Sympathetic hyperactivity, respiratory failure, pruritus, and anesthesia after unintentional epidural injection of potassium chloride: Case report

Background and Objectives. A combination of epidural and general anesthesia has been widely used to attenuate the surgical stress response and to provide postoperative analgesia. This case report illustrates the use of this anesthetic technique. Analgesia was induced with local anesthetic in the immediate postoperative period using unintentional 19.1% potassium chloride (KCI) as diluent. Methods. An ASA I male patient was scheduled for surgical correction of idiopathic megaesophagus under continuous epidural anesthesia combined with general anesthesia. In the postoperative period, while preparing 10 mt 0.125% bupivacaine to be administered through the epidural catheter for pain control, 5 mt 19.1% KCI was unintentionally used as diluent, resulting in a 9.55% potassium solution concentration. Results. The patient developed warmness of the lower limbs, tachycardia, hypertension, intense pruritus on the chest, agitation, exacerbation of sensory and motor blocks, and respiratory failure secondary to pulmonary edema, requiring ventilatory support. Total recovery was observed after 24 hours. Conclusions. Epidurally injected potassium leads to severe clinical manifestations caused by autonomic dysfunction, spinal cord irritation, and possible release of histamine. Despite continuous recommendations, ampule misidentification still happens in hospitals, frequently leading to serious accidents.

Preoperative combined with intraoperative skin-surface warming avoids hypothermia caused by general anesthesia and surgery

Study Objectives: To evaluate the effects of intraoperative skin-surface warming with and without 1 hour of preoperative warming, in preventing intraoperative hypothermia, and postoperative hypothermia, and shivering, and in offering good conditions to early tracheal extubation. Design: Prospective, randomized, blind study. Setting: Teaching hospital. Patients: 30 ASA physical status I and II female patients scheduled for elective abdominal surgery. Interventions: Patients received standard general anesthesia. In 10 patients, no special precautions were taken to avoid hypothermia. Ten patients were submitted to preoperative and intraoperative active warming. Ten patients were only warmed intraoperatively. Measurements and Main Results: Temperatures were recorded at 15-minute intervals. The patients who were warmed preoperatively and intraoperatively had core temperatures significantly more elevated than the other patients during the first two hours of anesthesia. All patients warmed intraoperatively were normothermic only at the end of the surgery. The majority of the patients warmed preoperatively and intraoperatively or intraoperatively only were extubated early, and none had shivering. In contrast, five unwarmed patients shivered. Conclusions: One hour of preoperative warning combined with intraoperative skin-surface warming, not simply intraoperative warming alone, avoided hypothermia caused by general anesthesia during the first two hours of surgery. Both methods prevented postoperative hypothermia and shivering and offered good conditions for early tracheal extubation. © 2003 by Elsevier B.V.

Effects on mother and fetus of epidural and combined spinal-epidural techniques for labor analgesia

OBJETIVO: A peridural (AP) e a técnica de duplo bloqueio (DB) são utilizadas em analgesia para o trabalho de parto. Este estudo comparou os efeitos na mãe e no feto de ambas as técnicas em analgesia e anestesia para o parto. MÉTODOS: Quarenta parturientes ASA I e II receberam por via peridural 15 ml de ropivacaína a 0,125% (grupo AP) e 5 µg de sufentanil com 2,5 mg bupivacaína por via subaracnóidea (grupo DB). Foram avaliados: intensidade de dor, altura do bloqueio sensitivo, tempo de latência, bloqueio motor, duração da analgesia de parto, tempo para a resolução do parto, hipotensão materna e presença de prurido. Os recém-nascidos foram avaliados pelo índice de Apgar e escore da capacidade adaptativa e neurológica (ECAN), método de Amiel-Tison. RESULTADOS: Não houve diferenças significativas entre os grupos na intensidade da dor, no tempo de latência, no nível do bloqueio sensitivo e no índice de Apgar. O bloqueio motor, a duração da analgesia e o tempo para resolução do parto foram maiores no grupo DB, do qual sete parturientes apresentaram prurido leve. ECAN foi maior no grupo AP após meia hora, duas horas e 24 horas. Noventa e cinco por cento dos recém-nascidos do grupo AP e 60% do grupo DB foram considerados neurologicamente vigorosos ao exame de 24 horas. CONCLUSÃO: As duas técnicas mostraram-se eficazes para analgesia do trabalho de parto. As parturientes do grupo DB apresentaram prurido e trabalho de parto mais prolongado. Recém-nascidos de mães que receberam analgesia de parto via peridural apresentaram melhor ECAN.

Severe esophageal injuries occurring after general anesthesia in two cats: case report and literature review

Two healthy cats underwent elective surgical procedures under general anesthesia. One developed severe esophagitis leading to esophageal rupture, mediastinitis, and pyothorax. The other cat developed esophageal stricture, diverticulum formation, and suspected iatrogenic perforation. Both cats had signs of dysphagia and regurgitation beginning a few days after anesthesia. The first cat also had severe dyspnea due to septic pleural effusion and pneumomediastinum. In the second cat, endoscopy revealed diffuse esophagitis, an esophageal stricture, and a large esophageal diverticulum. Rupture of the esophageal wall occurred while inflating the esophagus for inspection. Due to the poor prognosis, both cats were euthanized. Necropsy revealed severe esophageal changes. Postanesthetic esophagitis has been previously described in dogs and cats; however, severe life-threatening esophageal injuries rarely occur as a sequel to general anesthesia. To the authors' knowledge, esophageal rupture secondary to perianesthetic reflux has never been reported in cats.

General anesthesia with sevoflurane decreases myocardial blood volume and hyperemic blood flow in healthy humans

BACKGROUND Preservation of myocardial perfusion during general anesthesia is likely important in patients at risk for perioperative cardiac complications. Data related to the influence of general anesthesia on the normal myocardial circulation are limited. In this study, we investigated myocardial microcirculatory responses to pharmacological vasodilation and sympathetic stimulation during general anesthesia with sevoflurane in healthy humans immediately before surgical stimulation. METHODS Six female and 7 male subjects (mean age 43 years, range 28-61) were studied at baseline while awake and during the administration of 1 minimum alveolar concentration sevoflurane. Using myocardial contrast echocardiography, myocardial blood flow (MBF) and microcirculatory variables were assessed at rest, during adenosine-induced hyperemia, and after cold pressor test-induced sympathetic stimulation. MBF was calculated from the relative myocardial blood volume multiplied by its exchange frequency (β) divided by myocardial tissue density (ρT), which was set at 1.05 g·mL(-1). RESULTS During sevoflurane anesthesia, MBF at rest was similar to baseline values (1.05 ± 0.28 vs 1.05 ± 0.32 mL·min(-1)·g(-1); P = 0.98; 95% confidence interval [CI], -0.18 to 0.18). Myocardial blood volume decreased (P = 0.0044; 95% CI, 0.01-0.04) while its exchange frequency (β) increased under sevoflurane anesthesia when compared with baseline. In contrast, hyperemic MBF was reduced during anesthesia compared with baseline (2.25 ± 0.5 vs 3.53 ± 0.7 mL·min(-1)·g(-1); P = 0.0003; 95% CI, 0.72-1.84). Sympathetic stimulation during sevoflurane anesthesia resulted in a similar MBF compared to baseline (1.53 ± 0.53 and 1.55 ± 0.49 mL·min(-1)·g(-1); P = 0.74; 95% CI, -0.47 to 0.35). CONCLUSIONS In otherwise healthy subjects who are not subjected to surgical stimulation, MBF at rest and after sympathetic stimulation is preserved during sevoflurane anesthesia despite a decrease in myocardial blood volume. However, sevoflurane anesthesia reduces hyperemic MBF, and thus MBF reserve, in these subjects.

Evaluation of liver parenchyma and perfusion using dynamic contrast-enhanced computed tomography and contrast-enhanced ultrasonography in captive green iguanas (Iguana iguana) under general anesthesia.

BACKGROUND Contrast-enhanced diagnostic imaging techniques are considered useful in veterinary and human medicine to evaluate liver perfusion and focal hepatic lesions. Although hepatic diseases are a common occurrence in reptile medicine, there is no reference to the use of contrast-enhanced ultrasound (CEUS) and contrast-enhanced computed tomography (CECT) to evaluate the liver in lizards. Therefore, the aim of this study was to evaluate the pattern of change in echogenicity and attenuation of the liver in green iguanas (Iguana iguana) after administration of specific contrast media. RESULTS An increase in liver echogenicity and density was evident during CEUS and CECT, respectively. In CEUS, the mean ± SD (median; range) peak enhancement was 19.9% ± 7.5 (18.3; 11.7-34.6). Time to peak enhancement was 134.0 ± 125.1 (68.4; 59.6-364.5) seconds. During CECT, first visualization of the contrast medium was at 3.6 ± 0.5 (4; 3-4) seconds in the aorta, 10.7 ± 2.2 (10.5; 7-14) seconds in the hepatic arteries, and 15 ± 4.5 (14.5; 10-24) seconds in the liver parenchyma. Time to peak was 14.1 ± 3.4 (13; 11-21) and 31 ± 9.6 (29; 23-45) seconds in the aorta and the liver parenchyma, respectively. CONCLUSION CEUS and dynamic CECT are practical means to determine liver hemodynamics in green iguanas. Distribution of contrast medium in iguana differed from mammals. Specific reference ranges of hepatic perfusion for diagnostic evaluation of the liver in iguanas are necessary since the use of mammalian references may lead the clinician to formulate incorrect diagnostic suspicions.

Combined free and forced convection along a rotating vertical cylinder

The steady incompressible laminar mixed convection boundary layer flow along a rotating slender vertical cylinder with an isothermal wall has been studied. The transformed coupled nonlinear partial differential equations have been solved numerically using the Keller box method. In general, the rotation of the cylinder, the buoyancy forces and the curvature parameter are found to significantly affect the skin friction, heat transfer, velocity and temperature profiles as well as the pressure distribution. The buoyancy forces cause an overshoot in the axial velocity profile but the rotation and curvature parameters reduce it.

Fracture criteria for combined cleavage and dislocation emission

A general theory of fracture criteria for mixed dislocation emission and cleavage processes is developed based on Ohr's model. Complicated cases involving mixed-mode loading are considered. Explicit formulae are proposed for the critical condition of crack cleavage propagation after a number of dislocation emissions. The effects of crystal orientation, crack geometry and load phase angle on the apparent critical energy release rates and the total number of the emitted dislocations at the initiation of cleavage are analysed in detail. In order to evaluate the effects of nonlinear interaction between the slip displacement and the normal separation, an analysis of fracture criteria for combined dislocation emission and cleavage is presented on the basis of the Peierls framework. The calculation clearly shows that the nonlinear theory gives slightly high values of the critical apparent energy release rate G(c) for the same load phase angle. The total number N of the emitted dislocations at the onset of cleavage given by nonlinear theory is larger than that of linear theory.

Nonlinear dynamics of the patient’s response to drug effect during general anesthesia

In today’s healthcare paradigm, optimal sedation during anesthesia plays an important role both in patient welfare and in the socio-economic context. For the closed-loop control of general anesthesia, two drugs have proven to have stable, rapid onset times: propofol and remifentanil. These drugs are related to their effect in the bispectral index, a measure of EEG signal. In this paper wavelet time–frequency analysis is used to extract useful information from the clinical signals, since they are time-varying and mark important changes in patient’s response to drug dose. Model based predictive control algorithms are employed to regulate the depth of sedation by manipulating these two drugs. The results of identification from real data and the simulation of the closed loop control performance suggest that the proposed approach can bring an improvement of 9% in overall robustness and may be suitable for clinical practice.

Nonlinear dynamics of the patient’s response to drug effect during general anesthesia

In today’s healthcare paradigm, optimal sedation during anesthesia plays an important role both in patient welfare and in the socio-economic context. For the closed-loop control of general anesthesia, two drugs have proven to have stable, rapid onset times: propofol and remifentanil. These drugs are related to their effect in the bispectral index, a measure of EEG signal. In this paper wavelet time–frequency analysis is used to extract useful information from the clinical signals, since they are time-varying and mark important changes in patient’s response to drug dose. Model based predictive control algorithms are employed to regulate the depth of sedation by manipulating these two drugs. The results of identification from real data and the simulation of the closed loop control performance suggest that the proposed approach can bring an improvement of 9% in overall robustness and may be suitable for clinical practice.

Comparación de la anestesia espinal con anestesia general endovenosa para legrado uterino obstétrico

Introducción: La elección de la técnica anestésica para cualquier procedimiento quirúrgico debe estar basada en su seguridad, la rapidez para su aplicación, la recuperación óptima para el paciente y minimización de los efectos secundarios, la anestesia raquídea es una técnica anestésica que puede ser utilizada con buenos resultados clínicos y minimas complicaciones . Materiales y métodos: Se realizó un estudio observacional con recolección prospectiva en mujeres clasificadas como ASA I - II y que posteriormente fueron llevadas a la realización de legrado uterino obstétrico por embarazo no viable durante las primeras 12 semanas de gestación, las técnicas anestésicas fueron anestesia espinal o anestesia general endovenosa dependiendo de la elección hecha por el anestesiólogo previo al procedimiento. Se midieron variables hemodinámicas, control del dolor postoperatorio, tiempo de recuperación y complicaciones perioperatorias con el fin de determinar si se presentaban diferencias significativas entre estas dos técnicas anestésicas. Resultados: Se incluyeron un total de 110 pacientes, 63.6% (n=70) con anestesia general y 36.4% (n40) con anestesia espinal. Ambas poblaciones fueron comparables. Se presentaron menos efectos secundarios con la técnica espinal, hay una diferencia estadísticamente significativa en cuanto al dolor a favor de la anestesia espinal (p0,000) Discusión: La anestesia raquídea es una opción viable, sencilla , fácil y eficaz para la realización de legrados obstétricos, se puede realizar con monitorización básica y las complicaciones son mínimas. Se requieren estudios más amplios para determinar el papel de cual es la mejor técnica. Palabras claves: legrado uterino instrumentado, anestesia espinal, anestesia general endovenosa

A combined statistical and dynamical approach for downscaling large-scale footprints of European windstorms

The occurrence of mid-latitude windstorms is related to strong socio-economic effects. For detailed and reliable regional impact studies, large datasets of high-resolution wind fields are required. In this study, a statistical downscaling approach in combination with dynamical downscaling is introduced to derive storm related gust speeds on a high-resolution grid over Europe. Multiple linear regression models are trained using reanalysis data and wind gusts from regional climate model simulations for a sample of 100 top ranking windstorm events. The method is computationally inexpensive and reproduces individual windstorm footprints adequately. Compared to observations, the results for Germany are at least as good as pure dynamical downscaling. This new tool can be easily applied to large ensembles of general circulation model simulations and thus contribute to a better understanding of the regional impact of windstorms based on decadal and climate change projections.

Palaeobiology of the medieval population of Albano (Rome, Italy): a combined morphological and biomolecular approach

Recent years have seen increased interest in skeletal populations from the Imperial Roman Age in Italy, but much less is known about diet and standards of living in the subsequent medieval period. To fill this gap, we conducted a morphological analysis of human remains from Albano, an Italian town near Rome, as well as a stable isotope analysis of bone collagen to reconstruct diet. The sample was recovered from a Medieval cemetery (1040–1220 cal. yr. BP) located in the gardens of the historical Palazzo Doria Pamphili in Albano. A minimum number of 40 individuals (31 adults and 9 sub-adults) were examined using standard methods. Though the general health status of the population was good, signs of cribra orbitalia and diffuse enthesopathies were noted during the morphological examination. Stable carbon and nitrogen isotope analyses of the bone collagen from 24 adult humans and three faunal bones indicate that the diet of the population may be described as predominantly terrestrial and C3-plant based although the data for some of the individuals suggest a modest consumption of C4-(millet) based or aquatic proteins. No evidence of significant dietary differences between the sexes was found. The comparison of the isotope data from Albano with those from populations recovered in the same region is consistent with a shift from a terrestrial, possibly plant foods-dominated subsistence in the Early Middle Ages to a diet with a higher contribution from animal proteins, both terrestrial and aquatic, in the Later Middle Ages.