alpha,25-dihydroxyvitamin D3 on monocytic differentiation is discussed.

Calcitriol↗
PubMed1987

Cerebral glucose consumption following verbal auditory stimulation.

We studied the effect of auditory stimulation upon cerebral glucose metabolism in young normals. The stimulus consisted of a non-English discourse which was presented monaurally to 10 normal blindfolded subjects (5 left ear, 5 right); the opposite ear was plugged. Six subjects studied blindfolded and with ears plugged served as controls. Sixteen discrete homologous cortical and subcortical regions of interest were examined. Regional glucose consumption and side-to-side differences in glucose metabolism were analyzed. Monaural stimulation produced significant increases in temporal metabolism contralateral to the side of stimulation. Significant asymmetries in metabolism were found at the temporoparietal junction, inferior parietal region, insula and corpus collosum. The left frontal speech areas remained unaffected. These findings demonstrate that in man the primary auditory pathways retain a contralateral organization. Further, cerebral activation induced by non-meaningful verbal stimulation is widespread within the left temporal and parietal regions but does not impact upon the frontal speech cortices.

Adult↗
PubMed1987

Fetal hydronephrosis: selection and surgical repair.

Newly developed diagnostic techniques allowed us to select a fetus with potentially reversible renal damage from the usually fatal group with bilateral hydronephrosis and severe oligohydramnios early in gestation. Fetal surgery to marsupialize the fetal bladder at 24 weeks gestation restored normal amniotic fluid dynamics and allowed sufficient pulmonary and renal development to insure survival after delivery near term.

Adult↗
PubMed1987

Extradural infusion of 0.125% bupivacaine at 10 ml h-1 to women during labour.

One hundred primigravidae were allocated randomly to receive either an extradural infusion of 0.125% bupivacaine (Marcain) 10 ml (12.5 mg) per hour during labour, or no infusion. Both groups had intermittent "top-ups" of 0.5% bupivacaine when indicated. The mean interval between top-ups was significantly longer in the infusion group (218 min v. 152 min). Seventy-six percent of the mothers in the infusion group required no or only one top-up. Although the infusion patients received a higher mean dose of bupivacaine (178 mg v. 130 mg), there was no difference between the groups with respect to mode of delivery, need for urinary catheterization, adverse cardiovascular effects on mother or fetus, or the time taken after delivery to recover sensation and motor power. The only real disadvantage was that the infusion group had an increased incidence of lower limb weakness (64% v. 44%). The neonates had similar Apgar scores, times to sustained respiration and requirements for resuscitation. The technique, therefore, should be safe if coupled with testing of sensory level, as no block extended higher than T6.

Adult↗
PubMed1987

Recovery of bowel motility after surgery. Detection of time of first flatus from carbon dioxide concentration and patient estimate after nalbuphine and placebo.

Co-ordinated bowel motility has been studied after surgery. The time to first flatus (TFF) was noted by 20 patients aged 60 yr or older and measured simultaneously using a carbon dioxide analyser. After cystoscopy under general anaesthesia, 10 patients received nalbuphine 20 mg i.v., and 10 patients had placebo (normal saline). In 16 patients (80%) the two observed times coincided and there were no false reports. Two patients were asleep, and did not report TFF. In two others the sampling tube became obstructed. Therefore, both methods are of value; the carbon dioxide analyser, however, is a sensitive and accurate monitor of the initial passage of flatus which does not require patient co-operation. In the i.v. nalbuphine group, the median TFF was more than three times as long (212 min) as that in the placebo group (64 min) (P less than 0.01).

Aged↗