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CASE REPORT

Fat Syndrome Dinesh Dhar

ABSTRACT Nearly all following fractures of bones develop sub-clinical form of fat embolism but the classical form of (FES) presents with triad of respiratory, neurologic and dermal manifestations. Non-traumatic conditions can also have fat embolism, but the incidence is very low. The diagnosis is mainly clinical supported by laboratory and radiological finding. Treatment is mainly supportive with early stabilization of fractured bones. In most cases, prognosis is good if the condition is detected and treated early. High index of suspicion in is the key to early diagnosis of this condition. This report describes two cases of FES, the second case being fulminant fat embolism with added mortality.

Key words: Fat embolism. Fat embolism syndrome. Polytrauma. Adult respiratony distress syndrome.

INTRODUCTION CASE REPORT The term 'fat embolism' indicates the presence of fat Case 1: A 21 years old male patient was involved in a globules in the peripheral circulation after major trauma road traffic accident (RTA) and sustained bilateral closed associated with fractures of long bones, and in fractures of the shaft of with open of setting of elective or emergency orthopaedic proce- right ankle. Patient was admitted to Nizwa Regional dures. Fat embolism syndrome (FES) is a serious Referral Hospital nearly 3 hours after accident. He was clinical manifestation of fat embolism characterized by resuscitated in the accident and emergency. The right the triad of respiratory distress, deteriorating level of foot wound was dressed with application of compression consciousness and petechiae.1 bandage. Routine blood work up along with coagulation profile, biochemistry, grouping with cross matching and Zenker (1861) first described the presence of fat droplets ECG was performed. All needful radiographs were done on in lung parenchyma of a railroad worker who prior to shifting the patient to the ward. Patient was sustained fatal thoraco-.2 The true admitted for emergency wound debridement for the incidence of fat embolism is difficult to assess as sub- open bleeding wound of the right foot. Both fractured clinical forms go unrecognized. The incidence is less femora were immobilized in sliding skeletal traction with than 1.1%.1 It is frequent in young men and high velocity upper tibial pin. accidents and rare in children as the bone marrow in On the evening following wound debridement of right children contains more haematopoietic tissue and less foot patient developed altered sensorium without any fat.3 FES can also be associated with other non-trauma haemodynamic instability. Oxygen saturation (SPO2) of settings such as pancreatitis, diabetes mellitus, 96% at room air was recorded without any focal liposuction, sickle cell disease, , , neurologic deficit. An urgent CT scan of brain was done , collagen disease, neoplasm, renal trans- to rule out any head trauma which was reported as plantation and orthopaedic procedures as medullary normal. ABG (arterial blood gases) were within normal reaming.3 limits. Within next few hours patient developed This report describes two cases of fat embolism tachypnea (breath rate of 30/minute) and syndrome (FES) in polytrauma patients. The aim is to (pulse rate 150 – 160 / minute) along with deteriorating highlight this serious condition which has a high sensorium. Oxygen saturation on pulse oximetery (SPO ) had dropped to 85 – 90% at room air and morbidity and mortality if unrecognized. Various theories 2 improved to 96% with 60% oxygen flow by ventimask. of pathogenesis along with review of recent manage- ECG showed sinus tachycardia with incomplete right ment and existing literature on this subject is discussed. bundle branch block. Repeated ABG showed pH 7.4,

partial pressure of oxygen in arterial blood (PaO2) as 80 Department of Orthopaedics, Nizwa Regional Referral Hospital, mmHg, partial pressure of carbon dioxide in arterial Sultanate of Oman. blood (PaCO2) as 35 mmHg and HCO3 level of 23 mmol/l. Correspondence: Dr. Dinesh Dhar, Nizwa Regional Referral Full blood count (FBC) showed thrombocytopenia with Hospital, P.O. Box 1222, Nizwa-611, Sultanate of Oman. other blood parameters within normal limits. Follow-up E-mail: [email protected] chest radiograph showed bilateral perihilar haziness Received August 05, 2011; accepted April 26, 2012. with basal infiltrates. No petechial or sub-conjunctival

800 Journal of the College of Physicians and Surgeons Pakistan 2012, Vol. 22 (12): 800-802 Fat embolism syndrome haemorrhages were found. Physician’s consultation patient was found to be febrile with petechial was sought as tachycardia persisted along with haemorrhages on the anterior aspect of upper chest tachypnea and hypoxemia. A diagnosis of fat embolism wall, axilla and neck. Fundoscopy examination was syndrome on the basis of clinical findings, ABG report normal. and chest radiograph findings was established. The On the third day, chest examination revealed bilateral patient was shifted to the for closer basal crepitations and radiographs of chest showed observation where he was sedated, and kept on bilateral haziness with infiltrates suggestive of adult supportive management with 60% oxygen by ventimask respiratory distress syndrome (ARDS). Patient was to maintain his SPO2 around 96 – 98%. Over the next 6 diagnosed a case of head with multiple fractures, days, patient’s level of consciousness improved, his fat embolism syndrome and ARDS. The anaesthetist respiratory rate and pulse rate stabilized and oxygen tried to reduce FlO2 over the following days but failed saturation at room air returned to 98%. Chest radio- and patient continued to be febrile with high-grade fever, graphs showed improvement and thrombocytopenia got reaching 40°C, along with persistent tachycardia. Septic corrected. Prophylaxis against deep vein screening was unremarkable. On the 7th day of and fluid intake and output was maintained during his admission, patient had cardio-respiratory arrest from stay in hospital. which he could not be resuscitated. The probable cause On the 10th and 12th day of admission, patient underwent of was adult respiratory distress syndrome surgical stabilization of left and right femur respectively. following FES secondary to multiple . Postoperatively, patient was kept under close observation initially in intensive care unit and then in DISCUSSION high dependency ward till his discharge from the hospital The pathophysiology of FES is not definitively under- th on the 18 day of admission with un-eventful recovery. stood. Various theories have been put forward. The Case 2: A 25 years old male was transferred from a mechanical theory states that fat droplets released from peripheral hospital 6 hours after being involved in RTA. the bone marrow after fracture of long bones enter the He had been intubated in peripheral hospital due to low torn veins due to high intramedullary pressure and reach GCS. On arrival, patient was attended by the trauma pulmonary vasculature where large fat globules > 8 team and connected to the ventilator. Oxygen saturation microns result in mechanical obstruction of lung on pulse oximetery (SPO2) was recorded as 94% with capillaries. Smaller fat globules of 7 microns or less may of 110/70 mmHg, pulse rate of 130 cross pulmonary circulation into systemic circulation beats/minute with bilateral sluggish reacting pupils. He causing embolization to brain, kidney, and skin. Another was found to have sustained closed fracture of the shaft way the fat globules can cross-over to the systemic of right humerus, bilateral fractures of the shaft of femur, circulation is through the pre-existing arteriovenous with open wound on right and fractured patella. shunts or patent foramen ovale.4 The delay of 12 – 48 Initial chest, abdominal, spine and pelvic examination hours between trauma and development of FES in non- was normal. Full blood work-up including FBC, traumatic settings cannot be explained by mechanical biochemistry, coagulation profile, group cross match and theory. radiographs of head, cervical spine, chest, extremities The biochemical theory postulates that the embolised and pelvis were obtained. fat is degraded to free fatty acids which leads to Patient was resuscitated, fractured limbs were splinted endothelial damage, extravasation of fluid, perivascular after preliminary wound debridement of open wound of haemorrhages and oedema.3 The coagulation hypo- right knee. CT scan of head was normal. Initial chest thesis considers that in FE a disseminated coagulation radiograph was unremarkable. Investigations showed state is present and that combined fat, , fibrin, low haemoglobin 8 gm/dl with normal count, leucocytes and red blood cells would be responsible for and biochemical parameters. Patient was planned for onset of FES.4 The last two theories explain appearance definitive fracture fixation after correction of his hemo- of petechiae, acute respiratory distress syndrome globin. Blood transfusion was started in emergency. (ARDS) and account for non-traumatic FES. He was admitted to the intensive care unit and placed Diagnosis of FES is primarily clinical and investigations on ventilator in synchronized intermittent mandatory are only supportive to clinical diagnosis and monitoring ventilation (SIMV) mode with PEEP adjusted to maintain the future course of disease. The diagnostic work-up of oxygen saturation above 90%, FlO2 60% and PEEP suspected FES should include serial arterial blood 7 cms H2O. He was started on broad spectrum anti- gases (ABG) as hypoxaemia is one of the early features. biotics along with prophylactic low molecular weight Serial chest radiographs repeated over the period of heparin. Both lower limbs were placed in traction. time as the disease progresses may show infiltrates in His fluid administration was monitored to maintain CVP lungs suggestive of ARDS. Other laboratory markers and urine output. On the second day of admission, such as un-explained thrombocytopenia, hypocalcaemia,

Journal of the College of Physicians and Surgeons Pakistan 2012, Vol. 22 (12): 800-802 801 Dinesh Dhar hypofibrogenemia, elevated serum lipase and lipid uria Mechanical ventilation and PEEP should be considered may be seen 3 – 5 days after onset of embolization. only if FIO2 of > 60% and CPAP > 10 cm are required to Centres where facilities are available Transesophageal achieve a PaO2 > 60 mmHg. One must remember that echocardiography can be used to evaluate the neither mechanical ventilation nor PEEP is always embolization. CT Chest and MRI brain may be valuable beneficial as they may promote acute lung injury, so its tools of investigation for picking-up early emboli to lungs use is only to accomplish adequate gas exchange.1,3 and brain where other investigations are inconclusive. use in FES has been a topic of debate. Corticosteroids inhibit activation of complement system, Gurd and Wilson proposed one major and four minor protect capillary endothelium, stabilize the granulocyte criteria for diagnosis of FES. Lindeque et al. proposed membrane and retard platelet aggregation. A recent diagnosis on involvement of respiratory system and meta-analysis found that corticosteroids reduce the 5 Schonfeld et al. proposed seven-feature criteria. incidence of FES and hypoxemia in adult patients who Gurd and Wilson criteria for fat embolism syndrome are have suffered isolated diaphyseal long bone fractures.9 divided into a major and minor criteria. Major criteria In the first case there was no delay in the treatment and include petechiae over the anterior chest wall, axilla and patient did not have any associated , while in sub-conjunctiva, hypoxaemia PaO2 < 60 mmHg and the second case definitive treatment got delayed due to FlO2 = 0.4, central nervous system dis- time lost in transferring the patient and associated head proportionate to hypoxaemia and pulmonary oedema. injury which might have contributed to the mortality. Minor criteria included tachycardia (< 110 beats/ minute), The FES continues to remain a diagnostic dilemma. pyrexia < 38.5oC, emboli present in retina on fundo- Therefore, prompt recognition and aggressive multi- scopy, fat in urine or sputum, unexplained drop in disciplinary management remains the key in reducing platelet count or haematocrit and increasing ESR. the morbidity and mortality arising from this condition. Lindeque's criteria include sustained PaO2 (< 8 kPa) sustained PCO2 of > 7.3 kPa or a PH < 7.3, sustained REFERENCES respiratory rate > 35 bpm, despite sedation and labored 1. Sharma RM, Setlur R, Upadhyay KK, Sharma AK, Mahajan S. breathing suggested by dyspnea, accessory muscle Fat embolism syndrome: a diagnostic dilemma. MJAFI 2007; use, tachycardia and anxiety. Schonfeld's criteria 63:394-6. included petechiae (5), chest X-rays changes (diffuse 2. Shaikh N, Parchani A, Bhat V, Kattren MA. Fat embolism syndrome: clinical and imaging considerations: case report and alveolar infiltrates, (4)) hypoxaemia (PaO2 < 9.3 kPa, 3) fever (> 38°C), tachycardia (> 120 bpm, 1) and review of literature. Indian J Crit Care Med 2008; 12:32-6. tachypnea (> 30 respiratony pm, 1). Cumulative score of 3. Jain M, Mittal M, Kansal A, Singh Y, Kolar PR, Saigal R. Fat > 5 is required for diagnosis. Any patient with one of the embolism syndrome. JAPI 2008; 56:245-9. above criteria is strongly in favour of FES. Lindeque's 4. Filomeno LT, Carelli CR, Silva CL, Filho TE, Amatuzzi MM. Fat criteria has shortcoming that it is based only on lung embolism: a review for current orthopaedic practice. Acta Ortop function. Bras 2005; 13:196-208. Various orthopaedic procedures such as intramedullary 5. Shaikh N. Emergency management of fat embolism syndrome. J Emerg Trauma 2009; 2:29-33. nailing for fractures of shaft femur, , hip and knee replacement where reaming of the medullary 6. Galway U, Tetzlaff JE, Helfand R. Acute fatal fat embolism syndrome in bilateral total knee arthroplasty: a review of the fat canal increases intramedullary pressure and may embolism syndrome [Internet]. Internet J Anesthesiol 2009; 19. propagate marrow fat into venous circulation increasing Available from: http://www.ispub.com/journal/the-internet- risk of FES.6 Unreamed intramedullary nailing and journal-of-/volume-19-number-2/acute-fatal-fat- cementless hip arthroplasty procedures decrease risk of embolism-syndrome-in-bilateral-total-knee-arthroplasty-a- FES.7,8 review-of-the-fat-embolism-syndrome.html The mainstay treatment of FES is supportive. Early 7. Giannoudis PV, Christopher T, Pape HC. Fat embolism: the reaming controversy. Injury 2006; 37:50-8. diagnosis, prevention by early immobilization of fractures, stable haemodynamics, and adequate tissue 8. Powers KA, Talbot LA. Fat embolism syndrome after femur fracture with intramedullary nailing: case report. Am J Crit Care oxygenation, with idea of maintaining arterial oxygen 2011; 20:267, 264-6. saturation of more than 90% should be the goal. 9. Cavallazzi R, Cavallazzi AC. The effect of corticosteroids on the Ancillary measures like adequate hydration, prophylaxis prevention of fat embolism after long of lower against deep vein thrombosis and ulcers should limbs: a systematic review and meta-analysis. J Bras Pneumol be part of the regimen. 2008; 34:34-41.

802 Journal of the College of Physicians and Surgeons Pakistan 2012, Vol. 22 (12): 800-802