An autopsy case of intraoperative death due to pulmonary fat embolism—possibly caused by release of tourniquet after multiple muscle-release and tenotomy of the bilateral lower limbs

Limb Occlusion Pressure Versus Standard Pneumatic Tourniquet Pressure in Open Carpal Tunnel Surgery – A Randomized Trial

Introduction: Pneumatic tourniquets are used extensively in orthopedic hand/wrist surgery. Complications, while rare, are associated with elevated pressure and duration of tourniquet use. Limb occlusion pressure (LOP) is the minimum tourniquet pressure at which arterial blood flow is restricted. Therefore, we performed a cross-sectional double-blinded randomized control trial to assess if there is a difference in post-operative pain at the surgical and tourniquet site between LOP and standard tourniquet pressure and if there is a difference in post-operative opioid usage.

Methods: A total of 44 patients (Age 60±13, 30 female, 14 male) were randomized into two groups (LOP, 191±14 mmHg | STP, 250 mmHg) of 22 patients controlling for gender (15 female, seven male). The primary outcome was a visual analog scale (VAS) for pain at the tourniquet and surgical sites, recorded for the first two weeks post-operative. Daily pain medication usage was recorded and quantified using oral morphine milligram equivalents (MME). A group-by-time generalized mixed-model ANOVA was used to detect within-group and between group (LOP vs STP) differences in VAS at the surgical and tourniquet sites as well as medication use. 

Results: LOP significantly decreased post-operative pain medication usage across the first week (-50%; p<0.05). Both groups had similar VAS pain at the surgery site, but the LOP group had 80% reduced pain at the tourniquet site when averaged across the first post-operative week (p<0.05). 

Conclusions: The use of LOP compared to STP elicits reduced post-operative pain at the tourniquet site and reduces post-operative pain medication use in the first post-operative week.

Microscopic and Macroscopic Fat Embolism: Solving the Puzzle with Case Reports

BACKGROUND

The frequency of fat embolism mortality after liposuction has increased. As the only dependable evidence for this problem is that available in the medical literature, a study of clinical case reports is warranted.

METHODS

The authors reviewed the medical literature by searching for case reports of fat embolism after liposuction in humans who manifested either of the variants of the condition: microscopic fat embolism or macroscopic fat embolism. The authors performed a literature search of the PubMed and PubMed Central databases from the first case of fat embolism syndrome associated with liposuction reported until March of 2017; keywords Fat Embolism (Fat Embolism Syndrome), Liposuction, and Case (((fat embolism) AND liposuction) AND case) were used. A detailed analysis of the data contained in the clinical case reports was conducted.

RESULTS

In total, 39 and 98 articles were found in PubMed and PubMed Central, respectively, using the keywords (((Fat + Embolism) + AND + Liposuction) + AND + Case). After analysis, only 15 reports corresponded to cases of macroscopic or microscopic fat embolism after liposuction, and the basic statistics of the two proposed variants were examined.

CONCLUSIONS

This work provides relevant information regarding very important characteristics of microscopic and macroscopic fat embolism. Despite the diagnostic difficulty, clinical diagnosis remains the gold standard for identifying microscopic and macroscopic fat embolism. The establishment of a rapid and timely diagnosis is of great help for appropriate treatment.

Fat transfer and fatal macroembolization

Fat embolism is usually associated with long bone fractures or other trauma. The diagnosis is usually clinical, and in most cases, emboli are not fatal and not usually seen on gross examination. At the Los Angeles County Coroner's Office, we autopsied the victim of fatal macroscopic fat embolization to the lungs. The patient died during buttock enhancement surgery when fat from liposuction was injected into her buttocks. Fat embolism from liposuction and fat injection is reportedly rare, and macroscopic embolization is rarer still. Varicose veins can occur in the area of the sciatic notch and are known to cause painful sciatica symptoms. We suggest them as a potential conduit for macroscopic fat to reach the lungs. Simple pre-operative questioning for sciatica symptoms and possible radiologic study to rule out sciatic varices seem prudent before undertaking buttock-enhancing surgery. Careful fat injection with pre-aspiration is always advised.

Autopsy diagnosis of fat embolism syndrome

The fat embolism syndrome (FES) is considered a clinical diagnosis. It typically occurs within several days following major traumatic injury, usually involving fractures of the pelvis and/or lower extremities. Fat embolism syndrome is characterized by the onset of respiratory, neurological, cutaneous, and hematologic manifestations and is thought to be related to intravascular embolization of fat, presumably arising from within the fractured bone marrow space. In its most severe form, FES can be lethal. The presence of fat emboli within the microvasculature of the lungs, brain, and sometimes other organs verifies the clinical impression of FES. Despite its relatively well-known clinical characterization, debate exists within the clinical literature regarding the most appropriate diagnostic criteria for FES. Given this fact, along with the fact that FES is a clinical diagnosis, it is not surprising that forensic pathologists may be somewhat reluctant to make a postmortem diagnosis of FES, especially in cases where insufficient clinical information is available. A case of fatal FES is presented in which rapid clinical deterioration occurred, followed by death, such that a clinical diagnosis of FES was never rendered. We propose that, given the correct circumstances, clinical scenario, and autopsy findings, it is appropriate and acceptable to make a postmortem diagnosis of FES. A multitiered approach to the postmortem diagnosis of FES is presented.