PMC:2675008 / 29031-32585 JSONTXT

{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/2675008","sourcedb":"PMC","sourceid":"2675008","source_url":"https://www.ncbi.nlm.nih.gov/pmc/2675008","text":"Strengths and limitations of the study\nA study published in 1981 described iatrogenic hyponatraemia to be caused mainly by electrolyte-free intravenous fluids administered as vehicle for oxytocin.1 The authors suggested that oxytocin should be administered at higher concentrations, and fluid balance supervised closely during labour.\nThe first advice changed practice of oxytocin administration, but more recent case reports of hyponatraemia during labour imply that the second advice was forgotten.34,35 Hyponatraemia during labour, now less frequently iatrogenic, is more often caused by overdrinking.12–14,31 Our study was therefore designed to evaluate the prevalence of hyponatraemia during modern management of labour. The women in our study received oxytocin in moderate fluid volumes, and most of the fluids administered were orally ingested. Nonetheless, 21 women in our study developed hyponatraemia during labour, thus illustrating that the oral route of administration does not diminish the risks of excess water. As in other studies, we found hyponatraemia in women receiving oxytocin as well as epidural analgesia.1,6 The multivariate regression analysis performed in our study shows that hyponatraemia was probably caused by fluid intake, but only associated with oxytocin and epidural analgesia. Modern low-dose epidural regimens do usually not call for large volumes of intravenous fluids to preserve blood pressure.\nOur results are all the more important as the habit of drinking large quantities of water has become quite common in the general population.10 Also, a more liberal attitude to fluid administration during labour might have developed. The comparison of fluid volumes administered during labour as reported in scientific papers indicates that such could be the case. In a study published in 1991, evaluating saline or glucose as vehicle for oxytocin, one study group received a mean of 710 ± 640 ml of intravenous glucose.2 A more recent work, published in 2005, studied the effect of unrestricted oral carbohydrate intake.32 The intervention group received 3234 ± 1473 ml of intravenous fluids.\nThe observational study design has limitations when compared with a randomised controlled trial. However, it can be doubted whether an ethical committee would permit a deliberate exposure to the degree and risks of hyponatraemia observed in the present study. Analysis would have benefited from hourly registration of fluid intake and urine output. This option was considered, but although desirable, the work load imposed could have jeopardised the realisation of the study. Also, such close monitoring of behaviour would have introduced an observational bias. However, it is possible that the women who developed hyponatraemia had larger hourly oral fluid intake leading to symptomatic hyponatraemia. Tiredness and irritability, initial symptoms of hyponatraemia, may have prompted energy supplement by intravenous glucose infusion. This alterative interpretation strengthens the need of registering all oral fluid intakes during labour and remembering hyponatraemia as possible diagnosis. Not all consecutive women were included, omitting many women in advanced labour. The proportion of nulliparas is therefore large in our study population, probably increasing the incidence of hyponatraemia. Infants were examined and treated according to departmental routine; therefore, only clinically significant symptoms were investigated. The results regarding neonatal outcome should be interpreted with these limitations in mind.","divisions":[{"label":"title","span":{"begin":0,"end":38}},{"label":"p","span":{"begin":39,"end":334}},{"label":"p","span":{"begin":335,"end":1434}},{"label":"p","span":{"begin":1435,"end":2127}}],"tracks":[{"project":"2_test","denotations":[{"id":"19175600-6790112-7908420","span":{"begin":196,"end":197},"obj":"6790112"},{"id":"19175600-17925046-7908421","span":{"begin":500,"end":502},"obj":"17925046"},{"id":"19175600-18162206-7908422","span":{"begin":503,"end":505},"obj":"18162206"},{"id":"19175600-12200908-7908423","span":{"begin":604,"end":606},"obj":"12200908"},{"id":"19175600-15569290-7908423","span":{"begin":604,"end":606},"obj":"15569290"},{"id":"19175600-15598305-7908423","span":{"begin":604,"end":606},"obj":"15598305"},{"id":"19175600-15663123-7908424","span":{"begin":610,"end":612},"obj":"15663123"},{"id":"19175600-6790112-7908425","span":{"begin":1129,"end":1130},"obj":"6790112"},{"id":"19175600-7657008-7908426","span":{"begin":1131,"end":1132},"obj":"7657008"},{"id":"19175600-12376390-7908427","span":{"begin":1575,"end":1577},"obj":"12376390"},{"id":"19175600-2040241-7908428","span":{"begin":1954,"end":1955},"obj":"2040241"}],"attributes":[{"subj":"19175600-6790112-7908420","pred":"source","obj":"2_test"},{"subj":"19175600-17925046-7908421","pred":"source","obj":"2_test"},{"subj":"19175600-18162206-7908422","pred":"source","obj":"2_test"},{"subj":"19175600-12200908-7908423","pred":"source","obj":"2_test"},{"subj":"19175600-15569290-7908423","pred":"source","obj":"2_test"},{"subj":"19175600-15598305-7908423","pred":"source","obj":"2_test"},{"subj":"19175600-15663123-7908424","pred":"source","obj":"2_test"},{"subj":"19175600-6790112-7908425","pred":"source","obj":"2_test"},{"subj":"19175600-7657008-7908426","pred":"source","obj":"2_test"},{"subj":"19175600-12376390-7908427","pred":"source","obj":"2_test"},{"subj":"19175600-2040241-7908428","pred":"source","obj":"2_test"}]}],"config":{"attribute types":[{"pred":"source","value type":"selection","values":[{"id":"2_test","color":"#ecb393","default":true}]}]}}