ICU Airway Management: Practice Variation, Inconsistent Evidence Base

Abstract & Commentary

Synopsis: Findings from this national survey of 1665 nurses and respiratory therapists suggest that airway management practices differ widely across institutions and professions and do not consistently reflect research findings.

Source: Sole ML, et al. A multisite survey of suctioning techniques and airway management practices. Am J Crit Care. 2003;12:220-232.

To determine practices regarding use of closed-system suctioning (CSS) and airway management of intubated patients, Sole and colleagues surveyed a national sample of 1665 registered nurses (RNs) and respiratory therapists (RTs) in 27 institutions. Of respondents, the majority had 6 or more years of ICU experience (61%) and a baccalaureate degree or higher (54%). The response rate was 55%, with replies received from 1186 RNs and 479 RTs. CSS was used on all intubated patients in 59% of facilities and, if specific criteria were met, in all of the remainder. CSS catheters were changed every 24-48 hours at 63% of sites, and at the remainder every 72 hours, "as needed" or weekly. Most institutions (81%) had policies that specified that respiratory therapists were to measure and record endotracheal tube cuff pressures every 8-12 hours, with the method evenly divided between minimal leak technique (48%) or a minimum cuff pressure (44%). Instillation of isotonic normal saline solution (NSS) was recommended for thick secretions in 74% of sites. Less than half (48%) of the hospitals had a specific procedure for oral care. Only 89% of respondents indicated that they wore gloves the majority of time when performing CSS. When practice differences were examined, RTs instilled NSS more often than RNs (51% vs 26%, respectively; P < 0.05). Compared to RTs, RNs performed oral suctioning, oral care and tooth brushing more often than RTs (P < 0.05). Many nurses did not know how often endotracheal tube cuff pressures were measured (38%) or the method for maintaining cuff pressures (46%). RTs said their practice was most often influenced by their educational program. RNs cited preceptors and their educational program.

Comment by Leslie A. Hoffman, RN, PhD

In this study, policies regarding airway management were found to vary widely and did not always reflect current research. Most sites reported changing CSS every 24-48 hours, although studies have indicated that replacement at 24-hour intervals is not necessary. The majority of sites (74%) had policies that included the instillation of NSS for thick secretions. However, prior studies investigating the efficacy of NSS instillation have consistently reported adverse effects and recommended avoiding this practice.1 These studies have primarily been published in nursing journals, which may explain why RTs were twice as likely to instill NSS as RNs. In addition, a large majority of respondents (83%) indicated that they based their practice on information gained from their educational program, rather than more recent research publications. Few sites had policies for oral care of intubated patients despite the known association between ventilator-associated pneumonia and micro-aspiration of oropharyngeal secretions.

Most sites had policies for the management of endotracheal cuffs and the frequency for measuring cuff pressures. Cuff pressures should be maintained between 20 and 25 mm Hg (24-30 cm H2O) to keep cuff pressure at a level sufficient to prevent micro-aspiration, but below tracheal perfusion pressure. In one study, pressures < 20 cm H2O were associated with a 2.5-fold increase in ventilator-associated pneumonia.2 Of concern, less than half (41%) of respondents stated that they kept cuff pressures at 20 cm H2O or greater, and 11% said they kept cuff pressure in the range of 15 cm H2O. Respondents indicated that use of gloves during CSS was common (89%), but not a universal practice.

Findings of this study are a concern because they suggest that practice often deviates from current research findings. While a partial explanation may be reliance on prior educational preparation and the relatively long (> 6 years) interval since graduation, Sole et al noted that there were substantial personnel resources available to provide updates, including clinical nurse specialists (74% of sites), unit-based educators (52% of sites), and respiratory therapy educators (52% of sites). Clearly, we have much progress to make in ensuring that patient care is carried out in the most optimal manner as determined from research findings.

Dr. Hoffman is Professor Medical-Surgical Nursing Chair, Department of Acute/Tertiary Care University of Pittsburgh School of Nursing.

References

1. Ackerman MH, et al. A review of normal saline instillation: Implications for practice. Dimens Crit Care Nurs. 1996;15:31-38.

2. Rello J, et al. Pneumonia in intubated patients: Role of respiratory airway care. Am J Respir Crit Care Med. 1996;154:111-115.