Clinical Analysis Of Patients With Syndrome Of Inappropriate Antidiuresis

Background and ObjectivesThe syndrome of inappropriate antidiuresis(SIAD)is the most common cause of hyponatremia in clinical practice.It always secondary to various diseases and have myriad etiologies.As a result,it suffers from a lack of specific symptoms and is often misdiagnosed.If SIAD is not corrected with prompt and reasonable treatments,it will cause poorer outcomes.In clinical practice,the selection of diagnostic measures and treatments was left up to the clinicians responsible for patients;Although SIAD is a diagnosis of exclusion,clinicians always diagnose hyponatremia as SIAD without excluding alternative causes.It leads to diagnose SIAD without accuracy.Many patients were discharged still hyponatremic.As such,the diagnosis and treatment of SIAD face a big challenge.It is meaningful for clinicians to know more about clinical characteristics,treatments and effects of patients with SIAD.Analyse clinical data and characteristics in patients with SIAD over the last 16 years.The objective of us is to estimate the current state of management of hyponatremia due to SIAD,particularly current diagnostic modalities,treatment and effects.A secondary objective was to assess the clinical characteristics of the cancer-related SIAD and non-cancer-related SIAD.and estimate whether existed clinical characteristic differences between two groups.Methods1.From January 2013 to September 2019,we analysed the clinical data in patients with SIAD of Qilu Hospital,Shandong University.Principal data collection items included the following:age,gender,time of hospitalization,first-visit department,laboratory examinations,diagnosis,treatments and so on.According to patients whether performed complete laboratory testing for diagonsing SIAD,the patients were divided into clinician-diagnosed SIAD group and laboratory-diagnosed SIAD group.2.According to the etiology of SIAD,the patients were divided into cancer-related SIAD group and non-cancer-related SIAD group.We assess the clinical characteristics of the cancer-related SIAD and non-cancer-related SIAD,and estimate whether existed clinical characteristics differences between two groups.3.Using SPSS(version 25.0)to analyze clinical data.Results1.There were 169 clinician-diagnosed SIAD patients admitted to Qilu Hospital,Shandong University over the last 16 years.We excluded 3 patients who suffered from glucocorticoid insufficiency or used diuretics.After adjudication,166 patients comprised the perprotocol data set.2.Among 166 patients,105 patients were male and 61 patients were female,male:female=1.72:1;Average age was 65.78±12.15 years old;The first-visit department of patients is various,Endocrinology department comprised the major part;The most frequent cause of SIAD was pulmonary diseases(28.9%),followed by malignant tumors(24.1%)and central nervous system disorders(21.1%);113 patients(68.1%)performed complete laboratory testing for diagonsing SIAD;Of note,the success rates of correcting hyponatremia was higher when patients performed these tests;The most common therapy was hypertonic saline+fluid restriction(42.2%),followed by fluid restriction(18.7%),tolvaptan+fluid restriction(15.1%).The treatments containing hypertonic saline or tolvaptan produced more pronounced effect.These treatments also had very high rates of increasing in serum sodium.3.Cancer-related SIAD and non-cancer-related SIAD existed differences in age(P<0.01);Mean age in cancer-related SIAD group was 60.90±13.09 years old,mean age in non-cancer-related SIAD group was 67.33±11.46 years old;There were differences between two groups(P<0.05),complete laboratory testing for diagonsing SIAD was performed in only 17(42.5%)cancer-related SIAD patients and 96(76.2%)non-cancer-related SIAD patients;Among the diagnostic procedures,computed tomography(CT)of chest demonstrated diagnostic rate(21.53%)in cancer-related SIAD patients,PET demonstrated diagnostic rate of 40.00%in cancer-related SIAD patients;As for cancer-related SIAD patients,it produced the biggest rate of change of[Na+]with a tolvaptan-containing therapy.Conclusions1.Most frequent causes of SIAD were pulmonary disease,malignant tumors.2.Clinicians sometimes diagnosed hyponatremia as SIAD without excluding alternative causes.Clinicians diagnosed SIAD without mandatory laboratory tests was widespread.However,the success rate of correcting hyponatremia was higher when patients performed these tests.3.The treatments containing hypertonic saline or tolvaptan produced more pronounced effect.These treatments also had very high rates of increasing in serum sodium.4.As for cancer-related SIAD patients,tolvaptan should be considered as an initial therapy for correcting hyponatremia.5.The starting dose of tolvaptan was 3.75 mg per day.It always combined with other treatments.6.Computed tomography(CT)of chest and PET-CT demonstrated higher diagnostic rate in cancer-related SIAD patients.As for unidentified etiologies of SIAD patients,it can perform the CT of chest when consider pulmonary diseases;It can perform the PET-CT when consider malignant tumors.