Crew and patient safety in ambulances: results of a personnel survey and experimental side impact crash test.

INTRODUCTION: Ambulance drivers often travel under stressful conditions at high speed while using vehicles with poor high-speed maneuverability. The occupant safety of ambulance vehicles has not yet been addressed by the automotive safety paradigm; particularly for the rear patient compartment. This study had two objectives: (1) to assess by survey the French Emergency Medical Services (EMS) to determine the layout of the vehicle most often used and the EMS personnel's behavior during transport; and (2) to conduct a crash test to analyze the injuries which may affect EMS personnel and patients in the rear patient compartment. METHOD: Firstly, a survey was distributed to the 50 largest metropolitan French EMS programs. Secondly, a crash test was performed with a Mobile Intensive Care Unit (MICU) in conditions closest to reality. RESULTS: Forty-nine of the 50 biggest metropolitan French EMS programs responded to the survey. This represents 108 French MICUs. During the last three years, 12 of 49 EMS programs (24%) identified at least one accident with an MICU, and six of these 12 (50%) suffered at least one death in those accidents. A crash test using a typical French EMS MICU showed that after impact of a collision, the ambulance was moved more than five meters with major consequences for all passengers. A study-approved human cadaver placed in the position of a potential patient was partially thrown from the stretcher with a head impact. The accelerometric reaction of the anthropomorphic manikin head was measured at 48G. CONCLUSION: The crash test demonstrated a lack of safety for EMS personnel and patients in the rear compartment. It would be preferable if each piece of medical equipment were provided with a quick release system resistant to three-dimensional 10G forces. The kinetic changes undergone by the "patient" substitute on the stretcher would probably have an effect of causing injury pathology. This study highlights the need for more research and development in this area.

Association of mechanical chest compression and prehospital thrombolysis.

Pulmonary embolism (PE) is a common cause of sudden death; the use of prehospital thrombolysis is currently a last-resort option and requires a prolonged cardiopulmonary resuscitation (CPR). Novel mechanical devices have recently been introduced that provides automatic mechanical chest compression (AMCC) according to the guidelines and continually without decrease efficiency throughout prolonged resuscitation. A 54 year-old woman with a history of breast cancer experienced sudden chest pain and severe dyspnea. A mobile intensive care unit was dispatched to her home. During physical examination, she suddenly collapsed with pulseless electrical activity as the initial rhythm. Prehospital thrombolysis during CPR combined with use of AMCC was performed based on a strongly suspected diagnosis of massive PE. After 75 minutes of effective CPR, return of spontaneous circulation was attained. After admission to an intensive care unit, computed tomographic scan confirmed bilateral PE. The patient was discharged 3 weeks after CPR in good neurologic condition. To our knowledge, this is the first case describing combined use of thrombolysis and AMCC in out-ofhospital cardiac arrest. However, for the time being, prehospital thrombolysis in CPR continues to be a measure that should only be performed on a case-by-case basis based on informed decision. Further studies are needed to evaluate the efficacy and safety of AMCC with thrombolysis and thus prolonged CPR.

Medical treatment of seafarers in the Southern Indian Ocean - interaction between the French Telemedical Maritime Assistance Service (TMAS) and the medical bases of the French Southern and Antarctic Lands (TAAF).

BACKGROUND: The waters surrounding the French Southern Lands are a fishing zone, accessible only by sailing for several days in a region where weather conditions are often difficult. The scientific bases of the region have medical staff whose services can be called upon if seafarers require assessment and rapid medical treatment. We conducted an epidemiological study of the maritime teleconsultations carried out by the French Telemedical Maritime Assistance Service (TMAS), where patients navigating in the Southern Indian Ocean zone were advised to disembark on the medical bases in the French Southern Lands, between 2015 and 2020, to receive medical treatment. MATERIALS AND METHODS: We extracted data from all of the maritime records from 1 January 2015 to 31 December 2020 relating to patients who attended a maritime teleconsultation with a French TMAS doctor in the Southern Indian Ocean zone and who had been redirected to the medical bases in the French Southern Lands. Data were collected on the patients' age, gender, nationality, rank, type of vessel, teleconsultation diagnosis, patient management on board and in the French Southern Lands medical bases, as well as the medical outcome. We carried out a descriptive data analysis. RESULTS: French TMAS doctors managed 11,908 cases including 76 in the Southern Indian Ocean zone (0.6%). Nineteen (25%) patients were redirected to the French Southern Lands over the study period. Eighteen patients were men with an average age of 45 ± 10 years. Eighteen patients were on board a trawler and 11 of them were sailors. Nine patients were treated for a trauma-related condition, 8 for a medical condition and 2 for a surgical disease. Eleven (58%) patients were evacuated to Reunion Island and 8 (42%) patients received medical treatment and were able to re-embark aboard their vessel. CONCLUSIONS: Relatively few patients are redirected to the French Southern Lands for medical assistance, but referrals occur on a regular basis. The presence of these medical bases is unusual in a maritime setting, but they can be a valuable asset when maritime medical assistance is required in this region. The type of condition encountered, and the patient profile, were typical of the fishing community. The presence of these bases and communication between the various stakeholders delivering maritime medical assistance provided these patients with optimal care despite their isolated location.

Short-term spirometric changes in wildland firefighters.

BACKGROUND: The short-term effects of smoke inhalation have been little studied in European wildland firefighters, especially in an intra-individual design. Our purpose is to study the spirometric changes from the early stage during a wildland fire season and to compare smokers and non-smokers. METHODS: A population of 108 firefighters from a Civil Security Unit, based in Corsica, was tested immediately after having been exposed to the smoke of coniferous trees. RESULTS: Out of 108 people, 59 were smokers and 49 were non-smokers without any acute or chronic pulmonary disease. Compared to baseline values, a decrease of spirometric parameters was observed immediately after the end of exposure and an even greater decrease was seen after 24 hr (FEV1 -0.53 L; FVC -0.59 L; PEF -53 L min(-1), P < 0.05 for each). None of the participants complained of respiratory symptoms. Three months after the end of the season, a final test was given which revealed a persistent decrease in spirometric parameters in comparison with baseline values (FEV1 -0.28 L; FVC -0.34 L; PEF -45 L min(-1), P < 0.05 for each). Comparison of smoking and non-smoking groups did not show any noteworthy difference for each parameter or the importance of their decline. CONCLUSIONS: The findings show that firefighters are likely to develop respiratory impairments after wood smoke exposure. We did not observe any statistical differences between smokers and non-smokers.

Tropheryma whipplei in patients with pneumonia.

Tropheryma whipplei is the etiologic pathogenic agent of Whipple disease (WD), characterized by various clinical signs, such as diarrhea, weight loss, lymphadenopathy, and polyarthritis. PCR-based methods for diagnosis of WD have been developed. T. whipplei has been identified in saliva and stool samples from patients with WD and from healthy persons. T. whipplei DNA has also been found in bronchoalveolar lavage (BAL) samples of a child with pneumonia. We detected DNA of T. whipplei in 6 (3%) of 210 BAL samples collected in intensive care units by using 16S rDNA and specific quantitative PCR. We identified 4 novel genotypes of T. whipplei. In 1 case, T. whipplei was the only bacterium; in 4 others, it was associated with buccal flora. We suggest that T. whipplei should be investigated as an etiologic agent of pneumonia.

Early onset pneumonia in severe chest trauma: a risk factor analysis.

BACKGROUND: The development of an early-onset pneumonia (EOP), occurring within the first 72 hours after admission, represents a critical event in severe thoracic trauma population. The aim of this study was to determine risk factors associated with the occurrence of this complication in this specific population. METHODS: A retrospective review of a prospective implemented trauma registry was conducted during a 4-year period in a Level I trauma center. Over the study period, 223 severely injured patients were admitted with severe thoracic trauma (Injury Severity Score >16 and Thorax Abbreviated Injury Score >2). Multiple logistic regression analysis was used to determine the independent predictors of EOP based on the clinical characteristics and the initial management both in the field and after admission in the trauma center. RESULTS: Independent predictors of EOP were the necessity of intubation and mechanical ventilation in the field (adjusted odds ratio [OR]: 11.8; 95% confidence interval [CI]: 4.3-32.7), a history of aspiration (OR: 28.6; 95% CI: 4.0-203.5), the presence of pulmonary contusion (OR: 7.0; 95% CI: 2.0-23.9), and the occurrence of a hemothorax (OR: 3.2; 95% CI: 1.4-7.6). CONCLUSION: These results emphasize the influence of prehospital and early factors in the further occurrence of EOP, which allows the development of early and specific clinical management to prevent it.

Medical kit for single-handed offshore yacht races.

BACKGROUND: The medical kit is the basis of medical support in maritime environment; it is defined by international or national regulations and guidelines. For offshore races, rules and recommendations are proposed by national or international sailing federations. Sailing and racing offshore alone presents specificities that sometimes make it difficult to apply the usual recommendations. The epidemiology of single-handed offshore race is dominated by traumatic risks. Medical events are relatively rare because competitors are high-level athletes, generally young and subject to complete medical assessments. The scarcity of available scientific data makes it necessary to choose appropriate methods for developing recommendations. The purpose of this work is to propose a medical kit adapted and applicable to these situations. MATERIALS AND METHODS: The method used was that of "Professional recommendations by formal consensus of experts" derived from the Rand/UCLA method. After a critical analysis of the literature, a panel of 19 experts having expertise in medicine in maritime environment was gathered from various medical specialties (cardiologist, internist, intensivist and emergency physician, ear-nose-throat physician and general practitioner) and from varied medical activities. They had not declared any direct conflict of interest. RESULTS: A medical kit proposal has been developed. The choice of drugs was based on the analysis of the epidemiology of medical events observed during the last offshore races. The experts' choice was to reduce the quantity of medication and medical devices in order to limit the risk of confusion of medicines and dosages. Drugs with significant side effects or requiring third party monitoring have been removed. Medical devices designed to do an intervention impossible to perform on oneself have also been eliminated. CONCLUSIONS: Solo sailing remains a marginal maritime activity with specific risks. The development of single-handed races requires an adaptation of medical support through the development of a specific medical kit and adapted training. The formalised consensus of experts seems to be an appropriate method for developing recommendations in the field of maritime medicine.

[Aspirin in decompression sickness]. / Place de l'aspirine dans le traitement médicamenteux de l'accident de désaturation.

OBJECTIVE: We have performed a survey on the use of aspirin in decompression sickness (DCS) treatment in French hyperbaric centers'. We also conducted a review of literature to determine if aspirin was beneficial to treat human victims of DCS. METHODS: Prospective observational study investigating French hyperbaric centers' prescription of aspirin to DCS' divers victims. The question we asked by mail or phone to French hyperbaric centers was: Do you give some aspirin to a diver with DCS if this treatment has not been given yet (on the site of accident). RESULTS: A large majority of French hyperbaric centers (77.5%) consider aspirin in DCS treatment. However this practice is not consensual. There is no evidence from the literature to support the efficiency of aspirin in DCS. CONCLUSIONS: Although aspirin is widely used for DCS treatment in France, more research is needed to determine if aspirin is useful.

A Medical Support in Offshore Racing - Workshop on Medical Kit Inventory in Offshore Yacht Racing, 12-13 May 2017, Lorient, France.

No abstract.

Comparison of lung injury after normal or small volume optimized resuscitation in a model of hemorrhagic shock.

OBJECTIVE: To compare lung injury induced by a hemorrhagic shock resuscitated with normal saline or with small volumes of a hypertonic/hyperoncotic solution. DESIGN AND SETTING: Randomized, controlled, laboratory study in an animal research laboratory. SUBJECTS: Nineteen pigs (43 +/- 4 kg). INTERVENTIONS: After anesthesia and mechanical ventilation animals were bled to induce a 2-h deep shock and resuscitated for 2 h using normal saline (NS, 2 ml/kg per minute, n = 7) or the association of 7.2% NaCl with 6% hydroxyethylstarch 200/0.5 (HSHES, 4 ml/kg in 10 min followed by 0.2 ml/kg per minute, n = 7) to reach cardiac index and mixed venous oxygen saturation goals. Lungs were removed 6[Symbol: see text]h after the initiation of hemorrhage. Five animals were used as controls without hemorrhage. MEASUREMENTS AND RESULTS: Resuscitation goals were achieved using 90 +/- 17 ml/kg NS or 6.8 +/- 1.9 ml/kg HSHES. Lung injury was noted in both hemorrhage groups but was not influenced by the type of resuscitation. Extravascular lung water was measured at 9.6 +/- 1.8 ml/kg in the NS group, 9.2 +/- 1.6 ml/kg in the HSHES, group and 6.4 +/- 1 m/kg in the control group. The degree of histological alveolar membrane focal thickening and interstitial neutrophil infiltration were significantly more pronounced in the hemorrhage groups with no difference between the two types of fluid loading. Finally, pulmonary levels of IL-8 were higher after hemorrhage regardless of the type of resuscitation. CONCLUSIONS: When included in an optimized and goal directed resuscitation, the use of normal saline or a small volume of hypertonic/hyperoncotic solution does not result in a different early hemorrhage-induced lung injury.

Preparation and medical follow-up for a single-handed transatlantic rowing race.

BACKGROUND: A single-handed transatlantic rowing race was organised between Senegal and French Guyana (2600 nautical miles). During the race, rowers adjust their lifestyle to maintain an optimal level of performance. Nutrition, circadian rhythm disturbance, psychological state, pain and other medical problems impact on physical abilities and increase the occurrence of accidents. We surveyed the prevalence of medical complications during this race and the preparation that we could suggest for this kind of activity. MATERIALS AND METHODS: This is a descriptive, retrospective case series study. Follow-up consisted of sending out a questionnaire and performing individual interviews. RESULTS: A total of 23 participants including 1 woman and 22 men; mean age of 46.5 years (range: 35-59) entered the race. The race lasted for 39 to 52 days with participants rowing between 10 and 12 h/day. Nine participants dropped out. Energy intake was 4500 to 6000 kcal/day and fluid intake was 4 to 5.5 L/day. Mean weight loss was 13.3 kg. The resting period was 6 ± 1 h/24 h divided into 1.5 to 2 h periods essentially during darkness. A total of 92% of the racers required medical care for dermatological problems; other conditions requiring medical care were: tendinitis in 10 cases, diarrhoea in 4, moderate to severe seasickness in 4, hallucinations in 3, panic attacks in 2, burns in 2, and disembarkation syndrome ("land sickness") lasting from 45 min to 6 h in 13. CONCLUSIONS: Physiological and psychological impact of this type of event is still unclear. The most common medical problems are dermatological, rheumatological complications and minor trauma. Medical and psychological preparation should be offered to candidates for these competitions.

Inhaled nitric oxide does not prevent pulmonary edema after lung transplantation measured by lung water content: a randomized clinical study.

STUDY OBJECTIVE: In order to assess the effects of inhaled nitric oxide (iNO) in preventing early-onset lung edema from occurring after lung transplantation, we measured extravascular lung water (EVLW) in a group of lung transplant recipients who were at high risk for developing ischemia-reperfusion-induced lung injury. DESIGN: Prospective, randomized study. SETTINGS: Surgical ICU in a teaching hospital. PATIENTS: Thirty double-lung transplant recipients. INTERVENTIONS: Patients were randomized to receive or not receive 20 ppm iNO at the time of reperfusion (ie, before any occurrence of lung edema). In the NO group, iNO was then administered for a 12-h period. A double-dilution technique was used for the serial assessment of EVLW, intrathoracic blood volume, and cardiac index. Standard hemodynamic and pulmonary parameters were also recorded during the first 3 postoperative days. MEASUREMENTS AND RESULTS: Patients who received iNO did not have a different lung water content compared to control subjects (p = 0.61 [by analysis of variance (ANOVA)]). Blood oxygenation (ie, Pao(2)/fraction of inspired oxygen [Fio(2)] ratio) did not differ between the two groups (p = 0.61 [by ANOVA]). In both groups, EVLW and Pao(2)/Fio(2) ratio dropped significantly over time, regardless of the use of iNO (p < 0.01 [by ANOVA]). CONCLUSIONS: In the population studied, prophylactic iNO that was administered at 20 ppm had no effect on pulmonary edema formation and resolution following lung transplantation.

Epidemiology of unintentional drowning in a metropolis of the French Mediterranean coast: a retrospective analysis (2000-2011).

Drowning affects more than 500,000 people worldwide and is responsible for at least 350,000 deaths each year. In France, 1235 drowning resulting in 496 deaths were recorded in the summer 2012. This retrospective study has investigated the epidemiology of drowning in the city of Marseille (South of France) between 2000 and 2011. We identified 449 cases of unintentional drowning. The highest incidence was found among males with a median age of 36 years. The incidence was 5.3 victims per 10,000 inhabitants with a mortality rate of 1.2 per 10,000. These accidents occurred mainly at sea (89%) and during the summer season. A majority of drowning victims (69%) were admitted in a hospital. This is the only study in France to analyse data on drowning throughout the year and over a long period. Drowning is a serious condition burdened by 22% of victims who die.

Perioperative risk factors for anastomotic leakage after esophagectomy: influence of thoracic epidural analgesia.

STUDY OBJECTIVES: Anastomotic leakage after esophagectomy is associated with high postoperative morbidity and mortality. The most important predisposing factors for anastomotic leaks are ischemia of the gastric conduit and low blood oxygen content. The aim of this study was to evaluate the influence of thoracic epidural analgesia (TEA) on the incidence of anastomotic leakage after esophagectomy. DESIGN: Retrospective study. SETTING: A thoracic surgery and anesthesia department in a teaching hospital. PATIENTS: Two hundred seven patients who underwent one-stage esophagectomy between 1998 and 2003. INTERVENTIONS: The effects of perioperative factors and postoperative complications on the incidence of anastomotic leakage were analyzed. Leakage was defined as an anastomotic disruption detected by an ionic x-ray contrast study and confirmed by upper endoscopy in the postoperative period. Analyzed factors included effective TEA placed before the surgical procedure. MEASUREMENTS AND RESULTS: Anastomotic leakage occurred in 23 patients (11%). This complication was associated with a significant increase in length of stay in the ICU and in the hospital (mean, 19 +/- 16 days vs 9 +/- 7 days [+/- SD], p = 0.008; and 43 +/- 27 days vs 23 +/- 11 days, respectively; p < 0.001). Mortality in patients presenting anastomotic leakage was 26%, compared with 5.4% in the remainder (p = 0.002). Factors independently associated with the incidence of leakage included estimated blood loss per milliliter during the surgical procedure (odds ratio [OR], 1.004; 95% confidence interval [CI], 1.001 to 1.007), the cervical location for anastomosis (OR, 5.4; 95% CI, 1.3 to 22.9), and the development of an ARDS in the postoperative period (OR, 4.1; 95% CI, 2.6 to 176.5). Ninety-three patients benefited from an effective TEA for 4.4 +/- 0.8 days. The use of TEA was independently associated with a decrease in the incidence of anastomotic leakage (OR, 0.13; 95% CI, 0.02 to 0.71). CONCLUSIONS: The results of this retrospective study suggest that TEA is associated with a decrease in occurrence of anastomotic leakage.

Accuracy and limits of transpulmonary dilution methods in estimating extravascular lung water after pneumonectomy.

STUDY OBJECTIVES: The measurement of extravascular lung water index by double indicator (EVLWIdi) or the measurement of extravascular lung water index by transpulmonary thermodilution (EVLWItt) could be useful after pneumonectomy. Since pulmonary blood flow and volume are altered after pneumonectomy, the validity of these methods is uncertain. This study has compared measurements of EVLWIdi and EVLWItt with measurement of extravascular lung water index by gravimetry (EVLWIg) in a porcine model of pulmonary edema induced after right pneumonectomy. DESIGN: Randomized laboratory study. SETTING: Animal research laboratory. SUBJECTS: Twenty-seven female pigs; mean weight, 35 +/- 5 kg (+/- SD). INTERVENTIONS: The pigs were anesthetized, placed on mechanical ventilation, and allocated to a two-lung group (n = 10) or a right pneumonectomy group (n = 17). EVLWIdi and EVLWItt were measured at baseline, 60 min after pneumonectomy, and 60 min after IV injection of oleic acid (OA). MEASUREMENTS AND RESULTS: There was a good correlation between EVLWIg and EVLWIdi values (r = 0.96, p < 0.0001 in the two-lung group; and r = 0.81, p = 0.02 in the pneumonectomy group). EVLWIdi underestimated EVLWIg in the two-lung group (- 3 mL/kg; 95% confidence interval [CI], - 7 to + 2 mL/kg) and in the pneumonectomy group (- 0.9 mL/kg; 95% CI, - 3.3 to + 1.5 mL/kg). After pneumonectomy, EVLWItt decreased in mean by 27% and increased in mean by 70% after OA acid. There was a good correlation between EVLWIg and EVLWItt values (r = 0.96, p < 0.0001 in the two-lung group; and r = 0.90, p < 0.0001 after pneumonectomy). EVLWItt slightly overestimated gravimetric value in the two-lung group (+ 1.5 mL/kg; 95% CI, - 1.5 to + 4.2 mL/kg) and largely overestimated gravimetric value after pneumonectomy (+ 5 mL/kg; 95% CI, + 3.4 to + 6.8 mL/kg). CONCLUSION: Double-indicator and transpulmonary thermodilution methods could be useful in monitoring extravascular lung water index (EVLWI) after pneumonectomy, but transpulmonary thermodilution largely overestimates EVLWI.

Usefulness of ultrasonography in predicting pleural effusions > 500 mL in patients receiving mechanical ventilation.

STUDY OBJECTIVE: To assess the accuracy of chest ultrasonography in predicting pleural effusions > 500 mL in patients receiving mechanical ventilation. DESIGN: Prospective study. SETTING: Surgical and medical ICU in a teaching hospital. PATIENTS: Forty-four patients receiving mechanical ventilation with indications of chest drainage of a nonloculated pleural effusion. INTERVENTIONS: Diagnosis of pleural effusion was based on clinical examination and chest radiography. Chest drainage was indicated when considered as potentially useful for the patient (hypoxemia and/or weaning failure). Sonograms were performed before drainage at the bedside, in the supine position, and measurements were performed at the end of expiration. Effusions were classified as > 500 mL or < or = 500 mL according to the drained volume. MEASUREMENTS AND RESULTS: The drained volume ranged from 100 to 1,800 mL (mean, 730 +/- 440 mL [+/- SD]). The distance between the lung and posterior chest wall at the lung base (PLDbase) and the distance between the lung and posterior chest wall at the fifth intercostal space (PLD5) were significantly correlated with the drained volume (PLDbase, r = 0.68, p < 0.001; PLD5, r = 0.56, p < 0.001). A PLDbase > 5 cm predicted a drained volume > 500 mL with a sensitivity of 83%, specificity of 90%, positive predictive value of 91%, and negative predictive value of 82%. Interobserver and intraobserver percentages of error were, respectively, 7 +/- 6% and 9 +/- 6% for PLDbase, and 6 +/- 5% and 8 +/- 5% for PLD5. The PaO2/fraction of inspired oxygen ratio significantly increased after chest drainage in patients with collected volumes > 500 mL (p < 0.01). CONCLUSIONS: Bedside pleural ultrasonography accurately predicted a nonloculated pleural effusion > 500 mL in patients receiving mechanical ventilation using simple and reproducible measurements.

Influence of support on intra-abdominal pressure, hepatic kinetics of indocyanine green and extravascular lung water during prone positioning in patients with ARDS: a randomized crossover study.

INTRODUCTION: Prone positioning (PP) on an air-cushioned mattress is associated with a limited increase in intra-abdominal pressure (IAP) and an absence of organ dysfunction. The respective influence of posture by itself and the type of mattress on these limited modifications during the PP procedure remains unclear. The aim of this study was to evaluate whether the type of support modifies IAP, extravascular lung water (EVLW) and the plasma disappearance rate of indocyanine green (PDRICG) during PP. METHODS: A prospective, randomized, crossover study of 20 patients with acute respiratory distress syndrome (ARDS) was conducted in a medical intensive care unit in a teaching hospital. Measurements were made at baseline and repeated after 1 and 6 hours of two randomized periods of 6 hours of PP with one of two support types: conventional foam mattress or air-cushioned mattress. RESULTS: After logarithmic transformation of the data, an analysis of variance (ANOVA) showed that IAP and PDRICG were significantly influenced by the type of support during PP with an increase in IAP (P < 0.05 by ANOVA) and a decrease in PDRICG on the foam mattress (P < 0.05 by ANOVA). Conversely, the measurements of EVLW did not show significant modification between the two supports whatever the posture. The ratio of the arterial oxygen tension to the fraction of inspired oxygen significantly increased in PP (P < 0.0001 by ANOVA) without any influence of the support. CONCLUSION: In comparison with a conventional foam mattress, the use of an air-cushioned mattress limited the increase in IAP and prevented the decrease in PDRICG related to PP in patients with ARDS. Conversely, the type of support did not influence EVLW or oxygenation.

Cardiopulmonary effects of lipid emulsions in patients with ARDS.

STUDY OBJECTIVES: Lipid emulsions have been suspected of inducing certain modifications in gas exchange and pulmonary hemodynamics. The aim of this prospective study was to evaluate the hemodynamic and pulmonary effects of two lipid emulsions. DESIGN: Prospective, randomized, double-blind, crossover study. SETTING: Medical and surgical ICU in a French university hospital. PATIENTS: Eighteen patients presenting ARDS. INTERVENTIONS: Each patient received a 6-h infusion of a 20% fat emulsion containing 100% long-chain triglycerides (LCTs) and a 6-h infusion of 50% LCTs/50% medium-chain triglycerides (MCTs) 20% lipid emulsion at the rate of 1.0 mL/kg/h. An 18-h period with no lipids separated the two periods. An additional 18-h period after the end of the second lipid emulsion administration was observed prior to the final measurements. MEASUREMENTS AND RESULTS: The MCT/LCT emulsion increased the PaO(2)/fraction of inspired oxygen (FIO(2)) ratio (p = 0.005) compared with LCT emulsion alone. The mean (+/- SD) PaO(2)/FIO(2) ratio increased from 165 +/- 55 to 191 +/- 64 mm Hg after 1 h of LCT/MCT administration (p < 0.03), and to 175 +/- 46 mm Hg after 6 h. Moreover, there was an increase in oxygen delivery after 6 h of LCT/MCT administration (p < 0.001 vs baseline). While a time-related increase in mean pulmonary artery pressure (p = 0.012) during lipid administration was found, no effect of the kind of lipid emulsion was observed. The time-related increase in cardiac index (p = 0.002) was more marked when the patients received the LCT/MCT emulsion (p = 0.002). Pulmonary vascular resistances were not affected by the kind of lipid emulsion. CONCLUSIONS: The present work showed that while the LCT emulsion induced no deleterious effects on oxygenation in ARDS patients, the LCT/MCT emulsion improved the PaO(2)/FIO(2) ratio and had a further beneficial effect on oxygen delivery.

Patients in the intensive care unit are exposed to amoeba-associated pathogens.

OBJECTIVE: To study the role of amoeba-associated alpha Proteobacteria as infecting agents in intensive care units (ICUs). DESIGN: Amoeba-associated alpha Proteobacteria were isolated from water samples taken from ICU taps and general hospital reservoir tanks using an amoebal co-culture procedure. Isolates were identified by 16S rDNA gene sequence comparison, and one isolate of each species was used as an antigen in a microimmunofluorescence assay to test the sera of the patients in the ICUs and compare them with those of control subjects. SETTING: The four university hospitals in Marseilles, France. PATIENTS: The sera of 85 patients in the ICUs with nosocomial pneumonia were tested. RESULTS: We isolated 64 bacterial strains that were identified as Afipia species or close relatives within the Rhizobiaceae subgroup of alpha Proteobacteria. These bacteria were assigned to 8 different species. Eleven patients were found to have an elevated antibody titer to either Afipia genospecies 1, or 3 still unnamed bacteria. No specific antibodies were detected in 100 control subjects (P < .01). CONCLUSION: These preliminary results support the hypothesis that ICU patients are exposed to amoeba-associated alpha Proteobacteria.

Conventional mechanical ventilation of healthy lungs induced pro-inflammatory cytokine gene transcription.

We investigated the potential inflammatory reaction induced by mechanical ventilation (MV) using 10 ml/kg tidal volume and no positive end-expiratory pressure (PEEP) in control (C, n = 8), spontaneously breathing (SB, n = 12) and mechanically ventilated (MV, n = 12) rabbits with normal lungs. After 6 h (MV and SB groups) or immediately (C group), lungs were removed for measurement of wet-to-dry (W/D) weight ratio and for bronchoalveolar lavage (BAL). Pulmonary mechanics were also studied. MV animals developed a modest but significant (P < 0.01) impairment of arterial blood oxygenation and had higher W/D lung weight ratio than C ones. In MV group, BAL macrophage count was greater (P < 0.05) than in SB one. MV induced an upregulation of MCP-1, TNF-alpha, and IL-1beta gene transcription (mRNAs), without significant elevation of the corresponding protein cytokines in the BAL supernatant, except for MCP-1 (P < 0.05). These data suggest that MV, even using moderate tidal volume, elicits a pro-inflammatory stimulus to the lungs.