Frequency and intensity of pulmonary bone marrow and fat embolism due to manual or automated chest compressions during cardiopulmonary resuscitation.

Iatrogenic consequences of cardiopulmonary resuscitation (CPR) include sternal or rib fractures, pulmonary bone marrow embolisms (BME) and fat embolisms (FE). This report aimed to analyze the frequency and intensity of pulmonary BME and FE in fatal cases receiving final CPR efforts with the use of automated chest compression devices (ACCD) or manual chest compressions (mCC). The study cohort (all cardiac causes of death, no ante-mortem fractures) consisted of 15 cases for each group 'ACCD', 'mCC' and 'no CPR'. Lung tissue samples were retrieved and stained with hematoxylin eosin (n = 4 each) and Sudan III (n = 2 each). Evaluation was conducted microscopically for any existence of BME or FE, the frequency of BME-positive vessels, vessel size for BME and the graduation according to Falzi for FE. The data were compared statistically using non-parametric analyses. All groups were matched except for CPR duration (ACCD > mCC) but this time interval was linked to the existence of pulmonary BME (p = 0.031). Both entities occur in less than 25% of all cases following unsuccessful CPR. BME was only detectable in CPR cases, but was similar between ACCD and mCC cases for BME frequency (p = 0.666), BME intensity (p = 0.857) and the size of BME-affected pulmonary vessels (p = 0.075). If any, only mild pulmonary FE (grade I) was diagnosed without differences in the CPR method (p = 0.624). There was a significant correlation between existence of BME and FE (p = 0.043). Given the frequency, intensity and size of pulmonary BME and FE following CPR, these conditions may unlikely be considered as causative for death in case of initial survival but can be found in lower frequencies in autopsy histology.

Role of Survival Time and Injury Severity in Fatal Pulmonary Fat Embolism.

Pulmonary fat embolism (PFE) is frequent in blunt trauma and may occasionally lead to death. A correlation between fracture grade and severity and PFE grade has been described before, but no correlation between PFE and survival time, fat crushing extent, fat crush grade, or number of body regions with fractures could be noted in this small study. To further examine this, we decided to examine the aforementioned points in a far larger study group.Autopsy protocols of 188 nonresuscitated fatalities with blunt trauma and without right heart injury, which underwent whole body dissection, were retrospectively reviewed concerning the presence and the severity of PFE, injuries, survival time, age, sex, and the body mass index.The fracture grade, the fracture severity, and the number of the fractured regions correlated very well with the grade of PFE, but the crushed regions, crush grade, and crush severity did not. We observed a time correlation between survival time and PFE only in the sense that very rapid deaths were often PFE negative. High-grade PFE was observed most often in patients having died less than 6 hours after the incident, and PFE grades of 2 or more were occasionally noted even after 48 hours.

Magnetic resonance imaging findings in cerebral fat embolism: correlation with clinical manifestations.

OBJECTIVES: Cerebral fat embolism (CFE) is a serious complication after fracture of long bones. The mortality rate of CFE may be high. However, recent progress in treatment may decrease the mortality. We studied the validity of magnetic resonance imaging (MRI) to detect and grade severity of CFE in 11 patients with CFE. METHODS: Glasgow Coma Scale score, PaO2, PaCO2 at the onset, and minimal hemoglobin and platelet levels were monitored, and phagocytes in bronchoalveolar lavage fluid were counted. Brain computed tomographic and MRI scans were performed serially. MRI findings were graded into four categories according to the severity of T2-weighted images. RESULTS: High-intensity T2 signals were identified in the various brain regions as early as 4 hours after onset of CFE. The maximum MRI grade significantly correlated with Glasgow Coma Scale score at the onset of CFE (p < 0.01). High-intensity T2 signal lesions fused and enlarged with time. In most cases, they diminished within 2 weeks. Three patients had persistent morbidity. CONCLUSION: MRI-T2-weighted imaging seems to be the most sensitive imaging technique for diagnosing CFE, and correlates well with the clinical severity of brain Injury. With the aid of proper treatment for pulmonary fat embolism, CFE is a potentially reversible disease that can have a good outcome.

Does the reamer type influence the degree of lung dysfunction after femoral nailing following severe trauma? An animal study.

In multiple trauma patients with lung contusion, pulmonary complications have been reported that were attributed to intramedullary stabilization of the femur. The reaming procedure of the medullary canal is thought to play a major role. We investigated whether different types of reamers might exert different amounts of fat mobilization into the vascular system and different degrees of pulmonary dysfunction. Adult female Merino sheep were submitted to hemorrhagic shock (2 h, 50 mm Hg) and a unilateral lung contusion; in addition, a lung lymph fistula was created. Pulmonary capillary permeability, central venous triglyceride levels, 11-dehydro-thromboxane B2 (dh-TXB2) levels, and pulmonary artery pressure were determined. After recovery, animals were randomly assigned to intramedullary femoral nailing using several types of reamers: group A, AO reamer (n = 8); group B, Biomet reamer (n = 7); group H, Howmedica reamer (n = 6); group C, controls, no reaming (n = 4). Intramedullary reaming caused a significant (p < 0.05) increase in pulmonary artery pressure in groups A and B; dh-TXB2 levels increased in all groups. Statistically significant (p < 0.05) pulmonary capillary permeability damage was measured in group A only. Intramedullary femoral nailing can cause transient pulmonary hemodynamic and mediator effects as well as increased pulmonary capillary permeability. In the present study, this effect was evident in group A reamer systems only, which may be due to reamer construction.

An application of a quantitative analytical system for the grading of pulmonary fat embolisms.

The severity of pulmonary fat embolism in 5 autopsied cases has been measured using a quantitative image analytical system. With reference to the mean size of the fat emboli, the cases were divided into 2 groupings regardless of the number of the emboli. The mean sizes of the emboli in 3 cases of the first group were significantly larger (about 490-600 microns 2) than those found in the 2 cases of the other group (about 220 and 235 microns 2). An investigation into the localization of fat emboli revealed that more were lodging in the small arteries and arterioles in the first group than in the second. Our results have indicated that a reliable grading of pulmonary fat embolism can not be established without a quantitative image analysis of the size and localization of the fat emboli, and that this quantitative analytical method is useful in achieving this reliable grading.