RESUMO
Heparin-induced thrombocytopenia (HIT) is a thrombotic complication of heparin therapy. The most used functional method for HIT diagnosis is serotonin release assay (SRA). A different functional method based on ATP release with luciferin/luciferase long-life and stable luminescent signal is used here, which is shown to be comparable for accuracy with SRA in both negative (patients 4Ts ≤3, and negative for both anti-PF4/heparin immunoassay and SRA) and positive (4Ts >3, and positive for both PF4/heparin antibodies and SRA) patients. Our results show that ATP release is higher in washed platelets activated by sera from positive patients than in platelets activated by sera from negative patients. In conclusion, we demonstrate that ATP release assay is a valid alternative method to SRA for the identification of pathogenic anti-PF4/heparin antibodies.
Assuntos
Trifosfato de Adenosina/sangue , Anticorpos/sangue , Anticoagulantes/efeitos adversos , Heparina/efeitos adversos , Medições Luminescentes/métodos , Serotonina/sangue , Trombocitopenia/diagnóstico , Adulto , Idoso , Anticoagulantes/imunologia , Plaquetas/imunologia , Plaquetas/patologia , Feminino , Luciferina de Vaga-Lumes/química , Seguimentos , Expressão Gênica , Heparina/imunologia , Humanos , Imunoensaio/métodos , Luciferases de Vaga-Lume/química , Masculino , Pessoa de Meia-Idade , Fator Plaquetário 4/genética , Fator Plaquetário 4/imunologia , Trombocitopenia/sangue , Trombocitopenia/induzido quimicamente , Trombocitopenia/imunologiaRESUMO
BACKGROUND: Currently, ventricular assist device (VAD) or total artificial heart (TAH) mechanical support provides an effective treatment of unstable patients with advanced heart failure. We report our single-center experience with mechanical circulatory support therapy. METHODS: From March 2002 to December 2012, 107 adult patients (mean age, 56.8 ± 9.9 y; range, 31-76 y) were primarly supported on temporary or long-term VAD or TAH support as treatment for refractory heart failure at our institution. Temporary extracorporeal radial VAD support (group A) was established in 49 patients (45.7%), and long-term paracorporeal and intracorporeal VAD or TAH (group B) in 58 patients (54.2%). Left ventricular (LVAD) support was established in 55 patients (51.4%; n = 33, Heartmate II; n = 6, Heartmate I XVE; n = 4, Heartware HVAD; and n = 12, Centrimag) and biventricular (BVAD/TAH) support (group B) in 28 patients (26.1%; n = 10, Thoratec paracorporeal; n = 2, Heartware HVAD, n = 1, Thoratec implantable; n = 1, Syncardia TAH; and n = 14, Centrimag). The temporary Centrimag was the only device adopted as isolated right ventricular (RVAD) support, and it was inserted in 24 patients (22.4%). RESULTS: In group A, overall mean support time was 10.2 ± 6.6 days (range, 3-43 d). In group B, LVAD mean support time was 357 ± 352.3 days (range, 1-902 d) and BVAD/TAH support time was 98 ± 82.6 days (range, 8-832 d). In group A, the overall success rate was 55.1% (27 patients). In group B, LVAD overall success rate was 74.4% (32 patients) and BVAD/TAH success rate was 50% (7 patients). Overall heart transplantation rate for both groups was 27.1% (n = 2, group A; n = 27, group B). Overall 1-year and 5-year survivals after heart transplantation were 72.4% (n = 21) and 58.6% (n = 17), respectively. CONCLUSIONS: Mechanical circulatory support is an effective strategy even in cases of end-stage heart failure according to our experience. Further improvement of VAD and TAH technologies may support their adoption as an encouraging alternative to heart transplantation in the near future.
Assuntos
Insuficiência Cardíaca/terapia , Coração Artificial , Coração Auxiliar , Adulto , Idoso , Insuficiência Cardíaca/fisiopatologia , Humanos , Pessoa de Meia-IdadeRESUMO
Carbapenem-resistant Klebsiella pneumoniae (CR-KP) is becoming a common cause of healthcare-associated infection in Italy, with high morbidity and mortality. Prevalent CR-KP clones and resistance mechanisms vary between regions and over time. Therapeutic approaches and their impact on mortality have to be investigated. We performed a prospective study of patients with CR-KP isolation, hospitalized in nine hospitals of Rome, Italy, from December 2010 to May 2011, to describe the molecular epidemiology, antibiotic treatment and risk factors for mortality. Overall, 97 patients (60% male, median age 69 years) were enrolled. Strains producing blaKPC-3 were identified in 89 patients, blaVIM in three patients and blaCTX-M-15 plus porin defects in the remaining five patients. Inter-hospital spread of two major clones, ST512 and ST258, was found. Overall, 36.1% and 20.4% of strains were also resistant to colistin and tigecycline, respectively. Infection was diagnosed in 91 patients who received appropriate antibiotic treatment, combination therapy and removal of the infectious source in 73.6%, 59.3% and 28.5% of cases, respectively. Overall, 23 different antibiotic regimens were prescribed. In-hospital mortality was 25.8%. Multivariate analysis adjusted for appropriate treatment, combination therapy and infectious-source removal, showed that Charlson comorbidity score, intensive-care unit onset of infection, bacteraemia and infection due to a colistin-resistant CR-KP strain were independent risk factors for mortality. The spread of clones producing K. pneumoniae carbapenemases, mainly ST258, is currently the major cause of CR-KP infection in central Italy. We observed a high rate of resistance to colistin that is independently associated with worse outcome.
Assuntos
Antibacterianos/farmacologia , Colistina/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/mortalidade , Klebsiella pneumoniae/efeitos dos fármacos , Idoso , Análise de Variância , Antibacterianos/uso terapêutico , Colistina/uso terapêutico , Feminino , Mortalidade Hospitalar , Humanos , Itália/epidemiologia , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Masculino , Pessoa de Meia-Idade , Tipagem Molecular , Estudos Prospectivos , Fatores de RiscoRESUMO
Prosthetic valve endocarditis (PVE) is a serious complication with potential fatal consequences, classified as early or late PVE, depending on whether typical symptoms occur within or later than 12 months from surgery. The incidence of early PVE is under 1%, but it carries high morbidity and mortality rates. There are few reported cases in literature of PVE due to Corynebacterium Jeikeium even though it is present in normal skin flora particularly in hospitalized patients. Corynebacterium species are, in fact, recognized as uncommon agents of endocarditis and little is known regarding species-specific risk factors and the outcome in this kind of endocarditis. Described is an unusual case report of a 57-year-old man who had early aortic PVE due to Corynebacterium Jeikeium infection complicated by dehiscence of the prosthesis, complete atrio-ventricular block, perforation of the interventricular septum and septic shock. Prompt diagnosis, choice of daptomycin as antibiotic therapy although it has only been approved by the European Medicine Agency (EMEA) for right-sided endocarditis and timely open heart surgery, resulted in a successful outcome.
Assuntos
Antibacterianos/uso terapêutico , Valva Aórtica/cirurgia , Infecções por Corynebacterium/tratamento farmacológico , Corynebacterium , Daptomicina/uso terapêutico , Endocardite Bacteriana/tratamento farmacológico , Próteses Valvulares Cardíacas/efeitos adversos , Infecções Relacionadas à Prótese/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: To investigate whether the effects of desflurane on inspiratory resistance are similar to those of isoflurane and sevoflurane during 30 min administration at 1 and 1.5 MAC in patients with healthy lungs. METHODS: Seventy-one patients undergoing elective surgery were randomly assigned to receive isoflurane, sevoflurane, or desflurane. Baseline inspiratory resistance was obtained after intubation and establishment of volume control ventilation. Anaesthesia was maintained with desflurane, isoflurane, or sevoflurane at 1 MAC for 30 min followed by 1.5 MAC for another 30 min. Tidal volume, flow, and inspiratory pressures were continuously recorded with a pneumotachograph. Total inspiratory resistance (R(rs)), minimal resistance (R(min)), and effective resistance (D(Rrs)) were calculated every 5 min using the end-inspiratory occlusion technique. RESULTS: No significant differences of the evaluated parameters (R(rs), R(min) and D(Rrs)) were observed during administration of the three agents at 1 MAC for 30 min. At 1.5 MAC, desflurane caused a maximum increase in R(rs) by 26% and in R(min) by 30% above baseline, in contrast to isoflurane and sevoflurane which did not display a significant effect on R(rs) (+3.7% by isoflurane and +7.6% by sevoflurane) and R(min) (+4.7% by isoflurane and +9.6% by sevoflurane). All parameters returned to baseline after discontinuation of the volatile agent. CONCLUSIONS: In healthy adults, neither sevoflurane nor isoflurane produced bronchodilation at 1 and 1.5 MAC. Desflurane did not affect respiratory resistance at 1 MAC, but at 1.5 MAC caused significant increase in both total and airway resistance with return to near baseline values after discontinuation of the agent.
Assuntos
Resistência das Vias Respiratórias/efeitos dos fármacos , Anestésicos Inalatórios/farmacologia , Isoflurano/análogos & derivados , Isoflurano/farmacologia , Éteres Metílicos/farmacologia , Adulto , Idoso , Desflurano , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , SevofluranoRESUMO
The method of laser osteoperforation was approved in 135 patients with chronic osteomyelitis. The diode laser with wave length 970 mm and peak power up to 30 Wt was used. Energy was delivered by the percutaneous contact method with a quartz light guide of 0.4 mm diameter. All the patients had a distinct positive reaction in the nearest days after operation. The fistulas were closed within 4-10 days. Stable remission was noted during 2-5 years by objective indices (X-ray, fluometry, densitometry, morphological data). Our experiences with clinical use of laser osteoperforation show its high efficiency in treatment of chronic osteomyelitis. The method is minimally invasive and allows to considerably shorten the terms of treatment and rehabilitation.
Assuntos
Terapia a Laser/métodos , Osteomielite/patologia , Osteomielite/cirurgia , Criança , Doença Crônica , Densitometria , Infecções por Enterobacteriaceae/microbiologia , Feminino , Humanos , Osteomielite/microbiologia , Indução de Remissão , Infecções Estafilocócicas/microbiologia , Infecções Estreptocócicas/microbiologia , Fatores de Tempo , Resultado do TratamentoRESUMO
We present three cases of deep sternal wound infections after sternotomy, with partial dehiscence and instability of sternum, successfully treated with combined therapy based on hyperbaric oxygen (HBO), parenteral and intranasal antibiotics, daily debridements and medications. After a short hospitalization (10 days) to detect involved bacteria, depth of the wounds and choice of right antibiotic therapy, all patients continued the treatment as outpatients, undergoing daily medications and antibiotic therapy before every HBO session. After 3 months the sternal wounds were completely epithelialized. This conservative therapy for deep sternal wound infections can be an alternative and inexpensive approach to surgical treatment. The aggressive surgical approach could be limited for those deep sternal wounds associated with broad dehiscence and instability of sternum, complicated by paradoxical breathing and/or mediastinitis and alteration of respiratory system mechanics.
RESUMO
Neuroleptic malignant syndrome (NMS) is a life-threatening reaction often related to neuroleptic drugs, characterized by rigidity, hyperthermia, altered consciousness, and fluctuating blood pressure. We present a case of NMS that followed a doubled oral dose of a drug compound: tranylcypromine sulfate, a monoamine oxidase inhibitor, and trifluoperazine (neuroleptic). The case was complicated by rhabdomyolisis and disseminated intravascular coagulation. It was treated successfully with dantrolene sodium and generous fluid therapy without using neuromuscular blocking agents or dopamine agonists.
Assuntos
Síndrome Maligna Neuroléptica/tratamento farmacológico , Resultado do Tratamento , Administração Oral , Adulto , Antipsicóticos/efeitos adversos , Dantroleno/uso terapêutico , Coagulação Intravascular Disseminada/complicações , Feminino , Hidratação , Humanos , Infusões Intravenosas , Itália , Inibidores da Monoaminoxidase/administração & dosagem , Inibidores da Monoaminoxidase/efeitos adversos , Relaxantes Musculares Centrais/uso terapêutico , Síndrome Maligna Neuroléptica/complicações , Rabdomiólise/complicações , Tranilcipromina/administração & dosagem , Tranilcipromina/efeitos adversos , Trifluoperazina/administração & dosagem , Trifluoperazina/efeitos adversosRESUMO
Substantiation of use of laser radiation Nd:YAG (1064 nm) and diode (805 nm) for destruction of thyroid tissue was the purpose of this study based on experimental research of reparative and adaptive processes in thyroid gland. The influence of high-intensity laser radiation was studied in vivo in thyroid gland of 41 dogs. The optimal modes of laser radiation ensured focal destruction of thyroid gland without damage of surrounding organs were selected. The developed modes were used in the treatment of 18 patients with recurrent nodal and multinodal euthyroid goiter. Exposure was performed by puncture method without denudation of thyroid gland. There were no complications during irradiation and nearest postoperative period. In dynamic ultrasonic examination over 2 years the decrease of nodes sizes was revealed in all the patients.
Assuntos
Bócio Nodular/cirurgia , Terapia a Laser , Adulto , Animais , Cães , Bócio Nodular/diagnóstico por imagem , Humanos , Recidiva , Glândula Tireoide/cirurgia , Fatores de Tempo , UltrassonografiaRESUMO
CONTEXT: Noninvasive ventilation (NIV) has been associated with lower rates of endotracheal intubation in populations of patients with acute respiratory failure. OBJECTIVE: To compare NIV with standard treatment using supplemental oxygen administration to avoid endotracheal intubation in recipients of solid organ transplantation with acute hypoxemic respiratory failure. DESIGN AND SETTING: Prospective randomized study conducted at a 14-bed, general intensive care unit of a university hospital. PATIENTS: Of 238 patients who underwent solid organ transplantation from December 1995 to October 1997, 51 were treated for acute respiratory failure. Of these, 40 were eligible and 20 were randomized to each group. INTERVENTION: Noninvasive ventilation vs standard treatment with supplemental oxygen administration. MAIN OUTCOME MEASURES: The need for endotracheal intubation and mechanical ventilation at any time during the study, complications not present on admission, duration of ventilatory assistance, length of hospital stay, and intensive care unit mortality. RESULTS: The 2 groups were similar at study entry. Within the first hour of treatment, 14 patients (70%) in the NIV group, and 5 patients (25%) in the standard treatment group improved their ratio of the PaO2 to the fraction of inspired oxygen (FIO2). Over time, a sustained improvement in PaO2 to FIO2 was noted in 12 patients (60%) in the NIV group, and in 5 patients (25%) randomized to standard treatment (P = .03). The use of NIV was associated with a significant reduction in the rate of endotracheal intubation (20% vs 70%; P = .002), rate of fatal complications (20% vs 50%; P = .05), length of stay in the intensive care unit by survivors (mean [SD] days, 5.5 [3] vs 9 [4]; P = .03), and intensive care unit mortality (20% vs 50%; P = .05). Hospital mortality did not differ. CONCLUSIONS: These results indicate that transplantation programs should consider NIV in the treatment of selected recipients of transplantation with acute respiratory failure.
Assuntos
Transplante de Órgãos , Complicações Pós-Operatórias , Respiração Artificial/métodos , Síndrome do Desconforto Respiratório/terapia , Feminino , Humanos , Intubação Intratraqueal , Masculino , Máscaras , Pessoa de Meia-Idade , Oxigênio/administração & dosagem , Respiração com Pressão Positiva , Estudos Prospectivos , Síndrome do Desconforto Respiratório/etiologia , Testes de Função Respiratória , Análise de SobrevidaRESUMO
A 38-year-old white male patient was admitted to the hospital for elective surgery. General anesthesia was performed with propofol, alfentanil, nitrous oxide and mivacurium as neuromuscular blocker. Seven months before he had the same surgery without anesthetic problems (he received: propofol, vecuronium bromide, fentanil, nitrous oxide). Neuromuscular monitoring was carried out because the patient was included in a study assessing the clinical effect of mivacurium in microlaryngoscopy surgery. After mivacurium administration the first signs of recovery from neuromuscular block were observed after 255 min. The tracheal tube was withdrawn after 410 min from mivacurium administration, at this time the T1 was 80% of the control values and 7 min later the T1 reached 98%.
Assuntos
Período de Recuperação da Anestesia , Isoquinolinas/efeitos adversos , Bloqueio Neuromuscular , Fármacos Neuromusculares não Despolarizantes/efeitos adversos , Adulto , Humanos , Laringoscopia , Masculino , MivacúrioRESUMO
OBJECTIVE: To evaluate treatment with noninvasive ventilation (NIV) by nasal mask as an alternative to endotracheal intubation and conventional mechanical ventilation in patients with hematologic malignancies complicated by acute respiratory failure to decrease the risk of hemorrhagic complications and increase clinical tolerance. DESIGN: Prospective clinical study. SETTING: Hematologic and general intensive care unit (ICU), University of Rome "La Sapienza". PATIENTS: 16 consecutive patients with acute respiratory failure complicating hematologic malignancies. INTERVENTIONS: NIV was delivered via nasal mask by means of a BiPAP ventilator (Respironics, USA); we evaluated the effects on blood gases, respiratory rate, and hemodynamics along with tolerance, complications, and outcome. MEASUREMENTS AND RESULTS: 15 of the 16 patients showed a significant improvement in blood gases and respiratory rate within the first 24 h of treatment. Arterial oxygen tension (PaO2), PaO2/FIO2 (fractional inspired oxygen) ratio, and arterial oxygen saturation significantly improved after 1 h of treatment (43+/-10 vs 88+/-37 mmHg; 87+/-22 vs 175+/-64; 81+/-9 vs 95+/-4%, respectively) and continued to improve in the following 24 h (p < 0.01). Five patients died in the ICU following complications independent of the respiratory failure, while 11 were discharged from the ICU in stable condition after a mean stay of 4.3+/-2.4 days and were discharged in good condition from the hospital. CONCLUSIONS: NIV by nasal mask proved to be feasible and appropriate for the treatment of respiratory failure in hematologic patients who were at high risk of intubation-related complications.
Assuntos
Leucemia/complicações , Máscaras , Respiração com Pressão Positiva/métodos , Síndrome do Desconforto Respiratório/complicações , Síndrome do Desconforto Respiratório/terapia , Adolescente , Adulto , Idoso , Gasometria , Feminino , Hemodinâmica , Humanos , Linfoma não Hodgkin/complicações , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Respiração com Pressão Positiva/instrumentação , Estudos Prospectivos , Síndrome do Desconforto Respiratório/fisiopatologia , Resultado do TratamentoRESUMO
OBJECTIVE: To evaluate respiratory mechanics in the early phase of decompensation in a group of seven patients with severe kyphoscoliosis (KS) (Cobb angle > 90 degrees) requiring mechanical ventilatory support. DESIGN: Prospective clinical study with a control group. SETTING: General intensive care unit at University of Rome "La Sapienza". PATIENTS: Seven consecutive patients affected by severe KS in the early phase of acute decompensation and a control group of six ASA (American Society of Anesthesiology) 1 subjects who were mechanically ventilated during minor surgery. MEASUREMENTS AND RESULTS: Respiratory mechanics were evaluated during constant flow-controlled mechanical ventilation at zero end-expiratory pressure with the end-inspiratory and end-expiratory occlusion technique. In five patients who showed increased ohmic resistance (RRSmin), we evaluated the possibility of reversing this increase with a charge dose of 6 mg/kg doxophylline i.v. In four KS patients, in whom a reliable esophageal pressure was confirmed by a positive occlusion test, we separated respiratory system data into lung and chest wall component. All KS patients showed reduced values of respiratory compliance (CRS) and increased respiratory resistance (RRS). The average basal values of CRS were 36 +/- 10 vs 58 +/- 8.5 cmH2O in control patients; RRSmax was 20 +/- 3.1 vs. 4.5 +/- 1.2 cmH2O/1 per s; RRSmin 6.2 +/- 1.2 vs. 2 +/- 0.5 cmH2O/1 per s: delta RRS 14 +/- 2.6 cmH2O vs 2.4 +/- 0.7 cmH2O/1 per s. All KS patients showed low values of intrinsic positive end-expiratory pressure (PEEPi) (1.8 +/- 1.5 cmH2O). Separation of lung and chest-wall mechanics, performed only in four patients, showed a reduction in both lung (66.7 +/- 7.2 ml/cmH2O) and chest wall values (84 +/- 8.2 ml/cmH2O), while both RmaxL and RmaxCW were increased (16.6 +/- 2 and 2.8 +/- 0.4 cmH2O/1 per s, respectively). Infusion of doxophylline did not significantly change respiratory mechanics when evaluated 15, 30, and 45 min after the infusion. CONCLUSIONS: During acute decompensation, both lung and chest-wall compliance are severely reduced in KS patients: conversely, and, contrary to that in patients with chronic obstructive pulmonary disease, increases in airway resistance and PEEPi seem to play only a secondary role.
Assuntos
Cifose/complicações , Respiração com Pressão Positiva , Insuficiência Respiratória/etiologia , Insuficiência Respiratória/fisiopatologia , Mecânica Respiratória/fisiologia , Escoliose/complicações , Resistência das Vias Respiratórias/fisiologia , Análise de Variância , Estudos de Casos e Controles , Progressão da Doença , Feminino , Humanos , Complacência Pulmonar/fisiologia , Masculino , Pessoa de Meia-Idade , Respiração por Pressão Positiva Intrínseca/fisiopatologia , Estudos ProspectivosRESUMO
The aim of this study was to investigate the short term effects of low doses of fentanyl and droperidol on central respiratory drive, gas exchanges, respiratory pattern and inspiratory impedance of the respiratory system in a group of ASA 1 patients. Fourteen ASA 1 patients scheduled for minor surgery or endoscopic procedures were enrolled in the study, thirty minutes before the intervention. During spontaneous breathing of air we evaluated, by recording airflow, airway opening pressure and volume, the following variables: Respiratory Rate (RR), Tidal Volume (TV), Total respiratory cycle, Inspiratory and Expiratory Time (Ti, Te), mean inspiratory flow, P0.1, pH, PaO2 and PaCO2. After obtaining basal measurements, droperidol and fentanyl were injected and the above mentioned variables evaluated at 5 min (T1), 10 min (T2), 15 min (T3) intervals. Arterial blood was age, sampled at T3 for blood gas evaluation. The administration of droperidol (0.1 mg/kg) and fentanyl (0.002 mg/kg) significantly reduced P0.1 and Tidal Volume comparing basal with T1 and, T2 values. The other variables did not significantly modify. Two patients showed transient respiratory rhythm abnormalities in the first 180 sec following the administration of droperidol+fentanyl. Our results suggest that, in ASA 1 patients, droperidol+fentanyl preoperative administration, has no significant effects on respiratory pattern, respiratory impedance and gas exchanges: however also at low doses, the association of droperidol+fentanyl can reduce the respiratory center activity, expressed as P0.1, with a consequent reduction in Tidal Volume.
Assuntos
Adjuvantes Anestésicos , Anestesia Intravenosa , Anestésicos Intravenosos , Droperidol , Fentanila , Troca Gasosa Pulmonar/efeitos dos fármacos , Mecânica Respiratória/efeitos dos fármacos , Adjuvantes Anestésicos/administração & dosagem , Anestésicos Intravenosos/administração & dosagem , Pressão Sanguínea/efeitos dos fármacos , Droperidol/administração & dosagem , Fentanila/administração & dosagem , Humanos , Injeções Intravenosas , Pessoa de Meia-Idade , Testes de Função RespiratóriaRESUMO
OBJECTIVE: 1) To compare the haemodynamic tolerance of ACV and PSV in patients mechanically ventilated after orthotopic liver transplantation; 2) to compare patients comfort during ACV and PSV. DESIGN: Prospective randomized cross-over study. SETTING: General ICU of the University of Rome "La Sapienza". PATIENTS: Eighteen patients admitted in ICU after orthotopic liver transplantation. MEASUREMENT AND RESULTS: Haemodynamic, oxygen transport and blood gas data were compared during an ACV and PSV trial (30'). A statistically significant decrease of mean pulmonary and systemic arterial pressure, PCOP, LVSWI, occurred during the PSV trial. PaO2 and DO2I decreased during PSV, but were still in supranormal range; 16 out of 18 patients described PSV as more comfortable. CONCLUSIONS: ACV and PSV provided a comparable haemodynamic tolerance in our patients, although during PSV the PaO2 was slightly decreased, probably due to decreased mean airway pressure (from 9.3 +/- 1.2 cmH2O during ACV to 6.6 +/- 1 cmH2O during PSV). PSV can be considered as a good alternative to the standard weaning techniques following orthotopic liver transplantation.
Assuntos
Hemodinâmica/fisiologia , Transplante de Fígado/fisiologia , Respiração Artificial , Mecânica Respiratória/fisiologia , Adulto , Gasometria , Estudos Cross-Over , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
OBJECTIVE: To evaluate the separate effects of sedation and paralysis on chest wall and respiratory system mechanics of mechanically ventilated, critically ill patients. SETTING: ICU of the University "La Sapienza" Hospital, Rome. PATIENTS AND PARTICIPANTS: 13 critically ill patients were enrolled in this study. All were affected by disease involving both lungs and chest wall mechanics (ARDS in 4 patients, closed chest trauma without flail chest in 4 patients, cardiogenic pulmonary oedema with fluidic overload in 5 patients). MEASUREMENTS AND RESULTS: Respiratory system and chest wall mechanics were evaluated during constant flow controlled mechanical ventilation in basal conditions (i.e. with the patients under apnoic sedation) and after paralysis with pancuronium bromide. In details, we simultaneously recorded airflow, tracheal pressure, esophageal pressure and tidal volume; with the end-inspiratory and end-expiratory airway occlusion technique we could evaluate respiratory system and chest wall elastance and resistances. Lung mechanics was evaluated by subtracting chest wall from respiratory system data. All data obtained in basal conditions (with the patients sedated with thiopental or propofol) and after muscle paralysis were compared using the Student's t test for paired data. The administration of pancuronium bromide to sedated patients induced a complete muscle paralysis without producing significant modification both to the viscoelastic and to the resistive parameters of chest wall and respiratory system. CONCLUSIONS: This study demonstrates the lack of additive effects of muscle paralysis in mechanically ventilated, sedated patients. Also in view of the possible side effects of muscle paralysis, our results question the usefulness of generalized administration of neuromuscular blocking drugs in mechanically ventilated patients.
Assuntos
Sedação Consciente/métodos , Hipnóticos e Sedativos/farmacologia , Fármacos Neuromusculares não Despolarizantes/uso terapêutico , Pancurônio/uso terapêutico , Propofol/farmacologia , Respiração Artificial , Mecânica Respiratória/efeitos dos fármacos , Tiopental/farmacologia , Adulto , Idoso , Monitoramento de Medicamentos , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
OBJECTIVE: To evaluate the efficiency of a new device developed to remove obstructions from endotracheal tubes (ETT) in mechanically ventilated patients. DESIGN: Open study in mechanically ventilated sedated and paralyzed ICU patients. SETTING: General ICU and Laboratory of Respiratory Mechanics of the University of Rome "La Sapienza". PATIENTS: 8 consecutive unselected mechanically ventilated, critically ill patients in which a partial obstruction of ETT was suspected on the basis of an increase of the peak inspiratory pressure (> 20%) plus the difficult introduction of a standard suction catheter. INTERVENTIONS: Obstructions to ETT were removed with an experimental "obstruction remover" (OR) MEASUREMENTS: "In vivo" ETT airflow resistance (0.25; 0.5; 0.75; 11/s) was evaluated before and after use of the OR; the work of breathing necessary to overcome ETT resistance (WOBett) was also evaluated before and after OR use. RESULTS: The use of OR significantly reduced in all patients the ETT "in vivo" resistance (From 5.5 +/- 2.3 to 2.9 +/- 0.5 cmH2O/l/s at 0.25 l/s, p < 0.05; from 9 +/- 2.4 to 3.8 +/- 0.8 cmH2O/l/s at 0.5 l/s; from 12.2 +/- 3.5 to 5.7 +/- 1.2 cmH2O/l/s at 0.75 l/s; from 16.9 +/- 6 to 9.3 +/- 3.8 cmH2O/l/s at 1 l/s, p < 0.01 respectively). Also the WOBett was significantly reduced after use of the OR (from 0.66 +/- 0.19 to 0.34 +/- 0.08 J/l; p < 0.05). CONCLUSION: this experimental device can be safely and successfully used to remove obstructions from the ETT lumen, without suspending mechanical ventilation, reducing the need for rapid ETT substitution in emergency and life-threatening situations.
Assuntos
Obstrução das Vias Respiratórias/terapia , Broncoscópios , Intubação Intratraqueal , Respiração Artificial , Adulto , Idoso , Obstrução das Vias Respiratórias/diagnóstico , Resistência das Vias Respiratórias , Feminino , Humanos , Intubação Intratraqueal/efeitos adversos , Masculino , Pessoa de Meia-Idade , Instrumentos Cirúrgicos , Trabalho RespiratórioRESUMO
The ionization method for determination of the energy deposited in sensitive sites of irradiated objects is usually used with the assumption that deposited energy is directly proportional to the number of ionizations in a site. This assumption fails in two cases important for nanometer-sized sites: (1) when the fluctuation characteristics of deposited energy such as higher moments, probability distributions, etc. are determined instead of the mean value; (2) when the radiation field in a site is spatially non-uniform. In this paper both cases are investigated. Exact formulae connecting energy and ionization quantities (moments, cumulants, probability distributions) are established as well as practical procedures to obtain energy quantities from those of ionization. The validity of the direct proportionality principle is analyzed and approximate methods to correct it are proposed. Some microdosimetric results are presented. The solution of these problems required that we refine some known notions and introduce new terms. In particular, in the paper the necessity of distinguishing two distinct types of events and correspondingly two sets of microdosimetric quantities is noted; new radiation parameters such as the fluctuation W value and non-equivalence factor for the events are defined and investigated numerically.