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1.
Anesthesiology ; 89(6): 1362-72, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9856710

RESUMEN

BACKGROUND: Anesthesia personnel are at risk for occupational infection with bloodborne pathogens from contaminated percutaneous injuries (CPIs). Additional information is needed to formulate methods to reduce risk. METHODS: The authors analyzed CPIs collected during a 2-yr period at 11 hospitals, assessed CPI underreporting, and estimated risks of infection with human immunodeficiency virus and hepatitis C virus. RESULTS: Data regarding 138 CPIs were collected: 74% were associated with blood-contaminated hollow-bore needles, 74% were potentially preventable, 30% were considered high-risk injuries from devices used for intravascular catheter insertion or obtaining blood, and 45% were reported to hospital health services. Corrected for injury underreporting, the CPI rate was 0.27 CPIs per yr per person; per full-time equivalent worker, there were 0.42 CPIs/yr. The estimated average 30-yr risks of human immunodeficiency virus or hepatitis C virus infection per full-time equivalent are 0.049% and 0.45%, respectively. Projecting these findings to all anesthesia personnel in the United States, the authors estimate that there will be 17 human immunodeficiency virus infections and 155 hepatitis C virus infections in 30 yr. CONCLUSIONS: Performance of anesthesia tasks is associated with CPIs from blood-contaminated hollow-bore needles. Thirty percent of all CPIs would have been high-risk for bloodborne pathogen transmission if the source patients were infected. Most CPIs were potentially preventable, and fewer than half were reported to hospital health services. The results identify devices and mechanisms responsible for CPIs, provide estimates of risk levels, and permit formulation of strategies to reduce risks.


Asunto(s)
Anestesiología , Patógenos Transmitidos por la Sangre , Transmisión de Enfermedad Infecciosa de Paciente a Profesional , Enfermedades Profesionales/etiología , Enfermedades Cutáneas Infecciosas/etiología , Piel/lesiones , Infecciones por VIH/transmisión , Hepatitis C/transmisión , Humanos , Enfermedades Profesionales/microbiología , Estudios Retrospectivos , Medición de Riesgo , Piel/microbiología , Enfermedades Cutáneas Infecciosas/microbiología
2.
Biochim Biophys Acta ; 1405(1-3): 110-20, 1998 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-9784619

RESUMEN

Fibroblasts in monolayer culture secrete gelatinase A (MMP2; 72 kDa type IV collagenase) only in its proenzyme form. Unlike other secreted matrix metalloproteinases, progelatinase A is refractory to activation by serine proteinases. Disparate agents, including monensin, cytochalasin D, and concanavalin A, have been found to mediate the activation of gelatinase A zymogen secreted by fibroblast monolayers. Our finding that monensin-mediated activation can be reversed by the protein tyrosine kinase inhibitor genistein (Li et al., Experimental Cell Research 232 (1997) 332) prompted us to investigate the effect of the specific inhibitor of protein tyrosine phosphatases, sodium orthovanadate, on progelatinase A activation. Treatment of fibroblast monolayers with orthovanadate also results in the secretion of activated gelatinase A. This activation is dose- and time-dependent, requires protein synthesis, and is associated with cell membranes. Vanadate-mediated activation does not occur in the presence of herbimycin A, a protein tyrosine kinase inhibitor. As with progelatinase activation mediated by monensin, concanavalin A, and cytochalasin D, orthovanadate treatment results in increased synthesis of the membrane proteinase MT1-MMP, that can catalyze the activation of progelatinase A. Protein tyrosine kinase inhibitors are able to prevent the increase of MT1-MMP mRNA, as shown by Northern blot and RT-PCR. In addition, orthovanadate potentiates the effects of monensin and concanavalin A. While treatment with monensin or concanavalin A result only in an increase of the putative activator MT1-MMP, orthovanadate also reduces the production of the specific inhibitor TIMP-2. These experiments implicate protein tyrosine phosphorylation in the signal transduction pathways which lead to the activation of progelatinase A.


Asunto(s)
Gelatinasas/metabolismo , Metaloendopeptidasas/metabolismo , Proteínas Tirosina Fosfatasas/antagonistas & inhibidores , Tirosina/metabolismo , Vanadatos/farmacología , Secuencia de Bases , Benzoquinonas , Células Cultivadas , Cartilla de ADN/genética , Activación Enzimática/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Humanos , Lactamas Macrocíclicas , Metaloproteinasa 2 de la Matriz , Metaloproteinasas de la Matriz Asociadas a la Membrana , Metaloendopeptidasas/genética , Monensina/farmacología , Fosforilación , Quinonas/farmacología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Rifabutina/análogos & derivados , Transducción de Señal , Inhibidor Tisular de Metaloproteinasa-2/metabolismo
3.
Exp Cell Res ; 232(2): 322-30, 1997 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-9168808

RESUMEN

In monolayer culture, fibroblasts secrete all matrix metalloproteinases, including gelatinase A (72-kDa type IV collagenase), as inactive zymogens. Whereas limited proteolysis by plasmin or other matrix metalloproteinases (MMPs) can accomplish the extracellular activation of other proenzymes in this family, gelatinase A proenzyme is uniquely refractory to cleavage by such proteinases. Previously it has been shown that fibroblasts cultured in the presumably more physiologic culture milieu of a type I collagen lattice can be induced to secrete active gelatinase A. In monolayer culture, however, the plant lectin concanavalin A will induce gelatinase A activation. Here we show that in monolayer culture activation of gelatinase A by normal fibroblasts is also induced by the sodium ionophore monensin. The monensin response is dose-dependent, time-dependent, requires protein synthesis, and is specific to gelatinase A among the secreted matrix metalloproteinases. The activator appears to be associated with cell membranes and may be membrane-type matrix metalloproteinase 1(MT-MMP1). Both mRNA and immunodetectable protein of MT-MMP1 are increased with monensin treatment while message for the protein inhibitor of gelatinase A, TIMP-2, is unchanged. The monensin-induced signal transduction pathway leading to gelatinase activation in monolayer culture appears to be different from the integrin-mediated pathway operative in the collagen lattice system. The tyrosine kinase inhibitor genistein blocks monensin activation of gelatinase A in monolayer culture. In contrast, genistein has no effect on proenzyme activation in the collagen lattice. Likewise, the cyclooxygenase inhibitor indomethacin abrogates the monensin effect in monolayer culture and can be reversed by addition of exogenous prostaglandin E2 (PGE2). Neither indomethacin nor PGE2 affects activation of gelatinase A in the collagen lattice.


Asunto(s)
Fibroblastos/efectos de los fármacos , Gelatinasas/metabolismo , Ionóforos/farmacología , Metaloendopeptidasas/metabolismo , Monensina/farmacología , Sodio/fisiología , Células Cultivadas , Colagenasas/análisis , Medios de Cultivo Condicionados/química , Cicloheximida/farmacología , Inhibidores de la Ciclooxigenasa/farmacología , Dinoprostona/farmacología , Activación Enzimática/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Precursores Enzimáticos/metabolismo , Fibroblastos/enzimología , Genisteína , Humanos , Indometacina/farmacología , Integrinas/fisiología , Transporte Iónico/efectos de los fármacos , Isoflavonas/farmacología , Metaloproteinasa 2 de la Matriz , Metaloproteinasa 3 de la Matriz/análisis , Inhibidores de la Síntesis de la Proteína/farmacología , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Proteínas/metabolismo , Transducción de Señal/efectos de los fármacos , Piel/citología , Inhibidor Tisular de Metaloproteinasa-2
4.
Proc Natl Acad Sci U S A ; 94(9): 4424-9, 1997 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-9114005

RESUMEN

Normal fibroblasts cultured as monolayers secrete matrix metalloproteinases (MMP), including gelatinase A (72-kDa type IV collagenase) as inactive zymogens. Previously we found that normal fibroblasts cultured in a type I collagen lattice (dermal equivalent) secrete active gelatinase A. Here we show that the activation of progelatinase A occurs within the cell and that the activator copurifies with Golgi membranes. Cell extracts of fibroblasts cultured in collagen lattices contain active 62-kDa gelatinase A at least 4-6 h before active enzyme is detected in the culture medium. Pulse-chase experiments confirm these results. The activator is membrane-bound and localizes to the Golgi-enriched fraction. Highly purified plasma membranes from lattice cultures are unable to convert gelatinase A from the zymogen to its active form. The activator may be a metalloproteinase because EDTA prevents activation of exogenous proenzyme by membrane fractions. Membrane-type MMP1, the enzyme thought to be responsible for activation of gelatinase A on the plasma membrane of tumor cells, shows no significant change in either mRNA or protein levels during lattice culture. Intracellular levels of gelatinase A mRNA and protein increase during the culture period, and tissue inhibitor of metalloproteinases concentration does not change. Because of the greater availability of tissue inhibitor of metalloproteinases-free proenzyme as a substrate for the activator, it is possible that membrane-type MMP1 is the activating enzyme. In that case, malignant transformation may involve a change in the localization of the activator to the plasma membrane.


Asunto(s)
Precursores Enzimáticos/metabolismo , Fibroblastos/metabolismo , Gelatinasas/metabolismo , Aparato de Golgi/metabolismo , Integrinas/metabolismo , Metaloendopeptidasas/metabolismo , Biomarcadores , Células Cultivadas , Colágeno/farmacología , Activación Enzimática , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Humanos , Pruebas de Precipitina , Receptores de Colágeno , Fracciones Subcelulares/metabolismo
5.
J Clin Anesth ; 8(6): 475-9, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8872687

RESUMEN

STUDY OBJECTIVE: To conduct a feasibility study of the mechanics of recycling single-use anesthesia breathing systems and practices of anesthesiologists and nurse-anesthetists in a tri-state region. STUDY DESIGN: Two-part, open, prospective analysis using pre-printed questionnaire and cost/time analysis of labor and materials. SETTING: Questionnaire sent to 413 anesthesiology departments in Pennsylvania, New Jersey, and Delaware, and hospital/recycling facility for evaluation of time and cost. MEASUREMENTS AND MAIN RESULTS: Time to disassemble and sort the breathing circuits, analysis of costs and obtainable income from byproducts of recycling, and standard survey questionnaire concerning demographic characteristics of respondents and individual department/hospital practitioners. Data analysis included analysis of variance and Kruskal-Wallis tests. Pilot analysis: Sorting of circuits to economic component required ten minutes at an average cost of $1.60 Value of scraps obtainable was $3.44, leaving a gross margin of $1.84 for a box of 18 circuits. Benefit analysis: Extended reduction in the regulated medical waste in our operating room of 16,875 lb, saving $4,387.50 per year. With generation of revenue from scrap, the net gain is $5,994.64 per yr. Questionnaire: Majority (83%) of departments polled would participate in recycling implemented by suppliers. Most respondents would not consider (58%) recycling unless mandated by law. CONCLUSION: The program described is cost-effective and environmentally beneficial.


Asunto(s)
Anestesiología/instrumentación , Contaminación Ambiental/prevención & control , Residuos Sanitarios/prevención & control , Anestesiología/economía , Delaware , Contaminación Ambiental/economía , Estudios de Factibilidad , Residuos Sanitarios/economía , New Jersey , Enfermeras Anestesistas , Pennsylvania , Médicos , Encuestas y Cuestionarios
6.
Biochim Biophys Acta ; 1293(2): 259-66, 1996 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-8620038

RESUMEN

The gelatinases (type IV collagenases) are members of the matrix metalloproteinase family that not only have a high degree of structural homology but are known to be nearly identical in their digestion profile against macromolecular substrates. We have shown previously that the preferred cleavage sites in the hydrolysis of type I gelatin, catalyzed by gelatinase A (72 kDa type IV collagenase), are bracketed by hydroxyproline in the P5 and P5' positions. In this report, a kinetic investigation using a series of collagenous dodecylpeptides in which the P5 and P5' hydroxyprolines were systematically varied and used as substrates for recombinant human gelatinase A, we show that replacement with either proline or alanine always resulted in increased Km. In contrast, substitution of the hydroxylated amino acids tyrosine and serine at P5 and P5' reduced the Km significantly, indicating that the hydroxyl moiety of the hydroxyproline is the functional group responsible for favorable enzyme-substrate affinity. This was shown by the kcat/Km ratio, which was doubled by the substitution of serine in that site. Cleavage of the same series of dodecylpeptides by recombinant human gelatinase B (92 kDa type IV collagenase) showed a very different kinetic profile for which no patterns were discernible. In subsequent comparisons of the two enzymes, it was found that gelatinase B cleaved the thiopeptolide substrate AcProLeuGly-S-LeuGly-OC2H5 at double the velocity of gelatinase A. In contrast, gelatinase A digested type I gelatin about 2.5-times faster than gelatinase B. SDS-PAGE analysis of gelatin cleavage products showed different patterns of product peptides for each enzyme. Further comparisons of the proteinases using synthetic peptide substrates with variations in size and in substituents at the P2' site again showed marked kinetic differences. Although these two matrix metalloproteinases seem similar in that they are both gelatinolytic and can degrade a nearly identical battery of macromolecular matrix components including type IV collagen, it is clear from these results that they are very different enzymatically. Since the regulatory portions of gelatinases A and B differ markedly, it has been assumed that the enzymes serve the same function, but respond to different stimuli. The differences in substrate specificity described herein suggest that their proposed physiological roles may require reevaluation.


Asunto(s)
Colágeno/metabolismo , Colagenasas/metabolismo , Gelatina/metabolismo , Gelatinasas/metabolismo , Metaloendopeptidasas/metabolismo , Oligopéptidos/metabolismo , Secuencia de Aminoácidos , Células Cultivadas , Colagenasas/química , Electroforesis en Gel de Poliacrilamida , Precursores Enzimáticos/metabolismo , Gelatinasas/química , Hidrólisis , Hidroxiprolina/química , Cinética , Metaloproteinasa 2 de la Matriz , Metaloproteinasa 9 de la Matriz , Metaloendopeptidasas/química , Datos de Secuencia Molecular , Oligopéptidos/síntesis química , Proteínas Recombinantes/metabolismo , Especificidad por Sustrato
7.
Anesth Analg ; 80(3): 583-90, 1995 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7864430

RESUMEN

This study was designed to evaluate effects of enalaprilat, an angiotensin-converting enzyme inhibitor, on hemodynamic and hormonal responses during surgery at endotracheal intubation, incision, and limb-tourniquet inflation. Thirty patients undergoing limb procedures with general anesthesia (N2O/narcotic technique) and a pneumatic tourniquet were randomized to receive either preoperative enalaprilat (1.25 mg intravenously [i.v.] 20 min prior to induction) or intraoperative enalaprilat (0.625 mg i.v. at the onset of tourniquet-associated hypertension), with appropriate placebo controls. Arterial blood pressure and heart rate increased significantly in response to intubation in the placebo group. Although there were no significant differences in catecholamine levels, plasma renin activity was significantly increased at postincision in the preoperative-enalaprilat group versus the placebo group. This suggests that activation of the renin-angiotensin system may play a key role in mediation of intraoperative hemodynamic responses to endotracheal intubation. With respect to tourniquet hypertension, preoperative or intraoperative treatment with enalaprilat reduced neither the pressor response to tourniquet inflation nor the amount of enflurane subsequently required to control arterial blood pressure. These findings suggest that this response is mediated by pain pathways, and may be treated more effectively with anesthesia/analgesia.


Asunto(s)
Catecolaminas/sangre , Enalaprilato/administración & dosificación , Renina/sangre , Procedimientos Quirúrgicos Operativos , Adolescente , Adulto , Anciano , Presión Sanguínea/efectos de los fármacos , Enalaprilato/farmacología , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Infusiones Intravenosas , Periodo Intraoperatorio , Persona de Mediana Edad , Cuidados Preoperatorios
8.
Exp Cell Res ; 213(2): 365-74, 1994 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-7519563

RESUMEN

The matrix metalloproteinase 72-kDa type IV collagenase (also known as gelatinase A) is thought to be involved in both normal connective tissue remodeling and invasive pathological processes. Like other matrix metalloproteinases, 72-kDa type IV collagenase is secreted by fibroblast monolayers as an inactive proenzyme, but is unique among this enzyme family in that it is not activated by serine proteinases such as plasmin. However, when fibroblasts are cultured in a collagen lattice, a situation thought to better approximate in vivo conditions, we have invariably found much of the secreted 72-kDa type IV collagenase in its enzymatically active 62-kDa form. Although collagen lattice contraction appeared to be required for the activation of 72-kDa type IV collagenase, we have found that the process of contraction can be dissociated from proenzyme activation. Both cytochalasin D and alpha-methylmannoside completely blocked lattice contraction, but not proenzyme activation. Furthermore, the monoclonal antibody M-13, which is directed against the beta 1 integrin chain, blocked collagen lattice contraction but not 72-kDa type IV procollagenase activation. At concentrations significantly higher than required to block lattice contraction or cell adhesion to collagen, M-13 was able to inhibit proenzyme activation. A second monoclonal antibody to the beta 1 integrin, P5D2, had little effect on collagen lattice contraction at low concentrations, but could significantly inhibit the activation of 72-kDa type IV procollagenase. Antibodies to the integrin alpha 2 chain also inhibited proenzyme activation. These data show that the activation of 72-kDa type IV collagenase proenzyme, like collagen lattice contraction, is mediated by beta 1 integrin receptors, possibly alpha 2 beta 1. Although both anti-beta 1 antibodies used are directed to the same site on the integrin chain, the fact that each antibody preferentially blocks a different event, either lattice contraction or activation of 72-kDa type IV collagenase, suggests the existence of branch points in the receptor-mediated signal transduction pathway.


Asunto(s)
Colágeno/metabolismo , Fibroblastos/enzimología , Gelatinasas/metabolismo , Integrinas/metabolismo , Metaloendopeptidasas/metabolismo , Anticuerpos Monoclonales/inmunología , Citocalasina D/farmacología , Activación Enzimática , Fibroblastos/citología , Integrina beta1 , Integrinas/inmunología , Metaloproteinasa 2 de la Matriz , Proteínas/farmacología , Inhibidor Tisular de Metaloproteinasa-2
10.
J Clin Anesth ; 5(5): 404-7, 1993.
Artículo en Inglés | MEDLINE | ID: mdl-8217177

RESUMEN

STUDY OBJECTIVE: To investigate whether the use of methylmethacrylate cement causes hemodynamic or pulmonary instability during total shoulder replacement surgery. DESIGN: Prospective, nonrandomized study. SETTING: Operating room. PATIENTS: 9 ASA physical status I and II patients. INTERVENTIONS: A 20-gauge radial artery catheter was placed in the wrist opposite the surgical site. Sedation with midazolam was provided, and a pulmonary artery catheter was placed through an 8.5-Fr introducer into the patient's right internal jugular vein. MEASUREMENTS AND MAIN RESULTS: Before induction of anesthesia, systolic, diastolic, and mean arterial blood pressures; heart rate; central venous pressure; systolic, diastolic, and mean pulmonary artery pressures; pulmonary capillary wedge pressure; and thermodilution cardiac output measurements were obtained. Arterial and mixed venous blood gas samples also were collected and analyzed for calculation of Qs/Qt. These hemodynamic and pulmonary parameters were measured again just before cementing of each prosthesis with methylmethacrylate cement and at 1, 5, 10, and 20 minutes after cementing. There were no statistically significant changes in any of the measured hemodynamic parameters at any time. There was no statistically significant difference in the calculated intrapulmonary shunt fraction. CONCLUSION: In this study population, the use of methylmethacrylate for total shoulder replacement was not associated with adverse hemodynamic events or increased intrapulmonary shunting.


Asunto(s)
Cementación/efectos adversos , Hemodinámica/efectos de los fármacos , Prótesis Articulares/métodos , Circulación Pulmonar/efectos de los fármacos , Articulación del Hombro/cirugía , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Metilmetacrilatos/efectos adversos , Persona de Mediana Edad
11.
J Clin Anesth ; 5(2): 122-8, 1993.
Artículo en Inglés | MEDLINE | ID: mdl-8476618

RESUMEN

STUDY OBJECTIVE: To compare desflurane with isoflurane in several anesthetic situations. DESIGN: Intubating conditions, hemodynamic response to intubation, maintenance hemodynamics, and speed of recovery from desflurane and isoflurane anesthesia were evaluated. In addition, interaction with a muscle relaxant at low and high concentrations of the anesthetics were compared. SETTING: Thomas Jefferson University Hospital. PATIENTS: Thirty-two patients who received general anesthesia for lengthy, mostly orthopedic procedures. INTERVENTIONS: Immediately after induction with thiopental sodium, desflurane or isoflurane in nitrous oxide-oxygen was administered via face mask. Anesthesia was deepened until end-tidal concentration reached 1.7 minimum alveolar concentration (MAC). The trachea was intubated without the aid of a muscle relaxant. Heart rate (HR) and blood pressure (BP) were recorded before and at 1, 2, 4, 5, and 10 minutes after intubation. Noninvasive cardiac output (CO) and systemic vascular resistance (SVR) were determined while the patient was awake, immediately before intubation, and at 5 and 10 minutes after intubation. Following intubation, the concentration of desflurane or isoflurane was lowered until the end-tidal concentration reached 0.65 MAC (low-MAC group), 1.25 MAC (high-MAC group), or 0 MAC (control group). Pancuronium bromide in 0.005 mg/kg doses was administered incrementally until T1 (first twitch of train-of-four) was depressed more than 90%. ED50 and ED95 for pancuronium with balanced anesthesia and for desflurane or isoflurane in low and high MACs, as well as speed of recovery, were determined. The time to responsiveness and awakening also was determined. MEASUREMENTS AND MAIN RESULTS: There was no significant difference between desflurane and isoflurane in intubating conditions or in BP or HR response to tracheal intubation. Both anesthetics increased HR significantly during induction. BP rose with desflurane at the preintubation point; other points showed no difference. A hyperdynamic response of increased HR and BP above 20% of baseline values was seen more frequently with desflurane (n = 7) than with isoflurane (n = 1). CO was elevated at all times after induction for low and high concentrations of both drugs, while SVR decreased over the same time with no significant difference between drugs. ED50 and ED95 for pancuronium were similar under desflurane and isoflurane at both low and high MAC, but they were significantly lower than under balanced anesthesia. Awakening times were similar for desflurane and isoflurane. CONCLUSIONS: Desflurane is similar to isoflurane in providing anesthesia for intubation and maintenance. Desflurane tends to increase HR and occasionally causes a hyperdynamic response during rapid deepening of anesthesia. It is very similar to isoflurane in its interaction with pancuronium.


Asunto(s)
Anestesia por Inhalación , Anestésicos , Isoflurano , Isoflurano/análogos & derivados , Adulto , Periodo de Recuperación de la Anestesia , Anestésicos/administración & dosificación , Anestésicos/farmacología , Presión Sanguínea/efectos de los fármacos , Gasto Cardíaco/efectos de los fármacos , Desflurano , Interacciones Farmacológicas , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Intubación Intratraqueal , Isoflurano/administración & dosificación , Isoflurano/farmacología , Masculino , Persona de Mediana Edad , Unión Neuromuscular/efectos de los fármacos , Pancuronio/farmacología , Intercambio Gaseoso Pulmonar , Volumen de Ventilación Pulmonar , Factores de Tiempo , Resistencia Vascular/efectos de los fármacos
12.
Anesth Analg ; 75(6): 965-71, 1992 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-1443715

RESUMEN

Postoperative respiratory depression after alfentanil administration has been described in several case reports. The effects of a prolonged alfentanil infusion on the CO2 response curve or cognitive function have not been studied. Twenty-one ASA physical status I or II patients were studied after a prolonged alfentanil infusion (> 90 min) to determine the incidence of postoperative respiratory depression, arterial O2 desaturation, and impairment of cognitive function. Each patient's recovery was observed at 30-min intervals for evidence of respiratory depression (utilizing the Read CO2 rebreathing method), desaturation by pulse oximetry (severe desaturation defined as arterial O2 saturation < 90%), and cognitive function (utilizing Trieger dot and digit substitution tests). Plasma samples were also examined for secondary elevations in alfentanil plasma concentrations. Significant depression of the CO2 response curve and cognitive function was found up to 1 h postoperatively. Arterial O2 desaturation was seen in 11 of 21 patients (52%). No correlation was found between arterial O2 desaturation and cognitive function scores or CO2 rebreathing results. Increased depression of the CO2 response curve was not necessarily associated with severe desaturation episodes. A secondary increase in plasma alfentanil concentration was detected in 5 of the 21 patients (24%), but these patients did not experience further depression of the CO2 response curve. We conclude that prolonged alfentanil administration may result in severe arterial O2 desaturation with significant depression of the hypercapnic respiratory drive during the first hour in the postanesthesia care unit, even though the majority of our patients were easily aroused in response to verbal stimuli.


Asunto(s)
Alfentanilo/administración & dosificación , Respiración/efectos de los fármacos , Adulto , Cognición/efectos de los fármacos , Cognición/fisiología , Depresión Química , Humanos , Infusiones Intravenosas , Oxígeno/sangre , Periodo Posoperatorio , Respiración/fisiología , Factores de Tiempo
14.
Percept Psychophys ; 51(5): 500-3, 1992 May.
Artículo en Inglés | MEDLINE | ID: mdl-1594439

RESUMEN

Previous investigations indicated that thresholds to nonpainful tactile stimuli were elevated in chronic-pain patients when compared with pain-free individuals (Seltzer & Seltzer, 1986; Seltzer et al., 1988). The present study attempted to determine whether thresholds to tactual and visual stimuli also were elevated by chronic pain. Furthermore, lateralization of the pain effect on tactile thresholds was assessed by obtaining thresholds from both left and right arms. A decrease in tactile sensitivity to nonpainful stimuli in chronic-pain patients was confirmed, but laterality of the effect was not demonstrated. Visual thresholds were not significantly affected by chronic pain. The data in the present study, taken together with other data, support the proposition that pain does not affect right hemispheric processes more than left hemispheric processes.


Asunto(s)
Nivel de Alerta , Percepción de Profundidad , Dominancia Cerebral , Dolor/psicología , Tacto , Enfermedad Crónica , Aprendizaje Discriminativo , Humanos , Umbral Sensorial
15.
J Clin Anesth ; 4(3): 220-5, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1610579

RESUMEN

STUDY OBJECTIVE: To determine the effects of three different prone support systems (Andrews spinal surgery frame, Cloward surgical saddle, and longitudinal bolsters) on inferior vena cava (IVC) and superior vena cava (SVC) pressures; the validity of measuring central venous pressure (CVP) for the determination of ideal positioning of the patient; and the relationship among frame type, blood loss, and hemodynamic measurements. DESIGN: Prospective, randomized study of the hemodynamic effects of the prone position. SETTING: Inpatient surgery at a university hospital (regional spinal cord injury treatment center). PATIENTS: Eighteen patients free of significant coexisting disease (ASA physical status I and II) undergoing elective lumbar laminectomy. INTERVENTIONS: Patients were assigned to one of three support frames and measurement of SVC pressure, IVC pressure, and mean arterial pressures (MAP) were obtained supine, prone, and after repositioning. These pressures and measured blood loss were obtained every 15 minutes during the surgical laminectomy portion of the procedure. MEASUREMENTS AND MAIN RESULTS: Patients positioned on the Andrews frame had decreased mean SVC and IVC pressures from 8.7 mmHg and 8.4 mmHg in the supine position to 3.3 mmHg and 1.8 mmHg in the prone position, respectively (p less than 0.001). Prone position CVP also was significantly lower in the Andrews group compared with that in the other two groups (p less than 0.001). Repositioning efforts did not significantly decrease CVP. Blood loss was higher in the Cloward group (1,150 +/- 989 ml) than in the Andrews (245 +/- 283 ml) and bolsters (262 +/- 188 ml) groups (p less than 0.02). CONCLUSIONS: Increased blood loss was not associated with increased SVC or IVC pressure, nor was there any significant correlation between any demographic or hemodynamic variable and blood loss. There was no evidence that CVP is useful in determining the ideal prone position in patients undergoing lumbar laminectomy.


Asunto(s)
Pérdida de Sangre Quirúrgica , Presión Sanguínea/fisiología , Laminectomía , Vértebras Lumbares/cirugía , Equipo Ortopédico , Posición Prona/fisiología , Humanos , Estudios Prospectivos , Distribución Aleatoria
16.
Hosp Formul ; 27(4): 379-80, 386-92, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10117768

RESUMEN

P & T Committees are entering an exciting era in which the introduction of biotechnology-derived pharmaceuticals is providing life-saving opportunities for conditions for which there was little or no hope for a cure. The P & T Committee at Thomas Jefferson University Hospital has anticipated the challenge that these novel therapeutics present, and has already positioned itself for the pending approval of the first therapeutic human monoclonal antibody. Nebacumab (HA-1A, formerly known as Centoxin; by Centocor) will be used for the treatment of gram-negative sepsis. Although this antiendotoxin has a good side effect profile, its use also carries a high price tag. This will raise several difficult ethical issues once the product is introduced. In this exclusive Hospital Formulary roundtable, members of Thomas Jefferson's P & T Committee and Technology Assessment Subcommittee provide their insights for responsibly managing a high-tech, high-cost product such as nebacumab.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Utilización de Medicamentos/normas , Infecciones por Bacterias Gramnegativas/tratamiento farmacológico , Comité Farmacéutico y Terapéutico , Biotecnología/tendencias , Protocolos Clínicos , Costos de los Medicamentos , Control de Formularios y Registros , Hospitales con más de 500 Camas , Hospitales Universitarios/organización & administración , Hospitales Universitarios/normas , Humanos , Política Organizacional , Philadelphia , Estados Unidos , United States Food and Drug Administration
18.
J Clin Anesth ; 3(3): 202-6, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1652264

RESUMEN

STUDY OBJECTIVE: To determine the intubating conditions following the administration of pipecuronium bromide in doses of two (0.07 mg/kg) or three (0.1 mg/kg) times ED95 (average dose that gives 95% block of the first twitch). DESIGN: To compare intubating conditions at 11/2 and 21/2 minutes in 41 patients receiving balanced anesthesia. SETTING: Surgical patients at Thomas Jefferson University Hospital. PATIENTS: Forty-one patients undergoing surgical procedure who received general anesthesia. INTERVENTIONS: After obtaining a stable baseline of train-of-four (TOF), 41 patients randomly received either 0.07 mg/kg or 0.1 mg/kg of pipecuronium as a single intravenous (IV) bolus dose, and the trachea was intubated either at 11/2 or 21/2 minutes. MEASUREMENTS AND MAIN RESULTS: Intubating conditions at 21/2 minutes appeared significantly better than those at 11/2 minutes, regardless of the pipecuronium dose. The mean time for T1 (first twitch of TOF) to reach 50% and 90% suppression was 1.36 +/- 0.51 minutes and 2.29 +/- 0.8 minutes, respectively, for the 0.07 mg/kg dose and 1.07 +/- 0.27 minutes and 1.72 +/- 0.45 minutes, respectively, for the 0.1 mg/kg dose. This did not make a significant difference in intubating conditions at either time. The time to 25% recovery of T1 was 68.2 +/- 22 minutes for the 0.07 mg/kg dose and 121.5 +/- 49 minutes for the 0.1 mg/kg dose. In patients who had spontaneous recovery of T1 to between 10% and 25% of control, administration of neostigmine or edrophonium resulted in identical recovery in 10 minutes. However, in patients with less than 10% spontaneous recovery of T1, neostigmine appeared to be superior to edrophonium. CONCLUSION: Pipecuronium has a relatively rapid onset. The trachea could be intubated successfully in 11/2 minutes with a dose of either 0.07 mg/kg or 0.1 mg/kg. If the clinical situation requires perfect relaxation with no movement or bucking, we recommend waiting at least 21/2 minutes.


Asunto(s)
Androstano-3,17-diol/análogos & derivados , Intubación Intratraqueal , Fármacos Neuromusculares no Despolarizantes/uso terapéutico , Piperazinas/uso terapéutico , Adulto , Androstano-3,17-diol/administración & dosificación , Androstano-3,17-diol/antagonistas & inhibidores , Androstano-3,17-diol/uso terapéutico , Anestesia General , Diafragma/efectos de los fármacos , Edrofonio/farmacología , Femenino , Humanos , Contracción Isométrica/efectos de los fármacos , Masculino , Neostigmina/farmacología , Bloqueantes Neuromusculares/administración & dosificación , Bloqueantes Neuromusculares/antagonistas & inhibidores , Bloqueantes Neuromusculares/uso terapéutico , Unión Neuromuscular/efectos de los fármacos , Fármacos Neuromusculares no Despolarizantes/administración & dosificación , Fármacos Neuromusculares no Despolarizantes/antagonistas & inhibidores , Pipecuronio , Piperazinas/administración & dosificación , Piperazinas/antagonistas & inhibidores , Transmisión Sináptica/efectos de los fármacos , Factores de Tiempo , Pliegues Vocales/efectos de los fármacos
19.
Med Teach ; 13(1): 89-92, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1865805

RESUMEN

A pilot study of the levels of stress among residents was conducted in three departments in a university hospital prior to initiating a programme in stress management for residents. The Beck Depression Inventory, which is a brief, standardized self-report measure of depression, was given to residents in anaesthesiology, paediatrics and psychiatry. Six additional questions were asked about the functioning of peers and services residents would like to have available. Of the 113 residents surveyed, 16% were experiencing a mild mood disturbance. The researchers feel this is probably under-reported. Residents felt that about 15% of their colleagues were emotionally impaired; 10% may have a drug and/or alcohol problem; 12% were having marital problems. Eighty per cent of all residents studied said that they would attend support groups if they existed. Approximately 60% thought coping skills/stress management seminars would be useful, and 30% of the paediatric and anaesthesiology residents (60% of the psychiatry residents) said they would use confidential individual psychotherapy if it were available.


Asunto(s)
Educación Médica , Internado y Residencia , Especialización , Estrés Psicológico/psicología , Anestesiología/educación , Depresión/diagnóstico , Humanos , Pediatría/educación , Inventario de Personalidad , Proyectos Piloto , Psiquiatría/educación , Psicoterapia , Apoyo Social
20.
J Clin Anesth ; 3(1): 11-3, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-2007035

RESUMEN

STUDY OBJECTIVE: To evaluate the effect of a preprinted, risk-specific consent form on the amount of anesthetic risk information patients retain from the preoperative interview. DESIGN: Postoperative survey of consecutive inpatients to determine risk information retained before and after implementation of a preprinted anesthesia consent form, using standard preoperative risk discussions. SETTING: Inpatient units of a university medical center. PATIENTS: Two groups of patients, both of whom received a standard oral discussion of anesthetic risk information, were compared. Patients in the control group (125 consecutive inpatients) received this information only orally and were interviewed two weeks prior to implementation of a preprinted anesthesia consent form. Patients in the study group (92 consecutive inpatients) received this information orally and via a preprinted consent form and were interviewed between the fourth and sixth weeks after implementation of a preprinted anesthesia consent form. INTERVENTIONS: Anesthesia residents discussed five standard anesthetic risks with elective, adult inpatients (n = 233) during a two-week period immediately before and between the fourth and sixth weeks after instituting the mandatory use of a risk-specific anesthesia consent form. These patients were interviewed postoperatively by one of the authors to determine the amount of anesthesia risk information they retained. MEASUREMENTS AND MAIN RESULTS: Results of the postoperative survey showed that patients in the control group retained more information concerning anesthetic risks than did those in the study group (33% vs 19%, p less than 0.01). CONCLUSIONS: To improve the informed consent process, either a better method of presenting the preprinted, risk-specific consent form or another method of simultaneously conveying and documenting risk information is needed.


Asunto(s)
Anestesiología , Comunicación , Consentimiento Informado , Anestesiología/estadística & datos numéricos , Humanos , Consentimiento Informado/estadística & datos numéricos , Riesgo
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