RESUMEN
BACKGROUND: National guidelines exist for the treatment of acute gallstone pancreatitis, but not for the management of acute cholecystitis (AC). AIMS: To establish the preferred management of uncomplicated AC and adherence to guidelines for the management of mild gallstone pancreatitis in the west of Scotland. METHODS: A postal survey of all 100 consultant general surgeons in the west of Scotland. RESULTS: 67 of 71 responses received were suitable for analysis. For uncomplicated AC, 24 (36%) perform urgent laparoscopic cholecystectomy (LC), 16 (24%) perform same admission LC after clinical improvement. 23 (34%) perform interval LC after discharge. Within this group, 9 surgeons (13%) manage AC conservatively due to insufficient operating time or equipment when on call. In mild gallstone pancreatitis, 33 (49%) perform same admission LC, 13 (19%) perform sphincterotomy, 3 (4.5%) perform one of these depending on the patient and 6 (9.5%) refer to a colleague with an interest in upper gastrointestinal surgery. CONCLUSIONS: The majority of surgeons (over 60%) manage AC with same admission LC. Of those who do not, more than a third report lack of resources as being the reason. The majority of surgeons in the West of Scotland manage mild gallstone pancreatitis in accordance with current guidelines.
Asunto(s)
Colecistectomía Laparoscópica/estadística & datos numéricos , Colecistitis Aguda/cirugía , Cálculos Biliares/cirugía , Pancreatitis/cirugía , Pautas de la Práctica en Medicina/estadística & datos numéricos , Enfermedad Aguda , Humanos , Escocia , Especialidades Quirúrgicas , Encuestas y CuestionariosRESUMEN
In patients with unilateral central retinal vein occlusion (CRVO), we retrospectively examined whether cone electroretinogram (ERG) subnormality to red flash (ratio of the b-wave amplitude in the CRVO eye to that in the normal fellow eye < 1) found at the time of diagnosis of the CRVO was a predictor of later ocular neovascularisation. Ganzfeld ERG cone and rod responses had initially been obtained in a consecutive series of 21 patients with unilateral CRVO. Patients were re-evaluated 6-55 months later to determine whether ocular neovascularisation had developed. Of the 21 CRVO eyes, 6 (29%) were subnormal to red in the affected compared with the normal fellow eye. At follow-up, all 6 (100%) patients had developed ocular neovascularisation compared with 1 (7%) of the 15 patients who were supernormal to red (p = 0.00013). Cone ERG subnormality to red flash in CRVO eyes compared with normal fellow eyes may be a predictor of later development of ocular neovascularisation.
Asunto(s)
Ojo/irrigación sanguínea , Neovascularización Patológica/fisiopatología , Células Fotorreceptoras Retinianas Conos/fisiopatología , Oclusión de la Vena Retiniana/fisiopatología , Adaptación Ocular/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Color , Electrorretinografía , Femenino , Estudios de Seguimiento , Predicción , Humanos , Masculino , Persona de Mediana Edad , Estimulación Luminosa , Células Fotorreceptoras Retinianas Conos/efectos de la radiación , Estudios RetrospectivosAsunto(s)
Fondo de Ojo , Pentoxifilina/farmacología , Pulso Arterial/efectos de los fármacos , Vasos Retinianos/efectos de los fármacos , Vasodilatadores/farmacología , Presión Sanguínea/efectos de los fármacos , Presión Sanguínea/fisiología , Estudios Cruzados , Método Doble Ciego , Humanos , Presión Intraocular/efectos de los fármacos , Presión Intraocular/fisiología , Pulso Arterial/fisiología , Ensayos Clínicos Controlados Aleatorios como Asunto , Flujo Sanguíneo Regional/efectos de los fármacos , Flujo Sanguíneo Regional/fisiología , Vasos Retinianos/fisiologíaRESUMEN
Peri-operative increase of oxygen delivery has been shown to reduce mortality in high-risk surgical patients. This study compares the effectiveness of dopexamine and dobutamine when used to increase cardiac output as part of a regimen to increase oxygen delivery. Sixteen surgical patients were randomly allocated to receive either dopexamine or dobutamine, which was increased to a stable dose defined as either oxygen delivery index > 600 ml/min/m2, or tachycardia > 20% above baseline, other dysrhythmias or angina. At this "stable" dose there were significant increases in cardiac index (2.4 +/- 0.2 vs 3.7 +/- 0.3 l/min/m2) and oxygen delivery (380 +/- 73 vs 579 +/- 40 ml/min/m2) in the dopexamine group (P < 0.05); but not the dobutamine group. Five out of eight patients receiving dopexamine and three out of eight receiving dobutamine reached target oxygen delivery. Three dobutamine patients, but no dopexamine patients, had angina or dysrhythmias. In preoperative high-risk surgical patients, dopexamine can allow greater increases in oxygen delivery than dobutamine, due to cardiac effects that limit the dobutamine infusion rate.
Asunto(s)
Agonistas Adrenérgicos beta/uso terapéutico , Cardiotónicos/uso terapéutico , Dobutamina/uso terapéutico , Dopamina/análogos & derivados , Consumo de Oxígeno/efectos de los fármacos , Oxígeno/sangre , Procedimientos Quirúrgicos Operativos , Vasodilatadores/uso terapéutico , Agonistas Adrenérgicos beta/administración & dosificación , Agonistas Adrenérgicos beta/efectos adversos , Anciano , Anciano de 80 o más Años , Angina de Pecho/inducido químicamente , Arritmias Cardíacas/inducido químicamente , Función del Atrio Derecho/efectos de los fármacos , Presión Sanguínea/efectos de los fármacos , Gasto Cardíaco/efectos de los fármacos , Cardiotónicos/administración & dosificación , Cardiotónicos/efectos adversos , Dobutamina/administración & dosificación , Dobutamina/efectos adversos , Dopamina/administración & dosificación , Dopamina/efectos adversos , Dopamina/uso terapéutico , Frecuencia Cardíaca/efectos de los fármacos , Hemoglobinas/análisis , Humanos , Persona de Mediana Edad , Arteria Pulmonar , Factores de Riesgo , Tasa de Supervivencia , Taquicardia/inducido químicamente , Resistencia Vascular/efectos de los fármacos , Vasodilatadores/administración & dosificación , Vasodilatadores/efectos adversosRESUMEN
OBJECTIVE: To investigate the effects of various insertion depths and sidearm functions of the introducer sheath of pulmonary artery flotation catheters on cardiac output measurement. DESIGN: Prospective, randomized, crossover study. SETTING: A general intensive care unit. PATIENTS: Ten patients who had a pulmonary artery flotation catheter placed in the right internal jugular vein as part of their clinical management. INTERVENTIONS: Cardiac output was measured at three insertion depths of the pulmonary artery catheter, each with a different rate of flow into the introducer sheath. MEASUREMENTS AND MAIN RESULTS: Significant differences of up to 23% occurred in the measurement of cardiac output under the various conditions. Cardiac output measurement is greater, the closer the injection port lies to the introducer sheath and the more open the introducer sheath sidearm. CONCLUSIONS: All users of pulmonary artery catheters should be alert to this problem. For reliable measurements of cardiac output by thermodilution, the cold saline injection port of the pulmonary artery catheter must be downstream of the introducer sheath, and the introducer sidearm must be closed.
Asunto(s)
Gasto Cardíaco , Cateterismo Periférico/métodos , Arteria Pulmonar , Adulto , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Cateterismo Periférico/instrumentación , Cateterismo Periférico/estadística & datos numéricos , Humanos , Venas Yugulares , Persona de Mediana Edad , Estudios Prospectivos , Termodilución/métodos , Termodilución/estadística & datos numéricosRESUMEN
The differences in effects of anaesthetic agents on right ventricular function have not been studied. We have developed a cross-over study design to compare the effects of propofol and isoflurane on cardiac and specifically right ventricular function. Ten patients were anaesthetised with equivalent MAC of isoflurane to MIR of propofol. After measurements had been taken on the randomly assigned first agent the patients were crossed over to the other agent and measurements were repeated. Cardiac function was assessed using a pulmonary artery catheter with a fast response thermistor. There were no differences in heart rate or blood pressure between the two agents suggesting that equivalent anaesthetic doses had been given. There were significantly (P < 0.05) higher cardiac output (4.0 to 4.5 l.min-1), right ventricular ejection fraction (35.1 to 39.4%), stroke volume (35.4 to 39.6 ml) and right ventricular end-diastolic volume index (102 to 110 ml.m2-1) with propofol compared to isoflurane. We conclude that propofol results in improved right ventricular performance compared to isoflurane. We have also shown that anaesthetic agents can be compared using a cross-over study design, and have demonstrated that MAC of isoflurane and MIR of propofol can be directly compared. We suggest that propofol may be a more suitable agent than isoflurane for anaesthesia in patients who may already have impaired right ventricular function and in whom maintaining high cardiac output may be beneficial.
Asunto(s)
Anestesia por Inhalación , Anestesia Intravenosa , Corazón/efectos de los fármacos , Isoflurano/farmacología , Propofol/farmacología , Función Ventricular Derecha/efectos de los fármacos , Anciano , Anciano de 80 o más Años , Presión Sanguínea/efectos de los fármacos , Gasto Cardíaco/efectos de los fármacos , Volumen Cardíaco/efectos de los fármacos , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Volumen Sistólico/efectos de los fármacosRESUMEN
It is often necessary to adjust a patient's sedation level while they are in the intensive care unit. The purpose of this study was to compare propofol with midazolam for controlling short-term alterations in sedation. Twenty-three patients undergoing an interactive procedure, physiotherapy, during mechanical ventilation of the lungs were studied. The patients were randomly assigned to receive infusions of propofol or midazolam for sedation. Sedation was assessed using the method of Ramsay, where 3 is drowsy responding only to commands; and 5 is asleep with a slow response to light glabellar tap. Prior to physiotherapy sedation was deepened from 3 to 5 by increasing the sedative infusion rate, and level 5 was maintained during physiotherapy by adjusting the infusion rate whenever necessary. After physiotherapy, the sedative dose was reduced until level 3 was again achieved. During physiotherapy, sedation level 5 was achieved for 53.9% of the time with propofol but for only 25.7% with midazolam (P < 0.01). After physiotherapy, those patients sedated with propofol re-awakened to level 3 faster (8.3 +/- 2.3 min, mean +/- SE) than those receiving midazolam (92.8 +/- 35.0 min, P < 0.05). After physiotherapy, a further 1.8 +/- 0.5 dose adjustments were required to the midazolam infusion while only 0.4 +/- 0.2 adjustments were required to the propofol infusion (P < 0.05). During physiotherapy 3.0 +/- 0.5 dose adjustments to the propofol dose were required compared with 3.6 +/- 0.5 adjustments to the midazolam dose (NS).(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Sedación Consciente , Midazolam , Modalidades de Fisioterapia , Propofol , Respiración Artificial , Anciano , Anestesia Intravenosa , Ansiedad/diagnóstico , Presión Sanguínea/efectos de los fármacos , Conducta Cooperativa , Método Doble Ciego , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Infusiones Intravenosas , Masculino , Midazolam/administración & dosificación , Midazolam/farmacología , Cuidados Posoperatorios , Propofol/administración & dosificación , Propofol/farmacología , Estudios Prospectivos , Sueño , Fases del SueñoRESUMEN
PURPOSE: To examine the S-cone ERG in subjects with and without L and M-cone function. METHODS: Ganzfeld spectral flashes in the presence of strong Ganzfeld adapting fields are used to elicit S-cone ERGs. RESULTS: The S-cone ERG b-wave ranges from 0.2 to 4 mV in amplitude and 38-45 msec in implicit time. There is a progressive decrease in amplitude with age. The response is similar in subjects with or without L and M cone function. CONCLUSION: The S-cone ERG is detectable in subjects of all ages, but intersubject variability limits its diagnostic usefulness. The S-cone ERG is slightly later than but does not appear to be obviously influenced by the L and M-cone ERG.
Asunto(s)
Defectos de la Visión Cromática/fisiopatología , Electrorretinografía , Células Fotorreceptoras/fisiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Afaquia/fisiopatología , Niño , Humanos , Persona de Mediana Edad , Estimulación LuminosaRESUMEN
The measurement of gastric intramucosal pH (pHi) has been advocated to assist in decision-making for critically ill patients. To assess whether the information obtained from the measurement of pHi can be obtained from other measurements of metabolic acidosis, we studied 20 consecutive patients admitted to the intensive care unit. A mean of eight (range two to fourteen) data sets per patient were obtained, comprising measurement of arterial pH, pO2, pCO2, and oxygen saturation, tonometer balloon fluid pCO2, arterial pressures, and cardiac output. Bicarbonate concentration, base deficit or excess in blood and extracellular fluid, and pHi were calculated from these measurements. Relations between the variables and pHi were assessed by within-subject correlation comparisons. There were significant correlations (r > 0.6, p < 0.001) between markers of metabolic acidosis (base deficit in blood and extracellular fluid and bicarbonate concentration) and pHi. A blood base deficit of -4.65 or less and an extracellular-fluid base deficit of -6.13 or less could estimate pHi below 7.32 (lower limit of normal range) with sensitivity of at least 77% and specificity of at least 96%. There was no patient in whom either pHi or blood base deficit consistently reflected acidosis when the other variable did not. We conclude that the information that is obtained by gastric tonometry for pHi can be obtained more simply from measurements of metabolic acidosis; these variables can be calculated from routinely available blood-gas measurements.
Asunto(s)
Acidosis/diagnóstico , Análisis de los Gases de la Sangre , Determinación de la Acidez Gástrica , Adolescente , Adulto , Anciano , Femenino , Humanos , Concentración de Iones de Hidrógeno , Masculino , Persona de Mediana EdadRESUMEN
In 12 successive cases of unilateral central retinal vein occlusion (CRVO), the strongly light-adapted cone electroretinogram (both a- and b-wave) was always slower and larger (supernormal) to long-wave stimuli compared with that of the unaffected eye. This supernormality became less as the level of light adaptation decreased; in the dark-adapted state, long-wave stimuli produced subnormal responses from the affected eye in all but two subjects. This supernormality was not caused by ineffectiveness of the adapting light related to a reduced cone quantal catch because it occurred in the dark. At any one state of adaptation, the supernormality increased with the wavelength of stimulation, paralleling the relative absorption ratio of long-middle wavelength-sensitive cones. This suggests that cones, especially long wavelength-sensitive cones, are less able to reduce their responsiveness to light with increasing levels of light adaptation in a retina affected by CRVO.
Asunto(s)
Electrorretinografía , Células Fotorreceptoras/fisiopatología , Oclusión de la Vena Retiniana/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Pruebas de Percepción de Colores , Adaptación a la Oscuridad , Humanos , Luz , Persona de Mediana Edad , Umbral SensorialRESUMEN
An electroretinographic response of the human short wavelength (S) cone system can be distinguished from that of the longer wavelength (L or M) cone system by using ganzfeld short-wavelength stimulation at relatively high levels of retinal adaptation. The S cone response has both an a- and b-wave component in its ERG, both of which are slower than those of the L or M cone response at the same level of retinal adaptation. Proof that this is the S cone response is obtained by action spectra and by examination of a sex-linked achromat who is known to have only S cone and rod vision. This approach allows the simultaneous and rapid assessment of both the S and the L or M cone systems in the human retina using conventional electroretinogram (ERG) equipment, ganzfeld blue flashes on a white background, and computer averaging.
Asunto(s)
Electrorretinografía/métodos , Células Fotorreceptoras/fisiología , Adolescente , Adulto , Anciano , Niño , Defectos de la Visión Cromática/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estimulación Luminosa , Agudeza VisualRESUMEN
The cone electroretinogram has been examined at different levels of ganzfeld adaptation in normals and subjects with retinitis pigmentosa (RP). As light adaptation increases, the amplitude and time course (measured as b-wave implicit time) of the cone ERG decrease in both normal and RP subjects. The same level of light adaptation, however, decreases the amplitude and the implicit time more in normal than in RP subjects. The ineffectiveness of light for adapting the ERG of RP subjects is most easily explained by assuming that RP cones absorb less light than normal cones. By comparing these parameters between normal and RP subjects at different levels of light adaptation, it is possible to estimate this ineffectiveness of cone absorption in RP subjects. The results imply that RP cones can transduce and adapt but fail to absorb light as effectively as normal cones. The quantitative relationship between cone b-wave implicit time and retinal illumination provides a unique method for examining cone function as well for standardizing ganzfeld backgrounds in ERG laboratories.
Asunto(s)
Adaptación Fisiológica , Luz , Retinitis Pigmentosa/fisiopatología , Adulto , Electrorretinografía , Humanos , Células Fotorreceptoras/fisiopatología , Tiempo de Reacción , Valores de ReferenciaRESUMEN
The human cone electroretinogram gradually increases in amplitude an average of 75% (range 23 to 157%) during light adaptation, over a period of approximately 20 min. This increase involves both the a- and b-wave components of this response, and both waves follow a similar time course, implying that the photoreceptors themselves are responsible for the effect. The phenomenon occurs with suprathreshold, but not with threshold, levels of stimulation, and the stronger the test light, the greater the effect. An increase in the intensity of the adapting light shortens the time course of the ERG response, measured as b-wave implicit time, but this occurs almost immediately, and the implicit time then remains constant during the slow increase in response amplitude. The stronger the background adapting light, the smaller is the ERG amplitude, but the percentage growth (or rate of recovery) is unchanged. This slow increase in amplitude is thought to reflect the redepolarization of the cones, after their initial hyperpolarization to an adapting field. It does not reflect the d.c. potential of the eye (the EOG). It is essential to control this phenomenon in any studies of the human cone ERG, in order to minimize variability.
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Adaptación Fisiológica , Luz , Células Fotorreceptoras/fisiología , Electrorretinografía , HumanosRESUMEN
Seven related patients had a progressive pigmentary retinal degeneration, characterized by nyctalopia, visual field restriction, and cystic macular degeneration in younger patients and a macula of nonspecific atrophic appearance in older patients. In addition, each patient had high hyperopia (+9.50 to +16.00) and nanophthalmos (axial lengths, less than 20 mm), with diffuse choroidal thickening on ultrasound. Younger patients had slitlike anterior chamber angles; older patients developed progressive synechial angle closure and eventual glaucoma. Chromosomes were normal. On electroretinographic testing, younger patients had absent rod signals, with normal cone wave form and near-normal b-wave amplitudes but markedly delayed cone b-wave implicit times; older patients had severely diminished or extinguished electroretinograms. This family appears to represent a newly recognized autosomal-recessive syndrome.
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Glaucoma/genética , Edema Macular/genética , Microftalmía/genética , Degeneración Retiniana/genética , Adulto , Electrorretinografía , Femenino , Fondo de Ojo , Glaucoma/diagnóstico , Glaucoma/fisiopatología , Humanos , Edema Macular/diagnóstico , Edema Macular/fisiopatología , Masculino , Microftalmía/diagnóstico , Microftalmía/fisiopatología , Persona de Mediana Edad , Linaje , Degeneración Retiniana/diagnóstico , Degeneración Retiniana/fisiopatología , Agudeza VisualRESUMEN
We report the results of an exposure chamber study in which volunteers were exposed to 0, 950 mg.m-3 (175 ppm) and 1,990 mg.m-3 (350 ppm) of 1,1,1-trichloroethane for 3.5 hours. The time-course of the behavioral changes and the relationship to blood concentrations of 1,1,1-trichloroethane were investigated. A pattern of performance deficits consistent with earlier work was found for some of the tests of psychomotor performance. The time-course of these appeared to be rapid, occurring in some cases within 20 minutes of exposure. For those tasks shown to be sensitive to 1,1,1-trichloroethane exposure, the development of performance changes followed the time-course of blood solvent levels. Two behavioral tests not previously used in this type of work were also employed. One was concerned with the distractability of attention and concentration (the Stroop test), and the other was concerned with analysing grammatical statements (the syntactic reasoning test). Different effects were found. In the Stroop test, enhanced performance was observed following exposure; however, the syntactic reasoning test was found to be resistant to solvent effects. Measures of short-term subjective well-being were not affected by exposure. It is suggested that the observations of time-course effects in performance and their relationship to change in blood solvent levels have implications for psychological test selection and for study designs for examining field exposure.
Asunto(s)
Conducta/efectos de los fármacos , Hidrocarburos Clorados/efectos adversos , Tricloroetanos/efectos adversos , Análisis de Varianza , Atención/efectos de los fármacos , Humanos , Masculino , Pruebas Psicológicas , Desempeño Psicomotor/efectos de los fármacos , Tiempo de Reacción/efectos de los fármacos , Factores de Tiempo , Tricloroetanos/sangreRESUMEN
Behavioural effects of occupational exposure to vapour from styrene-based resin were investigated in 10 female workers with a portable test of choice reaction time. Testing was carried out both at the beginning and end of the day's shift. Uptake and metabolism of styrene were assessed by monitoring post-shift urinary mandelic acid excretion rates. By using these data workers were allocated to three groups reflecting zero, low or high exposure. After exposure slowing of reaction times was found in those with the highest mandelic acid excretion rates, whereas a slight improvement or no change was found in those with low or zero exposure. Subsequent improvements in extraction and ventilation in the workroom were shown to be associated with both decreased mandelic acid excretion and absence of long reaction times in those previously most heavily exposed.