Modified Mach-Zehnder interferometer for spatial coherence measurement.

Spatial coherence of light sources is usually obtained by using the classical Young's interferometer. Although the original experiment was improved upon in successive works, some drawbacks still remain. For example, several pairs of points must be used to obtain the complex coherence degree (normalized first-order correlation function) of the source. In this work, a modified Mach-Zehnder interferometer which includes a pair of lenses and is able to measure the spatial coherence degree is presented. With this modified Mach-Zehnder interferometer, it is possible to measure the full 4D spatial coherence function by displacing the incoming beam laterally. To test it, we have measured only a 2D projection (zero shear) of the 4D spatial coherence, which is enough to characterize some types of sources. The setup has no movable parts, making it robust and portable. To test it, the two-dimensional spatial coherence of a high-speed laser with two cavities was measured for different pulse energy values. We observe from the experimental measurements that the complex degree of coherence changes with the selected output energy. Both laser cavities seem to have similar complex coherence degrees for the maximum energy, although it is not symmetrical. Thus, this analysis will allow us to determine the best configuration of the double-cavity laser for interferometric applications. Furthermore, the proposed approach can be applied to any other light sources.

Two-dimensional quantification of the corrosion process in metal surfaces using digital speckle pattern interferometry.

The applicability of digital speckle pattern interferometry (DSPI) to the analysis of surface corrosion processes has been evaluated by studying the evolution of an Fe surface immersed in sulfuric acid. This work describes the analysis process required to obtain quantitative information about the corrosion process. It has been possible to evaluate the corrosion rate, and the results agree with those derived from the weight loss method. In addition, a two-dimensional analysis has been applied, showing that DSPI measurements can be used to extract information about the corrosion rate at any region of the surface.

[Orotracheal tube ignited by an electrocautery device during tracheostomy]. / Ignición del tubo orotraqueal inducida por electrocauterio durante una traqueostomía.

Endotracheal tube fire during surgery is a rare complication associated with carbon dioxide laser surgery and, less often, with electrocautery. We report a case in which tracheostomy was performed because of recurrence of a laryngeal tumor. During the procedure the endotracheal tube ignited when the lumen was opened with the electrocautery device.

[Spinal cord compression by tumor with onset following epidural catheterization]. / Compresión medular neoplásica iniciada tras cateterización peridural.

We report the case of a 16-year-old boy with a pelvic tumor who developed signs of spinal cord compression following placement of a lumbar epidural catheter to obtain a percutaneous biopsy. The fact that a catheter had been inserted led us to suspect epidural hematoma as a complication, but surgery revealed that the pelvic tumor had spread to the lumbar epidural space and was causing motor blockade of both legs.

[Anesthetic considerations in primary immunodeficiencies]. / Consideraciones anestésicas en las inmunodeficiencias primarias.

Primary immunodeficiencies are a group of mostly hereditary, or congenital, disorders. Some cases, however, show no hereditary pattern despite an evident familial distribution. The incidence of these cases is variable and the most frequent of them is immunoglobulin A deficiency. Many are pediatric disorders that are occasionally so serious that the patient does not survive the first year of life due to the development of systemic infections. In other cases, survival is much longer and it is possible to find adult carriers in routine clinical practice. These are less aggressive cases that form part of specific clinical syndromes that must be recognized so that appropriate anesthetic management can be planned. We review the clinical characteristics of primary immunodeficiencies that may be relevant to anesthetic management in these patients.

[Cellular immune response to 3 anesthetic techniques for simple abdominal hysterectomy]. / Estudio de la respuesta celular inmune de tres técnicas de anestesia para histerectomía abdominal simple.

BACKGROUND AND OBJECTIVE: The effect of surgery and anesthesia on the immune response may have a significant effect on perioperative tumor surveillance. The aim of this study was to characterize the cellular immune response of patients undergoing simple abdominal hysterectomy under 3 types of anesthesia. PATIENTS AND METHODS: ASA 1-2 patients undergoing simple abdominal hysterectomy were enrolled prospectively after they gave informed consent; the patients were randomized to 3 groups of 20 each to receive balanced anesthesia (group A), remifentanil-based anesthesia and analgesia (group B), or combined general-epidural anesthesia (group C). Postoperative analgesia was provided in accordance with group assignment. Four and 24 hours after surgery, 20 mL of blood was drawn from each patient for analysis of leukocyte populations and lymphocyte subpopulations. Statistics were calculated with the SPSS software package, version 12.0. RESULTS: All groups had elevated neutrophil counts after surgery; the lowest levels were in group C (P<.05). Patients in all 3 groups developed lymphopenia, which was still evident 24 hours after surgery (P<.05). CD3 cell counts at 4 hours were lowest in patients who had received combined anesthesia (group C), CD19 cell counts were highest in group A, and CD16 cell counts were lowest in group C; this last difference was maintained at 24 hours (P<.05 for all these comparisons). CONCLUSION: Combined general-epidural anesthesia seems to lower the counts of natural killer cells that are involved in tumor surveillance and destruction.

[Complex regional pain syndrome type 2 after radial artery catheterization: a case report]. / Síndrome de dolor regional complejo tipo II tras cateterización de arteria radial. A propósito de un caso.

Complex regional pain syndrome has multiple causes. The clinical picture includes pain that can be debilitating, along with vascular and motor abnormalities, changes in sweating, delayed recovery, eating disorders, and occasionally psychological changes. Treatment is complex and should be started early if symptoms are to be reversed. We report the case of a man who developed complex regional pain syndrome type 2 in his left arm after surgery with extracorporeal circulation to repair an interatrial septal defect. The clinical picture was believed to have been triggered by catheterization of the radial artery.

[Metabolic and immune response to spinal vs intravenous morphine for analgesia after radical prostatectomy]. / Estudio comparativo de la respuesta metabólica e inmunológica de la morfina administrada vía subaracnoidea frente a morfina endovenosa para el control del dolor postoperatorio en prostatectomía radical.

OBJECTIVE: To study differences between the endocrine-metabolic and immune cell responses to spinal or intravenous administration of morphine for analgesia after radical prostatectomy. MATERIAL AND METHODS: Prospective study of 60 patients randomized to 2 groups: in group A (n=30) morphine for postoperative analgesia was infused intravenously and in group B (n=30) morphine was infused into the spinal canal. Changes in leukocyte populations and lymphocyte subpopulations in peripheral blood and blood from surgical drains (local) were analyzed to study immune cell response to morphine administration. Cortisol, corticotropin, growth hormone, glucose, and immunoglobulin levels in peripheral blood were measured as indicators of metabolic and humoral immune responses. RESULTS: Both groups developed lymphopenia in peripheral blood. The group treated with spinal morphine had significantly lower CD4+ cell counts in peripheral blood P<0.05. No differences were found in the local leukocyte response in either group. Significant differences were found in natural killer and CD4+ cell counts both locally and in peripheral blood P<0.05. There was humoral immune response suppression in both groups; however, it was more marked in the group treated with spinal morphine and the difference was significant P<0.05. The metabolic response was greater in the group treated with intravenous morphine. CONCLUSION: Patients who received morphine by spinal infusion had a less marked endocrine-metabolic response. Although local cell responses were similar in the 2 groups, the response in peripheral blood was different, possibly reflecting different mechanisms of central modulation of the inflammatory response to stress.

[Systemic lupus erythematosus in the pregnant patient. Implications for anesthesia]. / Lupus eritematoso sistémico en la paciente gestante. Implicaciones anestésicas.

A 28-year-old woman with systemic lupus erythematosus and a history of aseptic meningitis, digestive bleeding due to thrombopenia and deep venous thrombosis underwent elective cesarean for transverse presentation at 35 weeks. Preoperative blood work-up showed an antinuclear antibody titre that was slightly positive and steroid treatment was started. Surgery operation was performed with general anesthesia. The outcome was satisfactory even though serious complications can develop during the management of anesthesia in such patients. Systemic lupus erythematosus is a chronic, multisystemic disease that mainly affects women of childbearing age. Antibodies and immunocomplexes play a fundamental role. Given the multiorgan involvement in this disease, preoperative study of the lupus patient should assess all such involvement, including maternal-fetal risk, as well as consider the drug and anesthetic management to be applied. Among the clinical signs that can affect management of anesthesia are the following: aseptic meningitis, high blood pressure, pericarditis, pneumonitis and recurrent venous thrombosis. Anemia, thrombopenia and significantly altered coagulation events are common.

[Tetraplegia in the immediate postoperative period of stapedectomy]. / Tetraplejía en el postoperatorio inmediato de una estapedectomía.

Management of the cervical spine in orotracheal intubation for general anesthesia is an important aspect of daily practice in anesthesiology. Also important are the requirements, techniques and consequences of patient position during surgery. We report a case of tetraplegia during the early postoperative period after stapedectomy for otosclerosis. After surgery, the spontaneously breathing patient was transferred to the recovery room, where a clinical picture of anesthesia and paralysis of all four limbs was evident. We ordered an emergency magnetic resonance image of the cervical spine, which revealed a massive acutely herniated disk at C6-C7 with signs of ischemia or necrosis of the medulla at the same level. After eight months, the patient was still paraplegic and lacked sensation in the lower limbs. Sensation and motor function in the upper limbs was nearly normal. We review the etiopathogenetic mechanisms that might be responsible for this clinical profile.