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Biomedical subjects

A Fernandes

Publications and source records attributed to A Fernandes.

At least 127 records · Page 7Linked to original sources
PubMed1982

The use of epidural analgesia for delivery in a patient with pulmonary hypertension.

In a patients with severe pulmonary hypertension, haemodynamic observations, including cardiac output and pressure measurement in the systemic and the pulmonary circulation, were performed during vaginal delivery under selective segmental epidural block from T9 to L1 combined with bilateral pudendal blocks. No hypotensive episodes were observed in connection with the epidural block, but a gradual increase in the pulmonary pressures was observed during the stages of delivery. After perineal analgesia was achieved with bilateral pudendal blocks, a 2100 g girl with an Apgar score of 9 at 1 min was delivered by vacuum extraction. The patient died 9 days after the delivery because of intractable cardiac failure.

Anesthesia, Epidural↗
PubMed1981

Effect of changes in PCO2 and body positions on intraocular pressure during general anaesthesia.

Elevated arterial carbon dioxide tension, induced by the administration of CO2 via the respiratory air or by hypoventilation, entailed a gradual increase in the IOP in patients without eye diseases under general anaesthesia. A sudden cessation of CO2 administration or hyperventilation caused such a rapid, simultaneous fall in IOP to values below the initial level that the pressure variations must be of vascular nature, presumably related to changes in choroidal blood volume. The above-mentioned procedures always cause a change in the central venous pressure (CVP) simultaneously with the IOP changes. Alterations of the CVP induced by hydrostatic factors in postural changes, placing the head 15 degrees above or below the horizontal level while keeping the PaCO2 constant, caused IOP changes of the same configuration and magnitude as described above. It is concluded, therefore, that presumably the CO2-conditioned IOP changes are due predominantly to changes in central venous pressure, being one link in a CO2-conditioned action upon the general circulation, entailing passive secondary changes in the choroidal venous blood volume and thereby an influence upon the IOP. On the basis of the present results it appears rational to recommend hyperventilation to keep the PaCO2 between 25 and 30 mm and a 15 degree anti-Trendelenburg position in operations on the eye under general anaesthesia, since both procedures afford a low central venous pressure and consequently a low pressure in the posterior segment of the eye, with its attendant advantages as regards vitreous complications and the insertion of intraocular lenses. Owing to the risk of an unacceptable fall in BP in the combined procedure, a frequent checking of the BP is needed.

Adult↗
PubMed1978

ABO and Rh phenotyping of foetal blood obtained by foetoscopy.

Blood samples taken from the foetus by foetoscopy early in the 2nd trimester of pregnancy can be used for reliable blood grouping. However, the sampling technique is not perfect. In 5 out of 15 pregnant women, no foetal blood was obtained, although between 1 and 10 samples were taken on each occasion. One-third of 56 samples from the 10 women contained foetal blood. Contamination of samples with amniotic fluid varied, but did not interfere with the blood grouping. ABO and Rh typing of the foetus was possible even if the samples were contaminated with large amounts of maternal blood. In nine cases, blood grouping of the foetus was performed on red cells from foetoscopy samples. Control blood samples from the foetus following abortion were obtained in seven of these cases, and the foetoscopic results were confirmed.

ABO Blood-Group System↗
PubMed1977

The blocking effect of epidural analgesia on the adrenocortical and hyperglycemic responses to surgery.

The adrenocortical and hyperglycemic responses to hysterectomy were studied in five groups of patients receiving: general anesthesia (group I), general anesthesia + epidural analgesia extending from Th10-S5 (group II), general anesthesia + epidural analgesia extending from Th8-S4--5 (group III), general anesthesia + epidural analgesia extending from Th4--6-S5 (group IV) and epidural analgesia extending from Th4-S5 without general anesthesia (group V). The results showed that the cortisol response was abolished in group V, inhibited in group IV and normal in groups II and III. The hyperglycemic response to surgery was inhibited in groups II, III and IV, and abolished in group V. Epidural analgesia from Th4 to S5, preventing the adrenocortical and hyperglycemic responses to hysterectomy, and possibly also inhibiting other components of the endocrine-metabolic response to surgery, may have important applications in further studies of the physiologic significance of the endocrine-metabolic response to surgery.

Adrenal Cortex↗
PubMedDate not supplied

Multifocal versus monofocal correction of neonatal monocular aphakia.

We compared the efficacy of monofocal and multifocal intraocular lenses (IOLs) as a means of optically rehabilitating eyes with monocular congenital cataracts using a primate model. A congenital cataract was simulated in the right eye of 20 monkeys from birth to 2 weeks of age with an opalescent contact lens. A lensectomy was then performed and a monofocal IOL was implanted in 11 eyes and a multifocal IOL in 9 eyes. Any residual refractive error was then corrected with an extended-wear contact lens. The fellow eyes were then randomized to no treatment or 70% occlusion therapy. Grating acuity was assessed using forced-choice preferential looking with Teller acuity cards at regular intervals. At 32 weeks of age, the pseudophakic eyes were mildly amblyopic, but the grating acuities were not significantly different between the pseudophakic eyes with multifocal versus monofocal IOLs or between subjects who had received occlusion therapy versus no treatment of the fellow eye. We conclude that at least through 32 weeks of age, multifocal and monofocal IOLs are of similar efficacy and occlusion therapy may be less important to prevent amblyopia from developing in pseudophakic eyes compared to contact-lens corrected aphakic eyes.

Amblyopia↗
PubMedDate not supplied

Haptic breakage following neonatal IOL implantation in a nonhuman primate model.

To evaluate the long-term safety of implanting intraocular lenses (IOLs) in neonatal eyes using a nonhuman primate model, a one-piece all-polymethylmethacrylate (PMMA) IOL was implanted into the posterior chamber of 21 neonatal Rhesus monkey eyes following a lensectomy and anterior vitrectomy. These monkeys then were monitored for 26 to 40 months for complications. The eyes from seven monkeys were studied histopathologically. One or both haptics broke on 7 of the 21 (33%) IOLs in a mean of 21 months (range 6 to 31 months) after their implantation. Only one of the haptics from these seven eyes was found to be in the capsular bag when these eyes were studied histopathologically. Nine haptics had eroded into the iris leaflets, two into the ciliary body, and one into the anterior chamber. One additional haptic was in the sulcus. The haptics of one-piece all-PMMA IOLs may break if implanted in neonatal eyes. A number of factors likely contributed to haptic breakage in these eyes, including an increased number of reoperations, malpositioning of IOL haptics, rapid circumferential and axial growth, and the formation of large Soemmerring's rings.

Animals↗
PubMedDate not supplied

Benign isolated fibrohistiocytic tumor arising from the central nervous system. Considerations about two cases.

Benign fibrous histiocytomas (BFHs) are tumors with fibroblastic and histiocytic components without histological anaplasia. Intracerebral lesions are exceptional and to our knowledge a spinal location was not yet described. We describe 2 cases of BFHs of the neural axis: the first, a 22-month-old boy with Down's syndrome, presented with a paraparesis and the magnetic resonance (MR) of the spine disclosed an intradural extramedullary, thoracic mass, totally resected; the second, a 13-year-old boy with left partial motor seizures, in whom the MR of the brain showed an intracerebral, right frontal tumor, also surgically removed. Both patients are free of recurrence, 6 years and 15 months after surgery, respectively. Histological examination and immunoreactivity for vimentin and histiocytic markers favored the diagnosis of BFH. It is likely that these tumors may originate from spinal dura mater mesenchymal stem cells and from the intracerebral perivascular pial sheath or the brain vessel walls themselves, respectively. Other benign, isolated, intracranial fibrohistiocytic neoplasms, namely the juvenile xanthogranuloma, can harbor a clinical, morphological and immunohistochemical profile overlapping the one of the BFH. Intracranial germ cell tumors may be associated with Down's syndrome, although harboring an unusual, non-pineal and non-chiasmatic location. One can speculate that a similar, still unknown genetic mechanism responsible for this association, could also induce the growth of other type of tumors in patients with this syndrome. BFHs should be added to the differential diagnosis of intracerebral or spinal dural attached tumors. Furthermore, we propose to name these intracranial tumors "benign isolated fibrohistiocytic tumors of the CNS".

Adolescent↗