Page 133 - Hall et al (2015) Principles of Critical Care-McGraw-Hill

CHAPTER 14: Chronic Critical Illness 99

Infectious complications were documented in a series of 100 patients
TABLE 14-3 Neuroendocrine Function in Acute and Chronic Phases of Critical Illness
admitted to a hospital unit dedicated to the care of patients with chronic
Acute Critical Illness Chronic Critical Illness critical illness. All patients were receiving mechanical ventilation
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ACTH ↑ ↓ through a tracheostomy after at least 2 weeks of critical illness. During
hospitalization on this unit, 61% of patients developed evidence of SIRS,
Cortisol ↑↑ ↑
and 11% developed septic shock. Line sepsis (11%), primary bacteremia
Prolactin ↑ ↓ (6%), tracheostomy-associated pneumonia (10%), and Clostridium dif-
Thyrotropin ↓ ↓ ficile colitis (10%) were the most common infections. Urosepsis was less
Gonadotropin ↓ ↓ common in this series, but the authors were appropriately conservative
in the diagnosis of urosepsis. This diagnosis required the presence of
Growth hormone ↑, pulsatile ↓, irregular SIRS and pyuria or a positive urine culture without any other obvious
source of infection.
The management of nosocomial infections in CCI patients begins
The hormonal changes that occur in acute illness may be posi- with prevention. Elimination of all unnecessary compromise of barriers
tive adaptations that help divert energy away from anabolism and to infection is paramount. Venous catheters should be well maintained
toward maintenance of vital tissues and immune function, for example. and removed as soon as possible. A patient who is hemodynamically
However, the hormonal responses to chronic critical illness may be mal- stable with a functioning gastrointestinal tract may be able to receive
adaptive. CCI patients suffer from significant protein deficiencies owing all medications enterally. Continued maintenance of a venous cath-
to ongoing degradation and suppressed production. This hypercatabolic eter out of habit or ICU policy in a hemodynamically stable patient is
state likely contributes to the severe and prolonged muscle weakness inappropriate. When central venous catheters are necessary for long
that is characteristic of these patients. While protein is lost despite periods, tunneled catheters or chlorhexidine-, silver-, or antimicrobial-
feeding, reesterification of free fatty acids allows fat stores to build impr egnated catheters should be considered. More importantly, stan-
up. Hyperglycemia, insulin resistance, and hypertriglyceridemia are dardized and checklist-monitored approaches to line placement and
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common. Prolonged hypercortisolism and low levels of GH and thyroid maintenance should be adopted. Bladder catheters should be removed
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hormone may contribute significantly to these processes. In addition to as soon as possible. Strategies to prevent ventilator-associated pneumonia
prolonged wasting, immune function is also likely to be affected as well. include semirecumbent positioning, oral decontamination, removal of
As a clinical correlate, prolonged weakness associated with ventilator the nasogastric tube when possible, closed endotracheal suctioning, and
dependence and recurrent infectious complications are hallmarks of the scheduled drainage of condensate from ventilator circuits. Minimizing
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CCI condition. sedation is also beneficial. As always, effective hand washing is
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essential. Judicious use of broad-spectrum antibiotics, reduced reliance
MANAGEMENT OF THE CCI PATIENT on proton-pump inhibitors, and effective isolation will decrease the
■ INFECTION CONTROL incidence of C difficile colitis and infections with multidrug-resistant
organisms. Routine surveillance for these organisms may be beneficial;
CCI patients are at very high risk for nosocomial infection. Perhaps however, a recent cluster randomized trial of ICUs revealed that univer-
their greatest risk factor is disruption of multiple infection barriers. sal decontamination using 5 days of twice-daily intranasal mupiricin
Most patients have tracheostomies or endotracheal tubes that promote and daily bathing with chlorhexidine-impregnated cloths was more
aspiration, inhibit cough, and greatly increase their risk of airway colo- effective than targeted decontamination or screening and isolation
nization with nosocomial organisms. Central venous catheters, includ- of colonized patients in reducing rates of MRSA clinical isolates and
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ing peri pherally inserted central catheters (PICC lines), are common bloodstream infections of any type. It is yet to be determined whether
and remain in place for long periods, significantly increasing the risk of similar results would be obtained in a ventilator weaning facility where
bloodstream infections. The presence of bladder catheters promotes uri- colonization with resistant organisms is more common.
Weeks of immobility and edema predispose patients to skin breakdown, ■ NUTRITION
nary tract infections, and nasogastric tubes increase the risk of sinusitis.
which provides another infection source. Some of the hallmarks of chronic critical illness include low protein
The underlying comorbidities that make patients susceptible to stores owing to impaired synthesis and persistent losses, muscle wasting
chronic critical illness also predispose to infections. COPD is often and atrophy, and weight loss (unless volume overload persists). Adequate
accompanied by bacterial colonization of lower airways and compro- nutrition is essential if a patient is going to improve respiratory and skel-
mised airway clearance. Neurologic impairment increases aspiration etal muscle function and avoid life-threatening infectious complications.
risk and weakens cough response. Diabetes mellitus, renal failure, Clinical studies specifically addressing nutrition management for CCI
congestive heart failure, and hepatic dysfunction are all associated patients are lacking. However, some systematic approaches have been
with compromised immune function and are important risk factors for developed based on principles derived from the literature for acutely
pneumonia. Diabetes mellitus and hepatic dysfunction also increase the critically ill patients and nonventilated long-term care patients. One
risk for fungemia. Immune function is further impaired by nutritional approach attempts to replace protein stores in the hypoalbuminemic
deficiencies, protein depletion, and ongoing catabolic processes. Recent patient while trying to avoid the common complication of overfeeding.
data indicate that “immune exhaustion” following severe sepsis can leave Caloric overfeeding results in volume expansion, hyperglycemia, steato-
patients effectively immune compromised as soon as 3 to 4 days follow- cholestasis, and possibly hypercapnea with increased ventilatory load. In
ing their acute presentation. 26 a study of 213 CCI patients from 32 hospitals, 58.2% of patients were
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Because CCI patients spend weeks in ICUs where multidrug-resistant receiving more than 110% of required calories according to indirect
bacteria are common, the incidence of infection or colonization with calorimetry, whereas only 12.2% were being underfed. To avoid this
these organisms is quite high. This problem is compounded by mul- syndrome, one initially can provide lower total calories (20-25 kcal/kg
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tiple rounds of broad-spectrum antibiotics over the course of their per day) and greater protein content (1.2-1.5 g/kg per day) than is
hospitalization. This is a particularly important issue for ventilator usually recommended for ICU patients. Patients with higher protein
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rehabilitation hospitals, where patients are admitted from numerous losses (eg, on renal replacement therapy or with a decubitus ulcer) may
different referring hospitals. Nearly every new admission brings unique need protein supplementation as high as 2.0 g/kg per day. This prescrip-
strains of resistant organisms. Containing the spread of these organisms tion can be adjusted by following clinical parameters and biochemical
is a constant challenge. measurements such as serum albumin and prealbumin levels, blood

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