Guillain-barré Syndrome And Hyponatremia

Objective: To assess the incidence of hyponatremia in patients withGuillain-Barré syndrom (GBS) and to explore whether hyponatremia is anindependent predictor of poor outcome.Method: Retrospectively collected patients with GBS from2003to2012admitted to the department of Neurology of Second Hospital and ThirdHospital of Hebei Medical University, Shijiazhuang. Patients were excludedwith the following features:1) existing other neurologic diseases likesubarachnoid hemorrhage and encephalitis;2) hyponatremia because ofinadequate intake or on medication with drugs like diuretics;3) hyponatremiabecause of thyroid, adrenal, hepatic or renal dysfunction or paraneoplasticsyndrome.4) history of suffering from neurologic or system diseases leftsequelae hard to evaluate the severity of GBS;5) absence of significantclinical data like the serum sodium concentration.Medical Research Council (MRC) sumscore was adopted for disabilityscale which was measured at the time of admission, nadir and discharge. TheMRC sumscore is defined as the sum of MRC scores from6musclesincluding shoulder abductors, and foot dorsiflexors on both sides, rangingfrom60(normal) to0(quadriplegic) in the upper and lower limbs on bothsides. GBS patients met the inclusion criteria were divided into three groups asmild, moderate and severe GBS according to MRC sumscore at nadir.Respiratory muscle paralysis was defined as a need for mechanical ventilation.Hyponatremia is defined as serum sodium concentration below135mmol/L.The incidences of hyponatremia in GBS patients with different MRCsumscore were analyzed by x2tests. Logistic regression models wererespectively performed to determine risk factors of hyponatremia and poorprognosis.Result:455who satisfied the diagnostic criteria were included in this study. There were283men and172women. The mean age was44.5years(range15-84y). The median time between GBS onset and admission tohospital was7.38days. Nearly seventy-five percent patients had a precedinginfection:151patients(33.2%) had upper respiratory infection and172(37.8%)patients had diarrhea. Of all the patients, mild, moderate and severe groupspatients were178,100and177respectively, bulbar weakness70(15.4%),facial paralysis151(33.2%), respiratory muscle paralysis61(13.4%),pneumonia47(10.3%).322(70.8%) patients received intravenous immuneglobulin（IVIg），5(1.1%) patients received plasma exchange(PE) and2(0.4%)received IVIg combined with PE.18(4.0%) died during the acute illness, allthe others took a turn for better at the time of discharge.Hyponatremia was detected in21.5%GBS patients. and36.2%severeGBS cases were found hyponatremia, which was more often than that of mild,moderate (11.8%,13.0%all p value <0.001), but with no significantlydifference between mild and moderate patients (p=0.769).Univariarate analysis showed showed strong associations withhyponatremia: age>50, MRC sumescore at nadir, facial paralysis, bulbarweakness, respiratory muscle paralysis and pneumonia (all p value <0.05).Age>50, facial paralysis and respiratory muscle paralysis were identified asindependent predictors of hyponatremia for multivariarate analysis logisticregression (odds ratio:2.013,2.493,12.871; all p value <0.05). MRCsumescore at nadir, pneumonia and bulbar weakness were not independentlyassociated with hyponatremia.Out of18patients died,12men. The mean age was53.2years old. All of18patients had respiratory muscle paralysis and15with hyponatremia.Univariarate analysis showed strong associations with motality in acute illness:Age>50, facial paralysis, bulbar weakness, pneumonia and hyponatremia (allp value <0.05). Bulbar weakness and hyponatremia identified as independentpredictors of death for multivariarate analysis logistic regression (odds ratio:3.391,12.770; all p value <0.05). Age>50, facial paralysis and pneumoniawere not independently associated with poor outcome. Conclusion:1. The incidence of hyponatremia is21.5%in GBS patients enrolled inthe study.2. Hyponatremia is more likely occurred in patients with higher age,cranial weakness or respiratory failure.3. Hyponatremia is an independent predictor of poor outcome in GBSpatients.