A human factors framework and study of the effect of nursing workload on patient safety and employee quality of working life.

BACKGROUND: Nursing workload is increasingly thought to contribute to both nurses' quality of working life and quality/safety of care. Prior studies lack a coherent model for conceptualising and measuring the effects of workload in healthcare. In contrast, we conceptualised a human factors model for workload specifying workload at three distinct levels of analysis and having multiple nurse and patient outcomes. METHODS: To test this model, we analysed results from a cross-sectional survey of a volunteer sample of nurses in six units of two academic tertiary care paediatric hospitals. RESULTS: Workload measures were generally correlated with outcomes of interest. A multivariate structural model revealed that: the unit-level measure of staffing adequacy was significantly related to job dissatisfaction (path loading=0.31) and burnout (path loading=0.45); the task-level measure of mental workload related to interruptions, divided attention, and being rushed was associated with burnout (path loading=0.25) and medication error likelihood (path loading=1.04). Job-level workload was not uniquely and significantly associated with any outcomes. DISCUSSION: The human factors engineering model of nursing workload was supported by data from two paediatric hospitals. The findings provided a novel insight into specific ways that different types of workload could affect nurse and patient outcomes. These findings suggest further research and yield a number of human factors design suggestions.

Effects of mental demands during dispensing on perceived medication safety and employee well-being: a study of workload in pediatric hospital pharmacies.

BACKGROUND: Pharmacy workload is a modifiable work system factor believed to affect both medication safety outcomes and employee outcomes, such as job satisfaction. OBJECTIVES: This study sought to measure the effect of workload on safety and employee outcomes in 2 pediatric hospitals and to do so using a novel approach to pharmacy workload measurement. METHODS: Rather than measuring prescription volume or other similar indicators, this study measured the type and intensity of mental demands experienced during the medication dispensing tasks. The effects of external (interruptions, divided attention, and rushing) and internal (concentration and effort) task demands on perceived medication error likelihood, adverse drug event likelihood, job dissatisfaction, and burnout were statistically estimated using multiple linear and logistic regression. RESULTS: Pharmacists and pharmacy technicians reported high levels of external and internal mental demands during dispensing. The study supported the hypothesis that external demands (interruptions, divided attention, and rushing) negatively impacted medication safety and employee well-being outcomes. However, as hypothesized, increasing levels of internal demands (concentration and effort) were not associated with greater perceived likelihood of error, adverse drug events, or burnout and even had a positive effect on job satisfaction. CONCLUSIONS: Replicating a prior study in nursing, this study shows that new conceptualizations and measures of workload can generate important new findings about both detrimental and beneficial effects of workload on patient safety and employee well-being. This study discusses what those findings imply for policy, management, and design concerning automation, cognition, and staffing.

Morphometric histology for infant gastroesophageal reflux disease: evaluation of reliability in 497 esophageal biopsies.

OBJECTIVES: We sought to determine the reliability of morphometric measurements on infant esophageal biopsies using a light microscope with eyepiece micrometer. METHODS: We measured epithelial thickness, basal layer thickness (B), papillary height (P) and epithelial lymphocyte and eosinophil numbers on approximately 500 existing esophageal suction biopsies from infants previously evaluated for reflux esophagitis. We tested these measurements for interobserver, test-retest and internal consistency reliability. RESULTS: Infants ages 0.25 to 23.75 (median, 6.25) months provided 497 biopsies. Both investigators scoring the biopsies independently judged 93% of them scorable. Of the biopsies scored by both, the 2 readings were within 0.15 of each other for P in 97% and for B in 81%. In addition to these correlative measures of consistency, categoric measures demonstrated that 373 (89%) of the 420 scorable biopsies with visible papillae produced agreement as to P being abnormal (317, 85%) or normal (56, 15%). Similarly, 360 (78%) of the 463 scorable biopsies produced agreement as to B being abnormal (339, 94%) or normal (21, 6%). P values were 0.17 to 0.94 (median, 0.67), and B values were 0.13 to 0.91 (median, 0.34). Lymphocytes numbered 0 to 40 (median 5) per high-power field. Only 12% had any eosinophils; none of those with completely normal morphometrics had any eosinophils; and only 2% had >5 eosinophils per high-power field. CONCLUSIONS: Simple quantitative esophageal histological morphometric parameters are reliably measurable on suction biopsies from infants using a light microscope fitted with an ocular micrometer, even by nonpathologists.

Sandifer syndrome posturing: relation to abdominal wall contractions, gastroesophageal reflux, and fundoplication.

Sandifer syndrome designates abnormal posturing in patients with gastroesophageal reflux. To explore its mechanisms via examining relationships among Sandifer syndrome posturing, abdominal wall contractions, and reflux episodes, we studied an affected child in detail. The study utilized esophageal pHmetry, surface electromyography, and split-screen videography. The multichannel physiologic study demonstrated association of rectus abdominis contraction with onset of reflux episodes (P < 0.001) and association of reflux episodes with Sandifer syndrome posturing. This child's subsequent course confirmed his diagnosis and suggested mechanisms of the association of reflux and Sandifer syndrome. We conclude that abdominal wall contractions may induce reflux episodes. Sandifer syndrome may be due to gastroesophageal reflux even without hiatal hernia, macroscopic esophagitis, or reflux symptoms. Despite the absence of more typical reflux symptoms and failure to respond to very aggressive medical therapy, Sandifer syndrome may resolve after fundoplication.

Natural history of infant reflux esophagitis: symptoms and morphometric histology during one year without pharmacotherapy.

OBJECTIVES: To determine the natural history of infant gastroesophageal reflux disease (GERD) with esophagitis, we periodically analyzed symptoms and biopsies during 1 yr in 19 infants randomly assigned to placebo in a pharmacotherapy study. METHODS: One hundred infants who were referred during 1994-1999 for GERD, were unresponsive to 2-wk life-style measures, and manifested morphometric reflux esophagitis, were assigned at random to one of four treatment arms. This analysis examines the 19 (ages 2.8-6.0 months) assigned to placebo who returned for initial follow-up. SYMPTOMS and esophageal biopsy were assessed at baseline and 2, 4, 6, and 12 months. At any visit with both symptoms and biopsy unimproved, infants were "rescued" to open label active drug. RESULTS: By 12 months, 10/19 completed without rescue; the 9 others withdrew (3) or required pharmacotherapy (6). SYMPTOMS: Among the 10 nonrescued completers, parents' global score rated 9 "completely well," and 1 "improved." Comparing 12-month symptoms to baseline symptoms in the 10 completers, fewer reported regurgitation >3/day, >1 Tbsp, or that was uncomfortable; crying >1 h/d, or during or after feeds; or arching spells or abnormal hiccups (p < 0.05, chi(2)). Biopsy: None of the 10 ever had normal biopsies (basal cell layer <25% and papillary height <53% of epithelial thickness). One had normal papillary height, but abnormal basal thickness. Five others had normal basal thickness, but all five of them had abnormal papillary height. CONCLUSION: Although symptoms improved in more than half of the infants with reflux esophagitis followed longitudinally for 1 yr without pharmacotherapy, histology remained abnormal.

The Effects of Increasing Doses of Ranitidine on Gastric pH in Children.

BACKGROUND: Ranitidine is widely used for gastroesophageal reflux disease (GERD) in children, but optimal dosing is unclear. We compared effects of weight-based doses of oral ranitidine on gastric pH in children with clinical GERD. METHODS: Children ages 4-11 years with clinical GERD were enrolled in a multi-center prospective randomized study comparing a fixed dose of ranitidine (Zantac 75) with placebo after an overnight fast; gastric pH was measured for 6 h after the fixed dose (Phase 1). Of the six enrollees from our center, four received active drug during Phase 1; 12 h after the fixed dose, these four children received ranitidine 5 mg/kg (maximum 150 mg) and gastric pH was measured for another 6-12 hours (Phase 2). This report details the effects of two dose ranges (Low Dose, < 3 mg/kg/dose, and High Dose, ≥ 3 mg/kg/dose) on gastric pH in children. RESULTS: The four children were 6.9-11.3 years old and weighed 20.4-49.5 kg. The Low Doses were 1.5-2.7 mg/kg; the High Doses were 3-5 mg/kg. Although the mean percentage of time with gastric pH > 4 during the entire 6 hours following dosing was similar after Low and High Dose (50% vs. 57%, NS), during the last two hours of this interval the mean percentage of time with gastric pH > 4 was only 29% for Low Dose vs. 89% for High Dose (P = 0.006). Moreover, during those two hours, none of the Low Doses kept gastric pH above 4 for > 60% of the time, while all of the High Doses kept pH above 4 for > 60% of the time (P = 0.03). In three of four patients who underwent extended (9-12 h) gastric pH monitoring after High Dose ranitidine, gastric pH was above 4 for more than 40% of total time. CONCLUSIONS: Doses of ranitidine ≥ 3 mg/kg/dose may be required for acid suppression lasting beyond 6 hours.

Eosinophilic esophagitis: strictures, impactions, dysphagia.

Eosinophilic esophagitis, long known to be a feature of acid reflux, has recently been described in patients with food allergies and macroscopically furrowed esophagus. The pathophysiology and optimal management of patients with eosinophilic esophagitis is unclear. We describe our clinical experience related to eosinophilic esophagitis and obstructive symptoms in children and propose etiopathogenesis and management guidelines. Twelve children with obstructive esophageal symptoms (11 male), median age 5 years, and identified to have eosinophilic esophagitis with > 5 eosinophils per high-power field (eos/hpf) are reported. Of these, four had strictures, six had impactions, and two had only dysphagia. A diagnostic evaluation included esophagogastroduodenoscopy with biopsies in all and upper gastrointestinal series, IgE, radioallergosorbent tests, and skin tests for food allergies in some cases. Esophageal histology specimens were independently analyzed for eosinophil density by two authors. Four of five children with > 20 eos/hpf responded to elimination diets/steroids. The fifth child responded to a fundoplication. Seven children had 5-20 eos/hpf and three of them with no known food allergies responded to antireflux therapy alone. Three others in this group with positive food allergies responded to treatment with elimination diets and/or steroids. The seventh patient in this group was lost to follow-up. In conclusion, on the basis of response to therapy, eosinophilic esophagitis can be subdivided into two groups: those with likely gastroesophageal reflux disease if < 20 eos/hpf and no food allergies, and others with allergic eosinophilic esophagitis associated with food allergies and often with > 20 eos/hpf.

Efficacy of telephone teaching of conservative therapy for infants with symptomatic gastroesophageal reflux referred by pediatricians to pediatric gastroenterologists.

OBJECTIVES: To evaluate the efficacy of a specific protocol of conservative therapy for infant gastroesophageal reflux. STUDY DESIGN: Retrospective evaluation of the response to telephone teaching of conservative therapy by a single instructor as part of the screening process for a pharmacotherapy study of infantile reflux. Feeding modifications included the use of a protein-hydrolysate formula thickened with one tablespoon of dry rice cereal per ounce, at restricted volumes. Positioning changes included avoidance of seated and supine positions. Elimination of all tobacco smoke exposure was advised. SETTING: Single-center, outpatient. SUBJECTS: 394 infants <12 months old. EFFICACY: the percentage responding to conservative therapy instruction. Factors possibly predicting success for isolated conservative therapy instruction: evaluated as explanatory variables by chi(2) analysis; significance at P <.05. RESULTS: Ninety-six infants (24%) had sufficient symptom improvement and no additional intervention was required. Infants with isolated vomiting or irritability were more likely to respond than infants with both or other symptoms (P <.001). Neither formula type fed nor use of pharmacotherapy at referral were significant in determining response to conservative therapy. CONCLUSIONS: As many as 24% of infants with gastroesophageal reflux disease may respond to conservative therapy instruction provided by telephone. Benefits include savings of cost, time, and drug exposure of infants.

Autosomal dominant infantile gastroesophageal reflux disease: exclusion of a 13q14 locus in five well characterized families.

OBJECTIVES: A genetic locus for pediatric reflux was proposed on chromosome 13q14, but is unconfirmed in independent kindreds. We sought to test this locus in families with multiple affected infants from our database of well characterized infants with reflux. METHODS: We screened the database for families with multiple affected infants. Affected proband phenotype required histological esophagitis; affected sibling/cousin phenotype required a threshold score on a diagnostic questionnaire. Screened families were reduced to five based on pedigree, consent, and phenotypic clarity. Linkage of the phenotype with the four previously reported markers (D13S218, D13S1288, D13S1253, and D13S263) was tested, using an autosomal dominant, 70% penetrance model. Linkage required logarithm-of-odds score > or = 3. RESULTS: Of 54 individuals in the five probands' generation, 21 (39%) were affected based on questionnaire, of whom nearly one half also had histological confirmation of esophagitis. Linkage to the defined region was excluded for the five families by two-point LOD scores (-1.47 at D13S218, -1.32 at D13S1288, -3.43 at D13S1253, and -3.92 at D13S263) and by multipoint (multipoint LOD scores less than -2 between D13S218 and D13S263) linkage analysis. No family demonstrated even suggestive positive linkage (i.e., LOD score >1). CONCLUSIONS: In five rigorously phenotyped families with autosomal dominant pattern infantile reflux, we excluded genetic linkage to the region of 13ql4 previously identified responsible for an autosomal dominant form of pediatric reflux. These results suggest genetic heterogeneity, possibly related to phenotypic heterogeneity, in familial pediatric gastroesophageal reflux disease.