Impact of intensive care unit relocation and role of tap water on an outbreak of Pseudomonas aeruginosa expressing OprD-mediated resistance to imipenem.

BACKGROUND: To assess the impact of the incidental relocation of an intensive care unit (ICU) on the risk of colonizations/infections with Pseudomonas aeruginosa exhibiting OprD-mediated resistance to imipenem (PA-OprD). AIM: The primary aim was to compare the proportion of PA-OprD among P. aeruginosa samples before and after an incidental relocation of the ICU. The role of tap water as a route of contamination for colonization/infection of patients with PA-OprD was assessed as a secondary aim. METHODS: A single-centre, observational, before/after comparison study was conducted from October 2013 to October 2015. The ICU was relocated at the end of October 2014. All P. aeruginosa-positive samples isolated from patients hospitalized ≥48 h in the ICU were included. Tap water specimens were collected every three months in the ICU. PA-OprD strains isolated from patients and tap water were genotyped using pulse-field gel electrophoresis. FINDINGS: A total of 139 clinical specimens of P. aeruginosa and 19 tap water samples were analysed. The proportion of PA-OprD strains decreased significantly from 31% to 7.7% after the relocation of the ICU (P = 0.004). All PA-OprD clinical specimens had a distinct genotype. Surprisingly, tap water was colonized with a single PA-OprD strain during both periods, but this single clone has never been isolated from clinical specimens. CONCLUSION: Relocation of the ICU was associated with a marked decrease in P. aeruginosa strains resistant to imipenem. The polyclonal character of PA-OprD strains isolated from patients and the absence of tap-water-to-patient contamination highlight the complexity of the environmental impact on the endogenous colonization/infection with P. aeruginosa.

Toxigenic Corynebacterium ulcerans in a fatal human case and her feline contacts, France, March 2014.

In March 2014, a person in their eighties who was diagnosed with extensive cellulitis due to toxigenic Corynebacterium ulcerans died from multiple organ failure. Environmental investigation also isolated C. ulcerans in biological samples from two stray cats in contact with the case. This finding provides further evidence that pets can carry toxigenic C. ulcerans and may be a source of the infection in humans.

Diagnostic accuracy of urinary dipstick to exclude catheter-associated urinary tract infection in ICU patients: a reappraisal.

OBJECTIVES: We wanted to assess the diagnostic accuracy of urinary dipstick testing in excluding catheter-associated urinary tract infection (CAUTI) in intensive care unit (ICU) patients with fever or hypothermia. METHODS: This was a prospective observational cohort study in a medical-surgical ICU. Patients with new-onset fever >38.3 °C or hypothermia <36 °C at least 48 h after urinary catheter insertion were included over a 2-year period. At each episode, a urinary dipstick test and a urine culture were performed as the criterion standard. Extensive microbiological investigations for extra-urinary infections were performed also. The performances of various urinary dipstick result combinations in ruling out CAUTI were compared based on the likelihood ratios (LR+ and LR-). RESULTS: Symptomatic CAUTI was diagnosed in 31 (24.4 %) of the 127 included patients (195 episodes of fever or hypothermia). LR+ was best for combined leukocyte esterase-positive and nitrite-positive dipstick results (overall population: 14.91; 95 % confidence interval [95 % CI], 5.53-40.19; patients without urinary symptoms: 15.63; 95 % CI, 5.76-42.39). LR- was best for either leukocyte esterase-positive or nitrite-positive dipstick results (overall population: 0.41; 95 % CI, 0.57-0.65; patients without urinary symptoms, 0.36; 95 % CI, 0.21-0.60). CONCLUSIONS: Urinary dipstick testing at the bedside does not help to rule out symptomatic CAUTI in medical or surgical ICU patients with fever or hypothermia.

Factores asociados a mortalidad en la pandemia de influenza H1N1 2009 en Paraguay / Factors associated to mortality in the influenza H1N1 pandemic in Paraguay in 2009

La presencia de condiciones médicas pre-existentes se ha asociado con la mortalidad relacionada al virus de influenza A (H1N1). El objetivo de este estudio fue determinar los factores asociados a mortalidad en personas con sospecha de infección con influenza A (H1N1) en Paraguay. Los datos clínicos y epidemiológicos fueron obtenidos a través del sistema de vigilancia para la infección por influenza A(H1N1) establecido en el país por el Ministerio de Salud Pública y Bienestar Social a partir del 28 de abril de 2009. Hasta el 30 de enero de 2010, fueron notificados a la Dirección General de Vigilancia de la Salud, 8303 casos con sospecha de Influenza A (H1N1). Tanto el análisis bivariado como el multivariado identificaron los siguientes factores de riesgo de mortalidad: obesidad (p=0,022; OR:13,5), embarazo (p<0,001; OR:11,0), Diabetes mellitus (p= 0,006; OR:5,7), enfermedad cardiovascular (p=0,002; OR: 4,6), sexo masculino (p <0,0001, OR: 3,0), edad mayor a 60 años (p =0,008; OR: 2,9) y no haber sido vacunado contra el virus de influenza estacional en el periodo 2009 (p<0,023; OR: 2,6). El embarazo como factor de riesgo de mortalidad ya había sido observado en las otras pandemias; no así la obesidad, la cual recién en la última pandemia, ha sido relacionada, por varios países, con complicaciones graves de infección por el virus A (H1N1). Esta asociación amerita el desarrollo de investigaciones que permitan un mejor abordaje promocional, preventivo y terapéutico de las personas con obesidad.

The presence of pre-existing medical conditions has been associated with mortality related to influenza A virus (H1N1). Our objective was to determine the risk factors associated to mortality in suspected cases of influenza A (H1N1) in Paraguay. Clinical and epidemiological data were obtained through the surveillance system of influenza A (H1N1) established in the country by the Ministry of Public Health and Social Welfare on April 28, 2009. Up to January 30, 2010, 8,303 suspected cases of influenza A (H1N1) were reported to the Dirección General de Vigilancia de la Salud. Bivariate as well as the multivariate analyses identified the following mortality risk factors: obesity (p<0.022, OR:13.5), pregnancy (p <0.001, OR: 11.0), diabetes mellitus (p= 0.006; OR:5.7); cardiovascular disease (p = 0.002; OR:4.6), male sex (p<0.0001, OR:3.0); age older than 60 years (p <0.008, OR:2.9), not been vaccinated against seasonal influenza virus during 2009 (p<0.023; OR:2.6). Pregnancy as a mortality risk factor for viral influenza infections was seen in other influenza pandemics, but no obesity, which has been reported by several countries as a risk factor for severe complication of A (H1N1) virus infection in the last pandemic. This association deserves the development of research studies that allow a better promotional, preventive and therapeutical approach of obese people.

Sistema de vigilancia epidemiológica comunitaria bonis: estado actualy proyecciones futuras / Community epidemiological surveillance system bonis: current status and future projections

El sistema actual de vigilancia epidemiológica en la zona del Centro de Ayuda Mutua y Salud para Todos (CAMSAT) del Bañado Sur, de Asunción, se basa en la búsqueda rutinaria de posibles casos febriles mediante visitas domiciliarias, realizadas por las agentes comunitarias adscritas a la Unidad de Salud Familiar (USF). Cada una de las diezagentes comunitarias de CAMSAT tiene asignada 150 hogares, y los resultados de susvisitas domiciliarias quedan recogidos en planillas que se reportan mediante medios tradicionales (papel, correo interno, fax, etc.) a la DGVS del Ministerio de Salud. La consecuencia de este modo de trabajo es que muchas veces las acciones de bloqueo de la transmisión llegan tarde con el coste social y económico que ello significa. El sistema Bonis introduce la telefonía móvil como elemento catalizador para transformar la búsqueda rutinaria de posibles casos febriles en una acción proactiva, y también la utilización de tecnologías web y bases de datos para el registro de pacientes y su correspondiente seguimiento por el personal sanitario. La utilización de estas tecnologíasde la información y comunicación (TICs) transforman el sistema de vigilancia epidemiológica en un caso de estudio de e-Salud en Paraguay. Se describe el estado actual y proyecciones futuras del sistema de vigilancia epidemiológica comunitaria “Bonis”,que utiliza las TICs para prevenir, alertar, supervisar y controlar la expansión de síndromes febriles en un área de influencia del Hospital Barrio Obrero (HBO), en la Unidad de Atención Primaria en Salud del Centro de Ayuda Mutua y Salud para Todos, Asunción,Paraguay.

The current system of epidemiologic surveillance in the area of Mutual Aid Centre and Health for All (CAMSAT in Spanish) in the “Bañado Sur” in Asuncion is based on routine screening of possible febrile cases through home visits made by community agents fromthe Primary Health Care Unit (USF in Spanish). Each of the ten community agents are assigned to 150 households and the results of these home visits are recorded on sheets that are reported through traditional means (paper, internal mail, fax, etc.) to the DGVSof the Ministry of Health. The consequence of this working system is that often the blocking actions arrive late with the social and economic costs that this implies. The Bonis system uses the mobile phone as a catalyst to transform the routine screening ofpotential feverish cases in a proactive action and the web technology and databases for patient records and appropriate follow-up by health personnel. The use of theseinformation and communication technologies of (ICTs) transforms the Epidemiological Surveillance System in a study case of e-Health in Paraguay. This document describes the current status and future projections of the community epidemiological surveillancesystem Bonis which uses Information and Communication Technologies (ICTs) to prevent, warn, monitor and control the spread of febrile syndromes in a catchment area of Barrio Obrero Hospital (HBO), Unit of Primary Health Care Center Mutual Aid and Health for All, Asuncion, Paraguay.

[Prevalence of dysphosphoremia in patients admitted in intensive care unit with an impaired renal function]. / Prévalence des dysphosphorémies chez les patients admis en réanimation avec une altération de la fonction rénale.

OBJECTIVE: To assess the frequency of dysphosphoremia in patients admitted in intensive care unit with an impaired renal function and to determine the associated risks factors. Study design. - Epidemiological prospective study. PATIENTS AND METHODS: The creatinine clearance and the phosphoremia were measured in 134 consecutive patients admitted in intensive care unit over a six-month period. Patients with chronic renal failure were excluded. Known risk factors for hypophosphoremia in intensive care unit were recorded. RESULTS: Seventy-nine out of one hundred thirty-four patients (59%) had an impaired renal function (arbitrarily defined by a creatinine clearance < 60 ml/min). The proportion of patients with impaired renal function that where hypo-, normo- (0.8 to 1.2 mmol/l) or hyperphosphoremic was 16, 34 and 50% respectively. Hypophosphoremia was severe (< 0.5 mmol/l) in 5 patients, all with impaired renal function. No risk factors usually associated with hypophosphoremia could be identified. CONCLUSION: As opposed to chronic renal failure patients who are mainly hyperphosphoremic, patients admitted in intensive care unit with an impaired renal function may present with a normo-, or hypophosphoremia. These dysphosphoremias are sometimes severe. Phosphate status should be promptly determined at admission.

["Post traumatic" leptospirosis complicated by acute respiratory insufficiency]. / Leptospirose ictéro-hémorragique << post traumatique >> compliquée d'insuffisance respiratoire aiguë

INTRODUCTION: Leptospirosis is a rare cause of alveolar haemorrhage. The diagnosis is often delayed particularly when the mode of infection is atypical. These serious complications require prompt antibiotic treatment. CASE REPORT: A 21-year-old man was involved in a road accident and found lying unconscious in a roadside ditch containing stagnant water. Ten days later he presented with bilateral interstitial pneumonia and rapidly increasing hypoxaemia associated with cholestasis and liver cell necrosis. Broncho-alveolar lavage revealed alveolar haemorrhage. There was satisfactory resolution following antibiotic therapy. CONCLUSIONS: The diagnosis of leptospirosis was considered initially despite negative serology (Martin and Petit) and confirmed by sero-conversion 20 days after the onset of symptoms.

Accuracy of a composite score using daily SAPS II and LOD scores for predicting hospital mortality in ICU patients hospitalized for more than 72 h.

UNLABELLED: In most databases used to build general severity scores the median duration of intensive care unit (ICU) stay is less than 3 days. Consequently, these scores are not the most appropriate tools for measuring prognosis in studies dealing with ICU patients hospitalized for more than 72 h. PURPOSE: To develop a new prognostic model based on a general severity score (SAPS II), an organ dysfunction score (LOD) and evolution of both scores during the first 3 days of ICU stay. DESIGN: Prospective multicenter study. SETTING: Twenty-eight intensive care units (ICUs) in France. PATIENTS: A training data-set was created with four ICUs during an 18-month period (893 patients). Seventy percent of the patients were medical (628) aged 66 years. The median SAPS II was 38. The ICU and hospital mortality rates were 22.7% and 30%, respectively. Forty-seven percent (420 patients) were transferred from hospital wards. In this population, the calibration (Hosmer-Lemeshow chi-square: 37.4, P = 0.001) and the discrimination [area under the ROC curves: 0.744 (95 % CI: 0.714-0.773)] of the original SAPS II were relatively poor. A validation data set was created with a random panel of 24 French ICUs during March 1999 (312 patients). MEASUREMENTS AND MAIN RESULTS: The LOD and SAPS II scores were calculated during the first (SAPS1, LOD1), second (SAPS2, LOD2), and third (SAPS3, LOD3) calendar days. The LOD and SAPS scores alterations were assigned the value "1" when scores increased with time and "0" otherwise. A multivariable logistic regression model was used to select variables measured during the first three calendar days, and independently associated with death. Selected variables were: SAPS II at admission [OR: 1.04 (95 % CI: 1.027-1.053) per point], LOD [OR: 1.16 (95 % CI: 1.085-1.253) per point], transfer from ward [OR: 1.74 (95 % CI: 1.25-2.42)], as well as SAPS3-SAPS2 alterations [OR: 1.516 (95 % CI: 1.04-2.22)], and LOD3-LOD2 alterations [OR: 2.00 (95 % CI: 1.29-3.11)]. The final model has good calibration and discrimination properties in the training data set [area under the ROC curve: 0.794 (95 % CI: 0.766-0.820), Hosmer-Lemeshow C statistic: 5.56, P = 0.7]. In the validation data set, the model maintained good accuracy [area under the ROC curve: 0.826 (95 % CI: 0.780-0.867), Hosmer-Lemeshow C statistic: 7.14, P = 0.5]. CONCLUSIONS: The new model using SAPS II and LOD and their evolution during the first calendar days has good discrimination and calibration properties. We propose its use for benchmarking and evaluating the over-risk of death associated with ICU-acquired nosocomial infections.

[Severe pulmonary embolism with two indications for inferior vena cava filter placement]. / Une embolie pulmonaire grave avec deux indications à la mise en place d'un filtre dans la veine cave inférieure.

A case of severe pulmonary embolism, treated with thrombolysis, and complicated by a haemorrhagic shock (peritoneal bleeding after a spleen trauma) is reported. A paradoxical renal artery embolism occurred, due to a patent foramen ovale. The benefit of a inferior vena cava filter insertion in case of paradoxical embolism is discussed.

A 3-level prognostic classification in septic shock based on cortisol levels and cortisol response to corticotropin.

CONTEXT: The hypothalamic-pituitary-adrenal axis is a major determinant of the host response to stress. The relationship between its activation and patient outcome is not known. OBJECTIVE: To evaluate the prognostic value of cortisol levels and a short corticotropin stimulation test in patients with septic shock. DESIGN AND SETTING: Prospective inception cohort study conducted between October 1991 and September 1995 in 2 teaching hospital adult intensive care units in France. PARTICIPANTS: A total of 189 consecutive patients who met clinical criteria for septic shock. INTERVENTION: A short corticotropin stimulation test was performed in all patients by intravenously injecting 0.25 mg of tetracosactrin; blood samples were taken immediately before the test (T0) and 30 (T30) and 60 (T60) minutes afterward. MAIN OUTCOME MEASURES: Twenty-eight-day mortality as a function of variables collected at the onset of septic shock, including cortisol levels before the corticotropin test and the cortisol response to corticotropin (delta max, defined as the difference between T0 and the highest value between T30 and T60). RESULTS: The 28-day mortality was 58% (95% confidence interval [CI], 51%-65%) and median time to death was 17 days (95% CI, 14-27 days). In multivariate analysis, independent predictors of death (P < or = .001 for all) were McCabe score greater than 0, organ system failure score greater than 2, arterial lactate level greater than 2.8 mmol/L, ratio of PaO2 to fraction of inspired oxygen no more than 160 mm Hg, cortisol level at T0 greater than 34 microg/dL and delta max no more than 9 microg/dL. Three groups of patient prognoses were identified: good (cortisol level at T0 < or = 34 microg/dL and delta max > 9 microg/dL; 28-day mortality rate, 26%), intermediate (cortisol level at T0 34 microg/dL and delta max < or = 9 microg/dL or cortisol level at T0 > 34 microg/dL and delta max > 9 microg/dL; 28-day mortality rate, 67%), and poor (cortisol level at T0 > 34 microg/dL and delta max < or = 9 microg/dL; 28-day mortality rate, 82%). CONCLUSION: Our data suggest that a short corticotropin test has a good prognostic value and could be helpful in identifying patients with septic shock at high risk for death.

[Regionalization of perinatal care and in utero referrals]. / Régionalisation des soins périnatals et transfert in utero.

Further improvement in perinatal morbidity and mortality figures implies in utero referral so high risk infants, particularly very early maturity infants, can be managed immediately in specialized centers. The success of such referrals depends directly on the coherence of the regional perinatal health care network. It has been demonstrated that the chances of survival and of sequelae-free survival are greater for very premature infants born in a center with a neonatal intensive care unit. The situation in France leaves room for improvement. Only 15% of the infants born before 33 months gestation and with birth weight under 1500 g are born in level III maternity wards equipped with a neonatal intensive care unit. The goal is 80%. We have tried to analyze the reasons behind this situation and propose ways to better organize perinatal health care.

Is the duration of mechanical ventilation predictable?

BACKGROUND: Prolonged mechanical ventilation (MV) is associated with high morbidity, mortality, and cost. However, few and limited data are available on the prediction of duration of MV. We conducted an observational cohort study to seek predictive criteria. METHODS: The study was performed in a surgical ICU (SICU) in a university hospital. One hundred ninety-five consecutive unselected patients and 203 episodes of MV were prospectively analyzed to determine if clinical features, physiologic parameters, or multifactor scoring systems, at the time of admission or intubation, could be used as predictors of MV > or = 15 days. A univariate statistical analysis and a multiple logistic regression were used. A prospective validation study was then conducted to determine the accuracy of the results. RESULTS: (1) Univariate statistical analysis indicated that SICU length of stay, emergent endotracheal intubation as opposed to elective intubation, indication for MV, sepsis score at the time of admission and intubation, lung injury score (LIS) at the time of admission and intubation, number of organ system failures at the time of admission and intubation, and serum albumin concentration were significantly different between the two groups. (2) Only the circumstances (emergency) of endotracheal intubation (odds ratio [OR]=3.5, p=0.02) and the LIS (OR=3.7, p=0.004) independently predicted a duration of endotracheal intubation > or = 15 days. One hundred twenty-eight consecutive patients requiring emergent intubation and MV were included in the prospective validation. The accuracy of the LIS > or = 1 used to predict MV > or = 15 days was as follows: sensitivity=0.88; specificity=0.28; positive predictive value=0.24; negative predictive value=0.91. CONCLUSION: Low incidence of MV > or = 15 days was observed (13% and 20%, respectively, in observational cohort study and validation study) in unselected SICU patients. LIS > or = 1 at the time of intubation provides excellent negative predictive value (0.93 and 0.91) of duration of MV > or = 15 days. These data suggest that tracheotomy should not be considered for patients with LIS < 1.

Acute pancreatitis and preeclampsia-eclampsia: a case report.

A case of preeclampsia-eclampsia leading to acute edematous pancreatitis is reported, probably related to microvascular abnormalities and splanchnic ischemia. Recovery was uneventful.

Renal effects of low-dose dopamine in patients with sepsis syndrome or septic shock treated with catecholamines.

OBJECTIVE: To evaluate the renal effects of low-dose dopamine in patients with sepsis syndrome or septic shock treated with catecholamines. DESIGN: Prospective, clinical study using sequential periods. SETTING: A 12-bed surgical intensive care unit in a university hospital. PATIENTS: 14 patients with sepsis syndrome and 15 patients with septic shock treated with exogenous catecholamines were studied. They had no diuretic treatment. INTERVENTION: Two periods of 2 h each with and without 2 micrograms.kg-1.min-1 of dopamine infusion. Hemodynamic and renal data were obtained at the end of each period. Measurements were repeated after 48 h of dopamine infusion in patients with sepsis syndrome. All data were evaluated by the Wilcoxon rank test. MEASUREMENTS AND RESULTS: In patients with sepsis syndrome, diuresis and creatinine clearance increased significantly by 100% and 60%, respectively, during low-dose dopamine infusion without any change in systemic hemodynamics. The renal response to dopamine decreased significantly after 48 h of dopamine infusion (P < 0.01). In patients with septic shock treated with catecholamines, no variation of either systemic hemodynamics or renal function was noted during low-dose dopamine infusion. CONCLUSION: The renal effects of low-dose dopamine in patients with sepsis syndrome decrease with time. No renal effect of low-dose dopamine was observed in patients with septic shock treated with catecholamines. These findings suggest a desensitization of renal dopaminergic receptors.

High incidence of hypophosphatemia in surgical intensive care patients: efficacy of phosphorus therapy on myocardial function.

OBJECTIVE: To determine the incidence of hypophosphatemia in a surgical intensive care unit and to determine whether or not a phosphorus challenge causes a change in cardiac performance in hypophosphatemic patients. DESIGN: Prospective clinical study and case reports. SETTING: Surgical intensive care unit in an university hospital. PATIENTS: A total of 208 consecutive patients admitted to the surgical ICU were evaluated over a 6 months period. INTERVENTIONS: All classical risk factors for hypophosphatemia were recorded. A group of 8 moderate or severe hypophosphatemic patients were evaluated for hemodynamic data before and after a phosphorus load. Glucose phosphate was given over 30 min by the intravenous route. Dosage regimen was 0.4 mmol/kg weight for moderate hypophosphatemia and 0.8 mmol/kg weight for severe hypophosphatemia. RESULTS: Risk factors were present in 134 patients and 60 patients were hypophosphatemic (44.8%). Only 3 risk factors were discriminant for hypophosphatemia: sepsis, diuretics and total parenteral nutrition. The mortality was higher in the hypophosphatemic group than in the normophosphatemic group (30% versus 15.2%; p < 0.05). Cardiac performance improved after phosphatemia normalization in all patients (cardiac index: 3.82 +/- 1.87 versus 4.52 +/- 1.83 1/min.m2; p < 0.01). CONCLUSION: This study underlines the high incidence (28.8%) of hypophosphatemia in surgical intensive care patients and its association with a high mortality rate (30%). A short course of phosphotherapy improves cardiac index (+18%).

Kinetics of elimination and acute consequences of cerebral air embolism.

The pathophysiology of arterial air embolism inducing brain injuries remains unclear. Previous experiments demonstrated the usefulness of computed tomography (CT) in the detection of air emboli in canine brain. This canine study investigates CT's ability to detect small air bubbles and to determine the kinetics of air elimination from cerebral arteries and its relationship with clinical, electroencephalographic (EEG), and histological manifestations. CT detects small air embolism, and intracerebral air volume strongly correlates with injected air dose (r2 = 0.86, p = 2 x 10(-3)). Air clearance time significantly depends on intracerebral air volume (r2 = 0.86, p = 0.04) and on the number of bubbles (r2 = 0.71, p = 0.03), whereas half-life of air elimination does not. No relationship was found between injected air dose, air clearance time, intracerebral volume of air, and clinical, EEG, and histological findings. The data indicate that CT accurately detects small air bubbles in the early course of cerebral air embolism, that air elimination from cerebral arteries follows a first-order compartment model, and that early CT findings do not correlate with clinical, EEG, and histological manifestations.

Effects of mechanical ventilation with normobaric oxygen therapy on the rate of air removal from cerebral arteries.

OBJECTIVE: We conducted the current study to evaluate the removal rate of air embolism from cerebral arteries after spontaneous breathing at a low FIO2 in comparison with mechanical ventilation at an FIO2 of 1.0. DESIGN: Randomized, experimental trial. SETTING: Neuroimaging department at a veterinary school hospital laboratory. SUBJECTS: Nine anesthetized beagles undergoing mechanical ventilation with previous normal cranial computed tomography (CT) scan. INTERVENTIONS: In each dog, after a control scan, air was infused at a constant flow rate, via a catheter inserted into the internal carotid artery. CT scan was repeated until typical bubbles appeared. Immediately after, the animals were randomly assigned to breathe room air (group A), or to be mechanically ventilated at an FIO2 of 1.0 (group B). CT scan was again repeated every minute until the removal of all bubbles. We compared the volume of air infused per kg of body and brain weights, the lowest density among bubbles (Hounsfield units), the duration of radiologic findings, and the ratio of volume/duration (mL/kg/min) between the two groups, using the Mann-Whitney test. RESULTS: The volume of air infused per kg of body and brain weights and density were not significantly different between the two groups. The duration of radiologic findings was shorter (p < .02) in group B (7.0 +/- 4.7) than in group A (20.4 +/- 3.8), and the air removal rate from cerebral arteries (expressed as volume/duration of radiologic findings) was dramatically improved (p < .02) in group B (0.159 +/- 0.042) in comparison with group A (0.046 +/- 0.016). CONCLUSIONS: These results suggest that the removal rate of air from cerebral arteries is dramatically increased by mechanical ventilation at an FIO2 of 1.0. Consequently, the time of cerebral ischemia may be decreased, but the result does not account for the effects of each factor separately. Further studies are required to evaluate the clinical benefits of high FIO2 administration and of mechanical ventilation separately. However, the prompt application of mechanical ventilation with an FIO2 of 1.0 may be recommended when air embolism is suspected.