One study found that the cardiovascular disease mortality rose 34% in men and 29% in women for each 5-unit increase in BMI.8 As an individual becomes more obese, fatty streaks along the tunica intima and fibrous plaque lesions become more common in the coronary arteries, as well as the aorta (see Figure 3).7
Fatty deposits can actually infiltrate the heart muscle itself and adipose tissue strands can begin to separate the myocardial cells. This leads to an obesity cardiomyopathy that will impair contractile force, cause left ventricular hypertrophy and decrease cardiac output.8 Additionally, the prevalence of congestive heart failure rises as it is also exacerbated by simultaneous rises in the frequency of hypertension, diabetes and coronary artery disease.
Effects on renal health
As mentioned previously, cytokines from adipose tissue stress renal function through constant RAA axis stimulation and hypertension. In addition to this, obese patients experience excessive renal vasodilation and glomerular hyperfiltration caused by the body’s excess fluid status. This increased renal workload stresses the kidneys and increases tubular and glomerular capillary wall stress, which over time leads to the loss of nephron function and glomerulosclerosis. Presently, there is no association between obesity and the development of end-stage renal disease or the need for dialysis.9
Effects on other systems
Nearly all organ systems are affected by obesity, some from excessive adipose tissue directly and others from the release of cytokines. These effects include an increased insulin resistance as a result of cytokines, and decreased sperm counts and fertility rates in men and women as a result of leptin. Other changes include pedal edema as a consequence of elevated ventricular filling pressures exerting additional pressures on the capillaries;7 increased weight on load-bearing joints in the skeletal system, increasing the frequency of arthritis; increased frequency of gallstones and pancreatitis; and increased frequency of bacterial and fungal skin infections, as well as psoriasis on the skin.
Obesity increases the prevalence of many medical conditions that are commonly treated by EMS providers, including cardiovascular and respiratory disease, as well as diabetes. Not only does increasing disease frequency increase EMS call volume, but each call becomes more challenging as assessing and managing obese patients presents unique challenges.
Almost equally challenging is the logistical issue of safely moving and transporting morbidly obese patients. The safety of both the patient and the crews needs to be considered carefully.
Providing a proper and thorough assessment on an obese patient can be quite challenging. To provide a proper assessment, take the time necessary and consider the following strategies to make a physical examination easier:
- Keep the patient on his or her side or upright as much as possible.
- Listen to lung sounds on the back just medial to the scapula; this is an area of decreased adipose tissue.
- Apply pulse oximetry on the earlobe, fifth digit, nose or temporal artery. These are areas where the meter’s light waveform is less likely to be dampened by adipose tissue.
- Assess for cyanosis inside the lips or eyelids.
- To listen to heart tones place the patient on his or her left side; this shifts the heart closer to the lateral aspect of the chest wall.
- Ensure a properly sized blood pressure cuff. Cuffs that are too small artificially inflate the blood pressure. Use a thigh cuff on the arm or a large cuff on the forearm as necessary.
- Avoid placing EKG electrodes on the abdomen as signals don’t transmit through adipose tissue well. Instead place leg leads on the lateral aspect of the lower abdomen.
Remember that most glucometers are calibrated to determine a capillary glucose, not venous blood such as that taken during an IV start. Studies have shown that there is a statistically significant difference in the values obtained when using a glucometer to test capillary and venous blood, which is why the glucometer is calibrated for capillary blood testing.10 However, there remains debate if this difference is significant enough to change clinical care in the emergency setting.10,11 Since fingers may be quite edematous and obtaining blood may be difficult, consider testing an area of skin that is capillary rich and tends to be fatty-tissue poor, such as the earlobe. While this is painful, it avoids the need for multiple needle sticks in an effort to obtain a blood sample.