Israel Medical Association Journal

Background: Intrathoracic cancer can cause hyponatremia, but it is uncertain whether mild hyponatremia in the outpatient setting should be regarded as an early sign of intrathoracic cancer.

Objectives: To evaluate the risk of undiagnosed intrathoracic cancer in patients with new persistent mild hyponatremia.

Methods: We conducted a retrospective cohort study using the electronic health record database of a large healthcare organization. The hyponatremia group included patients with sodium concentration of 130–134 mmol/L twice, after a previous normal value and without previous history of cancer or diseases related to hyponatremia. A control group with normal sodium concentration was matched by sex, age, and year of testing. We measured specific intrathoracic cancer incidence during 3 years of follow-up after sodium concentration test date. A logistic regression was used to adjust for further clinical information including smoking history, symptoms, and medications.

Results: The study comprised 1539 participants with mild hyponatremia and 7624 matched controls. New intrathoracic cancer diagnosis was more common in the hyponatremia group during a 3-year follow-up; 1.49% in the hyponatremia group and 0.39% in the control group, crude odds ratio (OR) 3.84, 95% confidence interval (95%CI) 2.22–6.63. After adjustment, hyponatremia remained a significant risk factor for the diagnosis of intrathoracic cancer; adjusted OR 3.61, 95%CI 2.08–6.28.

Conclusions: New mild persistent hyponatremia might be a significant predictive marker to a yet undiagnosed intrathoracic cancer.

Background: Crohn's disease and ulcerative colitis are inflammatory bowel diseases with an unknown etiology. Interleukin-18 is a pro-inflammatory cytokine that is up-regulated in Crohn’s disease. IL-18[1] binding protein neutralizes IL-18. The relationship of IL-18 and IL-18BP[2] and disease activity in these diseases is not fully understood.

Objectives: To investigate the correlation of IL-18 and IL-18BP with disease activity and other disease parameters in inflammatory bowel disease.

Methods: IL-18 and IL-18BP isoform α were measured in 129 patients and 10 healthy individuals. Patients' mean age was 40.5 (range 15–70 years) and 43 were women; 58 Crohn's and 28 colitis patients were in remission and 52 and 14, respectively, were in exacerbation. Twenty-three (19 and 4 respectively) were studied in both remission and exacerbation.

Results: The mean level of free IL-18 was significantly different between healthy individuals and Crohn's patients, and between Crohn's patients during exacerbation and remission (167 ± 32 vs. 471 ± 88 and 325 ± 24 pg/ml, respectively, P < 0.05). Mean level of IL-18BP was significantly different between healthy individuals and Crohn patients, and between Crohn patients during exacerbation and remission (2.1 ± 1.1, 7.5 ± 4 and 5.23 ± 2.8 ng/ml, respectively, P < 0.01). In the colitis patients, mean free IL-18 level and IL-18BP were significantly different between healthy individuals and patients, but not between disease remission and exacerbation (167 ± 32, 492 ± 247 and 451± 69 pg/ml for IL-18, and 2.1 ± 1.1, 7.69 ± 4 and 6.8 ± 7 ng/ml for IL-18BP, respectively, P = 0.05).

Conclusions: IL-18 and IL-18BP levels are higher in patients with inflammatory bowel disease compared to healthy individuals. In Crohn's disease, but not in ulcerative colitis, IL-18 (but not free IL-18) and IL-18BP levels are significantly higher during exacerbation compared to remission. This observation highlights the importance of IL-18 in the pathogenesis of inflammatory bowel diseases, especially in Crohn's disease.

Background: The emergency department is one of the hospital’s busiest facilities and is frequently described as a bottleneck. Management by constraint is a managerial methodology that helps to focus on the most critical issues by identifying such bottlenecks. Based on this theory, the benefit of adding medical staff may depend on whether or not physician availability is the bottleneck in the system.

Objective: To formulate a dynamic statistical model to forecast the need for allocating additional medical staff to improve the efficacy of work in the emergency department, taking into account patient volume.

Methods: The daily number of non-trauma admissions to the general ED[1] was assessed for the period 1 January 1992 to 1 December 1995 using the hospital computerized database. The marginal benefit to shortening patient length of stay in the ED by adding a physician during the evening shift was examined for different patient volumes. Data were analyzed with the SAS software package using a Gross Linear Model.

Results: The addition of a physician to the ED staff from noon to midnight significantly shortened patient LOS[2]: an average decrease of 6.61 minutes for 80–119 admissions (P<0.001). However, for less than 80 or more than 120 admissions, adding a physician did not have a significant effect on LOS in the ED.

Conclusions: The dynamic model formulated in this study shows that patient volume determines the effectiveness of investing manpower in the ED. Identifying bottleneck critical factors, as suggested by the theory of constraints, may be useful for planning and coordinating emergency services that operate under stressful and unpredictable conditions. Consideration of patient volume may also provide ED managers with a logical basis for staffing and resource allocation.