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Biomedical subjects

G K Arnold

Publications and source records attributed to G K Arnold.

6 recordsLinked to original sources
PubMed2001

Lung recruitment and breathing pattern during variable versus continuous flow nasal continuous positive airway pressure in premature infants: an evaluation of three devices.

OBJECTIVE: To determine whether lung volume changes and breathing pattern parameters differ among 3 devices for delivery of nasal continuous positive airway pressure (CPAP) in premature infants. METHODS: Thirty-two premature infants receiving nasal CPAP for apnea or mild respiratory distress were enrolled. Birth weight was (mean +/- standard deviation) 1081 +/- 316 g, gestational age 29 +/- 2 weeks, age at study 13 +/- 12 days, and fraction of inspired oxygen (FIO(2)) at study.29 +/-.1. Three devices, applied in random order, were studied in each infant: continuous flow nasal CPAP via CPAP prongs, continuous flow nasal CPAP via modified nasal cannula, and variable flow nasal CPAP. After lung recruitment to standardize volume history, changes in lung volume (DeltaV(L)) were assessed at nasal CPAP of 8, 6, 4, and 0 cm H(2)O using calibrated direct current-coupled respiratory inductance plethysmography. RESULTS: DeltaV(L) was significantly greater overall with the variable flow device compared with both the nasal cannula and CPAP prongs. However, DeltaV(L) was not different between the cannula and the prongs. Respiratory rate, tidal volume, thoraco-abdominal asynchrony, and FIO(2) were greater with the modified cannula than for either of the other 2 devices. CONCLUSION: Compared with 2 continuous flow devices, the variable flow nasal CPAP device leads to greater lung recruitment. Although a nasal cannula is able to recruit lung volume, it does so at the cost of increased respiratory effort and FIO(2).

Apnea↗
PubMed2000

Endogenous mediators in emergency department patients with presumed sepsis: are levels associated with progression to severe sepsis and death?

STUDY OBJECTIVE: We sought to determine whether levels of the endogenous mediators tumor necrosis factor (TNF)-alpha, interleukin (IL) 6, and nitric oxide (NO) measured in patients with presumed sepsis (systemic inflammatory response syndrome [SIRS] and infection) are different than levels in patients with presumed noninfectious SIRS, whether levels are associated with septic complications, and whether there are potential relationships between mediators. METHODS: A prospective, observational tricenter study of a convenience sample of adults presenting to the emergency department meeting Bone's criteria for SIRS (any combination of fever or hypothermia, tachycardia, tachypnea, or WBC count aberration) was performed. Mediator levels were determined and associated with deterioration to severe sepsis (hypotension, hypoperfusion, or organ dysfunction) and death in subjects admitted to the hospital with presumed sepsis. RESULTS: One hundred eighty subjects with SIRS were enrolled and classified into 3 groups: group 1 (SIRS, presumed infection, admitted; n=108), group 2 (SIRS, presumed infection, discharged; n=27), and group 3 (SIRS, presumed noninfectious, admitted; n=45). Group 1 TNF-alpha and IL-6 levels were significantly higher than those found in the other groups. NO levels for groups 1 and 2 were significantly lower than those for group 3. TNF-alpha and IL-6 levels were higher in the group 1 subjects who had bacteremia or progressed to severe sepsis or death. NO levels were not associated with these outcomes. CONCLUSION: ED patients admitted with presumed sepsis have elevated cytokine levels compared with patients with sepsis who are discharged and with those patients with presumed noninfectious SIRS. An association appears to exist between cytokines and subsequent septic complications in these patients. The importance of these measures as clinical predictors for the presence of infection and subsequent septic complications needs to be evaluated.

Adult↗
PubMed2000

Clinically meaningful changes in quantitative measures of asthma severity.

OBJECTIVE: To determine minimum clinically meaningful improvements in peak expiratory flow rate (PEFR) and dyspnea visual analog score (VAS) in patients with acute asthma exacerbation. METHODS: Patients presenting to the emergency department (ED) with acute asthma exacerbation were eligible. The PEFR and VAS were assessed at presentation and after initial asthma therapy. During reassessment, subjects were asked to describe their asthma symptoms as "much better," "a little better," "no change," "a little worse," or "much worse." Correspondence between self-reported improvement and changes in PEFR and VAS was assessed. The "minimum clinically significant change" in either index was defined as the difference between pre- and posttreatment measures in subjects reporting their symptoms "a little better." RESULTS: One hundred fifty-six subjects were included. Asthma symptoms were "much better" in 99 (64%), "a little better" in 41 (26%), and "unimproved" (composed of patients describing symptoms as "no change," "a little worse," or "much worse") in 16 (10%). The mean VAS change among the "a little better" subjects was 2.2 cm (95% CI = 1.1 to 3.4), significantly greater than the -0.4 cm (95% CI = -2.1 to 1.4) change in the "unimproved" subjects. The mean change in percent predicted PEFR among the "a little better" subjects was 11.9 (95% CI = 7.3 to 16.1), not statistically different from the change of 6.1 (95% CI = 1.1 to 11.3) in the "no change" subjects. The "much better" group showed significantly greater changes in both measures than either of the other groups. A VAS change of > or =0.5 cm reliably discriminated between subjects with and without symptom improvement. CONCLUSIONS: Improvements in VAS of 2.2 cm and in predicted PEFR of about 12 percentage points are minimal clinically significant improvements during ED asthma therapy. The dyspnea VAS is valid in assessing symptomatic changes and may detect small subjective improvements better than the PEFR.

Adult↗
PubMed1997

Examiner differences in the mini-CEX.

OBJECTIVE: The objective of this study was to analyze whether faculty ratings of residents, using the mini-CEX oral exam format, differed in stringency or were influenced by the clinical setting. It also sought to learn whether the examiners were satisfied with the format. METHOD: A mini-CEX encounter consisted of a single faculty member observing a resident conduct a focused history and physical examination in an inpatient, outpatient, or emergency room setting. After asking the resident for a diagnosis and treatment plan, the faculty member rated the resident and provided educational feedback. The encounters were intended to be short and occur as a routine part of the training, so each resident would be evaluated on many occasions by different faculty. SAMPLE: Sixty-four attending physicians evaluated residents from five internal medicine training programs; data were analyzed for 355 mini-CEX encounters involving 88 residents. RESULTS: There were not large differences among the examiners in their ratings. Moreover, there were not great differences among the ratings in terms of the training program with which the examiner was associated, the setting of the mini-CEX, or the nature of the patient. The examiners were generally satisfied with the format and their level of satisfaction was correlated with the residents' perceptions of the format. CONCLUSION: The mini-CEX adapts itself to a broad range of clinical situations, and these results show that it should produce roughly comparable scores over examiners and settings. This makes it a worthwhile device for evaluation at the local level.

Journal Article↗
PubMed1995

The mini-CEX (clinical evaluation exercise): a preliminary investigation.

OBJECTIVE: To gather preliminary data on the mini-CEX (clinical evaluation exercise), a device for assessing the clinical skills of residents. DESIGN: Evaluation of residents by faculty members using the mini-CEX. SETTING: 5 internal medicine training programs in Pennsylvania. PARTICIPANTS: 388 mini-CEX encounters involving 88 residents and 97 evaluators. MEASUREMENTS: A mini-CEX encounter consists of a single faculty member observing a resident while that resident conducts a focused history and physical examination in any of several settings. After asking the resident for a diagnosis and treatment plan, the faculty member rates the resident and provides educational feedback. The encounters are intended to be short (about 20 minutes) and to occur as a routine part of training so that each resident can be evaluated on several occasions by different faculty members. RESULTS: The encounters occurred in both inpatient and ambulatory settings and were longer than anticipated (median duration, 25 minutes). Residents saw either new or follow-up patients who collectively presented with a broad range of clinical problems. The median evaluator assessed two residents and was generally satisfied with the mini-CEX format; residents were even more satisfied with the format. The reproducibility of the mini-CEX is higher than that of the traditional CEX, and its measurement characteristics are similar to those of other test formats, such as standardized patients and standardized oral examinations. CONCLUSIONS: The mini-CEX assesses residents in a much broader range of clinical situations than the traditional CEX, has better reproducibility, and offers residents greater opportunity for observation and feedback by more than one faculty member and with more than one patient. On the other hand, the mini-CEX may be more difficult to administer because multiple encounters must be scheduled for each resident. Exclusive use of the mini-CEX also prevents residents from being observed while doing a complete history and physical examination. Given the promising results and measurement characteristics of the mini-CEX, however, the American Board of Internal Medicine encourages the use of this method in conjunction with or as an alternative to the traditional CEX.

Clinical Competence↗