Care of the Critically
Ill Bariatric Patient - 4 Nursing CEs
Critically Ill Bariatric Patient - 4 Nursing CEs Author:
RN, MSN, WCC
epidemic of obesity in the
United States creates the need for critical care nurses to understand
the physiologic needs and the psychosocial needs of this patient
population. This course will define and describe obesity so that
students will have the background to identify and treat the
consequences of obesity in the critically ill patient. The second part
of this course will focus on how obesity affects the care and
management of the critically ill patient by reviewing the effects of
obesity on the body systems. The top reasons patients with obesity are
admitted to the critical care area will be highlighted. The last part
of this course will focus on the issues that affect the critical care
nurses who care for the obese patient as well as safety for the obese
patient while in the intensive care unit. Course
Identify body mass
the correspondence to obesity
Define common terms
associated with obesity
State the prevalence of
obesity in the United States
Identify the most 3
reasons patients who are obese are admitted to the Intensive Care Unit
changes associated with obesity
List the consequences
physiologic changes when caring for the critically ill obese patient
Describe concerns for
caregivers caring for obese patients
Identify equipment that
help in caring for the critically ill obese patient
the obese patient in the intensive care unit
Description of Obesity Obesity
is a complex and
multifaceted disease that involves interactions between social,
behavioral, cultural, physiological, metabolic, and genetic factors.
Obesity is defined as an excess in body fat stores. Generally, obesity
is treated in the physician’s office. Obesity compromises
and leads to early death. Many patients who are obese are admitted to
the critical care unit due to the comorbidities associated with
obesity. When a patient is admitted to the critical care unit, obesity
affects both patient outcomes and how nurses care for the patient. Body
mass index is the most common
and accepted method of determining the degree of excess weight or
obesity. Body Mass Index is calculated by multiplying the
individual’s weight (in pounds) by 703, then, dividing by the
height (in inches) squared. This calculation approximates BMI in
kilograms per meter squared (kg/m2). There are also BMI charts to help
determine a patient’s BMI. Classifications
for BMI, adopted by
the Expert Panel on Identification, Evaluation, and Treatment of
Overweight and Obesity in Adults, are as follows:
obesity (Class 3)
Body mass index is strongly correlated with total body fat content and
should be used to monitor changes in body weight. However, caution
should be taken when calculating BMI in children, adults with edema,
ascites, pregnancy, or individuals with a high ratio of muscle mass
because the calculation may not accurately represent the true amount of
excess fat tissue. Body circumference indices may also be used to
assess for central pattern of obesity versus peripheral distribution of
body fat. Central pattern obesity and a waist circumference to hip
circumference ratio of > 0.9 in women and > 1.0 in men
associated with higher risk of morbidity and mortality due to
cardiovascular disease, diabetes, breast cancer, and stroke than
peripheral pattern of fat distribution.
Some diseases or risk factors associated with obesity place patients at
a higher risk for mortality in general. Diseases and conditions that
reflect a high risk of mortality include established coronary artery
disease, other atherosclerotic diseases, type 2 diabetes, and sleep
apnea. Three or more of the following risk factors also reflect a high
absolute risk of mortality: hypertension, cigarette smoking, high
low-density lipoprotein cholesterol, low high-density lipoprotein
cholesterol, impaired fasting glucose, family history of early
cardiovascular disease, and age (male > 45 years, female
Definitions associated with care of the obese patient include:
overweight, obesity, morbid obesity, and bariatrics.
Excess body weight compared to established standards, such as BMI
25-29.9 kg/m2. Excess weight may come from muscle, bone, fat, and/or
Abnormal proportion of body fat. It is possible to be overweight
without being obese (i.e. body builder), but many people are both.
Lifelong, progressive, life-threatening, genetics-related,
multifactorial disease of excess fat storage with multiple comorbidities
From the Greek baros for “weight”. Bariatrics
health care related to the treatment of obesity and associated
With an estimated 97 million adults that are overweight or obese,
obesity is an epidemic. Healthcare providers must understand the
potential consequences and realities of caring for this population
since 10% to 25% of people between the ages of 26 years and 75 years
are obese and more than 3% to 10% in this age range are morbidly obese.
In the last decade the percentage of adults, ages 20 yeas or older, who
are in the categories of overweight and obese has increased to 54.9
Many obese patients may seek treatment late due to impaired mobility,
limited transportation options, and embarrassment and, thus, end up
being admitted to the critical care units.
Care of the Obese Patient is
Important for the Critical Care Nurse
Patients who are obese enter critical care units for various reasons.
Three common reasons for admission are: acute complications associated
with gastric restrictive surgery, factors of the consequences of
obesity (i.e. cardiac, vascular, respiratory, endocrine, and
immunologic sequelae), and as a result of trauma injury that requires
admission to a critical care unit. Due the size and weight of the
patient this becomes an important consideration for nurses because the
patient may not be able to participate in care because of mobility and
ambulation difficulties. Additionally, most hospital equipment is not
designed for patients over 350 pounds. Prolonged lengths of stay may
also lead to complications and co-morbidities. Co-morbidities
associated with obesity include: pressure ulcers, wound infections,
respiratory problems, and urinary incontinence. Nursing care must focus
on the prevention of the potential complications. Physical assessments,
turning, transferring, ambulating, physical care, and pharmacology are
aspects of nursing care that are affected, and of special concern, for
this patient population.
of physiological system effects
An increase in caloric intake and decrease in physical activity leads
to obesity. Excess fat accumulation and the increased size of normal
structures and fat deposits interfere with the mechanics of numerous
body functions. Obesity is characterized by inflammation,
hypercoagulability, and insulin resistance and is considered to be a
chronic inflammatory state that diminishes immune and metabolic
functional reserve capacity
total lung capacity
expiratory reserve volume
sleep apnea syndrome
work of breathing
total blood volume
clearance of drug excretion
resting expenditure level
of critical illness may deplete protein
rather than glucose stores
tumor necrosis factor
gastric secretion volume
pain with movement
disuse atrophy of musculature
Both structural and physiological changes affect the pulmonary system
of the obese patient. Structural changes lead to restrictive lung
patterns and physiologic changes lead to increased work of
breathing. Functionally, there is a decrease in functional
residual capacity, vital capacity, total lung capacity, inspiratory
capacity, minute ventilation volumes, and expiratory reserve volumes
due to the increase in intraabdominal pressure and the diaphragm
pushing up on the lungs. Physiologically, increased pulmonary blood
volume and increases in carbon dioxide production lead to an increased
work of breathing. These structural and physiological changes lead to
what is called “obesity hypoventilation.” Sleep
very common in the obese patient due to airway narrowing from fat
distribution in the upper airway and tongue. Obstruction is
commonly due to relaxation of throat structures; the base of the tongue
falls against the posterior wall, occluding the pharynx and upper
airway and leads to hypoxia.
The end result of sleep apnea for the obese patient may be the failure
to breath. As breathing becomes more difficult in general for the
patient, the respiratory rate will increase and there is a
ventilation/perfusion mismatch. Hypoxemia and respiratory acidosis are
the usual results of the ventilation/perfusion mismatch. A large body
requires increased oxygen in order to maintain adequate tissue
perfusion. Alveolar hypoventilation and sleep apnea may be the main
reasons that the obese patient is hospitalized.
Continuous positive airway pressure (CPAP) may be used to treat the
obstructive sleep apnea. With CPAP the air flows through a nasal mask
against the airway resistance. The air enters the nasal pharynx and
pushes the tongue forward, preventing the recurrent obstructive events.
Body position will also influence respiratory status. Lying flat or in
the Trendelenburg position will increase respiratory problems.
Maintaining 30 to 45 degree semi-recumbent position is preferred.
Atelectasis and pneumonia may result in shallow respirations. Adequate
pain control will result in deeper respirations and more effective
coughing, especially if the patient has had surgery.
Regular tracheostomy tubes may be too short to fit the obese patient.
Using an extra long tracheostomy tube may be required. Tracheostomy
ties may cause skin irritation and burrow into the skin. Tissue erosion
can occur if ties are applied too tightly, so foam tracheostomy ties
may provide better protection against tissue erosion.
When an obese patient has respiratory failure and requires a mechanical
ventilator the delivered tidal volume should be calculated based on
ideal body weight (IBW) rather than actual body weight (ABW) to avoid
high airway pressures, alveolar over-distention, and barotraumas. The
obese patient may have higher peak and static airway pressures than are
usually recommended, but these may be necessary in order to oxygenate
and have adequate alveolar ventilation. Positive End Expiratory
Pressure (PEEP) may be needed to prevent closure of the alveoli and
Ventilatory discontinuance may become more difficult. Increased time on
the ventilator leads to an increased risk of ventilator associated
pneumonia and aspiration pneumonia. The reverse trendelenberg position
at 45 degrees may facilitate discontinuing the ventilator in these
Approximately 3 milliliters of blood volume are need per 100 grams of
adipose tissue to maintain perfusion. Due to the increase in adipose
tissue with obesity, circulating blood volume increases, preload
increases, stroke volume increases, cardiac output increases, and
myocardial workload increases in order to meet the perfusion demands.
In order to increase circulating blood volume there is increased red
blood cell production which causes increased blood viscosity. Increased
blood viscosity leads to an increased risk for thrombophlebitis and
Hyperinsulinemia in the obese patient can lead to sodium retention and,
as a result, the obese patient develops hypertension. Other body
processes that contribute to heart disease include increased
triglyceride levels and reduced high-density-lipoprotein (HDL)
cholesterol. Elevated circulating concentrations of catecholamines,
mineralocorticoids, renin, and aldosterone usually lead to increased
afterload, further contributing to heart disease. Cardiac disease
associated with obesity eventually causes myocardial hypertrophy and
decreased myocardial compliance. Diastolic dysfunction and ventricular
failure can lead to sudden cardiac death.
When admitted to critical care units, pulmonary artery catheters may be
need in the obese patient due to poor fluid tolerance that occurs with
diastolic dysfunction to closely monitor hemodynamic status.
Beta-blockers should be used cautiously in obese patients due to the
impaired ventricular contractility as a result of decreased beta
Urinary and fecal incontinence are more common in the obese patient due
to increased intra-abdominal pressure from excess abdominal weight.
Limited mobility may contribute to incontinence because the patient is
unable to ambulate or urinate independently.
Weight gain is associated with an increased demand for insulin and may
result in pancreatic failure. Increased food intake may also be
associated with an increase in T3 (triiodothyronine) produced from T4
(thyroxin), and lead to an increase in metabolic rate, causing an
increase in cardiac output.
Metabolic X syndrome is common in the obese population. This syndrome
is a culmination of insulin resistance, hyperinsulinemia,
hyperglycemia, coronary artery disease, hypertension, and
hyperlipidemia. Increased metabolic rate, accelerated net protein
breakdown, and alterations in lipid and carbohydrate metabolism of
critical illness exacerbate the preexisting metabolic problems for the
One source of tumor necrosis factor and interleukin-6 is adipose
tissue. As a patient becomes obese, the adipose tissue produces more of
these inflammatory mediators. Another immune consideration is that
neutrophils have impaired chemotaxis and activation, causing alteration
is response to infection.
Obese patients have an increase resting energy expenditure secondary to
Altered gastric pH and fluid volume have been found in obese surgical
Aspiration risk is increased in the obese patient due to the higher
volume of gastric fluid, a lower than normal pH of gastric fluid in
fasting obese patients, increased intra-abdominal pressure, a higher
incidence of gastroesophageal reflux, and a higher incidence of hiatal
Obese patients in intensive care units are likely to develop protein
energy malnutrition due to metabolic stress. Traumatized obese patients
mobilize more protein and less fat, compared with nonobese patients. In
part, this is due to the fact that central adipose tissue is more
metabolically active than peripheral adipose tissue, lipolysis and fat
oxidation may be blocked. The preferred use of carbohydrates for energy
may accelerate the body protein breakdown. The increased carbohydrate
use for fuel increases the respiratory complication and increase in CO2
production. Increased incidence of diabetes mellitus in the obese
population will often result in hyperglycemia and should, therefore, be
monitored carefully. Insulin infusions may be necessary due to the
difficulty in controlling blood sugars with a sliding scale.
Calories for nutrition in the intensive care unit should be given
primarily as carbohydrates with fats to prevent essential fatty acid
deficiency. Nutrition should not be withheld due to the belief that
losing weight during critical illness will be beneficial to the
patient. Enteral nutrition is the preferred route of feeding and is
only contraindicated in patients with bowel obstruction.
Obese patients have increased concentrations of fibrinogen and
plasminogen activator inhibitor-1 and decreased concentrations of
antithrombin-III and decreased fibrinolysis. The result is an increased
risk of developing deep vein thromboses due to increased blood
viscosity. Prevention of deep vein thrombosis should be a priority.
Low-molecular weight heparin (LMWH), oral anticoagulation or the
combination of pneumatic compression and LMWH should be considered for
Obese patients often have chronic dermatitis in skin folds. Perineal
skin breakdown can occur as a result of immobility, the inability to
get to the bathroom, and the inability of the patient to adequately
clean the perineal area. For men, it may be difficult to use the urinal
due to problems of either sitting on the side of the bed or standing at
the side of the bed. Catheterization of the obese patient may be
difficult for the nurse and assistance if often needed for correct
insertion technique. When an obese patient develops a wound the healing
of the wound may occur more slowly due to the increase in adipose
tissue which is less well vascularized. Wounds that develop in skin
fold areas may be more prone to infection due to the moisture build up
and the accumulation of bacteria.
Obese patients react differently to medications due to a high
percentage of adipose tissue and lower percentage of water and lean
body mass. Medications are absorbed differently due to body
composition. Drug levels may become sub-therapeutic or toxic.
Drugs that are highly soluble in fat and distribute mostly in adipose
Drugs that are highly soluble in adipose tissue should be calculated
using the patient’s actual body weight. Drugs that are
need an increase in dose, but the half-life and the elimination rate is
Drugs that are mainly distributed in lean tissue include:
Drugs that are mainly distributed in lean tissue should be dosed
according to ideal body weight to avoid toxicity.
Longer needles may need to be used.
Drugs that rely on normal gastric pH absorption may be altered due to
the lower pH.
Cutaneous tissue is not as well perfused in bariatric patients because
absorption rates are based on the tissue perfusion of persons of
average weight. Dosing and administration schedules may need to be
Monitoring of clinical endpoints, signs of toxicity, clinical response,
and serum drug levels, when appropriate, are essential components of
for caregivers caring for the bariatric patient
When caring for an obese, or morbidly obese patient, the care for the
patient becomes ever more intensive. Often patient’s may be
unable to participate in their own care. Safety of both the patient and
the caregiver is a major concern.
Weight limits of the hospital bed, including the bed frame and side
rails should be assessed. It is also important to know if the mattress
will provide pressure relief versus pressure reduction for the weight
of the patient. Specialty beds may be needed to provide the appropriate
support for the weight of the patient. The pressure-relieving
capabilities and whether the width of the bed is appropriate are two
points for concern. All patients who are bed-ridden are at risk for
skin breakdown, but those who are obese are at especially high risk.
Poor blood supply to fatty tissue reduces the nutrients needed for
healing. Also, pressure of skin folds may be enough to cause skin
breakdown. Many bed companies have beds that support 800 to 1,000
pounds. Adequate nutritional assessment should be completed by the
dietitian in any patient who is obese with a wound.
Wheelchairs and bedside commodes/shower chairs must be able to
accommodate the patient’s size and weight. Door frame sizes,
toilets, and sinks must be assessed prior to patient transfers and use
Supplies of large gowns, adequate walkers, and bedside chairs must be
in place. Tests and treatments may also be difficult due to the need to
transfer patients, use the x-ray, or place the patient on the OR table.
MRI weight capabilities should also be checked.
Over the bed trapezes may help the patient move in bed and reduce the
risk of back strain to the health care provider. When the patient is
immobile specialty beds and specialty lift and transfer equipment must
be used for the safety of the nurse and patient. Cardiac
that support the size and weight of the patient should be in place.
Proper use of body mechanics is essential.
Routine assessments of weight, respiratory status, and blood pressure
of the patient who is obese may be difficult. Auscultation of breath
sound may be impossible and pulse oximetery may not penetrate the layer
of fat requiring assessment of the respiratory status via arterial
blood gases measurement and the appearance of sputum. Measuring blood
pressure of a patient with a cuff that is too small for the upper arm
will cause a falsely high reading, as well as possibly cause tissue
injury to the patient’s arm. The width of the cuff bladder
be 40% to 50% of the arm’s circumference, and the length of
bladder must be 80% of the circumference to obtain an accurate reading.
A cuff created especially for the bariatric patient will help provide
the most accurate reading. When listening for breath sounds, displace
all skin folds over the area, and then place the diaphragm firmly over
the exposed area. Listen over dependent areas where the lung
tissue is closest to the chest wall, and where fluid is most likely to
collect. Listening for heart sounds either over the left lateral chest
wall while the patient is turned toward the left side, or over the
aortic or pulmonic areas to the left or right of the sternal border at
the second intercostal space is optimal for the obese patient. Bowel
sounds will take longer to distinguish than usual. Marking the location
where bowel sounds were most easily heard will help with the
consistency amongst the healthcare team. Obese patient are at special
high risk for developing pressure ulcers. Skin inspection must include
all skin folds – especially under breasts, abdominal folds,
skin folds, and perineal areas.
Nutritional assessment should be completed. Overweight patients are not
always well nourished. They may be protein deficient and lack essential
nutrients necessary for healing. Comprehensive assessment of
nutritional status should include an assessment of laboratory values.
Many obese patients may have obstructive sleep apnea. Apneic episodes
occur largely during rapid eye movement sleep. If a patient has had
surgery, the obstructive sleep apnea may not return until the 3rd to
5th night, which means the nurse must be aware of this possibility.
Central line placement on an obese patient is difficult due to the
stubby neck, loss of physical landmarks, and greater skin-blood vessel
distance. Catheters may be malpositioned more often with increased
attempts at line placement. Obese patients also have poor peripheral
venous sites. Central line should be vigilantly surveyed as central
catheters are usually kept in longer, because they are difficult to
insert, and the skin folds predispose the patient to infection.
Ambulation, mobilization, and physical and occupational therapy should
be initiated early in the hospital stay to prevent muscle atrophy and
weakness. Proper body mechanics for both the patient and caregiver are
essential to prevent injury for both. Prior to mobilizing patient
ensure that the appropriate equipment is available.
of the skin
Topical antifungal agents are frequently needed to treat fungal rashes
in skin folds. Powder should be avoided because it usually cakes under
skin folds, which can lead to skin breakdown due to friction.
Lubricants and ointments are better for treating superficial skin
irritations and wicking away moisture from the skin.
Consideration of adequate pressure relieving surfaces should be
evaluated in order to decrease the risk of the obese patient developing
pressure ulcers. No-rinse perineal cleansers are useful for perineal
care. The area should be thoroughly dried to maintain skin integrity.
Moisture-barrier ointments are great adjuncts to prevent irritation of
the skin from urine and feces.
When an obese patient has a wound, frequent dressing changes can place
the patient at greater risk for skin tears due to tape application and
removal. Consider using dressing that is changed less frequently to
avoid such problems. Common complications that are found with wounds in
obese patients include: infection, dehiscence, and hematoma and seroma
formation. Infection becomes a greater risk with insufficient oxygen to
the tissue to bring neutrophils and phagocytizing bacteria. Dehiscence
may be due to increased tissue pressure and lack of oxygen to the area
of the wound for healing. Hematomas and seromas may also create
increased pressure and add tension to the incision.
Issues of Care
Weight control is essential for this patient population, but may not be
the optimal topic of discussion during and acute care health crisis.
The effect of excess weight on health can be discussed with the patient
and family. Consultation to nutritional services should be included and
offered to the patient and family as appropriate in the acute care
setting. Including family members in the discussion is essential to
avoid sabotage of the patient attempts to control weight and nutrition.
Health care providers must also be mindful of facial expressions and
body language and the types of messages sent.
As critical care units are seeing more and more patients who are
overweight, obese, and morbidly obese. Critical care nurses must not
only be aware of how to care for these patients, but must be proactive
in creating guidelines and protocols that influence how patients are
cared for. Proactive guidelines and protocols will not only help
patients, but will help nurses in the resources needed to decrease the
risk of complications, such as pressure ulcers, that may result from
consequences of critical illness and the ability of the patient to
participate in self care. Protocols and guideline help bring awareness
of safety concerns for the obese patient population.
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