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1.
Mediators Inflamm ; 2019: 8071619, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31148947

RESUMO

BACKGROUND: It is not predictable which patients will develop a severe inflammatory response after successful cardiopulmonary resuscitation (CPR), also known as "postcardiac arrest syndrome." This pathology affects only a subgroup of cardiac arrest victims. Whole body ischemia/reperfusion and prolonged shock states after return of spontaneous circulation (ROSC) may both contribute to this devastating condition. The vascular endothelium with its glycocalyx is especially susceptible to initial ischemic damage and may play a detrimental role in the initiation of postischemic inflammatory reactions. It is not known to date if an immediate early damage to the endothelial glycocalyx, detected by on-the-scene blood sampling and measurement of soluble components (hyaluronan and syndecan-1), precedes and predicts multiple organ failure (MOF) and survival after ROSC. METHODS: 15 patients after prehospital resuscitation were included in the study. Serum samples were collected on the scene immediately after ROSC and after 6 h, 12 h, 24 h, and 48 h. Hyaluronan and syndecan-1 were measured by ELISA. We associated the development of multiple organ failure and 30-day survival rates with these serum markers of early glycocalyx damage. RESULTS: Immediate serum hyaluronan concentrations show significant differences depending on 30-day survival. Further, the hyaluronan level is significantly higher in patients developing MOF during the initial and intermediate resuscitation period. Also, the syndecan-1 levels are significantly different according to MOF occurrence. CONCLUSION: Serum markers of glycocalyx shedding taken immediately on the scene after ROSC can predict the occurrence of multiple organ failure and adverse clinical outcome in patients after cardiac arrest.


Assuntos
Parada Cardíaca/sangue , Ácido Hialurônico/sangue , Sindecana-1/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Reanimação Cardiopulmonar , Feminino , Parada Cardíaca/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Insuficiência de Múltiplos Órgãos/sangue , Estudos Prospectivos
3.
Unfallchirurg ; 117(5): 399-405, 2014 May.
Artigo em Alemão | MEDLINE | ID: mdl-24831869

RESUMO

We report on a 32-year-old patient, who developed septic shock, toxic shock-like syndrome, and multiple organ failure following nectrotizing fasciitis. Amputations had to be performed on all extremities. Subsequently, she developed secondary sclerosing cholangitis. Treatment goals had to be reassessed, since long-term survival seemed doubtful and, in the best case, burdened with severe handicap. We discuss the evaluation of the treatment goals, utilizing a structured model of goal-setting. In the first step the treatment goal is identified based on the patient's wishes. This goal's realistic achievability is verified considering scientific evidence and medical experience. The benefit of the aspired goal is set in relation to risks and burden of the necessary treatment measures in a third step. The resulting benefit-risk ratio must be evaluated by the patient or her representative. Treatment goals have to be reevaluated if the assessment of achievability or the benefit-risk ratio are disadvantageous. In this case, the initial therapeutic goal was retained. After an extraordinarily prolonged and complex therapy including reconstructive surgery the patient is now living independently at home.


Assuntos
Amputação Cirúrgica/ética , Estado Terminal/terapia , Tomada de Decisões/ética , Planejamento de Assistência ao Paciente/ética , Relações Médico-Paciente/ética , Procedimentos Cirúrgicos Operatórios/ética , Traumatologia/ética , Adulto , Técnicas de Apoio para a Decisão , Feminino , Alemanha , Humanos , Assistência Centrada no Paciente/ética
4.
Mediators Inflamm ; 2012: 435463, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22547904

RESUMO

Metalloproteinases are secreted in response to a variety of inflammatory mediators and inhibited by tissue inhibitors of matrixmetalloproteinases (TIMPs). Two members of these families, MMP-9 and TIMP-1, were differentially expressed depending on clinical parameters in a previous genomewide mRNA analysis. The aim of this paper was now to evaluate the posttraumatic serum levels and the time course of both proteins depending on distinct clinical parameters. 60 multiple traumatized patients (ISS > 16) were included. Blood samples were drawn on admission and 6 h, 12 h, 24 h, 48 h, and 72 h after trauma. Serum levels were quantified by ELISA. MMP-9 levels significantly decreased in the early posttraumatic period (P < 0.05) whereas TIMP-1 levels significantly increased in all patients (P < 0.05). MMP-9 and TIMP-1 serum concentration kinetics became manifest in an inversely proportional balance. Furthermore, MMP-9 presented a stronger decrease in patients with severe trauma and non-survivors in contrast to minor traumatized patients (ISS ≤ 33) and survivors, initially after trauma.


Assuntos
Metaloproteinase 9 da Matriz/sangue , Traumatismo Múltiplo/sangue , Inibidor Tecidual de Metaloproteinase-1/sangue , Ferimentos não Penetrantes/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Cinética , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , Fatores de Tempo
5.
Anaesthesist ; 61(7): 597-600, 2012 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-22699225

RESUMO

Tuberculosis is an infectious disease with a decreasing incidence in Germany. In particular, the occurrence of reinfections and possible complications associated with this disease, such as tuberculous meningitis/encephalitis and Landouzy sepsis are rare in industrial countries. In this article the intensive care treatment of a patient who initially underwent surgery for spinal stenosis is reported. Due to recurrent appearance of neurological symptoms with increasing severity and abscess formation in the spine, further surgery was performed. Additionally, the patient developed sepsis and meningitis. At this time an infection with Mycobacterium tuberculosis could be detected in both cerebrospinal fluid and abscess material of the spine suggesting a Landouzy sepsis, tuberculous meningitis/encephalitis and the suspicion of an underlying Pott's disease.


Assuntos
Encefalite/terapia , Complicações Pós-Operatórias/terapia , Sepse/terapia , Estenose Espinal/cirurgia , Tuberculose da Coluna Vertebral/complicações , Tuberculose da Coluna Vertebral/terapia , Antituberculosos/uso terapêutico , Cuidados Críticos , Encefalite/etiologia , Encefalite/fisiopatologia , Escala de Coma de Glasgow , Humanos , Pressão Intracraniana/fisiologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis , Paralisia/etiologia , Reação em Cadeia da Polimerase , Complicações Pós-Operatórias/fisiopatologia , Sepse/etiologia , Sepse/fisiopatologia , Tuberculose da Coluna Vertebral/etiologia , Tuberculose da Coluna Vertebral/microbiologia , Tuberculose da Coluna Vertebral/fisiopatologia
7.
Unfallchirurg ; 114(11): 973-80, 2011 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-22048451

RESUMO

Severe trauma triggers endocrine and inflammatory responses, leading to hyperglycaemia, insulin resistance and protein catabolism. Pharmacological and nutritional interventions cannot counteract these metabolic disturbances. However, adequate supply of energy and proteins may reduce excessive catabolism.Available guidelines recommend early use of enteral nutrition with energetic supply of about 25 kcal/kg and additional protein supply of 1.5 g/kg/day. These aims will be missed frequently by solely providing enteral nutrition in severely injured patients. Early supplemental parenteral nutrition should be used in these cases. Concomitantly, gastric paresis and paralytic ileus hampering enteral nutrition should be treated by propulsive and prokinetic drugs and by use of duodenal or jejunal site of application in selected cases.Euphoric hopes linked with intensified insulin therapy (IIT), targeting blood glucose levels <110 mg/dl in intensive care patients, had to be widely abandoned in recent years. The goal for blood glucose levels should be set at 180 mg/dl as the upper limit according to current knowledge, which promises to optimize the balance between efficacy and safety.


Assuntos
Cuidados Críticos/normas , Nutrição Enteral/enfermagem , Doenças Metabólicas/enfermagem , Distúrbios Nutricionais/enfermagem , Guias de Prática Clínica como Assunto , Traumatologia/normas , Ferimentos e Lesões/enfermagem , Alemanha , Humanos , Doenças Metabólicas/etiologia , Doenças Metabólicas/prevenção & controle , Distúrbios Nutricionais/etiologia , Distúrbios Nutricionais/prevenção & controle , Ferimentos e Lesões/complicações
8.
Am J Vet Res ; 71(7): 840-6, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20594088

RESUMO

OBJECTIVE: To compare the renal and cardiorespiratory effects of IV treatment with lactated Ringer's solution (LRS) or physiologic saline (0.9% NaCl) solution (PSS) in severely decompensated cats with urethral obstruction (UO). ANIMALS: 14 cats (4 cats were used only to establish infusion rates). PROCEDURES: An occluded urethral catheter was used to induce UO in each cat. After development of severe metabolic acidosis, hyperkalemia, and postrenal azotemia, the obstruction was relieved (0 hours); LRS or PSS (5 cats/group) was administered IV (gradually decreasing rate) beginning 15 minutes before and continuing for 48 hours after UO relief. Ten minutes before urethral catheter placement (baseline), at start of fluid therapy (SFT), and at intervals during fluid administration, various physical and clinicopathologic evaluations were performed. RESULTS: Metabolic acidosis was detected in the PSS-treated group at SFT and 2 hours after relief of UO and in the LRS-treated group only at SFT The PSS-treated group had significantly lower blood pH and bicarbonate concentrations at 8 through 48 hours and lower base excess values at 2 through 48 hours, compared with the LRS-treated group. Hypocalcemia and hypernatremia were detected in the PSS-treated group at 2 and 12 hours, respectively. Absolute serum potassium and chloride concentrations did not differ significantly between groups at any time point. CONCLUSIONS AND CLINICAL RELEVANCE: Treatment with LRS or PSS appeared to be safe and effective in cats with experimentally induced UO; however, LRS was more efficient in restoring the acid-base and electrolyte balance in severely decompensated cats with UO.


Assuntos
Doenças do Gato/tratamento farmacológico , Soluções Isotônicas/uso terapêutico , Rim/fisiologia , Cloreto de Sódio/uso terapêutico , Obstrução Uretral/veterinária , Animais , Temperatura Corporal/efeitos dos fármacos , Doenças do Gato/fisiopatologia , Gatos , Diurese/efeitos dos fármacos , Hidratação/métodos , Hidratação/veterinária , Frequência Cardíaca/efeitos dos fármacos , Rim/efeitos dos fármacos , Rim/fisiopatologia , Masculino , Orquiectomia , Lactato de Ringer , Albumina Sérica/efeitos dos fármacos , Albumina Sérica/metabolismo , Obstrução Uretral/tratamento farmacológico , Obstrução Uretral/fisiopatologia
10.
Int J Psychophysiol ; 134: 95-107, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30393110

RESUMO

Fear conditioning and extinction is a construct integral to understanding trauma-, stress- and anxiety-related disorders. In the laboratory, associative learning paradigms that pair aversive with neutral stimuli are used as analogues to real-life fear learning. These studies use physiological indices, such as skin conductance, to sensitively measure rates and intensity of learning and extinction. In this review, we discuss some of the potential limitations in interpreting and analysing physiological data during the acquisition or extinction of conditioned fear. We argue that the utmost attention should be paid to the development of modelling approaches of physiological data in associative learning paradigms, by illustrating the lack of replicability and interpretability of results in current methods. We also show that statistical significance may be easily achieved in this paradigm without more stringent data and data analysis reporting requirements, leaving this particular field vulnerable to misleading conclusions. This review is written so that issues and potential solutions are accessible to researchers without mathematical training. We conclude the review with some suggestions that all laboratories should be able to implement, including visualising the full data set in publications and adopting modelling, or at least regression-based, approaches.


Assuntos
Condicionamento Psicológico/fisiologia , Análise de Dados , Extinção Psicológica/fisiologia , Medo/fisiologia , Psicofisiologia/métodos , Humanos , Psicofisiologia/normas
11.
Vet J ; 171(3): 491-9, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16624715

RESUMO

The purpose of this study was to determine the effect of cellulose membrane or free fat grafts (FFG) on laminectomy membrane (LM) formation. Eighteen dogs were randomly divided into three groups of six dogs. All dogs underwent a modified dorsal laminectomy on T(13)-L(1). The laminectomy defect was left uncovered in the control group but either a FFG or a cellulose membrane implant was provided in the other two groups. The dogs were evaluated through neurological examination, myelography, macroscopic roundness index of spinal cord and histological evaluations of epidural fibrosis and spinal cord. The results showed a significant difference between the control and the FFG group, with the FFG causing neurological deficits and spinal cord compression as assessed by the roundness index of the spinal cord. Both FFG and cellulose membrane were partially effective in preventing LM formation. The use of FFG was associated with a high rate of significant neurological complications and spinal cord lesions.


Assuntos
Doenças do Cão/cirurgia , Laminectomia/veterinária , Doenças da Coluna Vertebral/veterinária , Telas Cirúrgicas , Tecido Adiposo , Animais , Celulose , Doenças do Cão/patologia , Cães , Laminectomia/métodos , Mielografia/veterinária , Complicações Pós-Operatórias/veterinária , Próteses e Implantes/veterinária , Distribuição Aleatória , Medula Espinal/patologia , Medula Espinal/cirurgia , Compressão da Medula Espinal/etiologia , Compressão da Medula Espinal/patologia , Compressão da Medula Espinal/cirurgia , Compressão da Medula Espinal/veterinária , Doenças da Coluna Vertebral/patologia , Doenças da Coluna Vertebral/cirurgia
13.
Pesqui. vet. bras ; 38(12): 2183-2189, dez. 2018. ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-976422

RESUMO

Adipose tissue-derived stem cells (ADSCs) are an attractive source of mesenchymal stem cells (MSCs) for use in tissue engineering and clinical applications. This paper focuses on the characterization of ADSCs used as immunosuppressive agent in rabbits undergoing partial allograft for urine bladder restorage. For this study highlighted the characterization of the ADSCs used as immunosuppressive agents in rabbits submitted to partial allograft for restoration of the urinary vesicle, using 25 animals, six months old, New Zealand. ADSCs at the third peal were characterized by the MSC-specific CD105, CD73 and CD90 expression and by the absence of the hematopoietic marker CD45, as revealed by flow cytometry analysis. Moreover, ADSCs were efficient in preventing allograft rejection from the urinary bladder, as judged by biochemical, clinical and ultrasonography analysis. Together, these results compose characterization of protein expression profiles and immunosuppressive functionality of ADSCs in rabbits, which had undergone partial allografts of the urinary bladder, foreseeing future applications in clinical practice.(AU)


As células mesenquimais derivadas de tecido adiposo (ADSCs) são uma fonte atraente de células-tronco mesenquimais (MSCs) para uso na engenharia de tecidos e suas aplicações clínicas. Este trabalho destacou a caracterização das ADSCs utilizadas como agentes imunossupressores em coelhos submetidos a aloenxerto parcial para restauração da vesícula urinária, sendo utilizados 25 animais, de seis meses de idade, Nova Zelândia. As ADSCs, após o terceiro repique, foram caracterizadas pela expressão específica de MSC CD105, CD73 e CD90 e pela ausência do marcador hematopoiético CD45, tal como revelado por análise de citometria de fluxo. Além disso, os ADSCs foram eficientes na prevenção da rejeição de aloenxertos da vesícula urinária, conforme avaliado por análises clínica, bioquímica e ultrassonográfica. Juntos, esses resultados compõem a caracterização dos perfis de expressão proteica e a funcionalidade imunossupressora de ADSCs em coelhos, que sofreram aloenxertos parciais da bexiga, prevendo futuras aplicações na prática clínica.(AU)


Assuntos
Animais , Coelhos , Coelhos , Bexiga Urinária/transplante , Aloenxertos/citologia , Terapia Baseada em Transplante de Células e Tecidos/veterinária , Imunossupressores , Citometria de Fluxo/veterinária
14.
Can J Vet Res ; 76(3): 201-8, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23277699

RESUMO

This study compared acid-base and biochemical changes and quality of recovery in male cats with experimentally induced urethral obstruction and anesthetized with either propofol or a combination of ketamine and diazepam for urethral catheterization. Ten male cats with urethral obstruction were enrolled for urethral catheterization and anesthetized with either ketamine-diazepam (KD) or propofol (P). Lactated Ringer's solution was administered by intravenous (IV) beginning 15 min before and continuing for 48 h after relief of urethral obstruction. Quality of recovery and time to standing were evaluated. The urethral catheter was maintained to measure urinary output. Hematocrit (Hct), total plasma protein (TPP), albumin, total protein (TP), blood urea nitrogen (BUN), creatinine, pH, bicarbonate (HCO3-), chloride, base excess, anion gap, sodium, potassium, and partial pressure of carbon dioxide in mixed venous blood (pvCO2) were measured before urethral obstruction, at start of fluid therapy (0 h), and at subsequent intervals. The quality of recovery and time to standing were respectively 4 and 75 min in the KD group and 5 and 16 min in the P group. The blood urea nitrogen values were increased at 0, 2, and 8 h in both groups. Serum creatinine increased at 0 and 2 h in cats administered KD and at 0, 2, and 8 h in cats receiving P, although the values were above the reference range in both groups until 8 h. Acidosis occurred for up to 2 h in both groups. Acid-base and biochemical stabilization were similar in cats anesthetized with propofol or with ketamine-diazepam. Cats that received propofol recovered much faster, but the ketamine-diazepam combination was shown to be more advantageous when treating uncooperative cats as it can be administered by intramuscular (IM) injection.


Assuntos
Equilíbrio Ácido-Base/efeitos dos fármacos , Período de Recuperação da Anestesia , Diazepam/farmacologia , Ketamina/farmacologia , Propofol/farmacologia , Obstrução Uretral/veterinária , Acidose , Anestesia Intravenosa/veterinária , Anestésicos Dissociativos/administração & dosagem , Anestésicos Dissociativos/farmacologia , Anestésicos Intravenosos/administração & dosagem , Anestésicos Intravenosos/farmacologia , Animais , Nitrogênio da Ureia Sanguínea , Doenças do Gato/cirurgia , Gatos , Creatinina/sangue , Diazepam/administração & dosagem , Quimioterapia Combinada , Hiperpotassemia , Ketamina/administração & dosagem , Masculino , Obstrução Uretral/sangue , Obstrução Uretral/cirurgia
15.
Br J Anaesth ; 97(2): 150-3, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16720674

RESUMO

We report a case of recurrent episodes of Torsades de Pointes arrhythmia in the setting of transiently impaired left ventricular ejection fraction, acute respiratory distress syndrome, transient hypokalaemia and QT-prolonging drugs, in a previously healthy 25-yr-old female patient. In the course of the clinical and genetic work-up this patient was newly diagnosed with a mutation in KCNH2 encoding the alpha-subunit of the human repolarizing potassium channel I(Kr). This case report illustrates the multivariate nature of long-QT syndrome, and emphasizes the usefulness of a pharmacological test for repolarization abnormalities.


Assuntos
Síndrome do QT Longo/congênito , Síndrome do Desconforto Respiratório/etiologia , Torsades de Pointes/complicações , Disfunção Ventricular Esquerda/complicações , Adulto , Antibacterianos/efeitos adversos , Antifúngicos/efeitos adversos , Canal de Potássio ERG1 , Ecocardiografia/métodos , Eritromicina/efeitos adversos , Canais de Potássio Éter-A-Go-Go/genética , Feminino , Fluconazol/efeitos adversos , Humanos , Hipopotassemia/complicações , Hipopotassemia/fisiopatologia , Síndrome do QT Longo/complicações , Síndrome do QT Longo/fisiopatologia , Mutação/genética , Recidiva , Síndrome do Desconforto Respiratório/fisiopatologia , Torsades de Pointes/fisiopatologia , Resultado do Tratamento , Disfunção Ventricular Esquerda/fisiopatologia
16.
Anaesthesist ; 46 Suppl 2: SI-SVII, 1997 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-9432870

RESUMO

Beyond strict selection of suitable patients the adequate choice of the best moment for discharge home is essential for safety and efficacy of outpatient surgery. Restitution of cardiovascular stability and psychomotoric function is completed at the end of observation in the recovery unit. Further prerequisites of home discharge are absence of postoperative nausea and vomitus as well as sufficient pain control by non-opioids and physical measures. The definition of fixed observation periods is unreasonable, technical examinations and psychomotoric tests are of minor importance. Home readiness has to be evaluated by a physician before discharge. Standardized scores or checklists may be of some help. The modalities of patient care after discharge are checked prior to surgery. During late postoperative recovery, continuous care of a responsible adult is required for at least 24 hours. During this time period certain restrictions must be respected, e.g. from driving and business contracts. Even after this time some residual effects of anesthesia may still be present.


Assuntos
Procedimentos Cirúrgicos Ambulatórios , Anestesia , Alta do Paciente , Adulto , Humanos
17.
Artigo em Alemão | MEDLINE | ID: mdl-9445556

RESUMO

A major complication of transurethral resection of the prostate (TURP) is the excessive absorption of irrigation solution resulting in hypervolemia and dilutional hyponatremia. Marking the irrigation fluid with ethanol is a method for the early detection of fluid absorption. Currently this method is being used in spontaneously breathing patients undergoing regional anaesthesia. The goal of this study was to determine whether this method is also reliable for patients undergoing general anaesthesia. Fifty-nine patients underwent TURP in either spinal anaesthesia (SPA), or general anaesthesia with semi-open (ITNO) and semi-closed (ITNC) systems. Plasma alcohol concentrations ([Eth]p), exhaled ethanol ([Eth]e), plasma sodium concentration ([Na+]), and central venous pressure (CVP) were measured. The irrigation fluid contained ethanol in an concentration of approx. 1%. We assumed that significant fluid absorption took place when [Eth]p exceeded 0.1/1000. Measurements were performed immediately prior to and during surgery at 10-minute intervals. [Eth]p correlated directly with [Eth]e for both forms of anaesthesia. [Eth]p and [Na+] correlated inversely both for SPA and ITNC. Changes in [Eth]p did not parallel changes in CVP. Clinically relevant episodes of fluid absorption were accompanied by the detection of exhaled ethanol in all groups. We conclude that measuring exhaled ethanol is a minimal invasive monitoring technique that allows the detection of significant fluid absorption in both spontaneously breathing as well as ventilated patients with sufficient sensitivity. The ethanol levels are not predictive of the sodium concentration both in SPA and general anaesthesia. Thus, additional determinations of [Na+] is recommended whenever [Eth]e exceeds 0.2/1000.


Assuntos
Etanol , Hiponatremia/diagnóstico , Complicações Intraoperatórias/diagnóstico , Prostatectomia , Respiração Artificial , Intoxicação por Água/diagnóstico , Anestesia Geral , Raquianestesia , Testes Respiratórios , Pressão Venosa Central/fisiologia , Etanol/farmacocinética , Humanos , Hiponatremia/sangue , Masculino , Sódio/sangue , Irrigação Terapêutica , Intoxicação por Água/sangue
18.
Anesthesiology ; 81(6): 1436-44, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7992913

RESUMO

BACKGROUND: Contradictory results have been reported in previous studies investigating the effect of isoflurane on hypoxic pulmonary vasoconstriction by indirect approaches. The current study measured the effects of one-lung ventilation (1LV) and isoflurane 1.5% by direct visual observation of the pulmonary microcirculation. METHODS: Ten New Zealand White rabbits were anesthetized with intravenous thiopental, alpha-chloralose, and piritramid. Arterial, central venous, pulmonary arterial, left atrial, and airway pressures and cardiac output were recorded continuously. 1LV was facilitated by a bronchial blocker in the right main bronchus. A transparent window was implanted into the right thoracic wall for videofluorescence microscopy of the subpleural pulmonary microcirculation. After intravenous injection of fluorescein isothiocyanate-labeled red blood cells, vessel diameters, red blood cell flux, red blood cell velocity, and dynamic microhematocrit were measured in pulmonary arterioles and venules during two-lung ventilation and 1LV during baseline anesthesia and with supplementary isoflurane 1.5%. RESULTS: During intravenous anesthesia, 1LV caused significant reduction of vessel diameters and red cell flux and velocity and an increase in microvascular hematocrit in pulmonary arterioles and venules. The decreases in arteriolar diameters and red blood cell flux and velocity induced by 1LV were significantly attenuated by isoflurane as compared with those measured during baseline anesthesia (P = 0.010, P = 0.029 and P = 0.047). Accordingly, 1LV-induced reduction of venular red cell flux (P = 0.023) and velocity (P = 0.036) were less pronounced during isoflurane. Isoflurane caused a significant decrease in arterial pressure. Venous admixture increased and arterial oxygen tension decreased significantly during 1LV; the changes were more pronounced during 1LV with isoflurane 1.5% than during 1LV with baseline anesthesia. CONCLUSIONS: 1LV leads to a marked reduction of microvascular diameters and blood flow in the hypoxic lung. Isoflurane 1.5% inhibits hypoxic pulmonary vasoconstriction in pulmonary arterioles and increases regional blood flow in the hypoxic lung.


Assuntos
Anestesia Intravenosa/efeitos adversos , Hipóxia/tratamento farmacológico , Isoflurano/uso terapêutico , Pulmão/efeitos dos fármacos , Vasoconstrição/efeitos dos fármacos , Animais , Hemodinâmica/efeitos dos fármacos , Hipóxia/etiologia , Microscopia de Fluorescência , Circulação Pulmonar/efeitos dos fármacos , Troca Gasosa Pulmonar , Coelhos , Tiopental
19.
Anaesthesist ; 44(5): 319-27, 1995 May.
Artigo em Alemão | MEDLINE | ID: mdl-7611578

RESUMO

The physiological pattern of regional pulmonary blood flow is mainly determined by the relationship of pulmonary arterial, venous, and alveolar pressures. Changes in alveolar pressure and pulmonary geometry may therefore be expected to influence regional perfusion, which is a key determinant of pulmonary gas exchange. Unilateral thoracotomy is usually performed with the patient in the lateral decubitus position. The present study examined the influence of mechanical factors on regional pulmonary blood flow distribution in rabbits in the lateral decubitus position during normoxia and unilateral hypoxia. METHODS. Anaesthetised white New Zealand rabbits (n = 8) weighing 2200-3900 g (mean = 2860 g) received central venous injections of radioactive microspheres while in the left lateral decubitus position during spontaneous breathing (SB) and during mechanical ventilation (two-lung ventilation, 2LV), under closed (2LVC) and open chest (2LVT) conditions, as well as during unilateral hypoxia of the nondependent lung induced by nitrogen inflation (1LVN) or atelectasis (1LVA). The method used for one-lung ventilation (1LV) has been previously described in detail. Arterial, central venous, and pulmonary arterial pressures were recorded continuously. Lungs were excised, dried in the inflated state, and cut into 16 sagittal slices, which were further divided into lobar components, the lower lobes into center and periphery. The radioactivity of each specimen was measured in a gamma-counter; perfusion of the individual tissue specimens was quantified using the software program MIC III. The Friedman test followed by paired comparisons according to Conover was used for statistical analysis of differences between the experimental phases. Perfusion of central and peripheral parts of isogravitational slices was compared by use of the Wilcoxon matched pairs test. Values are given as means +/- SE; the level of significance was P < 0.05 unless otherwise indicated. RESULTS AND DISCUSSION. Haemodynamic parameters did not differ significantly between the experimental phases (Table 1). Compared to 2LV, a significant increase in venous admixture (P < 0.05) and a corresponding decrease in PaO2 (P < 0.01) were observed during 1LV. This effect was significantly more pronounced during 1LVA as compared to 1LVN (P < 0.01). Since inspiratory pressure was kept constant throughout the experiments, moderate respiratory acidosis developed during both phases of 1LV. Regional perfusion (Qr) of the nondependent lung was slightly reduced during 2LVC compared to SB and 2LVT. One-lung ventilation induced a significant decrease in perfusion of the hypoxic lung (P < 0.001 1LVN, 1LVA vs. SB,2LVC,2LVT). In accordance with the data obtained from blood gas analysis and oximetry, this effect was more pronounced during N2 insufflation than during atelectasis (P < 0.01 1LVN vs. 1LVA). Among the factors that may account for this effect, PaCO2 did not differ significantly between both phases of 1LV. During N2 insufflation PO2 at the hypoxia-sensitive site is lower than during atelectasis, where it equals mixed-versus PO2 (PvO2). The difference in local PO2 is unlikely, however, to have caused the changes in regional perfusion between 1LVN and 1LVA, since PvO2 was as low as 40 mmHg during 1LVA and the pulmonary vascular response to hypoxia has been found to reach its maximum in this PO2 range [2, 11]. Enhanced redistribution of regional perfusion during 1LVN as compared to 1LVA is therefore most likely attributed to differences in alveolar pressure and pulmonary geometry. Apart from a radial perfusion gradient in the right lower lobe during 2LVC and 2LVT, no isogravitational Qr gradients were observed. CONCLUSION. We conclude that controlled mechanical ventilation in the lateral decubitus position causes only minor changes in vertical blood flow distribution.


Assuntos
Circulação Pulmonar/fisiologia , Respiração Artificial , Mecânica Respiratória/fisiologia , Toracotomia , Animais , Hemodinâmica/fisiologia , Hipóxia/fisiopatologia , Pulmão/anatomia & histologia , Pulmão/fisiologia , Coelhos
20.
Br J Anaesth ; 74(2): 209-16, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7696073

RESUMO

Isoflurane has been reported to inhibit hypoxic pulmonary vasoconstriction. However, the effects of one-lung ventilation and isoflurane on regional pulmonary blood flow (Qr) have not been investigated in detail. Therefore, using radionuclide labelled microspheres we measured Qr in rabbits (n = 8) in the left lateral decubitus position during two- and one-lung ventilation under i.v. baseline anaesthesia and during additional administration of 1.5% isoflurane. Macrohaemodynamic variables were recorded continuously. Isoflurane increased non-dependent lung blood flow during two-lung ventilation. One-lung ventilation caused a homogeneous decrease in Qr throughout the hypoxic lung, irrespective of isoflurane administration (P < 0.001). However, isoflurane significantly augmented Qr of the hypoxic lung during one-lung ventilation (P < 0.05). During all phases, Qr of the upper lobe was higher compared with that in the lower lobe in isogravitational slices of both lungs; a ventrodorsal perfusion gradient was found in the left upper lobe. We conclude that 1.5% isoflurane increased perfusion of the non-dependent lung, inhibited hypoxic pulmonary vasoconstriction-induced redistribution of pulmonary blood flow and did not influence isogravitational perfusion gradients.


Assuntos
Isoflurano/farmacologia , Pulmão/irrigação sanguínea , Anestesia Intravenosa , Animais , Gravitação , Hemodinâmica , Troca Gasosa Pulmonar , Coelhos , Fluxo Sanguíneo Regional/efeitos dos fármacos , Respiração Artificial
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