Sonographic assessment of abdominal vein dimensional and hemodynamic changes induced in human volunteers by a model of abdominal hypertension.

OBJECTIVE: In patients affected by intra-abdominal hypertension, bladder or gastric pressure measurement may be usefully integrated by ultrasounds in order to detect early hemodynamic impairment. The purpose of this study was to search for changes in abdominal vein size and flow induced by intra-abdominal hypertension. DESIGN: Physiologic study. SETTING: Postoperative intensive care unit of a university hospital. SUBJECTS: Sixteen healthy volunteers. INTERVENTIONS: Four echographic assessments of vessel sizes and blood velocities were randomly performed in the following settings: 1) baseline, 2) intra-abdominal hypertension simulated by a tight pelvic stabilizer around the waist, 3) noninvasive ventilation with a facial mask, and 4) intra-abdominal hypertension plus noninvasive ventilation. MEASUREMENTS AND MAIN RESULTS: The model of intra-abdominal hypertension was validated in eight subjects by measuring gastric pressure. During intra-abdominal hypertension, 1) the inferior vena cava was compressed (significant decrease of both anteroposterior and lateral diameters) and deformed (decreased anteroposterior/lateral diameter ratio), and deformation, but not compression, was attenuated by noninvasive ventilation associated with intra-abdominal hypertension; 2) the portal vein was also compressed (decreased diameter); and 3) blood velocities did not change significantly in the inferior vena cava, portal vein, right suprahepatic vein, or right external iliac vein. In the receiver operating characteristic curve analysis, an inferior vena cava section area (normalized for body surface) of lower than 1 cm²/m² discriminated between intra-abdominal hypertension presence and absence with a sensitivity of 65.6% and a specificity of 87.5% (p = .0001). Noninvasive ventilation alone did not significantly affect vein sizes and velocities. The resistive index, calculated by pulse wave Doppler signal from segmental branches of the right renal artery, increased slightly, but significantly, during intra-abdominal hypertension alone, suggesting an increase of intrarenal pressure. CONCLUSIONS: Simulated intra-abdominal hypertension was associated with decreased inferior vena cava section area and increased resistive index in renal arteries. Further studies are now needed to investigate whether these changes may be of value to integrate bladder or gastric pressure measurement in clinical practice.

The comprehensive medical preparedness in chemical emergencies: 'the chain of chemical survival'.

Medical management of victims of chemical incidents includes supportive therapy, decontamination and antidote administration. Chemical weapons of mass destruction are available to many countries and are a possible alternative to conventional weapons for terrorist groups. During the last 5 years, some Italian institutions have made big efforts to establish a national system of antidote stockpiling and distribution. Little or no efforts have been addressed to other aspects of the medical management of patients exposed to chemical agents, such as decontamination, personal protective equipment, and specific supportive therapy. Although antidotes are indispensable instruments for some poisonings, as nerve agent and botulin intoxication, antidote stockpiling cannot be considered the only objective of a comprehensive medical preparedness for chemical emergencies. This paper addresses the medical priority when approaching victims of chemical emergencies. The priority actually is to establish a chain of chemical survival in which antidote administration is one out of several links.

[A relational database to store Poison Centers calls]. / Un database relazionale per l'archiviazione delle chiamate ad un Centro antiveleni (CAV).

Italian Poison Centers answer to approximately 100,000 calls per year. Potentially, this activity is a huge source of data for toxicovigilance and for syndromic surveillance. During the last decade, surveillance systems for early detection of outbreaks have drawn the attention of public health institutions due to the threat of terrorism and high-profile disease outbreaks. Poisoning surveillance needs the ongoing, systematic collection, analysis, interpretation, and dissemination of harmonised data about poisonings from all Poison Centers for use in public health action to reduce morbidity and mortality and to improve health. The entity-relationship model for a Poison Center relational database is extremely complex and not studied in detail. For this reason, not harmonised data collection happens among Italian Poison Centers. Entities are recognizable concepts, either concrete or abstract, such as patients and poisons, or events which have relevance to the database, such as calls. Connectivity and cardinality of relationships are complex as well. A one-to-many relationship exist between calls and patients: for one instance of entity calls, there are zero, one, or many instances of entity patients. At the same time, a one-to-many relationship exist between patients and poisons: for one instance of entity patients, there are zero, one, or many instances of entity poisons. This paper shows a relational model for a poison center database which allows the harmonised data collection of poison centers calls.

Ultrasound artifacts mimicking pleural sliding after pneumonectomy.

STUDY OBJECTIVE: To determine the presence of pleural sliding on chest ultrasonography (US) in a series of patients admitted to a surgical intensive care unit (SICU). DESIGN: Prospective, observational study. SETTING: 16-bed SICU of a University hospital. PATIENTS: 8 patients (7 men, 1 woman), aged 64 - 73 years (mean 67.5 yrs). Seven patients underwent pneumonectomy for pulmonary neoplasms; one patient underwent an atypical lung resection after having undergone a pneumonectomy one year before. INTERVENTIONS: None. MEASUREMENTS: Chest ultrasounds were performed during mechanical ventilation and spontaneous ventilation after endotracheal tube removal. In both examinations, pleural sliding was searched bilaterally in brightness mode (B-mode) and motion mode (M-mode) on the anterior thoracic wall in the least gravitationally dependent areas. RESULTS: During mechanical ventilation, pleural sliding was always absent on the side of the pneumonectomy and present on the other side. During spontaneous ventilation, some artifacts mimicking pleural sliding were noted on the side of the pneumonectomy both in B-mode and M-mode (presence of the seashore sign) in all patients, except for the one patient who had undergone a pneumonectomy one year earlier. Those artifacts became more pronounced during deep breaths. CONCLUSIONS: Ultrasound artifacts mimicking pleural sliding may be observed in the absence of the lung and may originate from the activity of intercostal muscles since they become more evident during deep breathing.