From the Guidelines
The prognosis for a morbidly obese patient weighing 150 kg or more with pneumothorax and multiple fractures is generally guarded to poor, requiring intensive multidisciplinary management. These patients face significantly higher morbidity and mortality rates compared to non-obese individuals due to several compounding factors. The pneumothorax presents immediate respiratory challenges that are exacerbated by the patient's obesity, as excess weight restricts diaphragmatic movement and decreases lung compliance. Management typically involves chest tube insertion (large-bore 28-32 Fr tube recommended) for pneumothorax decompression, with careful attention to tube placement using longer instruments and possibly ultrasound guidance due to the thick chest wall, as suggested by 1.
Key Considerations
- Fracture management is complicated by weight limitations of standard imaging equipment, hospital beds, and surgical tables, often necessitating specialized bariatric equipment.
- Pain control requires weight-based dosing, with caution regarding respiratory depression; multimodal analgesia including NSAIDs (if not contraindicated), acetaminophen (up to 4g daily), and judicious opioid use is recommended.
- Respiratory support often requires higher positive pressure settings, and early mobilization is crucial despite being challenging.
- Thromboprophylaxis with higher doses of low molecular weight heparin (e.g., enoxaparin 40-60 mg twice daily) is essential due to the heightened risk of venous thromboembolism, as indicated by 1 and 1.
High-Risk Scenario
The combination of obesity, restricted mobility from fractures, and respiratory compromise creates a particularly high-risk scenario for complications including:
- Wound infections
- Delayed healing
- Respiratory failure
- Thromboembolic events All of which can significantly impact recovery and long-term outcomes. The Obesity Surgery Mortality Risk Stratification score (OS-MRS) may be useful in identifying high-risk patients, as mentioned in 1.
Preoperative Evaluation
Preoperative evaluation should focus on assessing functional capacity, cardiac risk factors, and potential cardiovascular symptoms, as outlined in 1. This may involve exercise testing, pharmacological stress testing, or a combination of both, depending on the patient's ability to exercise and the availability of facilities. The goal is to identify patients at high risk of perioperative cardiac complications and to optimize their management before surgery.
From the Research
Prognosis of Morbidly Obese Patients
The prognosis of morbidly obese patients (150 kg and above) with pneumothorax and multiple fractures is a complex issue. Several studies have investigated the outcomes of such patients.
Mortality and Morbidity
- Morbidly obese patients are at a higher risk of mortality and morbidity due to their increased body mass index (BMI) 2.
- A study found that morbidly obese patients (BMI > 40 kg/m2) had higher rates of mortality, nursing home admission, and intensive care unit complications, and longer stays in the intensive care unit and time on mechanical ventilation 2.
- Another study found that higher BMI quartiles had higher rates of ICU admission, mechanical ventilation, and tracheostomy, although hospital mortality did not significantly differ 3.
Management of Pneumothorax
- The management of pneumothorax in morbidly obese patients is challenging, and traditional methods such as chest x-ray and large-bore tube thoracostomy may not be effective 4.
- Lung ultrasound has proven to be a potentially more useful tool in the detection of pneumothorax in the trauma bay compared with chest x-ray, and has the potential to become the new gold standard for diagnosing traumatic pneumothorax 4.
- More conservative approaches, such as the use of pigtail catheters or observation, may be reasonable in patients with small or occult pneumothorax 4.
Impact of Obesity on Outcomes
- Obesity is a significant predictor of death or disposition to nursing home, even after controlling for age 2.
- A study found that factors such as high BMI, diabetes, hyperlipidemia, and hypertension at first diagnosis of severe obesity were each independently associated with an increased risk of death 5.
- Bariatric surgery has been shown to reduce the severity of the metabolic complications of obesity and improve the prognosis of severely obese patients 5.
Airway Management
- Morbidly obese patients with pneumothorax and multiple fractures may require difficult airway management, and the use of intubating laryngeal mask airway (ILMA) can be very useful in the management of difficult airway outside the operating room 6.