Which of the following is the earliest warning sign of Magnesium Sulphate toxicity?

Ans. B. Loss of DTRs. (Ref Textbook of Obstetrics D.C. Dutta 6th ed, 229)SEIZURE PROPHYLAXIS IN PIH - MAGNESIUM SULFATE# Is not a hypotensive agent# Works as a centrally acting anticonvulsant# Also blocks neuromuscular conduction# Serum levels: 6-8 mg/dL# Magnesium sulfate # Monitor urine output and DTR's- Cervical dilatation of 3 to 5 cm or more, in the presence of uterine contractions, can be taken to reliably represent the threshold for active labor.# With renal dysfunction, may require a lower doseToxicity# Respiratory rate < 12 (respiratory depression develops when levels go lOmEg/L)# DTR's not detectable (earliest warning sign of toxicity =/< 10 mEq/L)# Altered sensorium# Urine output < 25-30 cc/hour# Respiratory paralysis arrest ( 3 12 mEq/L)# Antidote: 10 ml of 10% solution of calcium gluconate IV over 3 minutes- The therapeutic level of serum magnesium is 4-7 mEq/L.- The normal level of serum (blood) magnesium is 1.5 - 2.0 mEq/L (1-2 mg/dl).Hypertension in pregnancy CommentsRxGestational hypertension (pregnancy-induced hypertension)BP > 140/90 mmHg after the 20th week of gestation. No preexisting hypertension. No proteinuria or end-organ damage.Treatment: antihypertensives (a- methyldopa, labetalol, hydralazine, nifedipine), deliver at 39 weeks.Preeclampsia- Defined as hypertension (> 140/90 mmHg) and proteinuria (> 300 mg/24 hr) after 20th week of gestation to 6 weeks postpartum (< 20 weeks suggests molar pregnancy).Severe features include BP > 160/110 mmHg with or without end-organ damage, e.g., headache, scotoma, oliguria,*AST/ ALT, thrombocytopenia.- Caused by abnormal placental spiral arteries, results in maternal endothelial dysfunction, vasoconstriction, or hyperreflexia.- Incidence<<in patients with preexisting hypertension, diabetes chronic renal disease, or autoimmune disorders.- Complications: placental abruption, coagulopathy, renal failure, uteroplacental insufficiency, or eclampsia.Antihypertensives, deliver at 34 weeks (severe) or 37 weeks (mild), IV magnesium sulfate to prevent seizure.EclampsiaPreeclampsia + maternal seizures. Maternal death due to stroke*intracranial hemorrhage or ARDS.Antihypertensives, IV magnesium sulfate, immediate delivery.