How Obesity Impacts Patient Health and EMS

Obese patients are already prone to depression and poor self-image. Avoid making the patient feel belittled during an assessment and remind them that you are there to help them not just physically but psychologically, as well. Stress that you need their help to make an accurate assessment in order to provide optimal care.

Patient Management

Airway management

Careful airway management is extremely important. Obese patients are known to have a decreased gastric pH as well as increased stomach sizes. Because of this, they are considered at particularly high risk for aspiration during airway management.⁶

The ability to BVM ventilate an obese patient is extremely important because they have decreased oxygen reserves and will not tolerate apnea for any period of time. One study demonstrated that a BMI over 26 was predictive of difficulty maintaining oxygen saturations greater than 92% with bag-mask ventilations alone.⁶ When bag-mask ventilating, utilize a two-person technique—one holding the mask, another ventilating the patient. Remember additional force is needed to displace the diaphragm inferiorly into the abdomen and to raise the chest wall with excessive adipose tissue. Some BVMs that have a pop-off valve may need the valve disabled.

An effective strategy to make mask ventilations easier is to ramp up the patient’s torso and head by using stacks of folded blankets and towels to elevate the head to at least 25 degrees and make the auditory canals line up with the sternum (see Figure 4). This ramped position decreases the risk for aspiration, makes ventilating the lungs easier and also eases the intubation process by shifting the chest and abdominal contents inferiorly. Placing an additional rolled towel between the scapulae can also displace excessive breast tissues laterally, which makes chest wall movement easier. While the use of the LMA has an increased risk of aspiration in obese patients, the use of supraglottic airway devices in general can help reduce hypoxic periods.⁶

The use of non-invasive positive airway pressure systems (CPAP and BiPAP) can be a very effective tool in managing obese patients with respiratory distress. However, when using them set the PEEP or ePAP to at least 10 cm H₂O; the use of 7.5 cm H₂O has been found to be ineffective in improving the oxygen reserve in morbidly obese patients.⁶

Intravenous Access

Excessive adipose tissue makes traditional landmarks difficult to visualize and palpate, making the identification of veins difficult. As a result multiple IV attempts are common, which increases infection, phlebitis and thrombosis risk. Traditional IV catheters are often not long enough to properly access a vein buried within subcutaneous adipose tissue. Consider catheters longer than the standard 1.5-inch needle and avoid the butterfly needles, as they are much shorter and even less likely to provide proper access.

Consider earlier use of IO needles during prehospital care. One IO needle attempt may have a lower infection rate than five, six or more IV attempts. There is a bariatric needle for the EZ-IO which is designed to be extra-long (44 mm compared to a standard 25 mm) to facilitate placement through adipose tissue in the leg or in the shoulder to access the humeral head.

Medicine administration

Differences in renal blood flow and filtration function in obese patients can cause drugs to be cleared more or less rapidly than anticipated. Additionally, the increased adipose tissue causes an increased distribution of lipophilic drugs that can lead to decreased serum levels, as well as prolonged elimination times. Other metabolic changes make predicting drug interactions even more complicated. As a general rule, anticipate the half-life of benzodiazepines and other sedatives to increase in obese patients; however, actual recommendations for altering dosing in these patients is still an area of active research.

Spine Stabilization

Standard EMS backboards are 16 inches wide. As any experienced EMT or paramedic knows, these backboards are barely wide enough for most average-size patients, much less the excessively wide patient. No bariatric spine immobilization device is available on the market. When managing a traumatically injured obese patient, it may be unrealistic to completely immobilize the spine without jeopardizing the safety of both the patient and the providers.