Prevalence and Severity of Neurologic Dysfunction in Critically III Patients: Influence on Need for Continued Mechanical Ventilation

doi:10.1378/chest.104.6.1818

Chest

Volume 104, Issue 6, December 1993, Pages 1818-1824

https://doi.org/10.1378/chest.104.6.1818 Get rights and content

Objective

The relative importance of neurologic dysfunction in critically ill mechanically ventilated patients has not been well studied. This study investigates the prevalence of neurologic dysfunction in critically ill mechanically ventilated patients and its influence on preventing the discontinuation of mechanical ventilation and patient outcome.

Design

Prospective study.

Setting

University-based, tertiary care center.

Patients

All eligible adult patients mechanically ventilated for more than 48 h were included. A total of 66 patients were evaluated.

Interventions

None.

Main outcome measures

Two independent questionnaires, one completed by the critical care attending physician documenting the major clinical factors necessitating continued mechanical ventilation, and a second questionnaire, completed by a critical-care trained neurologist documenting neurologic status and objective cardiopulmonary status formed the basis for outcome measurements. Respiratory and physiologic data, the patient's clinical conditions, and outcome (mortality) were also included in the database.

Results

Pulmonary factors were the major reason for prolonged ventilation in only 51 percent of the patient evaluations. Neurologic status was the major factor necessitating continued mechanical ventilation in 32 percent of the patient evaluations and a significant contributing factor in an additional 41 percent. Of the neurologic factors, diminished level of consciousness was the major cause of continued ventilatory support. This was usually due to a systemic illness, rather than a primary central nervous system disorder. Mortality was significantly lower in patients who continued to require mechanical ventilation after 48 h because of neurologic factors as opposed to pulmonary factors (15 percent vs 72 percent, p = 0.002).

Conclusions

There is a high prevalence of neurologic dysfunction in critically ill patients and this problem plays a significant role in preventing the discontinuation of mechanical ventilation. Altered mental status is a major factor necessitating continued mechanical ventilation in combined medical-surgical intensive care units.

Section snippets

Patient Selection

All adult patients at our 560-bed university medical center who required mechanical ventilation for more than 48 h were eligible for our study. The intensive care units (ICUs) at this center include a 22-bed combined medical and surgical intensive care unit, an 8-bed coronary care unit, and a 5-bed neurological (primarily neurosurgical) ICU. The group of patients studied is representative of a typical mixture of both surgical and medical critically ill patients seen at a university-based,

RESULTS

Overall, the primary diagnosis in 39 percent of the 66 patients was acute lung injury associated with sepsis or pneumonia, and another 10 percent had multiple organ failure in association with sepsis (Table 3). A primary central nervous system disorder was the primary diagnosis in only 20 percent of the patients (Table 3). Postoperative patients made up 32 percent (21/66) of the patients ventilated for more than 48 h. The remainder of the patients had medical causes requiring assisted

DISCUSSION

The primary purpose of this prospective study was to identify and quantify the relative contributions of pulmonary, neurologic, and other factors that prevented discontinuing mechanical ventilation in critically ill patients. The second goal was to determine the prognostic significance of the organ system primarily responsible for the need for continued mechanical ventilation on mortality. These goals were accomplished by a questionnaire that was completed by well-trained, experienced, critical

REFERENCES (33)

SahnSA et al.
Bedside criteria for discontinuation of mechanical ventilation
Chest
(1973)
GillespieDJ et al.
Clinical outcome of respiratory failure in patients requiring prolonged (>24 hours) mechanical ventilation
Chest
(1986)
FeinAM et al.
The risk factors, incidence and prognosis of the adult respiratory distress syndrome following septicemia
Chest
(1983)
Wiener-KronishJP et al.
The adult respiratory distress syndrome: definition and prognosis, pathogenesis and treatment
Br J Anaesth
(1990)
WagnerDP
Economics of prolonged mechanical ventilation
Am Rev Respir Dis
(1989)
FitzgeraldLM et al.
Weaning the patient from mechanical ventilation
Heart Lung
(1976)
SahnSA et al.
Weaning from mechanical ventilation
JAMA
(1976)
SivakED
Prolonged mechanical ventilation: an approach to weaning
Clev Clin Q
(1980)
TahvanainenJ et al.
Extubation criteria after weaning from intermittent mandatory ventilation and continuous positive airway pressure
Crit Care Med
(1983)
BrowneDRG
Weaning patients from mechanical ventilation
Intensive Care Med
(1984)

YangKL et al.

A prospective study of indexes predicting the outcome of trials of weaning from mechanical ventilation

N Engl J Med

(1991)

MorganrothML et al.

Criteria for weaning from prolonged mechanical ventilation

Arch Intern Med

(1984)

MariniJJ

Weaning from mechanical ventilation

N Engl J Med

(1991)

CoteR et al.

The Canadian neurologic scale: a preliminary study in acute stroke

Stroke

(1986)

AdamsRJ et al.

Graded neurologic scale for use in acute hemispheric stroke treatment protocols

Stroke

(1987)

Wood-DauphineeSL et al.

Examining outcome measure in a clinical study of stroke

Stroke

(1990)

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This work was supported in part by the National Institutes of Health Pulmonary Vascular SCOR grant HL 19155.

The views expressed are solely those of the authors and should not be construed as representing those of the Navy or the Department of Defense.

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clinical investigations in critical care: Journal Article: Research Support, U.S. Gov't, P.H.SPrevalence and Severity of Neurologic Dysfunction in Critically III Patients: Influence on Need for Continued Mechanical Ventilation

Objective

Design

Setting

Patients

Interventions

Main outcome measures

Results

Conclusions

Section snippets

Patient Selection

RESULTS

DISCUSSION

Chest

Chest

Chest

Br J Anaesth

Economics of prolonged mechanical ventilation

Am Rev Respir Dis

Weaning the patient from mechanical ventilation

Heart Lung

Weaning from mechanical ventilation

JAMA

Prolonged mechanical ventilation: an approach to weaning

Clev Clin Q

Extubation criteria after weaning from intermittent mandatory ventilation and continuous positive airway pressure

Crit Care Med

Weaning patients from mechanical ventilation

Intensive Care Med

A prospective study of indexes predicting the outcome of trials of weaning from mechanical ventilation

N Engl J Med

Criteria for weaning from prolonged mechanical ventilation

Arch Intern Med

Weaning from mechanical ventilation

N Engl J Med

The Canadian neurologic scale: a preliminary study in acute stroke

Stroke

Graded neurologic scale for use in acute hemispheric stroke treatment protocols

Stroke

Examining outcome measure in a clinical study of stroke

Stroke

clinical investigations in critical care: Journal Article: Research Support, U.S. Gov't, P.H.S
Prevalence and Severity of Neurologic Dysfunction in Critically III Patients: Influence on Need for Continued Mechanical Ventilation