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A variety of reproductive barriers can enable reproductive isolation and stable coexistence of plant species. Differing floral traits might play an important role in reproductive isolation imposed by pollinators. Such shifts in pollinator use have been hypothesized to contribute to the radiation of Erica (Ericaceae) in the Cape Floristic Region, South Africa. The sister species Erica shannonea and Erica ampullacea co-occur and overlap in flowering phenology. Both have unscented long-tubed flowers consistent with adaptations for pollination by long-proboscid flies (LPFs), but differences in flower orientation and corolla tube length are indicative of a shift in pollinator species. We conducted controlled pollination experiments and pollinator observations to determine the breeding system and pollinators of the two species. Both species are self-incompatible and require pollinator visits for seed production, suggesting that pollinators could strongly influence flower evolution. The horizontally orientated flowers of E. shannonea were found to be pollinated by Philoliche rostrata (Tabanidae), which has a long, fixed forward-pointing proboscis, while the vertically upright orientated flowers of E. ampullacea were found to be pollinated by Prosoeca westermanni (Nemestrinidae), which has a shorter proboscis that can swivel downwards. The nemestrinid fly's proboscis is too short to access the nectar in the relative long-tubed flowers of E. shannonea and the tabanid fly's proboscis cannot swivel down to access the upright flowers of E. ampullacea. Consequently, these traits are likely to act as reproductive barriers between the two Erica species and thereby might have contributed to speciation and enable stable coexistence.
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Ericaceae , Fitomejoramiento , Reproducción , Flores , PolinizaciónRESUMEN
BACKGROUND AND AIMS: Is the increase in species diversity patterns towards lower latitudes, linked to reproductive traits? Plant reproductive organs influence reproductive isolation and hence species divergence. Abiotic differences between temperate and tropical regions can also directly impact on plant reproductive traits. Here we provide a novel overview of southern hemisphere, Afromontane forest tree taxonomical patterns and ask whether reproductive traits relate to latitude, while accounting for environmental (tree height) and evolutionary (biogeographical affinity) selective forces. METHODS: We compiled a novel dataset with a) flower colour, size and pollination syndrome and b) fruit colour, size and dispersal syndrome for 331 tree species found in six Afromontane forest regions. We categorised each species into latitudinal distribution using these six regions, spanning the southern Cape (34º S) to Mount Kenya (0º S). Additionally, we gathered maximum tree height (m) for each species and determined the global distribution of all 196 tree genera (Afrotropical, Palaeotropical or Pantropical). KEY RESULTS: Species, genera and families showed a general decrease in richness away from tropical and subtropical forests towards warm temperate forests. Southern Afrotemperate forests (the furthest south) had the highest tree endemism. There was no relationship between latitude and the reproductive traits tested here. Biogeographical affinity related to fruit colour and dispersal syndrome, with palaeotropical genera showing relative increases in black-purple fruit colour compared to pantropical genera and palaeotropical genera showing relative increases in biotic seed dispersal compared to Afrotropical genera, which showed higher relative abiotic seed dispersal. Taller trees had a higher chance to be wind or insect pollinated (compared to bird pollinated) and had larger fruits. CONCLUSIONS: Latitude explained patterns in Afromontane tree taxonomical diversity, however tree reproductive traits did not relate to latitude. We suggest that phylogenetic conservatism or convergence, or both, explain the reported patterns.
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BACKGROUND: Posterior retroperitoneoscopic adrenalectomy (PRA) is purported to be superior to the laparoscopic transperitoneal approach (LA) in patients with a select spectrum of benign adrenal pathologies. Advantages attributed to the technique include minimal blood loss, shortened operative times, and decreased postoperative pain, explained anatomically by the direct access to the adrenal gland. Reduced workspace is a limitation. METHODS: A retrospective review of 22 consecutive PRAs performed in a single centre between 1 September 2016 and 30 October 2020 is presented. Two experienced laparoscopic surgeons operated on all patients after acquiring the technique at international centres. Suitable candidates were carefully pre-selected. Non-benign pathology, high vascularity, body mass index (BMI) ≥ 45 kg/m2 and anatomical concerns on prior computed tomography (CT) imaging were exclusion criteria. RESULTS: Twenty-two PRAs were performed for a spectrum of benign adrenal pathologies. Twenty-one surgeries (95%) were completed. A single case of pheochromocytoma required conversion. The procedure was safe, a minor postoperative complication (pneumaturia) occurred in one case, and the mortality rate was 0%. Median operative time (80 minutes) is comparable to other reported series in the literature, with a modest linear descending tendency noted over the study period. Underlying pathology influenced operative times. Pheochromocytomas proved to be most challenging and required careful preoperative evaluation. CONCLUSION: The PRA procedures performed at Tygerberg Academic Hospital were safe and reproducible in a select group of cases with benign adrenal pathology. Endocrine surgeons proficient with laparoscopic techniques should be encouraged to use the PRA approach when encountering adrenal neoplasms that fit the criteria.
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Neoplasias de las Glándulas Suprarrenales , Laparoscopía , Humanos , Adrenalectomía/métodos , Sudáfrica , Neoplasias de las Glándulas Suprarrenales/diagnóstico por imagen , Neoplasias de las Glándulas Suprarrenales/cirugía , Laparoscopía/métodos , Estudios RetrospectivosRESUMEN
Invasive plants displaying disparate pollination environments and abiotic conditions in native and non-native ranges provide ideal systems to test the role of different ecological factors driving flower colour variation. We quantified corolla reflectance of the ornithophilous South American Nicotiana glauca in native populations, where plants are pollinated by hummingbirds, and in populations from two invaded regions: South Africa, where plants are pollinated by sunbirds, and the Balearic island of Mallorca, where plants reproduce by selfing. Using visual modelling we examined how corolla reflectance could be perceived by floral visitors present in each region. Through Mantel tests we assessed a possible association between flower colour and different abiotic factors. Corolla reflectance variation (mainly along medium to long wavelengths, i.e. human green-yellow to red colours) was greater among studied regions than within them. Flower colour was more similar between South America and South Africa, which share birds as pollinators. Within invaded regions, corolla reflectance variation was lower in South Africa, where populations could not be distinguished from each other by sunbirds, than in Spain, where populations could be distinguished from each other by their occasional visitors. Differences in corolla colour among populations were partially associated with differences in temperature. Our findings suggest that shifts in flower colour of N. glauca across native and invaded ranges could be shaped by changes in both pollination environment and climatic factors. This is the first study on plant invasions considering visual perception of different pollinators and abiotic drivers of flower colour variation.
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Nicotiana , Polinización , Animales , Humanos , Color , Plantas , Flores , Aves , PercepciónRESUMEN
AIMS: The mounting evidence for effective delivery of psychological interventions by non-specialists in low- and middle-income settings has led to a rapid expansion of mental health and psychosocial support trainings globally. As such, there is a demand for strategies on how to train and implement these services to attain adequate quality. This study aims to evaluate the added value of a competency-driven approach to training of facilitators for a group intervention for children with severe emotional distress in Lebanon. METHODS: In a controlled before and after study, 24 trainees were randomly allocated to participate in either a competency-driven training (CDT) or training-as-usual (TAU) (1 : 1) for a psychological intervention for children with severe emotional distress. We assessed the change in demonstrated competencies, using standardised role-plays, before and after the training. Measures included the 13-item Working with children-Assessment of Competencies Tool (WeACT), the 15-item ENhancing Assessment of Common Therapeutic factors (ENACT) and the 6-item Group facilitation: Assessment of Competencies Tool (GroupACT). The trainer in the experimental arm used pre-training and during training competency assessment scores to make real-time adjustment to training delivery. Due to COVID-19 pandemic restrictions, all activities were done remotely. RESULTS: CDT resulted in significantly better outcomes on increasing competencies on the WeACT (repeated measures analysis of variance; F(1, 22) = 6.49, p < 0.018) and on the GroupACT (Mann-Whitney U = 22, p < 0.003), though not statistically significant on the ENACT. There is no significant between-group difference on the reduction of harmful behaviours, mainly because both forms of training appear equally successful in eliminating such behaviours. CONCLUSIONS: This proof-of-concept study demonstrates the potential of CDT, using standardised assessment of trainee competencies, to contribute to better training outcomes without extending the duration of training. CDT can result in up to 18% greater increase in adequate competency, when compared to TAU. The study also yields recommendations for further enhancing the benefits of competency-driven strategies. A fully powered trial is needed to confirm these findings.
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COVID-19 , Intervención Psicosocial , Niño , Humanos , Líbano , Salud Mental , PandemiasRESUMEN
BACKGROUND: There is a scarcity of evaluated tools to assess whether non-specialist providers achieve minimum levels of competency to effectively and safely deliver psychological interventions in low- and middle-income countries. The objective of this study was to evaluate the reliability and utility of the newly developed Working with children - Assessment of Competencies Tool (WeACT) to assess service providers' competencies in Gaza, Palestine. METHODS: The study evaluated; (1) psychometric properties of the WeACT based on observed role-plays by trainers/supervisors (N = 8); (2) sensitivity to change among service provider competencies (N = 25) using pre-and-post training WeACT scores on standardized role-plays; (3) in-service competencies among experienced service providers (N = 64) using standardized role-plays. RESULTS: We demonstrated moderate interrater reliability [intraclass correlation coefficient, single measures, ICC = 0.68 (95% CI 0.48-0.86)] after practice, with high internal consistency (α = 0.94). WeACT assessments provided clinically relevant information on achieved levels of competencies (55% of the competencies were scored as adequate pre-training; 71% post-training; 62% in-service). Pre-post training assessment saw significant improvement in competencies (W = -3.64; p < 0.001). CONCLUSION: This study demonstrated positive results on the reliability and utility of the WeACT, with sufficient inter-rater agreement, excellent internal consistency, sensitivity to assess change, and providing insight needs for remedial training. The WeACT holds promise as a tool for monitoring quality of care when implementing evidence-based care at scale.
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This article reviews the association between diabetes mellitus (DM) and COVID-19. We report on the convergence of infectious diseases such as coronavirus infections and non-communicable diseases including DM. The mechanisms for the interaction between COVID-19 and DM are explored, and suggestions for the management of DM in patients with COVID-19 in South Africa are offered.
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Infecciones por Coronavirus/terapia , Complicaciones de la Diabetes/terapia , Diabetes Mellitus/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Neumonía Viral/terapia , Guías de Práctica Clínica como Asunto , Antagonistas de Receptores de Angiotensina/uso terapéutico , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Betacoronavirus , COVID-19 , Infecciones por Coronavirus/complicaciones , Infecciones por Coronavirus/epidemiología , Diabetes Mellitus/epidemiología , Diabetes Mellitus/metabolismo , Manejo de la Enfermedad , Hospitalización , Humanos , Pandemias , Neumonía Viral/complicaciones , Neumonía Viral/epidemiología , SARS-CoV-2 , Índice de Severidad de la Enfermedad , Sudáfrica/epidemiologíaRESUMEN
Background: Non-thyroidal illness syndrome (NTIS) can be defined as the presence of abnormal thyroid function in the absence of primary thyroid dysfunction and is associated with acute illness. Thyroid function testing is generally not advised in the critically ill patient. Thyroid-stimulating hormone (TSH) measurement is the preferred screening test for thyroid disease, but results may be misleading and variable in the setting of critical illness. Objectives: To describe the pattern of requests for TSH testing in patients admitted to the emergency department and intensive care units at Tygerberg Hospital, Cape Town, South Africa. Methods: A retrospective, descriptive (observational) study was conducted over a 6-month period to determine the number of requests for TSH testing received for patients admitted to the emergency department and intensive care units. Results: A total of 1 139 requests for TSH testing were received from the emergency department and intensive care units, of which 166 were excluded. Of the 973 requests evaluated, 14% yielded abnormal results. The majority (79.4%) of the abnormal TSH results were most likely attributed to NTIS. Follow-up TSH results after 6 - 8 weeks were available in only 18% of cases with abnormal TSH levels at initial presentation. Conclusion: We found that TSH testing was often requested in critically ill patients, but that most results were either normal or indicative of NTIS. Follow-up testing of abnormal TSH results was rarely performed. We recommend continued education of junior clinicians regarding thyroid function testing in critically ill patients. Contributions of the study: This study describes the requesting pattern for TSH tests in patients admitted to the emergency department and intensive care unit at Tygerberg Hospital, South Africa. The findings emphasise the importance of prudent thyroid function testing in critically ill patients and follow-up in suspected cases of non-thyroidal illness syndrome.
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Ischemic heart disease, the leading cause of death worldwide, may result in devastating perioperative ischemia and infarction. The underlying pathophysiology, precipitating factors, and approach to prevention differ between patients presenting for noncardiac surgery, developing acute coronary syndrome versus stable angina. The first half of this article reviews the pathophysiology of acute coronary syndrome and stable angina. Acute coronary syndrome, otherwise known as Type 1 myocardial infarction, includes unstable angina, non-ST segment elevated myocardial infarction and ST segment elevated myocardial infarction. Acute coronary syndrome occurs as a result of vulnerable plaque rupture with subsequent varying degrees of thrombus formation, arterial spasm, and thus coronary occlusion. Stable angina, on the other hand, results from a myocardial oxygen delivery and demand mismatch in the setting of fixed coronary stenosis. After this discussion, the review article considers how both apply to perioperative myocardial infarctions and myocardial injury after noncardiac surgery. This article furthermore argues why myocardial oxygen delivery demand mismatch (Type 2) myocardial infarction is the most likely underlying pathophysiology responsible for perioperative myocardial infarctions. Being aware of this and knowledgeable about Type 2 infarctions may enable anesthetic providers to better predict the majority of triggers contributing to, and thus decreasing the incidence of, perioperative myocardial infarctions.
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Síndrome Coronario Agudo , Infarto del Miocardio , Isquemia Miocárdica , Placa Aterosclerótica , Trombosis , Humanos , Infarto del Miocardio/etiología , Isquemia Miocárdica/etiologíaRESUMEN
This article reviews the association between diabetes mellitus (DM) and COVID-19. We report on the convergence of infectious diseases such as coronavirus infections and non-communicable diseases including DM. The mechanisms for the interaction between COVID-19 and DM are explored, and suggestions for the management of DM in patients with COVID-19 in South Africa are offered
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COVID-19 , Diabetes MellitusRESUMEN
AIM: To evaluate point-of-care-testing (POCT) for the diagnosis of Type 2 diabetes mellitus 6-12 weeks post-partum in women with gestational diabetes (GDM). METHODS: Post-partum glucose assessment (75-mg oral glucose tolerance test, OGTT) was performed prospectively in 122 women with GDM (1 November 2015 to 1 November 2017) at Tygerberg Hospital, Cape Town, South Africa. Individuals with known pre-existing diabetes were excluded. The accuracy and clinical utility of POCT (capillary finger-prick) were compared with laboratory plasma glucose (hexokinase and glucokinase methods). The OGTT consisted of two time points (fasting and 2 h) during which concurrent glucose samples (POCT and laboratory) were obtained. Bland-Altman plots and paired analysis were used to assess the analytical accuracy of POCT, whereas its diagnostic performance was determined using positive and negative predictive values to calculate specificity and sensitivity. RESULTS: Spearman's ranked correlation analysis indicated a strong association between POCT and laboratory glucose values at both OGTT time points (fasting, r = 0.95, P < 0.0001; 2 h, r = 0.88, P < 0.0001). Thirty-six women were diagnosed with Type 2 diabetes based on gold standard laboratory glucose levels (fasting > 7 mmol/l; 2 h > 11.1 mmol/l). POCT correctly identified Type 2 diabetes in 78% of women (28 of 36) with a positive predictive value of 89.3% and a negative predictive value of 96.7% at the fasting time point. The sensitivity and specificity of POCT to diagnose Type 2 diabetes were 89% (fasting), 85.7% (2 h) and 96.7% (fasting), 98.5% (2 h) respectively. POCT proved less sensitive to diagnose pre-diabetes (69%) but displayed satisfactory specificity (92%) at both time points assessed. CONCLUSION: POCT accurately identifies women with Type 2 diabetes 6-12 weeks after GDM.
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Análisis Químico de la Sangre/métodos , Glucemia/análisis , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Gestacional , Pruebas en el Punto de Atención , Trastornos Puerperales/diagnóstico , Adulto , Recolección de Muestras de Sangre , Diabetes Mellitus Tipo 2/sangre , Diabetes Gestacional/sangre , Diabetes Gestacional/diagnóstico , Femenino , Prueba de Tolerancia a la Glucosa , Humanos , Periodo Posparto/sangre , Embarazo , Trastornos Puerperales/sangre , Sudáfrica , Factores de Tiempo , Venas/química , Adulto JovenRESUMEN
OBJECTIVE: To describe the knowledge and practices of New Zealand (NZ) General Dental Practitioners (GDPs) concerning the use of steroid prophylaxis. METHODS: An online survey was conducted in 2013 involving a sample of 500 NZ GDPs who met inclusion criteria and had email addresses on the Dental Council register. RESULTS: A total of 214 dentists responded, giving a 44.5% response rate after accounting for undelivered questionnaires. Nearly two-thirds (61 .7%) did not currently recommend corticosteroid prophylaxis, although nearly three-quarters (74.8%) believed that dental treatment posed a potential risk to patients with adrenal suppression. Over half (53.4%) believed that oral corticosteroids could cause adrenocortical suppression, and a similar proportion (58.3%) believed that a specific dose of oral prednisolone of 7.5 mg per day could do so. Most practitioners (79.6%) supported the formulation of steroid prophylaxis guidelines. CONCLUSION: Despite most NZ GDPs believing the dental setting to pose a risk of adrenal crisis for patients taking corticosteroids, there is some confusion among dentists identifying at-risk patients and their ability to manage if such an event was to occur in their practices. There is further confusion over whether steroid prophylaxis is warranted for perceived at-risk patients, and which regime to follow when it is. There is an associated tendency to be over-cautious when determining the need for steroid prophylaxis, and to rely on their undergraduate steroid prophylaxis guidelines when doing so. There is a need for evidence-based guidelines to be formulated by an expert panel.
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Corticoesteroides/uso terapéutico , Insuficiencia Suprarrenal/prevención & control , Competencia Clínica , Odontólogos , Odontología General , Pautas de la Práctica en Odontología , Premedicación , Atención Odontológica , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Nueva Zelanda , Encuestas y CuestionariosRESUMEN
Under certain circumstances, the placement of arterial catheters can be difficult. In these instances, a form of guidance is preferred to avoid repeated insertions of the arterial catheter. Ultrasonic guidance is generally used in these instances, but the equipment required is expensive and cumbersome. This study produced an arterial catheter that is guided by the impedance of biological tissue encountered between the patient's skin and the lumen of the artery, with the aim of producing a cheaper and manageable alternative to ultrasonic guidance. Additionally, this study has inspected the impedance of human tissue in order to determine whether or not a sufficient and discernable difference between the impedance of the different tissue types could be identified and thus be used to guide an arterial catheter based on said impedance differences. The results indicate that the difference between subcutaneous tissue, fat tissue and skeletal muscle tissue are not clear enough to make accurate discrimination between tissue types. However, the study shows a clear difference between the impedance of arterial blood and the aforementioned tissue, allowing for the device to determine when accurate placement has been achieved. From the results obtained in the studies, the discrimination between blood and other intermediary tissue can be made with 99,4% confidence.
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Catéteres de Permanencia , Impedancia Eléctrica/uso terapéutico , Animales , Electrodos , Diseño de Equipo , Humanos , Técnicas In Vitro , Sus scrofaRESUMEN
OBJECTIVES: To compare the physiotherapy service provided when therapists' decisions are guided by an evidence-based protocol with usual care (i.e. patient management based on therapists' clinical decisions). DESIGN: Exploratory, controlled, pragmatic sequential time block clinical trial. SETTING: Level 3 surgical unit in a tertiary hospital in South Africa. PARTICIPANTS: All patients admitted consecutively to the surgical unit over a 3-month period were allocated to usual or protocol care based on date of admission. INTERVENTIONS: Usual care was provided by clinicians from the hospital department, and non-specialised physiotherapists were appointed as locum tenens to provide evidence-based protocol care. MAIN OUTCOME MEASURES: Patient waiting time, frequency of treatment sessions, tasks performed and adverse events. RESULTS: During protocol-care periods, treatment sessions were provided more frequently (P<0.001) and with a shorter waiting period (P<0.001). It was more likely for a rehabilitation management option to be included in a treatment session during protocol-care periods (odds ratio 2.34, 95% confidence interval 1.66 to 3.43; P<0.001). No difference in the risk of an adverse event was found between protocol-care and usual-care periods (P=0.34). CONCLUSIONS: Physiotherapy services provided in intensive care units (ICUs) when the decisions of non-specialised therapists are guided by an evidence-based protocol are safe, differ from usual care, and reflect international consensus on current best evidence for physiotherapy in ICUs. Non-specialised therapists can use this protocol to provide evidence-based physiotherapy services to their patients. Future trials are needed to establish whether or not this will improve patient outcome.
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Enfermedad Crítica/terapia , Práctica Clínica Basada en la Evidencia , Unidades de Cuidados Intensivos/organización & administración , Evaluación de Resultado en la Atención de Salud , Especialidad de Fisioterapia/organización & administración , APACHE , Adulto , Anciano , Citas y Horarios , Enfermedad Crítica/enfermería , Femenino , Humanos , Masculino , Persona de Mediana Edad , Política Organizacional , Evaluación de Programas y Proyectos de Salud , Sudáfrica , Centros de Atención Terciaria/organización & administraciónRESUMEN
Objective: To assess the pressure flow relationship of the internal mammary artery (IMA) in situ; after skeletonisation and after anastomosis to the left anterior descending (LAD) coronary artery; using either halothane; sevoflurane or propofol as an anaesthetic agent. Methods: 15 Pigs were used in total; five received halothane; five sevoflurane and five propofol as an anaesthetic agent. The flow in the internal mammary artery in each of the pigs; was measured at various arterial pressures. This was done with the IMA in situ; then after dissecting the artery off the chest wall using the skeletonisation technique and finally after offpump grafting to the left anterior descending coronary artery. Results: The pressure flow relationship of the internal mammary artery after skeletonisation was found to be linear (r=0.8650). The pressure flow correlation after grafting the skeletonised internal mammary artery to the left anterior descending coronary artery was found to be similarly linear (r=0.8766). In the sevoflurane subgroup; with the IMA still in situ; a degree of autoregulation was found to be present; but after skeletonisation this was subsequently lost (p=0.011). Conclusions: The pressure flow relationship in the internal mammary artery after skeletonising the vessel and after OPCAB anastomosis to the LAD was found to be linear. In the subgroup of pigs receiving sevoflurane; some degree of autoregulation was demonstrated in the in situ IMA. This remnant of autoregulation was lost after skeletonisation and after grafting of the vessel to the left anterior descending coronary artery
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Puente de Arteria Coronaria , Anastomosis Interna Mamario-Coronaria , Arterias MamariasRESUMEN
PURPOSE: Halothane offers protection against the reperfusion injury of the myocardium. This study compared sevoflurane with halothane in its potential to modulate the effects of acute severe ischemia and reperfusion on the myocardium. METHODS: Experiments were conducted on 25 pigs. Anesthesia consisted of thiopental, vecuronium and fentanyl. The lungs were mechanically ventilated with oxygen and nitrogen. Animals were randomly allocated to receive either I MAC halothane or sevoflurane. A control group received fentanyl and pentobarbital. Regional myocardial function was measured with sonomicrometers. The left anterior descending coronary artery was occluded for 15 min followed by 60 min reperfusion. RESULTS: Neither halothane nor sevoflurane protected the heart against the effects of acute and severe regional myocardial ischemia. During reperfusion, 89% of the animals receiving sevoflurane suffered from ventricular fibrillation compared with 30% in the halothane group (P < 0.005). Five minutes into the reperfusion period the animals subjected to halothane anesthesia demonstrated an 88% recovery in regional myocardial systolic function while in the sevoflurane group the recovery was 40% of pre-ischemic control (P < 0.05). CONCLUSION: Halothane is associated with less reperfusion arrhythmias and, in addition, recovery of regional myocardial function during reperfusion was more rapid in the presence of halothane than with sevoflurane.
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Anestésicos por Inhalación/farmacología , Halotano/farmacología , Éteres Metílicos/farmacología , Isquemia Miocárdica/fisiopatología , Daño por Reperfusión Miocárdica/fisiopatología , Sustancias Protectoras/farmacología , Adyuvantes Anestésicos/administración & dosificación , Anestésicos por Inhalación/administración & dosificación , Anestésicos Intravenosos/administración & dosificación , Animales , Fentanilo/administración & dosificación , Halotano/administración & dosificación , Éteres Metílicos/administración & dosificación , Contracción Miocárdica/efectos de los fármacos , Fármacos Neuromusculares no Despolarizantes/administración & dosificación , Pentobarbital/administración & dosificación , Sustancias Protectoras/administración & dosificación , Distribución Aleatoria , Sevoflurano , Volumen Sistólico/efectos de los fármacos , Porcinos , Sístole , Tiopental/administración & dosificación , Bromuro de Vecuronio/administración & dosificación , Fibrilación Ventricular/etiología , Presión Ventricular/efectos de los fármacosRESUMEN
OBJECTIVE: To evaluate the effect of adrenaline on cardiac function when given early or later in the reperfusion period. DESIGN: Prospective study. SETTING: University laboratory. PARTICIPANTS: Wistar rats. INTERVENTIONS: Isolated rat hearts were subjected to 45 minutes of normothermic ischaemic arrest. During reperfusion, adrenaline was administered early (2 minutes) or later (12 minutes) after termination of ischaemic arrest in addition to a short (5 minutes) or longer (10 minutes) recovery period before function was resumed. MEASUREMENTS AND RESULTS: Aortic and coronary flow, peak systolic pressure and heart rate were determined before arrest, 10 and 15 minutes after termination of ischaemic arrest. Adenosine triphosphate and creatine phosphate levels were also determined after cardioplegic arrest and reperfusion. Results indicate that early administration of adrenaline was not detrimental but that a longer recovery period after arrest resulted in significantly better cardiac function. CONCLUSION: After ischaemic arrest of the isolated rat heart a longer recovery period resulted in better cardiac function than a shorter period of recovery.