bluuebunny/crossref_metadata_2025 huggingface dataset:
From Use Case to Use Case Slices
Authors: Chen Yangyang , Chen Cong , Wen Hao , Jiang Jian-min , Zeng Qiong , Shu Hongping , Zhong Hong
Published: November 2019

A use case has been widely adopted for requirements specification, which can be created on a high abstraction level or a very detailed level. A use case with a very detailed level can be a lot more useful for requirements elicitation, but such a model may become too complex and difficult to understand the whole context. A use case slice is introduced in order to simplify the requirements analysis and ensure the correctness of software incremental development process (e.g., the agile development process). However, a use case is usually divided into multiple use case slices in a manual way. Some errors may occur during this manual process. In this article, the authors present an automated approach for dividing a use case into use case slices. The approach first decomposes a use case into multiple use case stories, and then these stories can be composed into different use case slices according to different requirements. These use case slices cover all the functionality of the original use case. The authors give a decomposition theory and propose the corresponding algorithm. A case study demonstrates these results.
Nodus migrans: the case of the migrating knot
Authors: Ewer MS , Ali MK , Gibbs HR , Swafford J
Published: November 2019

Flow-directed pulmonary artery catheters provide important information regarding intravascular volume status, cardiac function and vascular resistance. We describe an unusual complication of pulmonary artery catheterization in which a knot formed at the distal end was torn away from the catheter body and migrated from its original position in the right subclavian vein to a distal branch of the right pulmonary artery. Careful attention to insertion and withdrawal techniques could prevent this potentially serious complication.
Characteristics and health service utilization patterns of ventilator-dependent patients cared for within a vertically integrated health system
Authors: Sevick MA , Zucconi S , Sereika S , Puczynski S , Drury R , Marra R , Mattes P , Taylor J
Published: November 2019

OBJECTIVE: To describe the characteristics and service utilization patterns of long-term ventilator-dependent patients. DESIGN: Using medical records, a cohort of ventilator-dependent patients was identified and followed. SETTING: A vertically integrated healthcare system in southwestern Pennsylvania. PATIENTS: Forty-nine adults requiring prolonged ventilatory assistance. MEASURES: Demographics, admission date, admission diagnosis, discharge diagnosis, reason for ventilator dependency, level of care to which the patient was admitted, dates of all transfer orders, dates of all transfers between levels of care, discharge destination and subsequent readmissions. RESULTS: The major reason for long-term ventilator dependency was progressive debilitating disease of either a pulmonary or nonpulmonary nature. The mean length of stay within the system was 72.6 days +/- 42.55 (median = 59 days, range = 24 to 267 days). Patients had an average of 3.3 transfers +/- 2.53 within the system (median = 3, range = 0 to 10). No delays in transfer to lower levels of care were found. Health utilization variables were largely unrelated to reason for ventilator dependency. Almost half of the patients (n = 24 or 49.0%) died in the system. Patients who died in the system were significantly older than patients for whom discharge home was possible. CONCLUSIONS: Additional studies are necessary to describe the prevalence, etiology, health status and functional status of ventilator patients at all levels of care; the impact of different system approaches on patient well-being and cost of care; and the process of medical decision making. Economic analyses of costs and outcomes for ventilator-dependent patients using a cost-utility approach are also needed.
Comparison of PT and aPTT values drawn by venipuncture and arterial line using three discard volumes
Authors: Konopad E , Grace M , Johnston R , Noseworthy T , Shustack A
Published: November 2019

BACKGROUND: Blood samples obtained through heparinized arterial catheters are used routinely for a variety of laboratory tests. Accuracy of coagulation studies performed from samples obtained in this fashion continues to be questioned, particularly in regard to the minimum discard volume necessary to clear the catheter of heparinized solution. OBJECTIVE: To examine differences between prothrombin time and activated partial thromboplastin time values obtained from blood drawn by venipuncture and from an indwelling intra-arterial line using three discard volumes. METHODS: Prothrombin time and activated partial thromboplastin time samples were drawn by venipuncture from 41 critically ill adult patients. Simultaneously, three consecutive blood samples of 2.3 mL were drawn from the arterial line after an initial discard volume of 3 mL (discard volumes of 3.0, 5.3 and 7.6 mL). RESULTS: Significant differences were found between arterial and venous prothrombin time values for the 3-mL discard volume group, as well as between arterial and venous activated partial thromboplastin time values for all three discard volume groups (paired t-test, Bonferroni correction). CONCLUSION: We recommend that when drawing prothrombin time and activated partial thromboplastin time samples from an arterial line, a 5.3-mL discard volume be used.
Echocardiographic determination of valid zero reference levels in supine and lateral positions
Authors: Kee LL , Simonson JS , Stotts NA , Skov P , Schiller NB
Published: November 2019

BACKGROUND: The phlebostatic axis--the junction of the fourth intercostal space and the midpoint of the anterior-posterior diameter--has been accepted as a reliable external reference point for the mid-right and mid-left atrium. Acceptance of this reference point is based upon research conducted in 1945 that measured venous pressures in the hands of subjects positioned with the head of the bed raised to different levels. The validity of this reference point for intracardiac pressure measurements in supine or laterally positioned patients has not been established. PURPOSE: To determine the validity of the phlebostatic axis in the supine and lateral positions. METHODS: To determine validity in the supine position, we compared the distance from the phlebostatic axis to a fixed external point (the bed surface) and the distance from the right and left atria in the supine position to this same fixed external point. The distances from the right and left atria to the bed surface were determined with echocardiography and were used as the standard for the proper position of external reference points. To determine the validity of the phlebostatic axis in lateral positions, we compared the distances from the right atrium and left atrium to the bed surface in the supine position with those distances in different lateral positions. RESULTS: We analyzed the data of 25 normal, healthy subjects. The study findings show that the phlebostatic axis is a valid reference point for the right atrium, and the phlebostatic axis and midanterior-posterior diameter are valid reference points for the left atrium in the supine position. However, neither is a valid external reference point in the lateral positions. Pressure measurements obtained when patients are in the lateral positions are not accurate. There remains a need to develop valid methods of accurate pressure measurements in various body positions.
Chest tube stripping in pediatric oncology patients: an experimental study
Authors: Oakes LL , Hinds P , Rao B , Bozeman P , Taylor B , Stokes D , Fairclough D
Published: November 2019

BACKGROUND: Stripping of chest tubes to promote drainage of the thorax of postthoracotomy patients has been routine practice, based on tradition. Recent published findings indicate that significant negative pressures are generated in the tube during stripping that could cause pain, bleeding and possible damage to the patient's lung tissue. OBJECTIVE: To determine whether pediatric oncology patients whose chest tubes were not stripped would differ in frequency of pain, fever or lung complications from patients who underwent routine tube stripping. METHODS: Data were collected at multiple points during the first 72-hour postoperative period from 16 patients assigned to the stripped or unstripped groups. Pain was measured by the Faces Pain Scale and the Visual Analogue Scale; temperature, by electronic thermometer; and lung complications, by stethoscope and radiographs. Both groups, which were comparable for age, primary diagnosis and prior history of lung problems, received identical supportive nursing and medical care, with the physicians blind to group assignment. RESULTS: The two groups did not differ significantly in frequency of pain, incidence of fever, breath sounds or radiographic findings across measurement points. A strong correlation was found between the pain scores using the two instruments. DISCUSSION: Patients whose tubes were not stripped did not have an increased risk of infection or lung complications. Study findings indicated that stripping did not increase the frequency of pain. CONCLUSIONS: Stripping of chest tubes as a routine postoperative measure is questioned.
A collaborative practice model for critical care
Authors: King L , Lee JL , Henneman E
Published: November 2019

Collaborative practice behavior is a concern for healthcare providers and administrators, because it is associated with positive outcomes for both patients and staff in the intensive care unit. Despite the documented benefits derived from collaborative practice, it remains the exception rather than the dominant pattern for nurse-physician interactions. National concern for quality care and rising healthcare costs mandates that collaborative practice behaviors between nurses and physicians replace competition as the means for resolving differences. The purpose of this article is to describe collaborative practice, propose a theoretical framework for collaborative practice and discuss the development, implementation and evaluation of a collaborative practice model.
Pain and pain-related side effects in an ICU and on a surgical unit: nurses' management
Authors: Tittle M , McMillan SC
Published: November 2019

BACKGROUND: Little research was found to indicate that pain is managed well in hospitalized patients and few studies were found regarding pain management for critical care patients. OBJECTIVE: To determine the extent to which nurses manage pain effectively without side effects related to narcotic analgesics in an intensive care and a surgical unit. METHODS: The sample consisted of 44 patients, 20 from an intensive care unit and 24 from a surgical unit. Patients completed a Visual Analogue Scale to measure pain intensity three times in 24 hours. The narcotic side effects of constipation and sedation were measured using the Constipation Assessment Scale and a sedation scale. Documentation was assessed using the Chart Audit for Pain. RESULTS: Patients in both units continued to experience pain even with pain management interventions. The critical care nurses administered an average of 30% of the maximum narcotic dose ordered and the surgical unit nurses, 36.8%. Documentation of the effect of the pain medication was scant on both units. Although sedation was not a problem in either unit, the majority of patients reported symptoms of constipation. Documentation of this problem was scant in both units. CONCLUSIONS: Results from this study suggest that nurses in both intensive care and surgical units do not appropriately assess, manage or evaluate pain and pain-related side effects. Patients who experience pain expect to have their pain controlled. Efforts must be made to change nurses' pain management behaviors.
Accuracy of infrared ear thermometry and other temperature methods in adults
Authors: Erickson RS , Meyer LT
Published: November 2019

OBJECTIVE: To compare the accuracy of infrared ear-based temperature measurement in relation to thermometer, ear position, and other temperature methods, with pulmonary artery temperature as the reference. METHODS: Ear-based temperature measurements were made with four infrared thermometers, three in the core mode and two in the unadjusted mode, each with tug and no-tug techniques. Pulmonary artery, bladder (n = 21), and axillary temperatures were read after each ear-based measurement and oral temperature was measured once when possible (n = 32). Subjects consisted of a convenience sample of 50 patients with pulmonary artery catheters who were in adult critical care units of a university teaching hospital. RESULTS: Ear-based measurements correlated well with pulmonary artery temperature (r = .87 to .91), although closeness of agreement differed among thermometer-mode combinations (mean offsets = -0.7 to 0.5 degree C) and had moderately high variability between subjects (SD = +/- 0.5 degree C) with all instruments. Use of an ear tug either made no difference or resulted in slightly lower readings. Bladder temperature was nearly identical to pulmonary artery temperature values (r = .99, offset = 0.0 +/- 0.2 degree C). Oral readings were slightly lower (r = .78, offset = -0.2 degree C) and axillary readings much more so (r = .80 to .82, offset = -0.7 degree C); both were highly variable (SD = +/- 0.6 degree C) and affected by external factors. CONCLUSIONS: Infrared ear thermometry is useful for clinical temperature measurement as long as moderately high variability between patients is acceptable. Readings differ among thermometers, although several instruments provide values close to pulmonary artery temperature in adults. Readings are not higher with an ear tug. Bladder temperature substitutes well for pulmonary artery temperature, whereas oral and axillary values may be influenced by external factors in the critical care setting.
Predicting hospital mortality in patients with acute myocardial infarction
Authors: Funk M , Pooley-Richards RL
Published: November 2019

BACKGROUND Patients who have a myocardial infarction are a heterogeneous group. If those at risk for early mortality could be readily identified, it would provide a more solid basis for management decisions. Although past research has explored factors associated with mortality, findings are inconsistent. Variables have also been combined into prognostic indices, but these tools have yet to be evaluated adequately. OBJECTIVES To determine factors predictive of hospital mortality in patients with acute myocardial infarction, and to examine the usefulness of two severity-of-illness indices. METHODS The medical records of 392 patients diagnosed with acute myocardial infarction who had undergone coronary angiography during 1989 at a university medical center were reviewed. RESULTS Overall mortality was 9.4% (n = 37). Logistic regression analysis demonstrated that history of myocardial infarction, cardiogenic shock, age, left ventricular ejection fraction, and the number of occluded coronary vessels were significantly associated with hospital mortality in patients with acute myocardial infarction. The two severity-of-illness indices were significant predictors of mortality, although sensitivity, specificity, and predictive values varied. A formula for determining the probability of mortality, based on logistic regression analysis, is also presented. CONCLUSIONS Five factors were found to predict hospital mortality. The two severity-of-illness indices were moderately useful in predicting mortality. Unlike previous indices that did not incorporate currently available diagnostic data, the new formula included data from coronary angiography and nuclear scans. Although this formula requires validation on independent samples of patients with myocardial infarction, the findings of this study advance clinicians' ability to predict patient outcome.
Effect of do-not-resuscitate orders on the nursing care of critically ill patients
Authors: Henneman EA , Baird B , Bellamy PE , Faber LL , Oye RK
Published: November 2019

BACKGROUND. The effect of a do-not-resuscitate order on the standard of care of critically ill patients is of concern to practitioners, patients, and their families. Because "do not resuscitate" may be misconstrued to include more than "no cardiopulmonary resuscitation," it may influence the aggressiveness with which some patients are managed. Nurses play a central role in determining standards of care. Hence, confusion on their part as to the meaning of this term can have a significant impact on patient care. OBJECTIVES. To compare nurses' attitudes about standards of care for critically ill patients with and without a do-not-resuscitate order. METHOD. A quasi-experimental design using simulation measurement was used for this study. RESULTS. Nurses reported that they would be significantly less likely to perform a variety of physiologic monitoring modalities and interventions for patients with a do-not-resuscitate order than for patients without such an order. Patients with a do-not-resuscitate order were more likely to receive psychosocial interventions including assessment of their spiritual needs and more flexible visiting practices. CONCLUSIONS. Our findings suggest that "do-not-resuscitate" may be misinterpreted to include more than "no cardiopulmonary resuscitation" even if the patient is receiving aggressive medical management. Misinterpretation of orders not to resuscitate may be related to a variety of factors including lack of understanding about hospital policy and ethical and moral values of the staff. We suggest replacing orders such as "Do not resuscitate" with clearly defined resuscitation plans that are jointly determined by the multidisciplinary team, patient, and family.
Spiritual care for the critically ill
Authors: Clark C , Heidenreich T
Published: November 2019

BACKGROUND: Spiritual well-being is the center of a healthy lifestyle and enables holistic integration of one's inner resources. However, the professional education process does not adequately provide socialization of nurses in the provision of spiritual care. Few studies exist that adequately address the spiritual aspect of nursing care. PURPOSE: To identify factors that contribute to providing spiritual care for patients in intensive care units. METHODS: A descriptive research design was used for this replication study conducted on a convenience sample of 63 patients in the critical care unit of a large midwestern military hospital. A trained interviewer asked each participant three open-ended questions regarding events that had created hope or meaning, created negative feeling, and could have contributed to hope or meaning. The interview took place 1 to 2 days after discharge from the intensive care unit. Predominant patterns were determined by content analysis. RESULTS: Three themes were identified as integral to the spiritual well-being of critical care patients: care providers, family/friends, and religion/faith. Nursing interventions identified for the three themes include establishing trusting relationships, providing in-depth spiritual assessment, conveying technical competence, and acting as facilitator among family, clergy, and other providers. CONCLUSIONS: We conclude that the key nursing interventions derived from this study include listening to patients' concerns and maintaining and conveying technical competence.
Endotracheal suctioning: time-worn ritual or timely intervention?
Authors: Copnell B , Fergusson D
Published: November 2019

BACKGROUND: Although many investigators have assessed the technique of endotracheal tube suctioning, the tissue of how frequently it should be performed remains controversial. No objective data is available to determine the answer. OBJECTIVE: To determine the criteria nurses use to make decisions regarding endotracheal suctioning. METHOD: Twenty-four registered nurses of varying levels of experience were asked a series of open-ended questions related to their theoretical knowledge, their ability to apply this knowledge, their suctioning practice, and how they made decisions regarding suctioning. RESULTS: All participants believed their patients required suctioning every 1 to 3 hours, with 17 performing it every 2 to 3 hours. Twenty criteria of which nine related to frequency were used in determining suctioning requirements. Eleven related to recognizing the need for immediate suctioning and were concerned with changes in the patient's condition. Common significant changes included desaturation, hemodynamic changes, loss of color, and blood gas changes. No single criterion was identified by all nurses. No differences were apparent between experienced and less experienced nurses. CONCLUSIONS: The large number of criteria identified suggests that the decision to suction is a complex one. It is a concern that many nurses rely on a deterioration in the patient's condition to indicate when suctioning is required. A policy of suctioning as necessary is provision of clear guidelines and education of all staff.
Effectiveness of a jet injection system in administering morphine and heparin to healthy adults
Authors: Baer CL , Bennett WM , Folwick DA , Erickson RS
Published: November 2019

BACKGROUND: Jet injection eliminates the risk of contaminated needlestick injuries when giving intramuscular or subcutaneous medications. Clinical efficacy of the Biojector System was equivalent to that of needle and syringe injection in unpublished trials with vaccines, but had not been studied using other drugs. OBJECTIVE: To compare the effectiveness of the Biojector with conventional needle and syringe injection in administering intramuscular morphine and subcutaneous heparin to healthy adults, as measured by plasma drug concentration. METHODS: Intramuscular injections of morphine 8 mg (5 mg if weight < or = 65 kg) were given 24 hours apart with the jet injector and with a needle and syringe to 30 subjects at the deltoid site and 10 subjects at the dorsogluteal site. Blood samples for plasma concentrations of free morphine were drawn at 15, 30, 45, 60, 120, and 240 minutes and were analyzed using radioimmunoassay. Abdominal subcutaneous injections of heparin 3500 U were given every 8 hours for 5 days with both injection methods to 29 subjects, with 48 hours between the two series. Daily blood samples for plasma heparin were analyzed by colorimetric assay for antifactor Xa activity. RESULTS: Mean free morphine concentration, peak value, and area under the curve did not differ significantly between the deltoid and dorsogluteal sites or between the jet injector and needle and syringe. Values of mean daily heparin concentrations and area under the curve were low and did not differ between the two injection methods. CONCLUSION: Plasma drug concentrations provided by the Biojector were equivalent to those provided by conventional needle and syringe when administering intramuscular morphine and low-dose subcutaneous heparin.
Clinical judgment and management of postoperative pain in critical care patients
Authors: Stannard D , Puntillo K , Miaskowski C , Gleeson S , Kehrle K , Nye P
Published: November 2019

BACKGROUND: Acute pain is a significant problem in critical care patients. Although many barriers to successful assessment and management of pain in critical care patients have been noted, little is known about how critical care nurses make clinical judgments when assessing and managing patients' pain. OBJECTIVE: This qualitative analysis is part of a pilot study evaluating nurses' use of a pain assessment and intervention notation algorithm in patients in critical care areas who have limited communication abilities after abdominal or thoracic surgery. METHOD: Transcribed audiotapes of nurse participants' "thinking aloud" while using the pain assessment and intervention notation algorithm were analyzed by using interpretive phenomenology. The interpretive account is based on 31 tape recordings of 14 nurses caring for 41 patients (12 patients in the ICU and 29 patients in the postanesthesia care unit). FINDINGS: The two domains of clinical judgment found were (1) assessing the patient and (2) balancing interventions. CONCLUSIONS: Many nurses' reports showed that they accurately assessed their patients' needs for analgesics. Through testing of and learning from their patients' responses, nurses were able to give amounts of analgesics that diminished patients' postoperative pain. Additionally, nurses had to balance analgesic administration against the patients' hemodynamic and respiratory conditions, medical plan and prescriptions, and the desires of the patients and the patients' families.
Effect of a music intervention on noise annoyance, heart rate, and blood pressure in cardiac surgery patients
Authors: Byers JF , Smyth KA
Published: November 2019

BACKGROUND: Exposure to noise in a critical care unit may trigger a response by the sympathetic nervous system, thereby increasing cardiovascular work in patients recovering from cardiac surgery. OBJECTIVE: To investigate the effects of a music intervention given twice on the first postoperative day on noise annoyance, heart rate, and arterial blood pressure in subjects with high (n = 22) and low (n = 18) sensitivity to noise. METHODS: A prospective, quasi-experimental, repeated-measures design was used. Based on results of power analysis, the sample size was 40. Subjects were recruited preoperatively, and their sensitivity to noise was assessed. On the first postoperative day, repeated-measures data were collected on levels of noise annoyance and physiological variables during 15 minutes of baseline and 15 minutes of music intervention on two occasions. Subjects completed a follow-up questionnaire regarding their perceptions of the noise in the critical care unit and the music intervention. RESULTS: Repeated-measures analysis of variance showed that subjects had lower levels of noise annoyance during music intervention than at baseline. Heart rate and systolic blood pressure decreased during the music intervention compared with baseline. Diastolic blood pressure decreased during the music intervention from baseline during time 2, but not time 1. Subjects with high baseline scores of noise sensitivity preoperatively had higher baseline levels of noise annoyance in the critical care unit the first postoperative day. Subjects rated the music intervention as highly enjoyable regardless of their baseline noise sensitivity or noise annoyance. CONCLUSION: Results of this study support the idea that noise annoyance is a highly individual phenomenon, influenced by a transaction of personal and environmental factors. Use of a music intervention with cardiac surgery patients during the first postoperative day decreased noise annoyance, heart rate, and systolic blood pressure, regardless of the subject's noise sensitivity.
A comparison of transparent polyurethane and dry gauze dressings for peripheral i.v. catheter sites: rates of phlebitis, infiltration, and dislodgment by patients
Authors: Tripepi-Bova KA , Woods KD , Loach MC
Published: November 2019

BACKGROUND: Before a meta-analysis by Hoffman et al was published, polyurethane dressings were used at insertion sites for peripheral i.v. catheters at our institution. On the basis of the results of the meta-analysis, we began to use gauze dressings. The change from polyurethane dressings to gauze dressings limited direct observation of the i.v. insertion site, and i.v. catheters were anecdotally reported not to be anchored as securely as before. OBJECTIVES: The purpose of this study was to compare the effects of the use of transparent polyurethane dressings and gauze dressings at insertion sites for peripheral i.v. catheters on the frequency of phlebitis, infiltration, and catheter dislodgment by patients. METHODS: Two hundred twenty-nine patients were randomized to receive either gauze (n = 121) or transparent polyurethane (n = 108) dressings, and observations were recorded. RESULTS: The frequency of catheter dislodgment by the patient was significantly higher (P < .05) in patients with the gauze dressing (15%) than in patients with the transparent polyurethane dressing (6%). A trend toward lower frequencies of phlebitis (1.8% vs 3.3%) and infiltration (17.6% vs 20.7%) was noted in the patients with the transparent polyurethane dressings. DISCUSSION: The clinical advantages of the transparent polyurethane dressings lie in the ease of direct visualization of the i.v. insertion site and the securement of the i.v. catheter. CONCLUSION: At our institution, given the decreased disruption of the i.v. therapy with the transparent polyurethane dressings and the lack of differences in the rates of phlebitis or infiltration with the two types of dressings, we prefer to use transparent polyurethane rather than gauze dressings at insertion sites for peripheral i.v. catheters.
Family members' experiences with decision making for incompetent patients in the ICU: a qualitative study
Authors: Jacob DA
Published: November 2019

BACKGROUND: Understanding the challenges faced by family members involved in decisions about the use of life-sustaining treatment for incompetent patients in the ICU is necessary for developing empirically based supportive interventions. OBJECTIVES: To describe and explain the experiences of family members who were involved in decisions on behalf of their loved ones in order to promote understanding of such experiences and to suggest areas for effective, supportive intervention. METHODS: The grounded-theory method of qualitative research was used. Data collection involved semistructured interviews of 17 persons who had been involved in decisions about the use of life-sustaining treatment for a family member in the ICU. RESULTS: Family members discussed the need to arrive at a judgment of the patient's condition and to work with caregivers to have the family member's decision about life-sustaining treatment enacted. Data analysis suggests that clinicians can best support family members by helping the members arrive at a judgment about the patient's condition and treatment desires and by connecting with the family members to ensure that treatment goals are mutual. Supporting family members in this way helps them accept and go on in a positive way after the experience. CONCLUSIONS: Family members of patients in the ICU are willing and able to take responsibility for decisions about the use of life-sustaining treatment for their loved ones. The long-term acceptance of the experience and the decisions made depends greatly on the interactions between the family member who makes the decision and nurses and physicians in the clinical setting.
Nitric oxide and regulation of vascular tone: pharmacological and physiological considerations
Authors: McHugh J , Cheek DJ
Published: November 2019

The endothelial cells of the vascular system are responsible for many biological activities that maintain vascular homeostasis. Responding to a variety of chemical and physical stimuli, the endothelium elaborates a host of vasoactive agents. One of these agents, endothelium-derived relaxing factor, now accepted as nitric oxide, influences both cellular constituents of the blood and vascular smooth muscle. A principal intracellular target for nitric oxide is guanylate cyclase, which, when activated, increases the intracellular concentration of cyclic guanosine monophosphate, which in turn activates protein kinase G. Acting by this pathway, nitric oxide induces relaxation of vascular smooth muscle and inhibits platelet activation and aggregation. Derangements in endothelial production of nitric oxide are implicated as both cause and consequence of vascular diseases, including hypertension, atherosclerosis, and coronary artery disease.
Bathing premature infants: physiological and behavioral consequences
Authors: Peters KL
Published: November 2019

BACKGROUND: Routine procedures are a large component of the caretaking day for preterm infants. Such procedures can have profound adverse effects on an infant's condition, to the point of disrupting normal growth and development. Despite this evidence, routine procedures are perpetuated in the neonatal ICU. OBJECTIVE: To determine the physiological and behavioral effects of a supposedly beneficial procedure, a sponge bath, on premature infants. METHODS: The study sample consisted of 14 preterm neonates with no neurological abnormalities at two tertiary neonatal ICUs. The ages of the subjects were 28.1 to 31.8 weeks postconception and 4 to 25 days after birth. The study was a prospective, quasi-experimental, repeated-measures design in which each infant acted as his or her own control. Oxygen delivery, heart rate, oxygen saturation, and behavioral responses were continuously recorded by computer or real-time videotape. Physiological and behavioral parameters were compared across three phases: 10 minutes before a bath (baseline), during a standardized bath, and 10 minutes after the bath. RESULTS: Physiological and behavioral disruptions occurred throughout the bath phase and in many cases beyond that phase. These disruptions included significant increases in heart rate, cardiac oxygen demand, and frequency of behavioral motoric cues. Significant decreases in oxygen saturation also accompanied the bath. Nine infants required increased concentrations of ambient oxygen. A significant association was found between physiological components and the frequency and timing of behavioral motoric cues. CONCLUSIONS: The results provide further evidence that routine care is not innocuous to neonates. Routine sponge bathing is not recommended for care of ill premature infants.
Validity of the numeric rating scale as a measure of dyspnea
Authors: Gift AG , Narsavage G
Published: November 2019

BACKGROUND: Dyspnea, a devastating sign, is rarely monitored by clinicians. One reason may be the lack of a valid measurement scale that is easy to use in a clinical setting. OBJECTIVES: To establish the validity of the numeric rating scale as a measure of present dyspnea (dyspnea at rest). METHODS: A total of 188 patients with chronic obstructive pulmonary disease rated their present dyspnea by using the Visual Analog Dyspnea Scale and the numeric rating scale. They also rated their usual dyspnea (dyspnea during the past week). Demographic information was collected from each patient's chart, and pulmonary status was assessed with portable spirometry, pulse oximetry, or both. RESULTS: Concurrent validity of the numeric rating scale was supported by the high correlation of its scores with scores from the Visual Analog Dyspnea Scale. Conversion of the numeric rating scale to a 0-to-100 scale and comparison with the visual analog scale (by using a paired t test to determine if the correlated scores were similar for clinical decision making) showed that scores were not significantly different. A paired t test showed a difference in scores on the numeric rating scale obtained before and after ambulation, supporting the construct validity of the numeric rating scale. Scores on the numeric rating scale for present dyspnea were poorly correlated with ratings of usual dyspnea, indicating that present dyspnea and usual dyspnea are different constructs. CONCLUSION: Present and usual dyspnea are different constructs. The numeric rating scale is a valid measure of present dyspnea.
The effect of earplugs on sleep measures during exposure to simulated intensive care unit noise
Authors: Wallace CJ , Robins J , Alvord LS , Walker JM
Published: November 2019

BACKGROUND: Sleep deprivation may contribute to impaired immune function, ventilatory compromise, disrupted thermoregulation, and delirium. Noise levels in intensive care units may be related to disturbed sleep patterns, but noise reduction has not been tested in this setting. OBJECTIVE: To measure the effect of a noise reduction intervention on the sleep of healthy subjects exposed to simulated intensive care unit noise. METHODS: After digital audiotape recording of noise and development of the noise reduction intervention, 5 nocturnal 8-hour periods of sleep were measured in 6 paid, healthy volunteers at 7-day intervals in a sleep disorders center. Polysomnographic data were collected by experienced sleep disorders technicians and scored by certified raters. After the first 3 quiet nights, earplugs were randomly assigned to be worn on the fourth and fifth nights during exposure to the recorded noise. Sound pressure levels were measured during all 5 nights. RESULTS: Sleep architecture and sound measurements on quiet nights did not differ significantly. Sound levels were significantly lower on quiet nights than on noise nights. Exposure to the noise increased the number of awakenings, percentage of stage 2 sleep, and rapid eye movement latency and decreased time asleep, sleep maintenance efficiency index, and percentage of rapid eye movement sleep. Earplugs worn during exposure to the noise produced a significant decrease in rapid eye movement latency and an increase in the percentage of rapid eye movement sleep. CONCLUSION: The results provide a reasonable basis for testing the effects of earplugs on the sleep of critically ill subjects.
Instillation of normal saline during endotracheal suctioning: effects on mixed venous oxygen saturation
Authors: Kinloch D
Published: November 2019

BACKGROUND: Instillation of normal saline before endotracheal suctioning is thought to facilitate removal of secretions and ultimately to improve the patient's oxygenation status. To date, no studies have used an in vivo measure of oxygenation such as mixed venous oxygen saturation to characterize the effects of instillation of normal saline. OBJECTIVES: To describe the effects of instillation of normal saline into an endotracheal tube before suctioning on mixed venous oxygen saturation in critically ill adult patients. METHODS: In a descriptive, observational study, 35 patients were assigned to either of 2 groups after coronary artery bypass grafting. One group had 5 mL of normal saline instilled at the start of endotracheal tube suctioning; the other group had the same endotracheal tube suctioning procedure without the use of saline. Data on mixed venous oxygen saturation were recorded at 1-minute intervals for a 5-minute baseline period and then throughout the suctioning procedure until mixed venous oxygen saturation returned to baseline levels. RESULTS: The time required for mixed venous oxygen saturation to return to baseline values after suctioning was an average of 3.78 minutes longer when saline was used. CONCLUSIONS: Instillation of normal saline before endotracheal suctioning has an adverse effect on oxygenation as indicated by mixed venous oxygen saturation. This finding contradicts the assumption that instillation of normal saline improves oxygenation status.
Obtaining blood samples for coagulation studies from a normal saline lock
Authors: Powers JM
Published: November 2019

OBJECTIVES: To determine the amount of blood that should be discarded from a peripheral normal saline lock, a capped-off intravenous port, before a blood sample is obtained for determination of activated partial thromboplastin time from patients being treated with heparin. METHODS: A prospective, quasi-experimental design was used with 32 patients. A blood sample was obtained via venipuncture from each patient to serve as the control for that patient. The normal saline lock was flushed with 2 mL of normal saline. Four consecutive 3-mL blood samples were obtained directly from the normal saline lock, representing samples obtained after discard volumes of 0, 2, 4, and 6 times the dead space of the catheter and extension set (1.5 mL). Activated partial thromboplastin times for the venipuncture blood sample were compared with the times for the blood samples obtained from the normal saline lock. RESULTS: The only significant difference (P = .02) was that activated partial thromboplastin time was 15% higher in the blood sample obtained from the normal saline lock with no blood discarded than in the venipuncture blood sample. CONCLUSIONS: Nurses can obtain accurate measurements of activated partial thromboplastin time with blood samples obtained from normal saline locks by first discarding a volume of blood equal to 2 times the dead space of the catheter and extension set. Obtaining blood samples in this manner reduces patients' discomfort due to repeated venipuncture and diminishes blood loss.
Measurement of dyspnea in patients treated with mechanical ventilation
Authors: Powers J , Bennett SJ
Published: November 2019

BACKGROUND: Dyspnea, or difficult breathing, is common in patients receiving mechanical ventilation; however, dyspnea is not routinely or systematically measured. OBJECTIVE: The primary purpose of this methodological study was to evaluate the test-retest reliability of 5 dyspnea rating scales and the criterion validity of 4 dyspnea rating scales in patients receiving mechanical ventilation. The secondary purpose was to examine the correlations between each of these 5 rating scales and physiological measures of respiratory function. METHODS: The convenience sample consisted of 28 patients on mechanical ventilation during their hospitalization in the intensive care units of a large, inner-city hospital. Patients rated their dyspnea twice at 30-minute intervals on the visual analogue scale, the vertical analogue dyspnea scale, the modified Borg scale, the numerical scale, and the faces scale. Test-retest reliability was computed by using the intraclass correlation coefficient. Criterion validity was evaluated by using the Spearman rank-order correlation coefficient. RESULTS: The 5 rating scales had acceptable test-retest reliabilities, with intraclass correlation coefficients ranging from 0.81 to 0.97. Criterion validity of the 4 scales also was acceptable, with Spearman rank-order correlation coefficients from 0.76 to 0.96. The rating scales were not correlated with most of the physiological variables. At least half of the patients reported moderate to severe dyspnea. CONCLUSION: The scales showed acceptable reliability and validity, and they will be useful in quantifying dyspnea experienced by patients receiving mechanical ventilation. Further work is needed to evaluate the extent and the severity of dyspnea in such patients in order to evaluate the effectiveness of interventions.
Predicting the risk of pressure ulcers in critically ill patients
Authors: Carlson EV , Kemp MG , Shott S
Published: November 2019

BACKGROUND: Critically ill patients are at high risk for pressure ulcers. OBJECTIVES: To determine the contributions of the Braden subscales in predicting pressure ulcers in critically ill patients and to investigate how often the Braden scale should be completed to assess the risk for pressure ulcers in critically ill patients. METHOD: The Braden scale was used to assess repeatedly 136 adult patients without pressure ulcers in a medical intensive care unit, a surgical intensive care unit, and a noninvasive respiratory care unit, and the patients' skin was inspected routinely for pressure ulcers. RESULTS: A total of 36 pressure ulcers, most commonly on the sacrum or coccyx and the heels (15 stage 1, 20 stage 2, 1 stage 3), developed in 17 patients (12%). In 14 (82%) of the 17, the ulcers developed within 72 hours of admission to the intensive care unit. The risk for pressure ulcers increased as the mean sensory perception (P = .01) and the mean total Braden (P = .046) scores decreased. The mean sensory perception scores obtained at 12 and 36 hours after admission also had a significant relationship to the risk for pressure ulcers (P = .03). CONCLUSIONS: Patients in intensive care units have an increased risk for pressure ulcers. Although waiting until 12 hours after a patient's admission to the intensive care unit to obtain the initial Braden rating may be reasonable (with the second rating obtained 36 hours after admission), additional research is needed before this practice can be recommended.
Prone positioning of patients with acute respiratory distress syndrome: a systematic review
Authors: Curley MA
Published: November 2019

A computerized bibliographic search of published research and a citation review of English-language publications about prone positioning of patients with acute respiratory distress syndrome were done. Information on prone positioning related to technique, patients' responses, complications, and recommendations to prevent complications was extracted. In the 20 pertinent clinical studies found, 297 patients (mean age, 39 years) with acute respiratory failure were positioned prone. Timing from the onset of respiratory failure to when the patient was first positioned prone varied, as did the frequency of prone positioning. Patients spent from 30 minutes to 42 hours prone. In 47% of the studies in which abdominal position was noted, chest and pelvic cushions were used to allow the abdomen to protrude while the patient was prone. Improved oxygenation within 2 hours was reported in 69% of patients, and the improvements were cumulative and persistent. Aside from early intervention, factors predictive of patients' responses were inconsistent, and patients' initial responses were not predictive of subsequent responses. Iatrogenic critical events were rare. Dependent edema of the face was prevalent. Pressure ulcers were reported in studies with longer periods of prone positioning. The most serious complication, corneal abrasion requiring corneal transplantation, was reported in one patient. Clinical knowledge about prone positioning is limited. Phase 1 studies focusing on how to safely turn and care for critically ill patients positioned prone for prolonged periods are needed.
Music: an intervention for pain during chest tube removal after open heart surgery
Authors: Broscious SK
Published: November 2019

BACKGROUND: Pain associated with chest tube removal is a major problem for patients who undergo open heart surgery. Because this pain is short-lived, timing the administration of pharmacological agents for pain relief is difficult and is therefore done inconsistently. OBJECTIVE: To examine the effect of music as an intervention for pain relief during chest tube removal after open heart surgery. METHODS: In an experimental design, 156 subjects (mean age, 66 years; 69% men) were randomly assigned to 1 of 3 groups: control, white noise, or music. All subjects preselected the type of music they preferred hearing. Ten minutes before the chest tube was removed, the patient's heart rate and blood pressure were measured, the patient rated pain intensity by using a numeric rating scale, and the prerecorded audiotape of music was begun. The patients rated their pain again immediately after chest tube removal and 15 minutes later. Physiological variables were assessed every 5 minutes until 15 minutes after the chest tubes were removed. RESULTS: Self-reported pain intensity, physiological responses, and narcotic intake after chest tube removal did not differ significantly among the 3 groups. CONCLUSIONS: Although the findings were not statistically significant, most subjects enjoyed listening to the music, and therefore the use of music as an adjuvant to other therapies may be an appropriate nursing intervention.