Successful management of respiratory distress in fat embolism syndrome: A case report and literature review

Abstract

Introduction and importance

Treatment of respiratory distress in fat embolism syndrome (FES) often ends in death. FES is generally associated with orthopedic trauma, with the highest incidence in long bone fractures.

Case presentation

We present a case, 20-year-old woman with an initial diagnosis of a closed fracture in the right femur and left cruris after traffic accidents, underwent open reduction and internal fixation 17 h after an incident. Thirty hours after the surgery, she experienced respiratory distress, loss of consciousness, and petechial rash. Thoracic radiography revealed bilateral patchy infiltrates; brain CT found cerebral oedema; brain MRI showed multiple small non-confluent lesions; arterial blood gas analysis indicated respiratory acidosis; pulse oximetry was 95 %, leading to a diagnosis of FES. Complete blood count revealed anaemia through a decrease in haemoglobin, haematocrit, increase in erythrocyte sedimentation rate, thrombocytopenia, hypocalcaemia, and hypoalbuminemia. The patient was promptly transferred to the intensive care unit with central venous pressure measuring, consulted to a neurologist, pulmonologist, anaesthesiologist, and cardiologist for supportive treatment and mechanical ventilation for nine days. The patient recovered gradually to be normal. FES treatment has been successful, and the patient discharged after 16 days.

Clinical discussion

The prevention of FES depends on timing, surgical technique, and early diagnosis. Early surgical fixation of long bone fractures within 24 h reduces pulmonary complications by 70 %. FES can present in a wide variety of severity and symptom. There is no specific treatment.

Conclusion

Prevention, early diagnosis, and prompt management of FES are the cornerstone in managing this condition.

Highlights

• •FES can present in a wide variety of severity and symptom, there is no specific treatment.
• •Successful management of FES is mainly prevention, supportive treatment, and mechanical ventilation.
• •Successful management can reduce the mortality rate to <10 %.

1. Introduction

Fat embolism syndrome (FES) in the trauma wards is not a rare occurrence, and it is common for a respiratory physician to receive a call for a patient in acute distress in the trauma wards [1]. FES is by far the most common and most overlooked cause of dyspnoea [2].

Circulating macro-globules of yellow fat present in the systemic pulmonary microvasculature reflect of FES [3]. Vascular obstruction, extensive damage from a fat embolism, and the inflammatory response of trauma have been proposed as FES. The pathophysiology of FES are including the mechanical and biochemical mechanisms [4]. The three characteristics of FES are pulmonary distress, neurological symptoms, and petechial rash, which may occur 12–72 h after a long bone fracture [5].

Incidences of FES range from 0.8 % to 23 %, and the mortality risk is 1 % to 10 % [3]. FES in our hospital is very rare, and all previous cases resulted in death. In this case, the patient could be saved.

2. Case description

This paper is reported in line with the SCARE 2023 criteria [6]. A rare case was found, 20-year-old woman, the initial diagnosis are multiple closed fractures in the right femur and left cruris after traffic accidents between motorbikes and cars; a Glasgow Coma Scale (GCS) score of 15, a visual analogue scale of 8, normal vital signs, and normal laboratory findings. The initial treatment included intravenous fluid drip (IVFD) Ringer's lactate 1500 cc, cefazolin 1 g, gentamicin 80 mg, ketorolac 30 mg, ranitidine 50 mg, and alignment of the lower legs with immobilisation using splints. Open reduction and internal fixation (ORIF) were performed 5 h after the patient arrived at the emergency room. During surgery, the patient had an American Society of Anaesthesiologists score of 2, blood loss of 300 cc, and normal vital signs. After surgery, the patient received IVFD Ringer's lactate 1500 cc/24 h, cefazolin 3 × 1 g, and ketorolac 3 × 30 mg. Image of radiological examination as shown in Fig. 1A, B, C, and D.

Fig. 1.

Image of radiological examination: A. Fracture of right femur, B. Fracture of left cruris, C. Femur dextra X-ray post-ORIF, D. Cruris sinistra X-ray post-ORIF.

Thirty hours after surgery, the patient experienced respiratory distress, loss of consciousness with a GCS score of 9, petechial rash, and a subconjunctival haemorrhage as shown in Fig. 2A and B. The patient's vital signs were normal, but the laboratory finding for complete blood count revealed anaemia due to a decrease in haemoglobin (8.9 g/dL), a haematocrit, an increase in erythrocyte sedimentation rate (ESR), as well as thrombocytopenia, hypocalcaemia, and hypalbuminaemia. Three hours later, the patient gradually lost consciousness, with a GCS score of 5. Her accompanying symptoms were dyspnoea, hypoxia, an increased respiratory rate, tachycardia, and hyperpyrexia. A complete blood count revealed anaemia (7.7 g/dL), an increased renal function test returned serum creatinine at 1.3 mg/dL, and blood urea nitrogen was at 29 mg/dL. An arterial blood gas analysis denoted respiratory acidosis with pH 7.25, pO₂ 78 mmHg, pCO₂ 53 mmHg, HCO₃–26 mEq/L, BE −2, and pulse oximetry 95 %. The laboratory results in a table organized by days of hospitalization as shown in Table 1. Thoracic radiography revealed bilateral patchy infiltrates as shown in Fig. 3A; a brain MRI showed multiple small nonconfluent lesions in the periventricular and subcortical white matter that were bright on T2 sequences as shown in Fig. 3B; and a brain CT found cerebral oedema as shown in Fig. 3C, leading to a diagnosis of FES.

Fig. 2.

A. Clinical images of axillary petechiae and B. subconjunctival haemorrhage.

Table 1.

Examination laboratory results.

Hematology complete	30 h after surgery Check-up result	33 h after surgery Check-up result	Normal value
Haemoglobin	8.9	7.7	12–16 g/dL
Haematocrit	31.6	29.8	36–46 %
ESR	5.7	5.9	4.0–5.5 juta/uL
Thrombocyt	110.000	100.000	150–400.000/uL
Calcium levels	7.9	7.8	8.5–10.2 mg/dL
Albumin levels	3.1	3.3	3.5–5.5 g/dL
Kidney physiology
Serum creatinine	1.4	1.3	0.5–1.1 mg/dL
BUN	30	29	6–20 mg/dL
Arterial blood gas analysis
pH	7.15	7.20	7.35–7.45
PCO2	50	52	35 45 mmHg
pO2	72	76	80–100 mmHg
BE	−2	−2	−2–+2
HCO3	24	26	22–26 mEq/L
Pulse oximetry	95	96	≥95 %

PCO₂: Partial pressure of carbon dioxide; pO₂: Oxygen partial pressure; HCO₃: Bicarbonate.

Fig. 3.

A. The chest X-ray indicated bilateral diffuse patchy infiltrates, B. The brain MRI showed multiple small nonconfluent lesions in the periventricular and subcortical white matter that were bright on T2 sequences, C. The CT scan showed cerebral oedema.

The patient was promptly transferred to the intensive care unit (ICU) with central venous pressure (CVP) measuring, consulted to a neurologist, pulmonologist, anaesthesiologist, cardiologist for supportive treatment and mechanical ventilation for nine days as shown in Fig. 4. Supportive treatment was administered to maintain aggressive volume resuscitation, circulation, intravenous crystalloid solutions by 2000 cc/day physiologic saline (0.9 % NaCl solution), blood thinners or anticoagulants (heparin or warfarin), thrombolytic agent (streptokinase 1000 to 2500 IU every 3 min for 10 h), vasopressors dopamine (initial dose is 2–10 μg/kg/min), corticosteroids (methylprednisolone 5 mg/kgBW), and nutrition. High flow oxygen and supportive mechanical ventilation was essential to address hypoxia and to prevent the worsening of arterial blood gas derangement. The patient recovered gradually to be normal. The patient discharged after 16 days of treatment.

Fig. 4.

The patient received supportive treatment and mechanical ventilation in the ICU.

3. Clinical discussion

FES is generally associated with orthopedic trauma, with the highest incidence in long bone fractures [7]. FES was found in the capillaries of the patient's pulmonary veins, causing hypoxia 96 %, neurological symptoms 86 %, respiratory failure 75 %, PaO₂ < 7.3 kPa, petechial rash, and a subconjunctival haemorrhage [5]. FES is the clinical manifestation of fat embolism and refers to the presence of fat globules in circulation and pulmonary parenchyma. It is associated with a complex alteration of haemostasis, usually presenting as a triad of respiratory insufficiency, altered sensorium, and petechial rash [8].

The pathophysiology of FES remains debatable, and there have been various mechanical and biochemical theories on this topic [9]. According to Vetrugno et al., mechanical theory explains that FES is caused by fat clots entering the veins and being released into the pulmonary artery until they are 80 % blocked, resulting in increased perfusion pressure, swelling of the pulmonary blood vessels, heart disorders, neurological disorders, and the appearance of petechial rash. Petechial rash appears when blood capillaries are dilated due to the extravasation of red blood cells [4]. Biochemical theory, according to Kumar et al., states that FES is caused by the presence of fat embolisms in the lungs that encourage the secretion of lipase by hydrolysing glycerol and free fatty acids, resulting in pneumocyte disorders, pulmonary endothelium, and leading to acute respiratory distress syndrome (ARDS) [9].

Risk factors for FES are being male and 10–40 years old. FES usually occurs 12–72 h after a long bone fracture. Relatively dominant hematopoietic tissue in young children causes resistance to FES [2,3].

A metabolic examination of FES patients showed an increase in glycaemic myalgia, a decrease in the ratio of alpha and beta lipoproteins, abnormal capillary brittleness tests, an increase in platelet count, and an increase in cortisol levels [10]. Blood tests showed a decrease in haemoglobin, haematocrit, increased ESR, and the presence of thrombocytopenia. Arterial blood gas examinations showed hypoxia, carbon dioxide retention, respiratory acidosis, and an increase in the alveolar-arterial gradient within 24–48 h [7].

A diagnosis of FES can be established by various examinations [11]. Chest radiographic examinations can show diffuse bilateral patchy infiltrates. Brain computed tomography (CT) scans can show normal conditions, cerebral oedema, or petechial haemorrhage in white matter. Meanwhile, brain magnetic resonance imaging (MRI) can show the presence of diffuse, nonconfluent, and hyperintense lesions and whether the periventricular and subcortical white matter are bright on T2 sequences [11].

A diagnosis of FES is based on respiratory distress, cerebral involvement, and clinical suspicion. The diagnostic criteria for FES were proposed by Gurd, Schonfeld, and Lindeque as shown in Table 2, Table 3, Table 4 [9]. The most widely used criterion is the Gurd criterion, which requires two major criteria or one major criterion plus two minor criteria. Lindeque's criteria only uses respiratory parameters to diagnose FES [9].

Table 2.

Gurd and Wilson's major and minor criteria for fat embolism syndrome.

Major criteria	Minor criteria
Petechial rash	Tachycardia
Respiratory symptoms and bilateral signs with positive radiographic changes	Pyrexia
Cerebral signs unrelated to head injury	1.Retinal fat or petechiae 2.Urinary fat globules or oligoanuria 3.Sudden drop in Hg level 4.Sudden thrombocytopenia 5.High erythrocyte sedimentation rate 6.Fat globules in sputum

Table 3.

Schonfeld's fat embolism index score.

Features	Pointsa
Diffuse petechiae	5
Alveolar infiltrates	4
Hypoxemia (<70 mmHg)	3
Confusion	1
Fever >38 °C	1
Heart rate > 120 beats/min	1
Respiratory rate > 30/min	1

^aFive or more points are needed to diagnose fat embolism syndrome.

Table 4.

Lindeque criteria.

1. Sustained PaO2 < 8 kPa

2. Sustained PaCO2 > 7.3 kPa or pH < 7.3

3. Sustained respiratory rate > 35/min despite sedation

4. Increased breathing, dyspnoea, accessory muscle use, tachycardia, and anxiety

Treatment of FES should begin by transferring the patient to an ICU, with CVP measuring to guide the treatment, with particular care taken to watch for right heart failure or pulmonary hypertension [12]. Albumin is preferred for restoring intravascular volume and is associated with additional lipophilic action. Hypovolaemia should be corrected with normal saline, Ringer's lactate, and dextrin. Plasma expanders should be administered if there is shock. Dobutamine is a more potent inotropic agent and so is recommended over norepinephrine. Corticosteroids (methylprednisolone) have been extensively used as an anti-inflammatory agent; however, there is insufficient data to support their use once FES has been established [13]. Aprotinin, a trypsin inhibitor, has been tried as an FES treatment because of its inhibition of platelet aggregation. However, this drug has been associated with increased renal dysfunction and anaphylaxis, and hence has been withdrawn from the market. Heparin has also been used with caution to prevent and treat the venous thrombosis that may occur in post-operative cases, but the regular use of heparin for FES has been contraindicated because of undue risks of bleeding in polytrauma patients [5]. Hypoxia is initially managed with oxygen inhalation, using a face mask or high-flow gas delivery systems such as venture masks or non-rebreather reservoir masks [7]. The oxygen content of the blood and the required FiO₂ should be calculated. The aperture of masks should be adjusted to deliver the required FiO₂. The flow rate of oxygen must also be taken care of and should match the FiO₂ requirement. PaO₂ may be improved with continuous positive pressure ventilation (CPAP) without increasing FiO₂. If a FiO₂ of >60 % and CPAP >10 cm are required to achieve PaO₂, then mechanical ventilation with positive end-expiratory pressure (PEEP) should be considered [1]. Vigilance should be maintained in case of a ventilator-induced lung injury and a decrease in cardiac output by increasing right ventricular pressure. Recent data suggests that PEEP may protect, and at times even delay, the onset of ventilator-associated lung injury. Close monitoring of arterial blood gases and the hemodynamic status is recommended when PEEP and mechanical ventilation are used [14]. Prone positioning and extracorporeal membrane oxygenation may also be applied for patients with severe pulmonary dysfunction [15].

The prevention of FES depends on timing, surgical technique, and early diagnosis [5]. Early surgical fixation of long bone fractures within 24 h reduces pulmonary complications by 70 % [16]. FES presents in a wide range of clinical symptoms with varying severity. There are no pathognomonic clinical signs, supporting examination, laboratory investigation, or imaging modality that can precisely offer an early diagnosis. A diagnosis of FES largely depends on clinical features and ruling out differential diagnoses. Close monitoring is highly essential to the early diagnosis of FES, with procedures including pulse oximetry and an arterial blood gas analysis of the long bone fracture. Various scoring systems can be used as adjuvants in the diagnosis of FES. The prognosis of FES depends on early diagnosis, supportive treatment, and mechanical ventilation; these can reduce the mortality rate to <10 %.

4. Conclusion

The recovery of FES cases is greatly influenced by high suspicion and close monitoring of FES after long bone surgery. Early FES management including prevention, supportive treatment, and mechanical ventilation provides satisfactory recovery results. Furthermore, the team must monitor and detect early signs of FES in the hospital.

Author contribution

I Nyoman Semita: Conceptualization or design, Visualization, Writing-original draft, Writing-review & editing

Heni Fatmawati: Conceptualization or design

Angga Mardro Raharjo: Conceptualization or design and Visualization

Parama Gandi: Visualization and Writing-original draft

Ni Njoman Juliasih: Writing-original draft, Writing-review & editing

Consent

Written informed consent was obtained from the patient for publication and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Ethical approval

This study was approved by the research ethics committee of Dr. Soebandi Jember (No. 420/3044/610/2024).

Guarantor

I Nyoman Semita.

Research registration number

• 1.Name of the registry: I Nyoman Semita
• 2.Unique identifying number or registration ID: IS
• 3.Hyperlink to your specific registration (must be publicly accessible and will be checked): https://www.sciencedirect.com/

Funding

This study received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Conflict of interest statement

The authors have no conflicts of interest to disclose.