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1.
Br J Anaesth ; 122(3): 361-369, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30770054

RESUMO

BACKGROUND: The aim of this post hoc analysis of a large cohort study was to evaluate the association between night-time surgery and the occurrence of intraoperative adverse events (AEs) and postoperative pulmonary complications (PPCs). METHODS: LAS VEGAS (Local Assessment of Ventilatory Management During General Anesthesia for Surgery) was a prospective international 1-week study that enrolled adult patients undergoing surgical procedures with general anaesthesia and mechanical ventilation in 146 hospitals across 29 countries. Surgeries were defined as occurring during 'daytime' when induction of anaesthesia was between 8:00 AM and 7:59 PM, and as 'night-time' when induction was between 8:00 PM and 7:59 AM. RESULTS: Of 9861 included patients, 555 (5.6%) underwent surgery during night-time. The proportion of patients who developed intraoperative AEs was higher during night-time surgery in unmatched (43.6% vs 34.1%; P<0.001) and propensity-matched analyses (43.7% vs 36.8%; P=0.029). PPCs also occurred more often in patients who underwent night-time surgery (14% vs 10%; P=0.004) in an unmatched cohort analysis, although not in a propensity-matched analysis (13.8% vs 11.8%; P=0.39). In a multivariable regression model, including patient characteristics and types of surgery and anaesthesia, night-time surgery was independently associated with a higher incidence of intraoperative AEs (odds ratio: 1.44; 95% confidence interval: 1.09-1.90; P=0.01), but not with a higher incidence of PPCs (odds ratio: 1.32; 95% confidence interval: 0.89-1.90; P=0.15). CONCLUSIONS: Intraoperative adverse events and postoperative pulmonary complications occurred more often in patients undergoing night-time surgery. Imbalances in patients' clinical characteristics, types of surgery, and intraoperative management at night-time partially explained the higher incidence of postoperative pulmonary complications, but not the higher incidence of adverse events. CLINICAL TRIAL REGISTRATION: NCT01601223.


Assuntos
Plantão Médico/estatística & dados numéricos , Complicações Intraoperatórias/epidemiologia , Pneumopatias/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Procedimentos Cirúrgicos Operatórios , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Incidência , Internacionalidade , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco
2.
JAMA ; 321(23): 2292-2305, 2019 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-31157366

RESUMO

Importance: An intraoperative higher level of positive end-expiratory positive pressure (PEEP) with alveolar recruitment maneuvers improves respiratory function in obese patients undergoing surgery, but the effect on clinical outcomes is uncertain. Objective: To determine whether a higher level of PEEP with alveolar recruitment maneuvers decreases postoperative pulmonary complications in obese patients undergoing surgery compared with a lower level of PEEP. Design, Setting, and Participants: Randomized clinical trial of 2013 adults with body mass indices of 35 or greater and substantial risk for postoperative pulmonary complications who were undergoing noncardiac, nonneurological surgery under general anesthesia. The trial was conducted at 77 sites in 23 countries from July 2014-February 2018; final follow-up: May 2018. Interventions: Patients were randomized to the high level of PEEP group (n = 989), consisting of a PEEP level of 12 cm H2O with alveolar recruitment maneuvers (a stepwise increase of tidal volume and eventually PEEP) or to the low level of PEEP group (n = 987), consisting of a PEEP level of 4 cm H2O. All patients received volume-controlled ventilation with a tidal volume of 7 mL/kg of predicted body weight. Main Outcomes and Measures: The primary outcome was a composite of pulmonary complications within the first 5 postoperative days, including respiratory failure, acute respiratory distress syndrome, bronchospasm, new pulmonary infiltrates, pulmonary infection, aspiration pneumonitis, pleural effusion, atelectasis, cardiopulmonary edema, and pneumothorax. Among the 9 prespecified secondary outcomes, 3 were intraoperative complications, including hypoxemia (oxygen desaturation with Spo2 ≤92% for >1 minute). Results: Among 2013 adults who were randomized, 1976 (98.2%) completed the trial (mean age, 48.8 years; 1381 [69.9%] women; 1778 [90.1%] underwent abdominal operations). In the intention-to-treat analysis, the primary outcome occurred in 211 of 989 patients (21.3%) in the high level of PEEP group compared with 233 of 987 patients (23.6%) in the low level of PEEP group (difference, -2.3% [95% CI, -5.9% to 1.4%]; risk ratio, 0.93 [95% CI, 0.83 to 1.04]; P = .23). Among the 9 prespecified secondary outcomes, 6 were not significantly different between the high and low level of PEEP groups, and 3 were significantly different, including fewer patients with hypoxemia (5.0% in the high level of PEEP group vs 13.6% in the low level of PEEP group; difference, -8.6% [95% CI, -11.1% to 6.1%]; P < .001). Conclusions and Relevance: Among obese patients undergoing surgery under general anesthesia, an intraoperative mechanical ventilation strategy with a higher level of PEEP and alveolar recruitment maneuvers, compared with a strategy with a lower level of PEEP, did not reduce postoperative pulmonary complications. Trial Registration: ClinicalTrials.gov Identifier: NCT02148692.


Assuntos
Cuidados Intraoperatórios , Pneumopatias/prevenção & controle , Obesidade/complicações , Respiração com Pressão Positiva/métodos , Complicações Pós-Operatórias/prevenção & controle , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Adulto , Anestesia Geral , Índice de Massa Corporal , Feminino , Humanos , Pneumopatias/etiologia , Masculino , Pessoa de Meia-Idade , Doenças Pleurais/etiologia , Doenças Pleurais/prevenção & controle , Atelectasia Pulmonar/terapia , Insuficiência Respiratória/etiologia , Insuficiência Respiratória/prevenção & controle , Volume de Ventilação Pulmonar , Resultado do Tratamento
3.
Br J Anaesth ; 121(4): 899-908, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30236252

RESUMO

BACKGROUND: There is limited information concerning the current practice of intraoperative mechanical ventilation in obese patients, and the optimal ventilator settings for these patients are debated. We investigated intraoperative ventilation parameters and their associations with the development of postoperative pulmonary complications (PPCs) in obese patients. METHODS: We performed a secondary analysis of the international multicentre Local ASsessment of VEntilatory management during General Anesthesia for Surgery' (LAS VEGAS) study, restricted to obese patients, with a predefined composite outcome of PPCs as primary end-point. RESULTS: We analysed 2012 obese patients from 135 hospitals across 29 countries in Europe, North America, North Africa, and the Middle East. Tidal volume was 8.8 [25th-75th percentiles: 7.8-9.9] ml kg-1 predicted body weight, PEEP was 4 [1-5] cm H2O, and recruitment manoeuvres were performed in 7.7% of patients. PPCs occurred in 11.7% of patients and were independently associated with age (P<0.001), body mass index ≥40 kg m-2 (P=0.033), obstructive sleep apnoea (P=0.002), duration of anaesthesia (P<0.001), peak airway pressure (P<0.001), use of rescue recruitment manoeuvres (P<0.05) and routine recruitment manoeuvres performed by bag squeezing (P=0.021). PPCs were associated with an increased length of hospital stay (P<0.001). CONCLUSIONS: Obese patients are frequently ventilated with high tidal volume and low PEEP, and seldom receive recruitment manoeuvres. PPCs increase hospital stay, and are associated with preoperative conditions, duration of anaesthesia and intraoperative ventilation settings. Randomised trials are warranted to clarify the role of different ventilatory parameters in obese patients. CLINICAL TRIAL REGISTRATION: NCT01601223.


Assuntos
Pneumopatias/etiologia , Obesidade/complicações , Obesidade/fisiopatologia , Complicações Pós-Operatórias/etiologia , Respiração Artificial , Anestesia Geral , Índice de Massa Corporal , Peso Corporal , Humanos , Estimativa de Kaplan-Meier , Tempo de Internação , Pneumopatias/epidemiologia , Respiração com Pressão Positiva , Complicações Pós-Operatórias/epidemiologia , Síndromes da Apneia do Sono/complicações , Volume de Ventilação Pulmonar
4.
Anaesthesia ; 73 Suppl 1: 25-33, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29313906

RESUMO

Postoperative pulmonary complications are a major determinant of outcome for patients and consume huge resources within hospital, particularly in critical care. Prediction and anticipation of postoperative pulmonary complications are vital for patient selection and, in some cases, for informed patient consent. Being able to assess the likelihood of postoperative pulmonary complications also allows research into methods to reduce them by allowing allocation of patients to the appropriate arms of research trials. Some patients have pre-operative characteristics or belong to patient groups such as those with chronic obstructive pulmonary disease or obstructive sleep apnoea, where techniques and evidence-based guidance to avoid or reduce complications are becoming established. Intra-operative ventilation and the use of lung-protective ventilation may be helpful during major surgery, but studies looking at reduced tidal volumes, recruitment and levels of positive end-expiratory pressure, have this far only led to a degree of consensus in terms of tidal volume, although parameters that predispose to postoperative pulmonary complications are becoming clearer. Optimal postoperative care in terms of analgesia, positioning, physiotherapy and mobilisation is another developing area. Techniques such as continuous positive airways pressure, non-invasive ventilation and high-flow nasal humidified oxygen appear to show some benefit, but the exact roles, pressures and timings of each are currently being explored. Much remains to be researched and developed into evidence-based practice.


Assuntos
Anestesia/efeitos adversos , Transtornos Respiratórios/etiologia , Humanos , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Complicações Pós-Operatórias/terapia , Transtornos Respiratórios/prevenção & controle , Transtornos Respiratórios/terapia , Respiração Artificial/métodos
5.
Anaesthesia ; 71(1): 58-66, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26526934

RESUMO

Large-scale audit and research projects demand robust, efficient systems for accurate data collection, handling and analysis. We utilised a multiplatform 'bring your own device' (BYOD) electronic data collection app to capture observational audit data on theatre efficiency across seven hospital Trusts in South Yorkshire in June-August 2013. None of the participating hospitals had a dedicated information governance policy for bring your own device. Data were collected by 17 investigators for 392 individual theatre lists, capturing 14,148 individual data points, 12, 852 (91%) of which were transmitted to a central database on the day of collection without any loss of data. BYOD technology enabled accurate collection of a large volume of secure data across multiple NHS organisations over a short period of time. Bring your own device technology provides a method for collecting real-time audit, research and quality improvement data within healthcare systems without compromising patient data protection.


Assuntos
Pesquisa Biomédica , Segurança Computacional , Coleta de Dados/métodos , Auditoria Médica/métodos , Estudos de Viabilidade , Humanos
6.
Br J Anaesth ; 109(3): 305-14, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22879654

RESUMO

Non-invasive ventilation (NIV) is a supportive therapy that improves mortality in acute respiratory failure (RF). It may also be used in patients recently extubated in intensive care units (ICUs), after operation, and to aid weaning from mechanical ventilation (MV) by reducing the morbidity and mortality associated with further MV. A meta-analysis of the available evidence was performed on the use of NIV in three areas: weaning, reduction in reintubation rates post-extubation on ICU, and reduction in RF after major surgery. Sixteen relevant randomized controlled trials were identified by three reviewers after a detailed search of identified medical databases. A meta-analysis of summary statistics relating to predetermined endpoints (ICU and hospital length of stay, ICU and hospital mortality, reintubation, pneumonia) was performed. NIV reduced the ICU length of stay when used for weaning (5.12 days) and post-surgery (0.44 days). NIV reduced reintubation rates post-surgery [odds ratio (OR) 0.24, 95% confidence interval (CI) 0.12-0.50] and the incidence of pneumonia in weaning (OR 0.12, 95% CI 0.05-0.31) and post-surgery (OR 0.27, 95% CI 0.09-0.77). There was insufficient evidence to suggest that NIV improves ICU survival, but an increased hospital survival in post-surgery (OR 4.54, [corrected] 95% CI 1.35-15.31) and a reduction after weaning (OR 0.55, 95% CI 0.31-0.98) [corrected] was seen. A meta analysis of NIV use in selected subgroups of recently extubated patients suggests that the judicious NIV use may reduce ICU and hospital length of stay, pneumonia, and reintubation rates and hospital survival.


Assuntos
Intubação Intratraqueal , Respiração Artificial , Insuficiência Respiratória/terapia , Desmame do Respirador , Extubação , Mortalidade Hospitalar , Humanos , Unidades de Terapia Intensiva , Tempo de Internação , Pneumonia/prevenção & controle , Período Pós-Operatório
7.
BJOG ; 117(5): 565-74, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20374595

RESUMO

OBJECTIVE: Pregnancy in women with pulmonary hypertension (PH) is reported to carry a maternal mortality rate of 30-56%. We report our experience of the management of pregnancies using a strategy of early introduction of targeted pulmonary vascular therapy and early planned delivery under regional anaesthesia. DESIGN: Retrospective observational study. SETTING: Specialist quaternary referral pulmonary vascular unit. POPULATION: Nine women with PH who chose to proceed with ten pregnancies. METHODS: A retrospective review of the management of all women who chose to continue with their pregnancy in our unit during 2002-2009. MAIN OUTCOME MEASURES: Maternal and fetal survival. RESULTS: All women commenced nebulised targeted therapy at 8-34 weeks of gestation. Four women required additional treatment or conversion to intravenous prostanoid therapy. All women were delivered between 26 and 37 weeks of gestation. Delivery was by planned caesarean section in nine cases. All women received regional anaesthesia and were monitored during the peripartum period in a critical care setting. There was no maternal mortality during pregnancy and all infants were free from congenital abnormalities. One woman died 4 weeks after delivery following patient-initiated discontinuation of therapy. All remaining women and infants were alive after a median of 3.2 years (range, 0.8-6.5 years) of follow-up. CONCLUSION: Although the risk of mortality in pregnant women with PH remains significant, we describe improved outcomes in fully counselled women who chose to continue with pregnancy and were managed with a tailored multiprofessional approach involving early introduction of targeted therapy, early planned delivery and regional anaesthetic techniques.


Assuntos
Hipertensão Pulmonar/terapia , Complicações Cardiovasculares na Gravidez/terapia , Cuidado Pré-Natal/métodos , Adulto , Anti-Hipertensivos/administração & dosagem , Índice de Apgar , Peso ao Nascer , Cateterismo Cardíaco , Cesárea , Feminino , Humanos , Equipe de Assistência ao Paciente , Gravidez , Resultado da Gravidez , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
8.
Trials ; 20(1): 213, 2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30975217

RESUMO

BACKGROUND: Postoperative pulmonary complications (PPC) may result in longer duration of in-hospital stay and even mortality. Both thoracic surgery and intraoperative mechanical ventilation settings add considerably to the risk of PPC. It is unclear if one-lung ventilation (OLV) for thoracic surgery with a strategy of intraoperative high positive end-expiratory pressure (PEEP) and recruitment maneuvers (RM) reduces PPC, compared to low PEEP without RM. METHODS: PROTHOR is an international, multicenter, randomized, controlled, assessor-blinded, two-arm trial initiated by investigators of the PROtective VEntilation NETwork. In total, 2378 patients will be randomly assigned to one of two different intraoperative mechanical ventilation strategies. Investigators screen patients aged 18 years or older, scheduled for open thoracic or video-assisted thoracoscopic surgery under general anesthesia requiring OLV, with a maximal body mass index of 35 kg/m2, and a planned duration of surgery of more than 60 min. Further, the expected duration of OLV shall be longer than two-lung ventilation, and lung separation is planned with a double lumen tube. Patients will be randomly assigned to PEEP of 10 cmH2O with lung RM, or PEEP of 5 cmH2O without RM. During two-lung ventilation tidal volume is set at 7 mL/kg predicted body weight and, during OLV, it will be decreased to 5 mL/kg. The occurrence of PPC will be recorded as a collapsed composite of single adverse pulmonary events and represents the primary endpoint. DISCUSSION: PROTHOR is the first randomized controlled trial in patients undergoing thoracic surgery with OLV that is adequately powered to compare the effects of intraoperative high PEEP with RM versus low PEEP without RM on PPC. The results of the PROTHOR trial will support anesthesiologists in their decision to set intraoperative PEEP during protective ventilation for OLV in thoracic surgery. TRIAL REGISTRATION: The trial was registered in clinicaltrials.gov ( NCT02963025 ) on 15 November 2016.


Assuntos
Ventilação Monopulmonar/métodos , Respiração com Pressão Positiva/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto , Procedimentos Cirúrgicos Torácicos/métodos , Humanos , Complicações Intraoperatórias/terapia , Projetos de Pesquisa , Tamanho da Amostra
10.
Trials ; 18(1): 202, 2017 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-28454590

RESUMO

BACKGROUND: Postoperative pulmonary complications (PPCs) increase the morbidity and mortality of surgery in obese patients. High levels of positive end-expiratory pressure (PEEP) with lung recruitment maneuvers may improve intraoperative respiratory function, but they can also compromise hemodynamics, and the effects on PPCs are uncertain. We hypothesized that intraoperative mechanical ventilation using high PEEP with periodic recruitment maneuvers, as compared with low PEEP without recruitment maneuvers, prevents PPCs in obese patients. METHODS/DESIGN: The PRotective Ventilation with Higher versus Lower PEEP during General Anesthesia for Surgery in OBESE Patients (PROBESE) study is a multicenter, two-arm, international randomized controlled trial. In total, 2013 obese patients with body mass index ≥35 kg/m2 scheduled for at least 2 h of surgery under general anesthesia and at intermediate to high risk for PPCs will be included. Patients are ventilated intraoperatively with a low tidal volume of 7 ml/kg (predicted body weight) and randomly assigned to PEEP of 12 cmH2O with lung recruitment maneuvers (high PEEP) or PEEP of 4 cmH2O without recruitment maneuvers (low PEEP). The occurrence of PPCs will be recorded as collapsed composite of single adverse pulmonary events and represents the primary endpoint. DISCUSSION: To our knowledge, the PROBESE trial is the first multicenter, international randomized controlled trial to compare the effects of two different levels of intraoperative PEEP during protective low tidal volume ventilation on PPCs in obese patients. The results of the PROBESE trial will support anesthesiologists in their decision to choose a certain PEEP level during general anesthesia for surgery in obese patients in an attempt to prevent PPCs. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02148692. Registered on 23 May 2014; last updated 7 June 2016.


Assuntos
Anestesia Geral , Cuidados Intraoperatórios/métodos , Pneumopatias/prevenção & controle , Pulmão/fisiopatologia , Obesidade/complicações , Respiração com Pressão Positiva/métodos , Procedimentos Cirúrgicos Operatórios , Anestesia Geral/efeitos adversos , Índice de Massa Corporal , Protocolos Clínicos , Feminino , Humanos , Cuidados Intraoperatórios/efeitos adversos , Pneumopatias/diagnóstico , Pneumopatias/etiologia , Pneumopatias/fisiopatologia , Masculino , Obesidade/diagnóstico , Obesidade/fisiopatologia , Respiração com Pressão Positiva/efeitos adversos , Fatores de Proteção , Projetos de Pesquisa , Fatores de Risco , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Fatores de Tempo , Resultado do Tratamento
11.
J Clin Pathol ; 44(6): 522-3, 1991 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1906072

RESUMO

A 60 year old man with panhypopituitarism due to a large meningioma and prolonged and exaggerated thyroid stimulating hormone (TSH) responses is described. Initial investigations showed a subnormal urinary free cortisol concentration, a low serum cortisol taken at 0900 hours, and a low free T4 concentration. The TSH was towards the upper end of the normal range. Subsequently pituitary function tests showed subnormal production of luteinising hormone in response to luteinising hormone releasing hormone (LHRH) and a short synacthen test with a low 30 minute cortisol value. Long synacthen testing showed a normal response at four days, confirming that the abnormalities were due to a pituitary or hypothalamic cause. A computed tomogram showed a large meningioma compressing the hypothalamus, pituitary, and temporal lobe. TRH testing showed a prolonged and exaggerated response, consistent with tertiary hypothyroidism.


Assuntos
Hipoparatireoidismo/etiologia , Neoplasias Meníngeas/complicações , Meningioma/complicações , Tireotropina/metabolismo , Humanos , Hipoparatireoidismo/sangue , Hipopituitarismo/etiologia , Masculino , Pessoa de Meia-Idade , Hormônio Liberador de Tireotropina , Fatores de Tempo
12.
Intensive Care Med ; 28(7): 891-7, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12122527

RESUMO

OBJECTIVES: To assess the effect of propofol on the change in airway pressure produced by diaphragmatic contraction. DESIGN AND SETTING: Prospective, controlled study in patients anaesthetised with propofol in a university hospital. PATIENTS AND METHODS: We stimulated the phrenic nerves before and immediately after induction of anaesthesia in 11 subjects, using a pair of 43-mm mean diameter double magnetic coils and measured the change in airway pressure at the mouth (TwPmo) produced by the resulting diaphragmatic contraction. Supramaximality of stimulation was confirmed with electromyogram and pressure measurements. We recorded the change in Resting End Expiratory Position (REEP) using a spirometer. We applied an approximate correction for the effect of lung volume on the amplitude of twitch pressure produced by diaphragmatic contraction. INTERVENTION: Following the initial stimulations, the patients were anaesthetised with a propofol infusion. Once stable, repeat measurements were made. MEASUREMENTS AND RESULTS: Following induction, REEP fell by mean 0.3 l standard deviation (SD) 0.2 l. TwPmo fell by mean 14.2% SD 14.0% ( P = 0.01), mean 22.3% SD 11.7% corrected ( P < 0.001). Twitch transdiaphragmatic pressure fell by 18.1% and 20.0% (25.8% and 27.7% corrected) in two further subjects studied with oesophageal and gastric balloon catheters. CONCLUSION: Propofol does reduce the effectiveness with which diaphragmatic contraction produces changes of pressure in the airway.


Assuntos
Resistência das Vias Respiratórias/efeitos dos fármacos , Anestésicos Intravenosos/farmacologia , Diafragma/inervação , Magnetismo/uso terapêutico , Nervo Frênico/efeitos dos fármacos , Propofol/farmacologia , Adulto , Idoso , Anestésicos Intravenosos/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Propofol/administração & dosagem , Estudos Prospectivos , Reino Unido
13.
J Appl Physiol (1985) ; 81(4): 1477-83, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8904556

RESUMO

Abdominal muscles are the principal muscles of active expiration. To investigate the possibility of abdominal muscle low-frequency fatigue after maximal ventilation in humans, we stimulated the nerve roots supplying the abdominal muscles. We used a magnetic stimulator (Magstim 200) powering a 90-mm circular coil and studied six normal subjects. To assess the optimum level of stimulation and posture, we stimulated at each intervertebral level between T7 and L1 in the prone, supine, and seated positions. At T10, we used increasing power outputs to assess the pressure-power relationship. Care was taken to avoid muscle potentiation. Twitch gastric pressure (Pga) was recorded with a balloon-tipped catheter. Mean (+/-SD) baseline twitch Pga measured with the subjects in the prone position at T10 was 23.5 +/- 5.4 cmH2O. Within-occasion mean twitch Pga coefficient of variation was 4.6 +/- 1.1%. Twitch Pga was measured with the subjects in the prone position with stimulation over T10 before and after 2 min of maximal isocapnic ventilation (MIV). Twenty minutes after MIV, mean twitch Pga fell by 17 +/- 9.1% (P = 0.03) and remained low 90 min after MIV. We conclude that after maximal ventilation in humans there is a reduction of twitch Pga and, therefore, of low-frequency fatigue in abdominal muscles.


Assuntos
Músculos Abdominais/fisiologia , Fadiga Muscular/fisiologia , Mecânica Respiratória/fisiologia , Potenciais de Ação/fisiologia , Campos Eletromagnéticos , Eletromiografia , Esôfago/fisiologia , Humanos , Contração Muscular/fisiologia , Estimulação Física , Postura/fisiologia , Pressão , Raízes Nervosas Espinhais/fisiologia
14.
Spine (Phila Pa 1976) ; 11(5): 427-32, 1986 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-3750079

RESUMO

The role of liquid crystal thermography (LCT) in the investigation of nerve root compression due to lumbosacral lateral spinal stenosis was evaluated using a quantitative analysis technique. In 28 healthy volunteers, normal lower limb dermatomal asymmetry was found to follow a Gaussian distribution, with a normal range of less than 1.0 degree for the lower limbs and less than 1.9 degrees for the feet. The results of LCT from a patient group were compared with those from other investigations, with the following results: clinical assessment (107 patients), 53% agreement; myelography (60 patients), 45% agreement; computerized tomography (35 patients), 46% agreement; electromyography (27 patients), 41% agreement; and surgical findings (19 patients), 53% agreement. Each method of investigation was compared against the surgeon's final overall assessment. Clinical assessment agreed in 76%, myelography in 71%, computerized tomography in 71%, and electromyography in 70%. However, agreement could be demonstrated in only 48% of cases using LCT; therefore, it would appear that LCT is by far the least reliable of these techniques in the diagnosis of nerve root compression.


Assuntos
Síndromes de Compressão Nervosa/etiologia , Raízes Nervosas Espinhais , Estenose Espinal/complicações , Termografia/métodos , Temperatura Corporal , Estudos de Avaliação como Assunto , Feminino , Humanos , Região Lombossacral , Masculino , Síndromes de Compressão Nervosa/fisiopatologia , Termografia/normas
15.
Artif Intell Med ; 32(3): 157-69, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15531148

RESUMO

A non-invasive and simple method of parameter estimation has been developed for the model-based decision support of the artificial ventilation in intensive care units. The parameter concerned was the respiratory shunt. Originally, the shunt had to be estimated using a numerical algorithm, which was slow and unreliable. The estimation process also required the knowledge of other parameters, whose values could only be obtained using invasive monitoring equipment. In this paper, the respiratory index is used for the shunt estimation. A linear regression model and a non-linear adaptive neuro-fuzzy inference system (ANFIS) model were used to describe the relationship between the respiratory index and the shunt. The shunts estimated using these models were then used to calculate the fractional inspired oxygen needed to attain the target arterial oxygen level of the model patient. The advisor also utilises population median values of the cardiac index and oxygen consumption index. This alleviates the need for invasive monitoring. In a simulation study, the mean squared error of the control using the ANFIS model was 0.75 kPa2 compared to 2.06 kPa2 using the linear regression model. Therefore, the performance of the FiO2 advisor was better when the shunt was estimated using the non-linear ANFIS model.


Assuntos
Algoritmos , Sistemas de Apoio a Decisões Clínicas , Modelos Teóricos , Oxigênio/sangue , Respiração Artificial , Lógica Fuzzy , Humanos , Unidades de Terapia Intensiva , Respiração
16.
Artif Intell Med ; 29(3): 185-201, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14656486

RESUMO

In recent years, much research has been done on the use of fuzzy systems in medicine. The fuzzy rule-bases have usually been derived after extensive discussion with the clinical experts. This takes a lot of time from the clinical experts and the knowledge engineers. This paper presents the use of the adaptive neuro-fuzzy inference system (ANFIS) in rule-base derivation for ventilator control. The change of the inspired fraction of oxygen (FiO(2)) advised by eight clinical experts responding to 71 clinical scenarios was recorded. ANFIS and a multilayer perceptron (MLP) were then used to model the relationship between the inputs (the arterial oxygen tension (PaO(2)), FiO(2) and the positive end-expiratory pressure (PEEP) level) and the change in FiO(2) suggested. Compared to a previous fuzzy advisor (FAVeM), both the ANFIS and the MLP were found to correlate with the clinicians' decision better (correlation coefficient of 0.694 and 0.701, respectively compared to 0.630). A formerly developed model-based radial basis network advisor (RBN-MB) was used for comparison. Closed-loop simulations showed that the ANFIS, MLP and the RBN-MB's performance were comparable to the clinicians' performance (correlation coefficients of 0.852, 0.962 and 0.787, respectively). The FAVeM's performance differed from the clinicians' performance (correlation coefficient of 0.332) but the resulting PaO(2) was still within safety limits.


Assuntos
Cuidados Críticos , Sistemas Inteligentes , Lógica Fuzzy , Modelos Teóricos , Redes Neurais de Computação , Ventiladores Mecânicos , Simulação por Computador , Humanos
17.
Int J Obstet Anesth ; 5(3): 198-201, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15321350

RESUMO

Two patients with Type I Klippel-Feil syndrome presented at the antenatal clinic. The first patient, who suffered from sleep apnoea, was delivered of a healthy infant by vacuum extraction. The second, who was profoundly deaf and had marked kyphoscoliosis, developed pregnancy-induced hypertension and urinary tract infection and was delivered at 38 weeks by vacuum extraction. In both cases epidural analgesia was employed to allow pain relief during labour. Anaesthetic management of Klippel-Feil syndrome is discussed and the benefits of early anaesthetic assessment and continued involvement of senior anaesthetic and obstetric staff emphasized.

18.
Int J Obstet Anesth ; 5(3): 160-4, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15321342

RESUMO

Occupational exposure to nitrous oxide may be increased in confined working environments where ventilation and scavenging are either ineffective or unavailable. This is particularly the case on the labour ward. To assess the exposure of midwives working on the labour ward, midwives were asked to wear personal nitrous oxide samplers during their shift periods. The nitrous oxide exposure during a total of 242 midwife shift periods was monitored in two hospitals. Seven (3%) of these midwife shifts demonstrated mean exposure levels of over 500 parts per million (ppm), the highest reaching 1638 ppm. Fifty-six (23%) had NZO levels over 100 ppm and 129 (53%) had levels above 25 ppm. During the 111 midwife shift periods where midwives did not work in a room where Entonox was in use, their mean exposure was 22 ppm (median 12 ppm), however in four of these midwife shift periods the mean exposure level exceeded 100 ppm. Chronic exposure to high levels of nitrous oxide which exceed the recently proposed UK standard of 100 ppm and those in force in the USA (25 ppm) and Sweden (100 ppm) are frequently encountered by midwives.

19.
J Health Organ Manag ; 18(2-3): 195-206, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15366283

RESUMO

Costing health care services has become a major requirement due to an increase in demand for health care and technological advances. Several studies have been published describing the computation of the costs of hospital wards. The objective of this article is to examine the methodologies utilised to try to describe the basic components of a standardised method, which could be applied throughout Europe. Cost measurement however is a complex matter and a lack of clarity exists in the terminology and the cost concepts utilised. The methods discussed in this review make it evident that there is a lack of standardized methodologies for the determination of accurate costs of hospital wards. A standardized costing methodology would facilitate comparisons, encourage economic evaluation within the ward and hence assist in the decision-making process with regard to the efficient allocation of resources.


Assuntos
Alocação de Custos/métodos , Custos Hospitalares/classificação , Quartos de Pacientes/economia , Análise Custo-Benefício/métodos , Eficiência Organizacional , Europa (Continente) , Pesquisa sobre Serviços de Saúde , Custos Hospitalares/estatística & dados numéricos , Humanos , Alocação de Recursos , Terminologia como Assunto
20.
Intensive Care Med ; 40(2): 202-210, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24306080

RESUMO

INTRODUCTION: Faecal peritonitis (FP) is a common cause of sepsis and admission to the intensive care unit (ICU). The Genetics of Sepsis and Septic Shock in Europe (GenOSept) project is investigating the influence of genetic variation on the host response and outcomes in a large cohort of patients with sepsis admitted to ICUs across Europe. Here we report an epidemiological survey of the subset of patients with FP. OBJECTIVES: To define the clinical characteristics, outcomes and risk factors for mortality in patients with FP admitted to ICUs across Europe. METHODS: Data was extracted from electronic case report forms. Phenotypic data was recorded using a detailed, quality-assured clinical database. The primary outcome measure was 6-month mortality. Patients were followed for 6 months. Kaplan-Meier analysis was used to determine mortality rates. Cox proportional hazards regression analysis was employed to identify independent risk factors for mortality. RESULTS: Data for 977 FP patients admitted to 102 centres across 16 countries between 29 September 2005 and 5 January 2011 was extracted. The median age was 69.2 years (IQR 58.3-77.1), with a male preponderance (54.3%). The most common causes of FP were perforated diverticular disease (32.1%) and surgical anastomotic breakdown (31.1%). The ICU mortality rate at 28 days was 19.1%, increasing to 31.6% at 6 months. The cause of FP, pre-existing co-morbidities and time from estimated onset of symptoms to surgery did not impact on survival. The strongest independent risk factors associated with an increased rate of death at 6 months included age, higher APACHE II score, acute renal and cardiovascular dysfunction within 1 week of admission to ICU, hypothermia, lower haematocrit and bradycardia on day 1 of ICU stay. CONCLUSIONS: In this large cohort of patients admitted to European ICUs with FP the 6 month mortality was 31.6%. The most consistent predictors of mortality across all time points were increased age, development of acute renal dysfunction during the first week of admission, lower haematocrit and hypothermia on day 1 of ICU admission.


Assuntos
Fezes , Peritonite/mortalidade , Idoso , Europa (Continente) , Feminino , Inquéritos Epidemiológicos , Hospitalização , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Peritonite/epidemiologia , Prognóstico , Estudos Prospectivos , Fatores de Risco
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