1. Hanneman, Sandra K. PhD, RN, FAAN
  2. Barber, Janet M. MSN, RN, FAAFS

Article Content

This issue of Critical Care Nursing Quarterly (25:2) presents some important clinical nursing research and new information about therapies used for select patients in the critical care environment.


Dr Sandra K. Hanneman, Associate Dean for Research and Evaluation at the University of Texas Health Science Center-Houston, edited "Critical Care Research: Part 1," which was published in February 2002. Because of size constraints, three of the scheduled articles were delayed until this issue.


In the first article, Dr Joanne Hickey and colleagues report the results of a pilot study of 24-hour blood pressure patterns in patients following acute ischemic stroke. All patients were hypertensive 7 days or more after their stroke, despite antihypertensive therapy. None of the patients exhibited the normal nighttime decline in blood pressure. These findings, albeit preliminary, raise a number of questions as to when, who, how, and how much to exercise patients during rehabilitation from stroke. While the meaning of "nondipping" or "rising" nighttime blood pressure is elusive at present, better control of daytime hypertension is intuitively appealing in a population at high risk for recurrent stroke and other cardiovascular morbidity. This research was done in an acute care setting with medically stable patients.


Nonetheless, the critical care nurse should readily appreciate how little is actually known about normal and abnormal patterns of physiologic function in critically ill patients. Health care providers have been educated within a homeostatic paradigm wherein snapshots of a person's condition are the basis for prognosis, diagnosis, and intervention. Engineering feats increasingly allow nearly continuous exploration of such dynamic phenomena as physiologic and pathophysiologic functions. As the video camera has largely replaced the instamatic camera to capture "the Kodak moment," so, too, will continuous measurement replace the static, point-in-time measurements that were used in the 20th century. Electrocardiogram, blood pressure, and actigraphy monitors are among the earliest noninvasive devices being used in ambulatory settings to capture dynamic, physiologic patterns over time. In the intensive care unit (ICU), continuous data from many sources are available, but these data have yet to be used to maximize understanding of physiologic responses to critical illness and recovery.


In the second article by Baun and colleagues, the advantages of the controlled laboratory are clearly illustrated. Baun et al report the results of suctioning interventions that have import for critical care clinicians. While the closed system used in this study (adapter) differs from that used currently in practice (in-line catheter), the principles underlying both methods are similar. Thus, even though the research was done with an animal model, the findings are applicable to clinical suctioning interventions. Of note is that despite the use of positive end-expiratory pressure (PEEP) and a closed system of suctioning, endotracheal suctioning impairs ventilation in compromised subjects. This finding provides additional evidence to justify brief suctioning times and frequency of suctioning that is dictated by clinical signs in contrast to routine frequency. Also of note are the combined effects of suction and hyperinflation on the cardiovascular system. Although it is not clear what the cumulative effects do to patients with compromised cardiopulmonary status, it is important to understand that interventions devised to prevent one problem (eg, hypoxemia) may create other problems (eg, cardiovascular depression). A major contribution of this article is the use of a controlled laboratory model that allowed exploration of the complex interaction of cardiopulmonary responses to the common nursing intervention of endotracheal suctioning with hyperinflation and hyperoxygenation. While clinicians and clinical researchers cannot easily replicate this model in patient populations, they can monitor clinically available indicators of cardiopulmonary response (eg, mean arterial pressure, pulse oximeter saturation) during endotracheal suctioning. Furthermore, suctioning protocols can be individually tailored to a patient's response in contrast to using one unit-based or institutional protocol for every patient.


Foster and associates change the pace with their findings from a national survey of practice with assessment and monitoring of neuromuscular blockade. Surveys are useful for describing the prevalence and nature of certain practices. In this case, of the units that use neuromuscular blocking agents, 63% assess and monitor blockade with a peripheral nerve stimulator, despite the recommendation by professional organizations and federal agencies that all adult critically ill patients having sustained blockade be monitored with a peripheral nerve stimulator. Critical care clinicians are well aware that recommendations involving the use of equipment, such as a stimulator, are less useful when technical difficulties erect barriers to using data in the way they are intended. After a complete review of neuromuscular blockade, the authors summarize the technical and interpretive barriers to the valid use of peripheral nerve stimulators. Unfortunately, the barriers are greatest in those patient populations where titration of neuromuscular blocking agents is most critical. The majority of survey respondents who do not use stimulators cited lack of equipment and inadequate training as the major reasons. These are problems that should be rectified with a sufficient evidence base for improved care with stimulator use, yet nearly one in four of those respondents indicated that such evidence does not exist. Evidence cannot be strong if the measurement lacks reliability and validity, however. Research, such as that reported by Foster and colleagues, can stimulate improvements in technology. In the meantime, it is reassuring to know that nurse clinicians revert to non-technologic observational data to provide vigilant monitoring of patients who are chemically paralyzed.


Special feature articles complete this issue. In "Heel Ulcers in Critical Care Units: A Major Pressure Problem," Burdette-Taylor and Kass provide current information on lower extremity perfusion and neuropathy associated with this serious and debilitating complication of bed rest and immobility. In addition to risk assessment tools and guidelines for intervention, the authors thoroughly explore the factors that contribute to heel ulcer development and offer valuable insight into modes of pressure sore prevention for this vulnerable area on the lower extremities. They explain how effective assessment, coupled with awareness of known risks, can facilitate reduction in incidence of partial- and full-thickness wounds that often require extensive treatment and may even lead to limb loss.


In the article, "Critical Care Family Members' Satisfaction with Bereavement Experiences," Warren uses Heideggerian hermeneutics, a method of textual analysis, to study the dialogue of 23 participants who had experienced the death of a family member in the ICU. Helpful and satisfying experiences between hospital staff and family included unrestricted visiting as well as information and emotional support. On the other hand, among unhelpful and dissatisfying experiences were inaccessibility of the physician, not being present at the time of death, and perceptions of uncaring staff and inadequate treatment. Other dissatisfying subjects included legal and financial issues, organ donation, and discussion of funeral arrangements. The article emphasizes the multiple stressors experienced by staff and family members during the patient's dying process and immediately after the death. It demonstrates the complexities and sensitivities associated with research on bereavement.


In an article by Sanford, Pugh, and Warren, entitled "Family Presence during CPR: New Decisions in the Twenty-First Century," the pros and cons of family presence during resuscitation events are considered. No answers are provided here, but the discussion will be helpful to staff members who are re-examining their own policies in this regard.


Angerio and Fink explore the relationships of thromboembolic disease and tumor formation in their article "Thromboembolic Disease and Cancer: Possible New Treatments." Two cellular messengers, hypoxia-inducted endothelin (ET) and vascular endothelial growth or permeability factor (VEGF), play an integral role in tumor development and promote thromboembolic disease. Thus new treatments may include agents directed against these messengers. The authors suggest new strategies for treating thromboembolic disease based on an understanding of tumor biology and cell mediators.