Fat Embolism Syndrome Todd Nickoles, MBA, RN, BSN

Transcription

1

2 Fat Embolism Syndrome Todd Nickoles, MBA, RN, BSN

3 Learning Objectives Identify the risk factors and causes of fat embolism syndrome Recognize the signs and symptoms of fat embolism syndrome following acute trauma Describe major and minor diagnostic criteria Describe the possible treatments and potential outcomes of pulmonary and cerebral fat embolism syndrome

4 Disclosure Statement Faculty/Presenters/Authors/Content Reviewers/Planners disclose no conflict of interest relative to this educational activity.

5 Successful Completion To successfully complete this course, participants must attend the entire event and complete/submit the evaluation at the end of the session. Society of Trauma Nurses is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's Commission on Accreditation.

6 What is Fat Embolism? Presence of fat droplets in the systemic circulation Mechanical and/or biochemical theories Following fractures (>95%), primarily long bone and pelvic Also found following bone marrow transplantation, osteomyelitis, pancreatitis, alcoholic fatty liver, liposuction, and child birth Become systemic through shunting (pulmonary or PFO) Fat emboli are unlike thrombus: Temporary or partial, d/t fluidity and deformability Fat is then hydrolyzed into free fatty acids and glycerol Toxic to lung tissue, endothelium, initiate inflammatory cascade

7 Theories Mechanical Increase in pressure within bone marrow forces marrow fat into circulation Fractures or reaming

8 Theories Mechanical Biochemical Following injury or insult Systemic release of free fatty acids (chylomicrons) and glycerol Acute phase reactants cause chylomicrons to form globules

9 Theories Mechanical Biochemical In either case: Multiple emboli collect in pulmonary vasculature, increase PA pressure and right heart failure, respiratory symptoms High pressure forces deformable fat globules through pulmonary shunts (PFO?), shower to head and upper body

10 Theories Mechanical Biochemical In either case: Accumulated fat globules are cytotoxic Trigger inflammatory cascade: Local endothelial injury Membrane permeability & edema Hemorrhage

11 What is Fat Embolism Fat Embolism Syndrome (FES)? End organ dysfunction related to multiple fat emboli Pulmonary acute respiratory failure, ARDS Cerebral confusion, loss of consciousness, cerebral edema Cutaneous petechial rash upper anterior torso, axillary, conjunctiva Presence of diagnostic criteria Traumatic or non traumatic

12 History First description in 1861 by German pathologist Zenker Discovered on autopsy of a farmer crushed between two wagons First clinical diagnosis in 1873 by Von Bergmann First in American literature in 1879 by Fenger & Salisbury Leading causative theories developed in 1924 and 1927 Diagnostic criteria developed in 1974 by Gurd & Wilson

13 Epidemiology Reported incidence (clinical criteria) during 1970 s up to 20% Reported incidence (cc) of FES following trauma, 1 2% With bilateral femur fractures, 5 7.5% Following IM nailing, 11% 5% of cases occur without trauma Incidence on autopsy, 20% Estimated mortality, 7 20% Assumed to be underdiagnosed

14 Case Study #1 16 year old restrained passenger, rear middle seat, high speed MVC vs tree.

15 15

16 16

17 17

18 Case Study #1 16 year old restrained passenger, rear middle seat, high speed MVC vs tree. Prolonged extrication, VSS at scene, A&Ox3, GCS 15. Scene VS: 116/68, 112, 20, 88%, GCS15 Scene time: 1:00 Transport time: 15min High energy? Expected body system injuries? Meet activation criteria? Occupant death, prolonged extrication, >1 long prox bone fracture, speed, intrusion MCI 2 Level 1 (1 prehospital arrest), 1 Level 2, 1 Level 3 + Another medical code at the same time

19 Risk factors FES High velocity trauma Young age Fracture related: Closed fractures Multiple fractures Conservative fracture management Presence of a contused lung? Theory: increased shunting burden on healthy lung

20 Case Study #1 16 year old restrained passenger, rear middle seat, high speed MVC vs tree. Prolonged extrication, VSS at scene, A&Ox3, GCS 15. Arrived at ED as Level 2 activation. Remained stable in ED ED VS: 130/84, 68, 33, 100%, 36.3, GCS15 Known injuries: Head SDH, SAH, IPH, scalp lac Neck C3 and C4 TP fractures Chest B pulm contusions, B PTX Abd Contusion of transverse colon Ext R midshaft femur fracture, left knee lac

21

22 Case Study #1 16 year old restrained passenger, rear middle seat, high speed MVC vs tree. Prolonged extrication, VSS at scene, A&Ox3, GCS 15. Arrived at ED as Level 2 activation. Remained stable in ED, admitted to PICU. ED VS: 130/84, 68, 33, 100%, 36.3, GCS15 Known injuries on admission to PICU (ED LOS >4hrs): Head SDH, SAH, IPH, scalp lac GCS15, PICU obs, Neurosurgery cx Neck C3 and C4 TP fractures Neurosurgery cx, stable with collar Chest B pulm contusions, small B PTX no chest tubes, sup O2 & PICU obs Abd Contusion of transverse colon Obs Ext R midshaft femur fracture, left knee lac Ortho cx, traction in PICU, plan for ORIF to follow

23 Case Study #1 16 year old restrained passenger, rear middle seat, high speed MVC vs tree. Prolonged extrication, VSS at scene, A&Ox3, GCS 15. Arrived at ED as Level 2 activation. Remained stable in ED, admitted to PICU. Seizure upon arrival in PICU

24 Cerebral signs FES **First rule out TBI Results from emboli to brain via carotid arteries Mechanical and biochemical effects Symptoms vary in severity and are non specific (nonfocal) Mild mental status changes Moderate decreased LOC, seizures Severe encephalopathy, coma Imaging: CT normal or non specific, eg. edema 16% show multiple infarcts MRI: >95% show starfield pattern Treatment: supportive, depend on severity (similar to DAI) Airway, ventilation, seizure control ICP, decompressive crani

25 Case Study #1 16 year old restrained passenger, rear middle seat, high speed MVC vs tree. Prolonged extrication, VSS at scene, A&Ox3, GCS 15. Arrived at ED as Level 2 activation. Remained stable in ED, admitted to PICU. Seizure upon arrival in PICU, intubated, ICP monitor placed

26 Pulmonary signs FES **First rule out other pulmonary diagnoses Pulmonary contusions Pulmonary edema Thrombus pulmonary embolism Aspiration Pneumonia

27 Pulmonary signs FES **First rule out other pulmonary diagnoses Results from emboli to pulmonary vasculature Mechanical obstruction and biochemical effects Respiratory distress symptoms Drop in SpO2, PaO2, increased O2 requirements Imaging: CXR bilat diffuse patchy opacities snowstorm CT ground glass opacities, nodules Treatment: supportive, depend on severity Airway, ventilation FIO2, PEEP, lung protective strategies

28 fat embolism

29 High Resolution Ct Findings In Mild Pulmonary Fat Embolism* Malagari K, Economopoulos N, Stoupis C, et al. Chest. 2003;123(4):

30 Lindeque s respiratory criteria Criteria Sustained PaO2 < 8kPa (60 mmhg) Sustained PaCO2 >7.3kPa (55 mmhg) or ph <7.3 Sustained RR >35 bpm after adequate sedation Increased WOB (dyspnea, accessory muscle use, tachycardia, anxiety) Lindeque et al. Fat embolism syndrome: A double blind therapeutic study. J Bone Joint Surg Br. 1987;69:

31 Case Study #1 16 year old restrained passenger, rear middle seat, high speed MVC vs tree. Prolonged extrication, VSS at scene, A&Ox3, GCS 15. Arrived at ED as Level 2 activation. Remained stable in ED, admitted to PICU. Seizure upon arrival in PICU, intubated, ICP monitor placed, HFOV started (8 hours after intubation)

32 Cutaneous signs FES classic feature Non dependent petechial rash Upper anterior torso Axillary regions Conjuctiva

33

34 Gurd s diagnostic criteria Fat Embolism Syndrome = 1 major + 4 minor Major Criteria Minor Criteria Hypoxia (<60mmHg O2) (95%) Pyrexia (>39 C) Confusion (60%) Tachycardia (>120 BPM) Petechial rash (33%) Retinal changes (petechiae) Anuria or Oliguria Anemia (Hgb drop 20%) Thrombocytopenia (drop 50%) High ESR (>71 mm/hr) Fat macroglobulinemia Gurd, Wilson. The fat embolism syndrome. J Bone Jt Surg Br. (1974)

35 Schonfeld s diagnostic criteria Symptoms Points Diffuse petechiae 5 Alveolar infiltrates on chest radiograph 4 Hypoxemia (<70 mmhg) 3 Confusion 1 Fever >38 C 1 Heart rate >120 BPM 1 Respiratory rate >30 BPM 1 *Five or more points required for diagnosis Schonfeld et al. Fat embolism prophylaxis with corticosteroids. Ann Int Med 99 (1983)

36 Case Study #1 16 year old restrained passenger, rear middle seat, high speed MVC vs tree. Prolonged extrication, VSS at scene, A&Ox3, GCS 15. Arrived at ED as Level 2 activation. Remained stable in ED, admitted to PICU. Seizure upon arrival in PICU, intubated, ICP monitor placed, HFOV started Fever, tachycardia, anemia, thrombocytopenia Gurd s Criteria: 3 Major 4 Criteria Schonfelds Criteria: 16 points (100%)

37 Treatments FES No specific treatment (yet) Supportive therapies (previously mentioned) Corticosteroids? Heparin?

38 Case Study #1 16 year old restrained passenger, rear middle seat, high speed MVC vs tree. Prolonged extrication, VSS at scene, A&Ox3, GCS 15. Arrived at ED as Level 2 activation. Remained stable in ED, admitted to PICU. Seizure upon arrival in PICU, intubated, ICP monitor placed, HFOV started, but patient continued to rapidly deteriorate. Withdrawal of support by family.

39 Autopsy findings Prospective autopsy for PFE and/or CFE Cohort of 50 patients 34 (68%) trauma, 16 (32%) medical, 15 (30%) CPR PFE 28/34 traumas; 10/16 medicals PFE 13/15 CPR No significant difference in patient characteristics Only 1 patient with CFE Eriksson et al. Incidence of pulmonary fat embolism on autopsy: An undiagnosed epidemic. J Trauma (2011) 71(2);

40 Autopsy findings peds Retrospective convenience sample of children <= 10 Cohort of 67 patients (median age 2.0) 21 (31%) trauma, 7 ( 10%) burn, 14 (21%) drowning, 25 (37%) medical, 42 (63%) CPR PFE 33% trauma, 36% drowning, 14% burn, 28% medical PFE 60% CPR CFE 7/48 (15%) with specimens, 10% trauma, 30% drowning, 12% medical 71% no PFO, 1 PFE & CFE, 6 CFE only, 15 PFE only Eriksson et al. Fat embolism in pediatric patients: An autopsy evaluation of incidence and etiology. J Critical Care (2015) 30;221.e1 e5.

41 Autopsy findings FES Post mortem diagnosis of FES appropriate if: Definitive clinical diagnosis; OR Clinical findings suggest, plus autopsy findings of moderate to extensive pulmonary intravascular fat emboli; OR Little/no clinical findings, but sudden cardiorespiratory collapse with trauma, plus autopsy findings (above) Miller, Prahlow. Autopsy diagnosis of fat embolism syndrome. Am J Forensic Medical Pathology (2011) 32(3);

42 Case Study #1 Autopsy findings

43 Pulmonary contusions

44 Photomicrograph contusion

45 Pulmonary arteries

46 Pulmonary arteries

47 IVC Thrombus

48 Photomicrograph embolus

49 Transverse colon contusion

50 Central Nervous System

51 Central Nervous System

52 Central Nervous System

53 Summary of Autopsy Findings

54 Prognosis FES 1970 s 15 20% mortality (Gurd 1974) 1980 s 7%(Bulger et al. 1997) Mild cases self resolving within weeks Severe cases Respiratory failure most common, ARDS and hypoxic arrest Severe cerebral edema contributing factor in many cases Death may occur within hours

55 Prevention FES Early timing of skeletal stabilization Risk of FES reduced X5 if surgery within 24 hrs Proposed role of DCO to reduce risk, versus IM nailing Corticosteroids Reduced risk of FES, with NNT 7/8 to prevent 1 (Bederman et al., 2009) No change in mortality, more study needed Heparin Insufficient evidence to recommend

56 Takeaways Fat emboli are very common in trauma and non trauma populations Fat embolism syndrome involves end organ dysfunction Pulmonary & cerebral involvement most significant High mortality rate has declined with improved recognition Identification requires high index of suspicion in at risk patients Challenging because of co occurring injuries High energy trauma, fractures with delayed repair, pulmonary injuries Treatment is supportive Prevention is focused on early fracture stabilization

57 References Bederman et al. Do corticosteroids reduce the risk of fat embolism syndrome in patients with long bone fractures? A meta analysis. Can J Surg J Can Chir (2009) 52: Bone et al. Early versus delayed stabilization of femoral fractures: A prospective randomized study. J Bone Jt Surg. (1989) 71: Bulger et al. Fat embolism syndrome: A 10 year review. Arch Surg (1997) 132: Gurd, Wilson. The fat embolism syndrome. J Bone Jt Surg Br. (1974) Eriksson et al. Incidence of pulmonary fat embolism on autopsy: An undiagnosed epidemic. J Trauma (2011) 71(2): Eriksson et al. Fat embolism in pediatric patients: An autopsy evaluation of incidence and etiology. J Critical Care (2015) 30;221.e1 e5. Lindeque et al. Fat embolism syndrome: A double blind therapeutic study. J Bone Joint Surg Br. 1987;69: Miller, Prahlow. Autopsy diagnosis of fat embolism syndrome. Am J Forensic Medical Pathology (2011) 32(3); Newbigin et al. Fat embolism syndrome: State of the art review focused on pulmonary imaging findings. Respiratory Medicine (2016) 113: Schonfeld et al. Fat embolism prophylaxis with corticosteroids. Ann Int Med 99 (1983)

58