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Biomedical subjects

Cindy L Munro

Publications and source records attributed to Cindy L Munro.

18 recordsLinked to original sources

Subglottic secretion viscosity and evacuation efficiency.

Ventilator-associated pneumonia (VAP) is a common nosocomial pneumonia that occurs in critically ill patients and results in mortality rates as high as 71%. Subglottic secretions (SSs) are a known risk factor. Several clinical trials have shown that continuous aspiration of subglottic secretions (CASS) reduces the risk of VAP by nearly half. Optimal suction pressure levels needed to efficiently evacuate viscous SSs are unknown. The purpose of this study was to describe SSs and the effective suction pressure (20 mmHg, 30 mmHg, 40 mmHg, and 50 mmHg) needed to maximize evacuation efficiency based on SS volume (2 ml, 4 ml, and 6 ml) and viscosity (watery, thick, and gel-like). A laboratory model was designed to replicate a human trachea. Thick secretions had the highest percentage of mean recovery representative of evacuation efficiency of SSs (mean recovery of 86%). The suction pressure of 30 mmHg had the highest overall mean of secretion recovery (83%) across all viscosity types and amounts. This study demonstrated that higher viscosity secretions were easier to evacuate than lower viscosity secretions when 30-mmHg suction pressure was applied. Management of secretion viscosity may assist in secretion removal and delay VAP development. With increased understanding of the molecular structure of SSs, there is the potential that clinicians will be able to manipulate secretion viscoelastic properties to maximize evacuation efficiency of the secretions. Further research is needed to identify safe suction pressures for optimal evacuation of SSs in human subjects.

Clinical Nursing Research↗

Oral health measurement in nursing research: state of the science.

Oral health can impact general health and systemic disease. Changes in dental plaque, oral microbial flora, and local oral immunity may be important in the development or exacerbation of disease in critically ill patients, trauma patients, adults with chronic obstructive pulmonary disease, and frail elderly. Inasmuch as oral health potentially can be influenced by nursing interventions, nursing research in this area can contribute greatly to improved patient outcomes in these diverse populations. The authors' research teams have conducted several federally funded projects focused on oral health and have developed synergy in research methods. A unifying theme for these research projects is the measurement of oral health. Standardized measures of components of oral health are available and applicable across populations, and their uses and relationship to nursing research and patient outcomes will be discussed.

Dental Health Surveys↗

Oral health status and development of ventilator-associated pneumonia: a descriptive study.

BACKGROUND: Ventilator-associated pneumonia is a significant cause of morbidity and mortality and may be influenced by oral health. OBJECTIVE: To describe the relationship between ventilator-associated pneumonia and oral health status, changes in oral health status during the first 7 days after intubation, and microbial colonization of the oropharynx and trachea. METHODS: A total of 66 patients were enrolled within 24 hours of intubation and were followed up for up to 7 days. Data on oral health measures and the Clinical Pulmonary Infection Score (CPIS) were collected at baseline, day 4 (n = 37), and day 7 (n = 21). A regression model was used to predict risk of pneumonia at day 4. RESULTS: Dental plaque and oral organisms increased over time. Correlations were significant for baseline and day 4 dental plaque (P < .001), baseline salivary lactoferrin and day 4 plaque (P = .01), and lower salivary volume and higher day 4 CPIS (P = .02). Potential pathogens were identified in oral cultures for 6 patients before or at the same time as the appearance of the organisms in tracheal aspirates. Correlations were significant with day 4 CPIS for score on the Acute Physiology and Chronic Health Evaluation (APACHE) II (P = .007), day 4 salivary volume (P = .02), interaction of APACHE II score and day 1 CPIS (P<.001), and interaction of day 1 CPIS and plaque (P=.01). CONCLUSIONS: Higher dental plaque scores confer greater risk for ventilator-associated pneumonia, particularly for patients with greater severity of illness. Salivary volume and lactoferrin may affect the risk.

Critical Illness↗

Identification of virulence determinants for endocarditis in Streptococcus sanguinis by signature-tagged mutagenesis.

Streptococcus sanguinis is a gram-positive, facultative anaerobe and a normal inhabitant of the human oral cavity. It is also one of the most common agents of infective endocarditis, a serious endovascular infection. To identify virulence factors for infective endocarditis, signature-tagged mutagenesis (STM) was applied to the SK36 strain of S. sanguinis, whose genome is being sequenced. STM allows the large-scale creation, in vivo screening, and recovery of a series of mutants with altered virulence. Screening of 800 mutants by STM identified 38 putative avirulent and 5 putative hypervirulent mutants. Subsequent molecular analysis of a subset of these mutants identified genes encoding undecaprenol kinase, homoserine kinase, anaerobic ribonucleotide reductase, adenylosuccinate lyase, and a hypothetical protein. Virulence reductions ranging from 2-to 150-fold were confirmed by competitive index assays. One putatively hypervirulent strain with a transposon insertion in an intergenic region was identified, though increased virulence was not confirmed in competitive index assays. All mutants grew comparably to SK36 in aerobic broth culture except for the homoserine kinase mutant. Growth of this mutant was restored by the addition of threonine to the medium. Mutants containing an insertion or in-frame deletion in the anaerobic ribonucleotide reductase gene failed to grow under strictly anaerobic conditions. The results suggest that housekeeping functions such as cell wall synthesis, amino acid and nucleic acid synthesis, and the ability to survive under anaerobic conditions are important virulence factors in S. sanguinis endocarditis.

Animals↗

The role of biobehavioral, environmental, and social forces on oral health disparities in frail and functionally dependent nursing home elders.

The purpose of this article is to review the literature on and discuss how interactions between bio-behavioral aging, nursing home environments, and social forces shaping current health care policies have contributed to oral health disparities in frail and functionally dependent elders who reside in nursing homes. Emerging empirical evidence suggests links between poor oral health with dental plaque deposition and systemic disease, such as nursing home-acquired pneumonia. The majority of nursing home residents lack either the functional ability or the mental capacity to perform their own mouth care and therefore must rely on others to perform mouth care for them. Certified nursing assistants (CNAs), who provide the majority of care activities, were unsure how to provide care to residents who engaged in care-resistive behaviors. The nurses who supervise the CNAs have limited knowledge regarding the provision of mouth care in general, and they specifically lack knowledge regarding the provision of mouth care to elders exhibiting care-resistant behavior. Elders in nursing homes have limited options when paying for dental care; Medicare does not generally cover routine dental care. Medicaid coverage varies widely between individual states; even when coverage exists, low Medicaid reimbursements discourage dentists from accepting Medicaid patients. The strategies needed to reduce these oral health disparities are complicated but not unrealistic. Investigators willing to embrace this cause will have no shortage of opportunities to test methods to improve the delivery of oral care as well as to monitor and reassess these methods.

Activities of Daily Living↗

Actigraphy in the critically ill: correlation with activity, agitation, and sedation.

OBJECTIVES: To determine the feasibility of continuous measurement of limb movement via wrist and ankle actigraphy (an activity measure) in critically ill patients and to compare actigraphy measurements with observed activity, subjective scores on sedation-agitation scales, and heart rate and blood pressure of patients. METHODS: In a prospective, descriptive, correlational study, all activity of 20 adult patients in medical and coronary care units in a university medical center were observed for 2 hours and documented. Wrist and ankle actigraphy, heart rate, and systolic and diastolic blood pressure data were collected every minute. The Comfort Scale and the Richmond Agitation-Sedation Scale were completed at the beginning of the observation period and 1 and 2 hours later. RESULTS: Wrist actigraphy data correlated with scores on the Richmond Agitation-Sedation Scale (r = 0.58) and the Comfort Scale (r = 0.62) and with observed stimulation and activity events of patients (r = 0.45). Correlations with systolic, diastolic, and mean arterial pressures were weaker. Wrist and ankle actigraphy data were significantly correlated (r = 0.69; P < .001); however, their mean values (wrist, 418; ankle, 147) were significantly different (t = 5.77; P < .001). CONCLUSIONS: Actigraphy provides a continuous recording of patients' limb movement. Actigraphy measurements correlate well with patients' observed activity and with subjective scores on agitation and sedation scales. Actigraphy may become particularly important as a continuous measurement of activity for use in behavioral research and may enhance early recognition and management of the excessive activity that characterizes agitation.

Adult↗

Effect of backrest elevation on the development of ventilator-associated pneumonia.

BACKGROUND: Ventilator-associated pneumonia is a common complication of mechanical ventilation. Backrest position and time spent supine are critical risk factors for aspiration, increasing the risk for pneumonia. Empirical evidence of the effect of backrest positions on the incidence of ventilator-associated pneumonia, especially during mechanical ventilation over time, is limited. OBJECTIVE: To describe the relationship between backrest elevation and development of ventilator-associated pneumonia. METHODS: A nonexperimental, longitudinal, descriptive design was used. The Clinical Pulmonary Infection Score was used to determine ventilator-associated pneumonia. Backrest elevation was measured continuously with a transducer system. Data were obtained from laboratory results and medical records from the start of mechanical ventilation up to 7 days. RESULTS: Sixty-six subjects were monitored (276 patient days). Mean backrest elevation for the entire study period was 21.7 degrees . Backrest elevations were less than 30 degrees 72% of the time and less than 10 degrees 39% of the time. The mean Clinical Pulmonary Infection Score increased but not significantly, and backrest elevation had no direct effect on mean scores. A model for predicting the Clinical Pulmonary Infection Score at day 4 included baseline score, percentage of time spent at less than 30 degrees on study day 1, and score on the Acute Physiology and Chronic Health Evaluation II, explaining 81% of the variability (F=7.31, P=.003). CONCLUSIONS: Subjects spent the majority of the time at backrest elevations less than 30 degrees . Only the combination of early, low backrest elevation and severity of illness affected the incidence of ventilator-associated pneumonia.

APACHE↗

Preventing ventilator-associated pneumonia: evidence-based care.

Ventilator-associated pneumonia is a common complication of mechanical ventilation with significant morbidity and mortality. This article summarizes the data related to specific risk factors associated with ventilator associated pneumonia (patient position, oral health, airway management, and gastrointestinal factors) and provides recommendations for practice based on the present evidence.

Critical Care↗

Oral health and care in the intensive care unit: state of the science.

Oral health is influenced by oral microbial flora, which are concentrated in dental plaque. Dental plaque provides a microhabitat for organisms and an opportunity for adherence of the organisms to either the tooth surface or other microorganisms. In critically ill patients, potential pathogens can be cultured from the oral cavity. These microorganisms in the mouth can translocate and colonize the lung, resulting in ventilator-associated pneumonia. The importance of oral care in the intensive care unit has been noted in the literature, but little research is available on mechanical or pharmacological approaches to reducing oral microbial flora via oral care in critically ill adults. Most research in oral care has been directed toward patients' comfort; the microbiological and physiological effects of tooth brushing in the intensive care unit have not been reported. Although 2 studies indicated reductions in rates of ventilator-associated pneumonia in cardiac surgery patients who received chlorhexidine before intubation and postoperatively, the effects of chlorhexidine in reducing ventilator-associated pneumonia in other populations of critically ill patients or its effect when treatment with the agent initiated after intubation have not been reported. In addition, no evaluation of the effectiveness of pharmacological and mechanical interventions relative to each other or in combination has been published. Additional studies are needed to develop and test best practices for oral care in critically ill patients.

Chlorhexidine↗

Effects of stress management on PNI-based outcomes in persons with HIV disease.

A pretest-posttest, repeated-measures design was used to evaluate the effects of two stress management interventions on a battery of outcomes derived from a psychoneuroimmunological (PNI) framework. The effects of cognitive-behavioral relaxation training groups (CBSM) and social support groups (SSG) were compared with a WAIT-listed control group on the outcomes of psychosocial functioning, quality of life, neuroendocrine mediation, and somatic health. Participants were 148 individuals (119 men, 29 women), diagnosed with HIV disease; 112 (76%) completing the study groups. Using analysis of covariance, the CBSM group was found to have significantly higher postintervention emotional well-being and total quality-of-life scores than did either the SSG or WAIT groups. SSG participants had significantly lower social/family well-being scores immediately postintervention and lower social support scores after 6 months. The findings point to a pressing need for further, well-controlled research with these common intervention modalities.

Adaptation, Psychological↗

Predictors of backrest elevation in critical care.

Low backrest and supine positions are associated with increased mortality and ventilator associated pneumonia (VAP). Data are not available across ICU settings about the level of backrest position used and its relationship to enteral feeding and hemodynamic status. The purpose of this descriptive study was to document the level of backrest elevation and position and identify factors associated with and predict positioning in a medical, surgical and neuroscience intensive care unit. Data were collected randomly in each unit over a 6-week period, resulting in 506 observations for170 patients. Backrest elevation was determined by electronic bed read-out or bed frame elevation gauge. BP, HR and enteral feeding status were retrieved from the medical record. Results showed that mean backrest elevation was 19.2 degrees and 70% of subjects were supine. No difference in backrest elevation among units was found. Significant correlations between backrest elevation and systolic BP (r=0.15, P=0.006); and backrest and diastolic BP (r=0.13, P=0.02) were found. There was no difference in backrest elevation between patients being fed and not being fed. Differences in backrest elevation for intubated versus nonintubated patients approached significance (P=0.07) with intubated patients at lower backrest elevations. In summary, use of higher backrest elevations (>30 degrees ) is minimal, is not related to feeding and minimally related to hemodynamic status. Strategies to meet published recommendations for backrest elevation (30-45 degrees ) must include repeated feedback about nurse's use of backrest elevation and estimates of elevation.

Beds↗

The sloABCR operon of Streptococcus mutans encodes an Mn and Fe transport system required for endocarditis virulence and its Mn-dependent repressor.

Streptococcus mutans belongs to the viridans group of oral streptococci, which is the leading cause of endocarditis in humans. The LraI family of lipoproteins in viridans group streptococci and other bacteria have been shown to function as virulence factors, adhesins, or ABC-type metal transporters. We previously reported the identification of the S. mutans LraI operon, sloABCR, which encodes components of a putative metal uptake system composed of SloA, an ATP-binding protein, SloB, an integral membrane protein, and SloC, a solute-binding lipoprotein, as well as a metal-dependent regulator, SloR. We report here the functional analysis of this operon. By Western blotting, addition of Mn to the growth medium repressed SloC expression in a wild-type strain but not in a sloR mutant. Other metals tested had little effect. Cells were also tested for aerobic growth in media stripped of metals then reconstituted with Mg and either Mn or Fe. Fe at 10 micro M supported growth of the wild-type strain but not of a sloA or sloC mutant. Mn at 0.1 micro M supported growth of the wild-type strain and sloR mutant but not of sloA or sloC mutants. The combined results suggest that the SloABC proteins transport both metals, although the SloR protein represses this system only in response to Mn. These conclusions are supported by (55)Fe uptake studies with Mn as a competitor. Finally, a sloA mutant demonstrated loss of virulence in a rat model of endocarditis, suggesting that metal transport is required for endocarditis pathogenesis.

ATP-Binding Cassette Transporters↗

Oral care interventions in critical care: frequency and documentation.

BACKGROUND: No data have been collected to describe the products, methods, and frequency of oral care needed to reduce dental plaque, oral colonization, and ventilator-associated pneumonia in critically ill patients. OBJECTIVES: To describe the frequency of use of oral care interventions reported by nurses in several intensive care units in a large southeastern medical center. METHODS: Staff members completed a written survey describing their oral care practices, and oral care interventions were recorded from the unit's flow sheet for the previous 24 hours for all patients at 5 randomly selected times during 1 month. RESULTS: Most respondents (75%) reported providing oral care 2 or 3 times daily for nonintubated patients, and 72% reported providing care 5 times daily or more for intubated patients. However, oral care was documented on the unit's flow sheet a mean of 1.2 times per patient. Reported use of toothpaste and a toothbrush was significantly greater in nonintubated patients (P < .001), and use of a sponge toothette was significantly greater in intubated patients (P < .001). Nurses' mean rating of oral care priority was 53.9 on a 100-point scale. CONCLUSIONS: Despite evidence that they are ineffective for plaque removal, sponge toothettes remain the primary tool for oral care, especially in intubated patients in intensive care units. Nurses report frequent oral care interventions, but few are documented. Education and focus on good oral care strategies are required; nursing research to delineate the best procedure for all patients in intensive care units is needed.

Critical Care↗

Vaccination with FimA from Streptococcus parasanguis protects rats from endocarditis caused by other viridans streptococci.

The FimA protein of Streptococcus parasanguis is a virulence factor in the rat model of endocarditis, and immunization with FimA protects rats against homologous bacterial challenge. Because FimA-like proteins are widespread among the oral streptococci, the leading cause of native valve endocarditis, we evaluated the ability of this vaccinogen to protect rats when challenged by other streptococcal species. Here we report that FimA vaccination produced antibodies that cross-reacted with and protected against challenge by the oral streptococci S. mitis, S. mutans, and S. salivarius. FimA thus has promise as a vaccinogen to control infective endocarditis caused by oral streptococci.

Animals↗

Nurses' accuracy in estimating backrest elevation.

BACKGROUND: Positioning patients is a key component of nursing care and can affect their morbidity and mortality. The Centers for Disease Control and Prevention recommend that patients receiving mechanical ventilation have the head of the bed elevated 30 degrees to 45 degrees to prevent nosocomial pneumonia. However, use of higher backrest positions for critically ill patients is not common nursing practice. Backrest elevation may be affected by the accuracy of nurses' estimates of patients' positions. OBJECTIVES: To determine the difference between nurses' estimates of bed angles and measured bed angles and to describe the relationship between nurses' characteristics and the accuracy of their estimates. METHODS: A convenience sample of 67 nurses attending the 1999 American Association of Critical-Care Nurses National Teaching Institute and Critical Care Exposition in New Orleans, La. Each subject provided demographic information and estimated 3 bed angles. The angles were preselected by using a random number table. Summary statistics were used and were categorized according to the demographic information provided by participants. Estimated angles were correlated with measured angles, and accuracies in estimating angles were correlated with demographic characteristics. RESULTS: Nurses were accurate in estimating bed angles (correlation, 0.8488). Demographic information, including sex, age, years of practice, years of critical care practice, basic education, highest educational level, and present position had no relationship to accuracy. CONCLUSIONS: Nurses are able to estimate backrest elevation accurately. Other explanations are needed to understand why recommendations for backrest elevation are not used in practice.

Adult↗

Duration of action of a single, early oral application of chlorhexidine on oral microbial flora in mechanically ventilated patients: a pilot study.

OBJECTIVE: The purpose of this study was to describe the effect of an early post-intubation oral application of chlorhexidine gluconate on oral microbial flora and ventilator-associated pneumonia. METHODS: Thirty-four intubated patients were randomly assigned to chlorhexidine gluconate by spray or swab or to control group. Oral cultures were done at study admission, 12, 24, 48, and 72 hours, whereas the Clinical Pulmonary Infection Score (CPIS) was documented at study admission, 48, and 72 hours. RESULTS: Reductions in oral culture scores (less growth) were only found in the treatment groups (swab and spray); no reduction was found in the control group. There was a trend for fewer positive cultures in the combined treatment groups. The mean CPIS for the control group increased to a level indicating pneumonia (4.7 to 6.6), whereas the CPIS for the treatment group increased only slightly (5.17 to 5.57). CONCLUSIONS: Trends in the data suggest that use of chlorhexidine gluconate in the early post-intubation period may mitigate or delay the development of ventilator-associated pneumonia.

Adult↗

Subject recruitment in critical care nursing research: a complex task in a complex environment.

PURPOSE: This article serves to describe subject recruitment issues in a funded study in a the medical respiratory intensive care unit. BACKGROUND: Subject recruitment can be difficult in the critical care environment. Inadequate recruitment can reduce the ability to detect treatment differences. Though causes of recruitment difficulty have been documented in medical trials, little is known concerning recruitment in critical care nursing studies. METHODS/RESULTS: All patients admitted to a medical respiratory intensive care unit (ICU) were reviewed daily for study eligibility. Demographics and reasons for ineligibility and failure to consent were documented. Five hundred ninety-three patients were reviewed; 42 (7.1%) were enrolled; 457 (77.1%) were not eligible and not enrolled and 94 (15.8%) were eligible but not enrolled. Of those reviewed, 52% were male; 57% were black, and 41% were white. Of those eligible, but not enrolled, 40% were because of family unavailability for consent and 27% because of family unwillingness to consent. There were no significant differences in patient age or gender between those who consented and those who did not. However, those who did not consent consisted of a greater proportion of blacks than the population screened. Families' stated reasons for not consenting were primarily related to the family's stress level. CONCLUSIONS: Conducting clinical studies in the critical care environment, enrolling subjects, and obtaining consent may be complicated by the critical nature of the patient's illness, and researchers must be aware of these issues for study success.

Black or African American↗

Quality improvement in backrest elevation: improving outcomes in critical care.

The positioning of critically ill patients is an independent nursing decision, often has multiple rationales, and may significantly affect morbidity and mortality. Recent evidence suggests that backrest elevation in critically ill patients may reduce ventilator-associated pneumonia. However, use of recommended levels of backrest elevation is infrequent in the critical care environment. In addition, published guidelines for backrest elevation to reduce pneumonia conflict with those for protecting skin integrity. This article reviews the benefits and complications of backrest elevation, data related to current positioning practices, and recommendations for backrest elevation. A quality improvement process to guide evidence-based care related to backrest positioning is also described.

Beds↗