Qualitative studies on the patient's experience of weaning from mechanical ventilation.

In contrast to primarily deductive quantitative research, qualitative research aims to interpret data to develop theoretical insights that describe and explain phenomena such as interactions, experiences, roles, perspectives, and organizations. In this review, we summarize qualitative studies that used primarily in-depth personal interviews as a data collection method and a grounded theory analytic approach. The liberal use of illustrative excerpts and interpretive descriptions offer clinicians vicarious accounts of patient experiences of weaning from mechanical ventilation. Important experiences of patients during their weaning from mechanical ventilation included frustration, uncertainty, hopelessness, fear, and lack of mastery. The extent to which, in at least some patients, these experiences were determinants of weaning failure, consequences of weaning failure, or both, was difficult to establish. An assumption of this genre of research is that if clinicians understand the lived experiences of patients, they can better appreciate patient needs during the weaning process, and by inference, their role as clinicians during weaning from mechanical ventilation.

Thermodynamic and kinetic characterization of the dissociation and assembly of quadruplex nucleic acids.

The dissociation and assembly of quadruplex DNA structures (and a few quadruplex RNAs) have been characterized at several levels of rigor, ranging from gross descriptions of factors that govern each process, to semiquantitative comparisons of the relative abilities of these factors to induce stabilization or destabilization, to quantitative studies of binding energies (thermodynamics), transformational rates (kinetics), and analysis of their transition-state energies and mechanisms. This survey classifies these factors, describes the trends and focuses on their interdependencies. Quadruplex assembly is induced most efficiently by added K(+) and elevating the strand concentration; however, Na(+), NH(4)(+), Sr(2+), and Pb(2+) are also very effective stabilizers. Quadruplex dissociation is typically accomplished by thermal denaturation, "melting"; however, when the quadruplex and monovalent cation concentrations are low enough, or the temperature is sufficiently high, several divalent cations, e.g., Ca(2+), Co(2+), Mn(2+), Zn(2+), Ni(2+) and Mg(2+) can induce dissociation. Stabilization also depends on the type of structure adopted by the strand (or strands) in question. Variants include intramolecular, two- and four-stranded quadruplexes. Other important variables include strand sequence, the size of intervening loops and pH, especially when cytosines are present, base methylation, and the replacement of backbone phosphates with phosphorothioates. Competitive equilibria can also modulate the formation of quadruplex DNAs. For example, reactions leading to Watson-Crick (WC) duplex and hairpin DNAs, triplex DNAs, and even other types of quadruplexes can compete with quadruplex association reactions for strands. Others include nonprotein catalysts, small molecules such as aromatic dyes, metalloporphyrins, and carbohydrates (osmolytes). Other nucleic acid strands have been found to drive quadruplex formation. To help reinforce the implications of each piece of information, each functional conclusion drawn from each cited piece of thermodynamic or kinetic data has been summarized briefly in a standardized table entry.

Therapeutic Intervention Scoring System used in the care of patients in pentobarbital-induced coma to determine nurse-patient ratios.

BACKGROUND: Critical care patients generally require extensive interventions, thereby consuming a large percentage of healthcare resources. Induced pentobarbital coma for the management of increased intracranial pressure is one such intervention, required to maintain patient stability. Quantification of these interventions, as well as the amount of nursing work required, has not been addressed in the literature. OBJECTIVE: To use the Therapeutic Intervention Scoring System to analyze and quantify how interventions affect nurse-patient ratios in the management of patients in pentobarbital coma for refractory increased intracranial pressure. METHODS: The medical records of patients with subarachnoid hemorrhage from aneurysmal rupture and subsequent increased intracranial pressure, in whom pentobarbital coma was salvage therapy, were reviewed retrospectively. The Therapeutic Intervention Scoring System was used to quantify the number of interventions required before, during, and after coma induction. The data were analyzed and daily Therapeutic Intervention Scoring System scores correlated with serum pentobarbital levels. Typically, a critical care nurse can manage a patient caseload of 40 to 50 Therapeutic Intervention Scoring System points. By quantifying the interventions, the score reflected the amount of care required to manage the patient in barbiturate coma. RESULTS: The intensity of interventions correlated with the level of coma, length of time in coma, and associated complications. CONCLUSIONS: The scores indicated the intensity of interventions used in pentobarbital coma and the use of resources. Nursing care and complications involved with this therapy were quantified and nurse-patient ratios were established.

Aminophylline use in the critically ill: an old ally or new foe?

Although the use of aminophylline as a first line bronchodilator has declined during the last 2 decades, there are other clinical indications for which aminophylline is effective and may be the drug of choice. In this article, the author describes the drug's pharmacokinetics, physiologic effects, and indications for use. In addition, research pertaining to contemporary use of the drug is summarized. It is hoped that this article will help the critical care nurse assess and care for those critically ill patients for whom in aminophylline is used as primary or adjunctive therapy.

Capnography: assessing end-tidal CO2 levels.

The purpose of this article is to describe the nurse's role in caring for patients with capnography. Capnography provides a continuous and non-invasive measure of arterial partial pressure of carbon dioxide (PaCO2) throughout the entire respiratory cycle. Used correctly, this technology assists the critical care nurse in providing adequate oxygenation and ventilation to the unstable patient.

Quantifying nursing care in barbiturate-induced coma with the therapeutic intervention scoring system.

The use of pentobarbital-induced coma to manage intractable increased intracranial pressure remains a viable option in the acutely brain-injured patient. In a retrospective review of 15 patients with a variety of neurological injuries at our institution, it was found that aggressive management of respiratory, hemodynamic, metabolic and neurological status was required with the use of pentobarbital coma. A scoring system to determine the amount of interventions and nursing care required was used in the review. The Therapeutic Intervention Scoring System (TISS) demonstrated that with the acuity of illness, there were predictably increased interventions. As a method for quantifying the amount of care in this group of individuals, scoring of the interventions before, during, and after barbiturate coma was assessed. The findings demonstrated a significant difference in the scoring. Mean scores were: pre-treatment = 31.8, s.d. = 7.5; during = 41.7, s.d. = 2.0; post-treatment = 36.4, s.d. = 5.2, p < 0.01. Further modifications of the TISS to include current neuroscience therapies, such as the monitoring of cerebral oxygen extraction by jugular bulb catheterization, may increase the utility of the TISS.