Fever management practices of neuroscience nurses, part II: nurse, patient, and barriers.

Fever is frequently encountered by neuroscience nurses in patients with neurological insults and often results in worsened patient outcomes when compared with similar patients who do not have fever. Best practices in fever management are then essential to optimizing patient outcomes. Yet the topic of best nursing practices for fever management is largely ignored in the clinical and research literature, which can complicate the achievement of best practices. A national survey to gauge fever management practices and decision making by neuroscience nurses was administered to members of the American Association of Neuroscience Nurses. Results of the questionnaire portion of the survey were previously published. This report presents a content analysis of the responses of neuroscience nurses to the open-ended-question portion of the survey (n = 106), which revealed a dichotomous primary focus on nursing- or patient-related issues. In addition, respondents described barriers and issues in the provision of fever-management care to neuroscience patients. In order to advance national best practices for fever management in neurologically vulnerable patients, further work needs to be conducted, particularly with regard to necessary continuing education for staff, facilitation of interdisciplinary communication, and development of patient care protocols. Neuroscience nurses are in an excellent position to provide leadership in these areas.     

Application of the 'pull-off' force method for measurement of surface tension of upper airway mucosal lining liquid

Upper airway luminal patency is influenced by a number of factors including: intraluminal air pressure, upper airway dilator muscle activity, surrounding extraluminal tissue pressure and surface tension acting within the liquid layer lining the upper airway. In this study we examine the performance characteristics for the 'pull-off' force method for measuring the surface tension (gamma) of liquids. This method is then used to examine the gamma of the liquid lining the oro-pharynx in awake human subjects. The gamma of UAL samples (approximately 0.2 microL) obtained from the posterior pharyngeal wall was quantified using the pull-off force technique in which gamma is measured as the force required to separate two curved silica discs bridged by the liquid sample. Pull-off force measurement was not influenced by sample volumes or under different temperature or humidity conditions. The coefficients of variation for repeated measurements using the pull-off force technique for the three standard liquids ranged from 1.2% to 5.6%. The pull-off method tended to give slightly lower values than the Wihelmy balance method with the mean difference being 2.4 +/- 1.8 mN m(-1). For the group, the gamma of saliva was 59.2 +/- 0.6 mN m(-1) (CV 4.9 +/- 0.9%) for five measurements of a single sample. There was no significant relationship between the measured gamma values for five subjects measured on five separate days and the day of collection of the sample for any of the subjects or the group as a whole (both p > 0.6). There was no significant difference (p = 0.53, ANOVA) between the gamma values for samples obtained from under the tongue (61.6 +/- 1.7 mN m(-1)), at the oral surface of the soft palate (56.1 +/- 3.2 mN m(-1)) and from the posterior oro-pharyngeal wall (58.1 +/- 2.4 mN m(-1)). The pull-off force method provides adequate reproducibility to be able to measure the gamma of UAL. In healthy humans the gamma of UAL is similar to that of saliva.     

The effects of hormonal status on upper airway patency in normal female subjects during propofol anesthesia

Study Objective

To determine the mechanical upper airway properties and compensatory neuromuscular responses to obstruction during propofol anesthesia in the follicular and luteal phases of the menstrual cycle.

Design

Prospective, randomized study.

Setting

University-affiliated hospital.

Subjects

12 premenopausal female volunteers for studies of upper airway collapse throughout their menstrual cycle during the follicular phase (6 -10 days) and mid-late luteal phase (20 - 24 days).

Measurements

The level of propofol anesthesia (1.5 - 2.0 μg/mL) required to suppress arousal responses was determined by Observer's Assessment of Alertness/Sedation scoring (level 2) and confirmed by bispectral index monitoring. Pressure-flow relationships were constructed to evaluate collapsibility (P_CRIT) and up-stream resistance (R_US) during acute [Passive; hypotonic electromyography (EMG)] and sustained (Active; elevated EMG) changes in nasal mask pressure. The difference between passive P_CRIT and active P_CRIT (ΔP_{CRIT A-P}) represented the magnitude of the compensatory response to obstruction.

Main Results

Passive P_CRIT was significantly higher in the mid-late luteal phase (-4.7 cm H₂O) than in the follicular phase (-6.2 cmH₂O; P < 0.05). Active P_CRIT significantly decreased compared with passive P_CRIT in the follicular phase (-10.1 cm H₂O) and in the mid-late luteal phase (-7.7 cm H₂O) and (P < 0.05). No significant difference was noted in ΔP_CRIT between the follicular (3.9 ± 2.9 cm H₂O) and mid-late luteal phases (3.0 ± 2.6 cm H₂O). No differences were seen in R_US between the menstrual phases for either the passive (P = 0.8) or active (P = 0.75) states.

Conclusions

Menstrual phase has an effect on anatomical alterations (mechanical properties) in the hypotonic upper airway during propofol anesthesia.     

Neurointensive care; impaired cerebral autoregulation in infants and young children early after inflicted traumatic brain injury: a preliminary report

The objective of this report is to describe cerebral autoregulation after severe inflicted pediatric traumatic brain injury (iTBI). We examined cerebral autoregulation of both cerebral hemispheres (mean autoregulatory index; ARI) in children <5 years with Glasgow Coma Scale (GCS) score of <9 and no evidence of brain death within the first 48 h of pediatric intensive care unit (PICU) admission. Discharge and 6-month Glasgow Outcome Scale (GOS) scores were collected. GOS of <4 reflected poor outcome. All three iTBI and all seven noninflicted TBI (nTBI) patients had admission GCS score of <9. Eight of 10 patients had Autoregulatory Index (ARI) of <0.4 (impaired cerebral autoregulation) of at least one hemisphere. All children with iTBI had poor outcome, and none had intact cerebral autoregulation in both hemispheres. Children with nTBI had better overall outcome than those with iTBI. Two of the children with nTBI had intact autoregulation in both hemispheres and good outcome. Two of the three children with iTBI had differential effects on autoregulation between hemispheres despite bilateral injury. These are, to our knowledge, the first data on cerebral blood flow autoregulation in the unique setting of iTBI and provide a rationale for further study of their relationship to outcome and effects of therapy.     

Nasal dilator strips delay the onset of oral route breathing during exercise.

The external nasal dilator strip (ENDS) device (Breathe Right, CNS Inc., Chanhassen, MN, USA) has been adopted by athletes to promote nasal route breathing during exercise. We studied the influence of ENDS on the switching point from nasal-only to oro-nasal breathing during exercise in 4 healthy men (age 25 +/- 2 yrs, mean +/- SEM) and 5 women (age 30 +/- 5 yrs). Resting inspiratory nasal airflow resistance decreased from 0.33 +/- 0.02 kPa/L/s without ENDS to 0.22 +/- 0.01 kPa/L/s with ENDS (p < 0.01). ENDS delayed the onset of oro-nasal breathing such that the time from commencement of exercise to switching increased by 15.2%, and maximum levels of inspiratory nasal airflow and ventilation achieved prior to switching increased by 14.9% and 14.3%, respectively (all p < 0.05). We conclude that, in normal healthy subjects, ENDS does promote nasal route breathing during exercise, but any delay in the onset of oral route breathing during a progressive exercise task appears relatively small.     

Botulinum toxin A-induced protective ptosis in corneal disease

Botulinum toxin A produces a temporary, flaccid ptosis when injected into the levator palpebrae superioris muscle. The resulting protective ptosis was used to aid healing in 21 cases of indolent ulceration, and, prophylactically, in 4 cases of neuroparalytic keratitis. Of the indolent ulcers, 90% healed completely. In all but one case, the cornea was covered completely by the lid and complete ptosis was produced in 75% of cases in an average of 3.6 days, lasting for 16 days on average before recovery began. Recovery of levator function was complete in 8.5 weeks on average. Superior rectus underaction was seen in 68% of cases but this recovered completely in all cases in an average of 6 weeks. Impression cytology showed a trend toward normal conjunctival morphology as healing progressed.     

Coexistent corneal disease and glaucoma managed by either drainage surgery and subsequent keratoplasty or combined drainage surgery and penetrating keratoplasty.

The results of penetrating keratoplasty following trabeculectomy in 26 eyes where there was coexistent corneal disease and glaucoma are presented. Patients were aged 16-80 years at the time of drainage surgery (mean = 51 years) and there was a mean of 33.5 months between trabeculectomy and keratoplasty. The mean pressure fell from 35.3 mm Hg prior to trabeculectomy to 14.9 mm Hg at the time of keratoplasty and 20 mm Hg 12 months after keratoplasty. There was a 0.45 probability of maintaining normal intraocular pressure with medication at 5 years after keratoplasty; and a similar graft survival probability. The probability of maintaining both a clear graft and a normal pressure was only 0.27 at 5 years. In another 22 eyes combined trabeculectomy and penetrating keratoplasty was performed. Patients' ages ranged from 21-82 years (mean 55) at surgery, and 73% were aphakic. The intraocular pressure dropped from a mean of 28.9 mm Hg preoperatively to 14 mm Hg at 12 months. There was a 5 year probability of 0.7 of maintaining a clear graft but if both a clear graft and normal intraocular pressure are considered then the probability falls to 0.5 at 5 years. The hazard ratio for intraocular pressure control and graft survival between the two groups suggests that combined surgery may offer a better prognosis.