Optimization models for patient and technician scheduling in hemodialysis centers.

Patient and technician scheduling problem in hemodialysis centers presents a unique setting in healthcare operations as (1) unlike other healthcare problems, dialysis appointments have a steady state and the treatment times are determined in advance of the appointments, and (2) once the appointments are set, technicians will have to be assigned to two types of jobs per appointment: putting on and taking off patients (connecting to and disconnecting from dialysis machines). In this study, we design a mixed-integer programming model to minimize technicians' operating costs (regular and overtime costs) at large-scale hemodialysis centers. As this formulation proves to be computationally challenging to solve, we propose a novel reformulation of the problem as a discrete-time assignment model and prove that the two formulations are equivalent under a specific condition. We then simulate instances based on the data from our collaborating hemodialysis center to evaluate the performance of our proposed formulations. We compare our results to the current scheduling policy at the center. In our numerical analysis, we reduced the technician operating costs by 17% on average (up to 49%) compared to the current practice. We further conduct a post-optimality analysis and develop a predictive model that can estimate the number of required technicians based on the center's attributes and patients' input variables. Our predictive model reveals that the optimal number of technicians is strongly related to the time flexibility of patients and their dialysis times. Our findings can help clinic managers at hemodialysis centers to accurately estimate the technician requirements.

This is a successful removal of more than 450 pieces of metal objects from a patient's stomach: a case report.

BACKGROUND: Ingestion of foreign bodies may be seen unconsciously or intentionally in patients with mental health problems. Most cases pass through the esophagus slowly; however, in some cases, the tumor may be located in narrower areas of the digestive tract that require endoscopic or surgical intervention. This study describes a rare case of successful removal of more than 450 pieces of metal objects from the stomach of a 36-year-old man via ingestion of foreign bodies at Imam Khomeini Hospital in Ahvaz. CASE PRESENTATION: A 36-year-old male patient (Aryan race) presented with complaints of chronic abdominal pain, frequent vomiting, and intolerance to liquids and food. The patient's companions mentioned a history of gradual ingestion of small metal objects 3 months prior. The patient was conscious and had stable vital signs. In the patient's X-ray and endoscopy, multiple metal objects inside the patient's stomach were observed, causing gastric outlet obstruction. The patient underwent gastrostomy surgery, and 452 screws, nuts, keys, stones, and other metal parts weighing 2900 g were removed from the stomach. Five days after the operation, the patient was transferred to the psychiatric service in good general condition and was diagnosed with psychosis, and her condition returned to normal at follow-up. CONCLUSION: Successful removal of this foreign body is rare. In chronic abdominal pain, especially in the context of psychiatric disorders, attention should be given to the ingestion of foreign bodies. In swallowing large amounts of sharp and metallic foreign objects, surgical intervention is necessary, especially in cases of obstruction, and saves the patient's life.

Evaluation of Hematoma Formation after Thyroidectomy Surgery and Its Related Factors.

Background: In the last decade, the number of patients undergoing thyroidectomy has increased. Compared to other methods, thyroidectomy is a relatively safe method for treating various types of thyroid diseases. However, the blood flow rate in the thyroid gland is high, and hematoma after thyroidectomy is one of its complications. We aimed to evaluate hematoma after thyroidectomy and its related factors. Methods: In this retrospective study, 2320 patients over 20 years of age who underwent thyroidectomy in Imam Khomeini, Arvand, and Mehr Ahvaz hospitals, Khuzestan Province, southern Iran between 2011 and 2022 were enrolled. Data were analyzed using SPSS software, version 22. Results: 70.7% of the patients were in the age range of 20-50 years. Twenty-five (1.1%) of patients developed a hematoma after thyroidectomy. Males are more likely to hematoma after surgery (P=0.01). Hematoma was significantly higher in patients with a history of hypertension (P=0.001). Moreover, a significant association was found between male gender, and age over 50 years with the risk of hematoma (P<0.05). The incidence of hematoma had a statistically remarkable correlation with follicular thyroid cancer pathology (P=0.001). Other pathology diagnoses were not significantly related to hematoma formation after thyroidectomy. Conclusions: Hematoma after thyroidectomy surgery is a rare, but dangerous and life-threatening complication. It is important to identify risk factors for hematoma formation.

Evaluation of antibody titers in COVID-19 patients with cerebral or pulmonary symptoms and mild symptoms.

Background and Objectives: This study aimed to compare the production of antibodies in three different groups of patients with COVID-19. These groups included patients with pulmonary and cerebral symptoms, as well as those with mild symptoms. Materials and Methods: Blood samples were collected from 80 patients admitted to COVID-19-specific hospitals. The patients had various forms of SARS-CoV-2 disease, including those with pulmonary symptoms, brain involvement, and those with positive PCR test results but mild symptoms. The enzyme-linked immunosorbent assay (ELISA) technique was used to determine the levels of IgM and IgG antibody titers. Results: The levels of IgM and IgG antibody production differed significantly between groups of patients experiencing pulmonary symptoms and cerebral symptoms, with mild symptom patients also showing differences (P=0.0068), (P=0.0487), (P<0.0001), and (P=0.0120), respectively. Furthermore, there was no significant relationship between IgM antibody secretion and age or pulmonary involvement (P=0.1959). However, there was a direct and significant relationship between age and brain involvement (P=0.0317). Conclusion: The findings of this study revealed that the risk of central nervous system involvement increases with age and that older people have lower antibody levels than younger people. Consequently, strengthening the immune systems of people over the age of 78 during this pandemic through vaccination and nutrition is very effective in reducing mortality in this age group.

COMPARISON BETWEEN OSTOMY CLOSURE USING PURSE-STRING VERSUS LINEAR IN CHILDREN.

BACKGROUND: Type of ostomy closure has connection with some complications and also cosmetic effects. AIMS: This study aimed to compare result of colostomy closure using purse-string method versus linear method in terms of surgical site infection, surgical time, and patient satisfaction. METHODS: In this study, 50 patients who underwent purse-string ostomy closure and 50 patients who underwent linear closure were included. Two groups were compared for surgical time, wound infection, patient satisfaction, scar length. A p-value <0.05 was considered significant. RESULTS: Wound infection was not reported among purse-string group compared to 10% in linear group (p=0.022). Scar length was 24.09±0.1 mm in purse string and 52.15±1.0 mm in linear group (p=0.033). Duration of hospital admission was significantly shorter in purse-string group (6.4±1.1 days) compared to linear (15.5±4.6 days, p=0.0001). The Patient and Observer Scar Assessment Scale scale for observer (p=0.038) and parents (p=0.045) was more favorable among purse-string group compared to linear. CONCLUSION: Purse-string technique has the less frequent surgical site infection, shorter duration of hospital admission, less scar length, and more favorable cosmetic outcome, compared to linear technique.

Comparison between ostomy closure using purse-string versus linear in children / Comparação entre o fechamento de ostomia em bolsa vs. grampeamento linear em crianças

ABSTRACT BACKGROUND: Type of ostomy closure has connection with some complications and also cosmetic effects. AIMS: This study aimed to compare result of colostomy closure using purse-string method versus linear method in terms of surgical site infection, surgical time, and patient satisfaction. METHODS: In this study, 50 patients who underwent purse-string ostomy closure and 50 patients who underwent linear closure were included. Two groups were compared for surgical time, wound infection, patient satisfaction, scar length. A p-value <0.05 was considered significant. RESULTS: Wound infection was not reported among purse-string group compared to 10% in linear group (p=0.022). Scar length was 24.09±0.1 mm in purse string and 52.15±1.0 mm in linear group (p=0.033). Duration of hospital admission was significantly shorter in purse-string group (6.4±1.1 days) compared to linear (15.5±4.6 days, p=0.0001). The Patient and Observer Scar Assessment Scale scale for observer (p=0.038) and parents (p=0.045) was more favorable among purse-string group compared to linear. CONCLUSION: Purse-string technique has the less frequent surgical site infection, shorter duration of hospital admission, less scar length, and more favorable cosmetic outcome, compared to linear technique.

RESUMO RACIONAL: A técnica de fechamento da ostomia tem relação com algumas complicações e também efeitos estéticos. OBJETIVOS: Comparar o resultado do fechamento da colostomia pelo método em bolsa versus método linear, em termos de infecção do sítio cirúrgico, tempo cirúrgico e satisfação do paciente. MÉTODOS: Foram incluídos 50 pacientes que não realizaram o fechamento da estomia em bolsa e 50 pacientes que foram submetidos ao fechamento linear. Os dois grupos foram comparados quanto ao tempo cirúrgico, infecção da ferida, satisfação do paciente, comprimento da cicatriz. Valor de p menor que 0,05 foi considerado significativo. RESULTADOS: A infecção da ferida não foi registrado no grupo de bolsa, em comparação com 10% no grupo linear (p=0,022). O comprimento da cicatriz foi de 24,09±0,1 mm no grupo de bolsa e 52,15±1,0 mm no grupo linear (p=0,033). O tempo de hospitalização foi significativamente menor no grupo em bolsa (6,4±1,1 dias) em comparação ao linear (15,5±4,6 dias, p=0,0001). A escala Patient and Observer Scar Assessment Scale para observador (p=0,038) e pais (p=0,045) foi mais favorável entre o grupo em bolsa, em relação ao linear. CONCLUSÕES: A técnica em bolsa apresentou infecção do sítio cirúrgico menos frequente, menor tempo de internação, menor comprimento da cicatriz e resultado cosmético mais favorável, em comparação com a técnica linear.