Promoting collaborative teaching in clinical education.

BACKGROUND: Although the practice of medicine is increasingly a multidisciplinary effort, clinical teaching of medical students is accomplished primarily within a departmental structure. PURPOSE: The purpose of this study was to identify subject matter within the clinical curriculum that could serve as focus for multidisciplinary teaching. METHODS: A questionnaire was sent to 13 clerkship directors (representing required clerkships) at a large Midwestern medical school in which they were asked to rate a list of 631 patient problems as critical (primary), important (secondary), or "nice to know," relevant to their respective clerkship objectives. RESULTS: All clerkship directors completed the questionnaire. There were 523 items that were considered primary, and over 90% of these items were listed as either primary or secondary in more than 1 clerkship. Twelve topics were considered primary or secondary by at least 5 clerkship directors. Four clerkship directors identified 43 patient problems, and 3 clerkship directors identified 92 topics as primary or secondary clerkship objectives. CONCLUSIONS: In this study, listing of patient problems across clerkships demonstrated significant overlap of the clinical curriculum, suggesting multiple opportunities for faculty collaboration in clinical education.

An outcomes research perspective on medical education: the predominance of trainee assessment and satisfaction.

CONTEXT: A fundamental premise of medical education is that faculty should educate trainees, that is, students and residents, to provide high quality patient care. Yet, there is little research on the effect of medical education on patient outcomes. OBJECTIVE: A content analysis of leading medical education journals was performed to determine the primary foci of medical education research, using a three- dimensional outcomes research framework based on the paradigm of health services outcomes research. DATA SOURCES: All articles in three medical education journals (Academic Medicine, Medical Education, and Teaching and Learning in Medicine) from 1996 to 1998 were reviewed. Papers presented at the Research in Medical Education conference at the Association of American Medical Colleges annual meeting during the same period, and published as Academic Medicine supplements, were also analysed. STUDY SELECTION: Only data-driven articles were selected for analysis; thus editorials and abstracts were excluded. DATA EXTRACTION: Each article was categorized according to primary participant (i.e. trainee, faculty, provider and patient), outcome (performance, satisfaction, professionalism and cost), and level of analysis (geographic, system, institution and individual(s)). DATA SYNTHESIS: A total of 599 articles were analysed. Trainees were the most frequent participants studied (68.9%), followed by faculty (19.4%), providers (8.1%) and patients (3.5%). Performance was the most common outcome measured (49.4%), followed by satisfaction (34.1%). Cost was the focus of only 2.3% of articles and patient outcomes accounted for only 0.7% of articles. CONCLUSIONS: Medical education research is dominated by assessment of trainee performance followed by trainee satisfaction. Leading journals in medical education contain little information concerning the cost and products of medical education, that is, provider performance and patient outcomes. The study of these medical education outcomes represents an important challenge to medical education researchers.

Evaluating a clerkship curriculum: description and results.

BACKGROUND: A comprehensive and up-to-date curriculum requires periodic formal review to ensure it continues to meet learners' needs. PURPOSE: This study describes a model for evaluating a surgery clerkship curriculum designed to determine the appropriateness of its learning objectives to the general professional education of a physician. METHODS: A survey was mailed to graduates who pursued generalist residencies. Respondents estimated the number of patients encountered annually with specified presenting complaints or disease entities and the percentage of time these were referred to surgeons. For 23 technical procedures, respondents estimated the frequency done annually and whether remaining proficient in the skill was considered important. RESULTS: The majority of graduates reported the need to remain proficient in 19 technical procedures. Numerous patient problems were identified as requiring careful instruction so that learners know when and when not to refer for surgical intervention. CONCLUSIONS: The clerkship was modified to include skills and topics not previously included or appropriately emphasized.

Development of a measure of attitude toward nutrition in patient care.

BACKGROUND: Development of reliable measures of medical student and resident attitudes about nutrition in patient care is needed before the effects of educational interventions or clinical experience can be gauged. This report describes the systematic development of a measure of attitude toward nutrition in patient care. It presents evidence about scale reliability and the absence of response bias that endorses the trustworthiness of data from the measure. METHODS: An eight-step attitude scale development procedure was used to create the Nutrition In Patient care Survey (NIPS). Data from five samples of first- and second-year medical students and first-year medical residents were subjected to factor analysis (PA2, varimax rotation), reliability analyses, and statistical analyses to test for demographic bias in the attitude data. RESULTS: A 45-item attitude measure was developed that contains five subscales derived from the factor analysis: (1) nutrition in routine care (NRC, 8 items); (2) clinical behavior (CB, 20 items); (3) physician-patient relationship (PPR, 8 items); (4) patient behavior/motivation (PBM, 3 items); and (5) physician efficacy (PE, 6 items). Each subscale yields reliable data in terms of internal consistency (alpha coefficients) and stability (test-retest reliability). Medical student and resident demographic variables have negligible influence on attitude scores. DISCUSSION: The NIPS subscales yield reliable data that can be used to assess outcomes in evaluation research on educational or clinical interventions or to predict patient care practices. Systematic attitude scale development increases the likelihood that the resulting measures will produce useful, trustworthy data.

Gangrenous cholecystitis: analysis of risk factors and experience with laparoscopic cholecystectomy.

BACKGROUND: Gangrenous cholecystitis occurs in up to 30% of patients admitted with acute cholecystitis. Factors predicting gangrenous disease in patients with acute cholecystitis remain poorly defined, making preoperative diagnosis difficult. Identification of these factors and early diagnosis of gangrenous cholecystitis will indicate more aggressive treatment, earlier operation, and a lower threshold for conversion of laparoscopic to open cholecystectomy. METHODS: We reviewed our experience with acute cholecystitis during the 2-year period of 1995 to 1996. Admitting history, physical examination, operative report, laboratory and radiology data, and pathology report were analyzed for each patient. Acute cholecystitis and its gangrenous complication were diagnosed by both gross and microscopic examination. RESULTS: One hundred fifty-four patients were admitted to the hospital with acute cholecystitis and underwent cholecystectomy; gallbladder gangrene was found in 27 (18%) of these patients. Four patients with gallbladder gangrene underwent open cholecystectomy and 23 patients underwent laparoscopic cholecystectomy, of which 15 (65%) were completed laparoscopically and 8 (35%) had open conversion as a result of severe inflammation. Risk factors for gallbladder gangrene included male gender, age older than 50 years, history of cardiovascular disease, and leukocytosis greater than 17,000 white blood cells/mL. CONCLUSIONS: Older male patients (age older than 50 years) with history of cardiovascular disease, leukocytosis greater than 17,000 white blood cells/mL, and acute cholecystitis have increased risk of gallbladder gangrene and conversion of laparoscopic cholecystectomy to open cholecystectomy. Urgent laparoscopic cholecystectomy with low threshold for conversion to open cholecystectomy should be considered in these patients at high risk for gallbladder gangrene.

A virtual reality module for intravenous catheter placement.

BACKGROUND: Virtual reality (VR) is a potential tool for technical skills training. We tested the validity and instructional effectiveness of a prototype VR module for learning intravenous (i.v.) catheter placement. METHODS: First-year medical students (n = 37), third-year medical students (n = 14), and surgical residents (n = 9) attempted two pretest i.v.s into each other, used the VR module for 12 minutes, and subsequently attempted two posttest i.v.s. Success or failure were recorded for each attempt. For each successful attempt, time and global rating of i.v. insertion were also recorded. RESULTS: The pretest success rate was significantly different between groups (chi square = 28.71, P <0.01). VR success rate was not significantly different between groups (F(2,57) = 1.47, ns). Although there was improvement in all groups during VR training (F(2,114) = 44.16, P <0.01), this did not result in improvement in posttest performance. CONCLUSIONS: Significant differences between groups were observed in performance of i.v. insertion in physical reality. However, no significant difference was observed in performance in VR. Thus, performance in VR demonstrated neither construct nor concurrent validity. While performance improved in VR, transfer of skill from VR to physical reality was not observed. Additional development and testing of VR as a training tool is warranted before its widespread use can be recommended.

Inflammation and a thickened mucus layer in mice with cholesterol gallstones.

BACKGROUND: Based on previous work which suggested that biliary crystals may induce inflammation in the gallbladder wall and that inflammation is an early event during the formation of pigment gallstones in the dog, studies were performed examining mucus layer thickness, myeloperoxidase activity, and interleukin-1 (IL-1) activity in the wall of mouse gallbladder during formation and growth of cholesterol gallstones. METHODS AND MATERIALS: The inflammatory effects of cholesterol gallstones at 2 and 4 weeks were studied in BalB/C mice fed a crushed standard mouse chow with added cholesterol (1.0%) and cholic acid (0.5%). Results were compared to those of normal mice fed standard mouse chow. The presence or absence of crystals and stones was determined by gross and microscopic examination of bile. Myeloperoxidase and IL-1 activity in the gallbladder wall was measured using well-established bioassays. Mucus layer thickness was measured by darkfield microscopy. RESULTS: All mice fed a lithogenic, 1.0% cholesterol/0.5% cholic acid diet developed cholesterol crystals and gallstones at 2 and 6 weeks. No control mice developed either crystals or gallstones. Myeloperoxidase and IL-1 activities, markers of an inflammatory response, increased significantly in the gallbladder of mice with crystals at 2 weeks. Myeloperoxidase activity increased two- to three-fold, and IL-1 activity sevenfold, by 6 weeks. Mucus layer thickness also progressively increased during the 6-week period. CONCLUSIONS: It is concluded that inflammation is an early event associated with the appearance of crystals and gallstones in bile.

The inflammatory effects of crystalline cholesterol monohydrate in the guinea pig gallbladder in vivo.

BACKGROUND: The etiologic role of crystalline material in inflammatory arthritis is well established. The role of crystals in cholecystitis is unclear. We hypothesized that crystalline cholesterol monohydrate stimulates guinea pig gallbladder inflammation in vivo. METHODS: Crystalline cholesterol monohydrate, lipopolysaccharide (LPS), lysolecithin, polystyrene latex spheres (noninflammatory particles), and saline were instilled into guinea pig gallbladders for 24 to 72 hours after cystic duct ligation. Water transport across gallbladder mucosa was measured. Gallbladder tissue was analyzed for mucus layer thickness, myeloperoxidase, prostaglandin E2 (PGE2) prostaglandin F-1 alpha (PGF-1 alpha), and interleukin-1. Luminal fluid was also examined for PGE2 and PGF-1 alpha. Values for each test were compared with saline controls by using Student's test (p < 0.05). RESULTS: Crystalline cholesterol, LPS, and lysolecithin caused significant reduction in mucus layer thickness, reversed water absorption to secretion across the gallbladder mucosa, caused significant increases in myeloperoxidase and interleukin-1 in gallbladder tissue, and caused significant increases in PGE2 and PGF-1 alpha in luminal fluid. These effects were generally dose- but not time-dependent. Polystyrene latex particles caused no difference in outcomes compared with saline controls. CONCLUSIONS: Crystalline cholesterol monohydrate has dose-dependent inflammatory effects in the guinea pig gallbladder in vivo that are not simply-due to mechanical irritation of the gallbladder wall by crystalline particles. Crystals in the gallbladder may have an etiologic role in cholecystitis.

Interleukin-1 mediates guinea pig gallbladder inflammation in vivo.

Interleukin-1 (IL-1) is a cytokine with multiple immunologic and inflammatory properties. We previously demonstrated that lipopolysaccharide (LPS) stimulates release of IL-1, and IL-1 stimulates inflammation in guinea pig gallbladder in vivo. We hypothesized that IL-1 mediates LPS-induced guinea pig gallbladder inflammation in vivo. LPS and IL-1 were instilled into guinea pig gallbladder lumen alone (with cystic duct ligation) and with IL-1 ra and indomethacin, respectively (n = 4). Water transport across gallbladder mucosa, myeloperoxidase and IL-1 release from gallbladder tissue, and prostaglandin E2 (PGE2) in lumenal fluid were measured. Values for test agents and inhibitory agents were compared to saline controls using Student's t test (P < 0.05). Intralumenal LPS and IL-1 both stimulated gallbladder inflammation. LPS-induced and IL-1-induced inflammation were inhibited by both IL-1 ra and indomethacin. LPS stimulated IL-1 release and IL-1 itself caused gallbladder inflammation. LPS stimulated gallbladder inflammation as manifest by increased myeloperoxidase and PGE2 release, and water secretion into the gallbladder lumen. The inflammatory effects of LPS were inhibited by IL-1 ra. Taken together, these findings indicate that IL-1 is a mediator of LPS-induced guinea pig gallbladder inflammation in vivo.

Neurogenic inflammation in cholecystitis.

Neurogenic inflammation implies stimulation of nerves with resultant inflammation in tissue surrounding the nerve terminals. We hypothesized that neurogenic inflammation has a role in cholecystitis. Capsaicin (stimulant of afferent, nociceptive neurons), 6-hydroxydopamine (stimulates release of peptides from sympathetic nerve terminals), bradykinin, lipopolysaccharide, and saline were instilled into guinea pig gallbladders for 24 hr (N = 5 in each group). In parallel, test agents were instilled with 1% Iidocaine. Water transport across gallbladder mucosa, myeloperoxidase and interluekin-1 release from gallbladder tissue, and prostaglandin E2 in luminal fluid were measured. Capsaicin caused water secretion and significant release of myeloperoxidase, interleukin-1, and prostaglandin-E2, effects that were blocked by Iidocaine. 6-Hydroxydopamine did not affect water transport or prostaglandin E2, but did cause myeloperoxidase and interleukin-1 release. Bradykinin- and lipopolysaccharide-induced inflammation were partially inhibited by lidocaine. Taken together, these results suggest that neurogenic inflammation has a role in the pathophysiology of cholecystitis.

Use of notebook computers for third-year surgical students.

BACKGROUND: Computer-aided instruction has become increasingly popular in medical education. Notebook computers (NCs) are attractive, convenient microcomputers. We hypothesized that use of NCs by third-year surgical students would enhance their performance of educational activities. METHODS: During the 1994-1995 academic year 25 student volunteers used NCs during the surgery clerkship. NC software included questions for self-examination, anatomy self-instruction program, word processing and electronic mail (e-mail) for recording and sending history and physicals (H & Ps) to faculty for review, and MEDLINE search software. Identical software was available to all students at on-campus computer centers. All students were asked to record the number of hours that they used the self-examination and anatomy programs, number of H & Ps performed and reviewed by faculty, and number of literature searches performed. NC users were interviewed regarding the value of NC use and their rating of software programs. RESULTS: NC users (n = 25) used the self-examination and anatomy programs more often, performed more literature searches, and had a greater percentage of their H & Ps reviewed by faculty compared with non-NC users (n = 143) (p < 0.05 for all outcomes). Most NC users agreed that NC use was enjoyable and valuable, and they believed that all students should have NCs during the surgery clerkship. Students rated software in order of preference: e-mail > self-examination > MEDLINE search > anatomy program. CONCLUSIONS: NC use enhanced performance of educational activities in the surgery clerkship. Effort toward developing educational software for surgical students is warranted because students are likely to use such programs.

Inflammatory properties of bile from dogs with pigment gallstones.

BACKGROUND: Gallbladder inflammation and mucus hypersecretion are prominent features of cholesterol and pigment gallstones in humans and animals. The factors leading to inflammation and mucus hypersecretion are poorly understood. These studies examine the inflammatory potential of bile from dogs with pigment gallstones. METHODS: Dogs fed a methionine-deficient diet that produces pigment gallstones by 6 weeks were compared to normal dogs. Mucus layer thickness, myeloperoxidase activity, and interleukin-1-like activities were measured in canine gallbladder. The inflammatory potential of canine bile was determined by measuring mucus layer thickness, sodium absorption, myeloperoxidase activity and interleukin-1-like activity in guinea pig gallbladders exposed to normal and lithogenic canine bile for 4 hours. RESULTS: Mean mucus layer thickness, myeloperoxidase, and interleukin-1 activity were significantly greater in canine gallbladders containing pigment gallstones. Bile from dogs with pigment gallstones markedly increased mucus layer thickness, myeloperoxidase activity, and interleukin-1 activity and decreased sodium absorption in normal guinea pig gallbladder. These effects were not eliminated by centrifuging bile to remove crystals and gallstones. CONCLUSIONS: Canine bile from dogs with pigment gallstones contains soluble factors capable of causing inflammation in the gallbladder wall.

Gastrointestinal tract complications after acute spine injury.

OBJECTIVES: To determine the incidence, risk factors, and mortality rate of gastrointestinal complications in patients with acute spine injury and to derive methods by which mortality can be reduced. DESIGN: Case series. SETTING: Regional tertiary care center. PATIENTS: Consecutive sample of 1952 patients with acute spine injury with complete medical records who were admitted from 1981 through 1990. MAIN OUTCOME MEASURES: Gastrointestinal tract complications, age, sex, time from injury to admission, cause of injury, level of spine injury, neurologic deficit, head injury, injury to other organ systems, incidence of surgical intervention for spine injury, length of hospital stay, and mortality rate. RESULTS: The incidence of gastrointestinal complications was 1.9%. Gastrointestinal hemorrhage was the most frequent complication. Risk factors for gastrointestinal complications were increasing age (P < .02), male sex (P < .01), injury to other organ systems (P < .02), head injury (P < .02), cervical spine injury (P < .02), and neurologic deficit (P < .005). The mortality rate was 19% in patients with gastrointestinal complications, significantly greater (P < .005) than the 2.9% rate in patients without gastrointestinal complications. CONCLUSIONS: Gastrointestinal complications after acute spine injury are uncommon but frequently lethal. Prophylaxis against hemorrhage and earlier diagnosis and surgical intervention are recommended.

Human polymorphonuclear leukocyte phagocytosis of crystalline cholesterol, bilirubin, and calcium hydroxyapatite in vitro.

We tested the hypothesis that human polymorphonuclear leukocytes (PMNs) phagocytize crystalline cholesterol, bilirubin, or calcium hydroxyapatite in vitro and in the process release oxygen metabolites and enzymes involved in the inflammatory process. Chemiluminescence (CL), elicited by the respiratory burst (release and activation of oxygen metabolites and enzymes) of PMNs during phagocytosis of a target particle, was used to quantitate PMN phagocytosis of each crystal. Significant CL (P < 0.05) was observed with cholesterol concentrations of 1.3-5.3 mg/ml and the dose-response was linear (r > or = 0.95). With bilirubin, significant CL was observed with concentrations of 0.07-0.33 mg/ml. The response to calcium hydroxyapatite was variable. Human PMNs phagocytize cholesterol, bilirubin, and to a lesser extent, calcium hydroxyapatite. PMN chemiluminescence was associated with phagocytosis, indicating that inflammatory substances are being released in the process. These results support the concept that crystals that occur in the gallbladder may initiate gallbladder inflammation.

Er:YAG laser ablation of prairie dog gallbladder epithelium for the prevention of gallstones.

We hypothesized that laser ablation of gallbladder epithelium would prevent gallstone formation in prairie dogs. An Er:YAG laser (lambda = 2.94 microns) was used to ablate the gallbladder epithelium of 24 prairie dogs; 20 sham-irradiated and 12 non-operated prairie dogs served as controls. Prairie dogs were sacrificed at time periods of 4 days, 2 weeks, and 8-12 weeks and evaluated for the presence of gallstones and cholesterol crystals. Laser-irradiated gallbladders demonstrated a lower rate of gallstone formation at 8-12 weeks than the sham-irradiated gallbladders (39% vs. 79%: P < .02). Crystal formation, however, was not different between laser-irradiated (88%) and sham-irradiated (100%) animals. The laser-irradiated group had less epithelium than the non-operated group at all time periods (P < or = .002) and compared to the sham-irradiated group at 4 days and 8-12 weeks (P < or = .001). These data suggest that laser ablation of gallbladder epithelium can reduce the rate of gallstone formation although this effect may be temporary.

Spontaneous bilateral pneumothorax--complication of laparoscopic cholecystectomy.

Pneumothorax is a rare complication of pneumoperitoneum. We report a case of spontaneous bilateral pneumothorax during laparoscopic cholecystectomy. The history, pathogenesis, and therapeutic options of this unusual occurrence are discussed. Because laparoscopic operations have become increasingly popular in recent years, we call attention to this rare but potentially life-threatening complication.

Laparoscopic inguinal hernia repair. A preliminary experience.

OBJECTIVE: To evaluate the safety and efficacy of laparoscopic inguinal hernia repair. DESIGN: Nonrandomized trial. SETTING: Veterans Affairs hospital and a large university hospital. PATIENTS: The study included 38 patients (36 male and two female) who had an acceptable risk for general anesthesia, presented electively, and gave informed consent; patients were excluded for whom general anesthesia had a high risk or who had incarcerated or strangulated hernias. INTERVENTION: Laparoscopic inguinal hernia repair was performed with general anesthesia through bilateral, lower-abdominal, 12-mm lateral rectus sheath ports with an umbilical 30 degrees viewing laparoscope. After the peritoneum was incised and flaps were raised, an onlay patch of polypropylene mesh, secured with staples, covered both indirect and direct hernia regions in each patient. Small hernia sacs were usually reduced or excised. RESULTS: From December 1991 through October 1992, 40 inguinal hernias were repaired; two patients had bilateral hernias. There were 22 indirect and 17 direct inguinal hernias and one femoral hernia. Nine of the hernias repaired were recurrent, and five were sliding hernias. Complications occurred in nine patients, but there were no recurrences during a median follow-up of 26 weeks. All but one patient resumed preoperative activities by 7 days after the operation. CONCLUSIONS: Laparoscopic inguinal hernia repair is an effective operation with low morbidity. Long-term follow-up is needed to determine the durability of the repair.

Optical properties of human gallbladder tissue and bile.

Knowledge of the optical properties of biliary tract tissues is useful for aiding in the development and understanding of clinical applications of lasers in the biliary tract. Human gallbladder and bile specimens were obtained during laproscopic cholecystectomy. The diffuse remittance and transmission of the samples were determined from 350 to 2450 nm. Collimated transmission was determined at 633 and 2100 nm. Using one-dimensional diffusion theory, we calculated micro(s), micro(a), and g as a function of wavelength. Both gallbladder and bile show absorption peaks at 1.4 and 1.9 microm. Bile has a peak at 400 nm; gallbladder has peaks at 410 and 550 nm. The absorption peaks are correlated with known tissue chromophores. The effect of the sample preparation on the results is discussed.

A performance analysis of an extracorporeal shock wave lithotripter: spatial pressure distribution and the effects of lithotripter voltage, electrode life, and tissue attenuation.

The Dornier MPL-9000 lithotripter was analyzed as a function of lithotripter voltage, electrode efficiency, and bovine muscle attenuation. The maximum pressure at 20 kV measured 65 +/- 4 MPa (mean +/- SD). The region containing 50% of the maximum pressure was a cylindrical volume with a diameter of 2.5 cm and a height of 7 cm. Pressure varied in a linear fashion with lithotripter voltage (r = 0.996). The average pressure produced by an electrode throughout the course of 2,200 shock waves was 78% of its maximum pressure. Shock wave pressure was reduced from 65 +/- 4 MPa to 49 +/- MPa, 44 +/- 3 MPa, and 44 +/- 1 MPa with 1-, 2-, and 3-cm thickness of intervening bovine muscle, respectively. There was a statistically significant decrease in pressure when muscle was interposed, but there was no significant difference in reduction of pressure between 1, 2, and 3 cm of muscle (ANOVA, Newman-Keuls, alpha = 0.01). Frequency spectral analysis revealed the major contribution to the shock wave comes from 0-200 kHz with a peak near 50 kHz. Major frequency intensities were reduced with a decrease in lithotripter voltage, attenuating tissue, and distance away from the center of the focal zone.