Hyperemesis Gravidarum (HG)

Quantify the volume deficit - Serial weights against the pre-pregnancy weight, mucous membrane dryness, capillary refill, and skin turgor at the bedside; urine specific gravity and ketones, and a hemoglobin and hematocrit that read falsely high from hemoconcentration. Rehydrate before you induce or dose a neuraxial, not after the pressure drops.

Metabolic panel before an elective case - Protracted vomiting moves potassium, magnesium, calcium, sodium and bicarbonate, and dehydration shows up as a rising creatinine and BUN with a fallen GFR. Hypokalemia is the one tied to real morbidity and mortality — correct it first.

Thiamine before any glucose - Glucose oxidation consumes thiamine and can precipitate Wernicke encephalopathy in a depleted patient. Give parenteral thiamine before or with any dextrose-containing fluid. Treatment dosing runs as high as 500 mg parenterally one to three times daily; oral absorption is unreliable and is not recommended.

Recognize Wernicke encephalopathy - Ophthalmoplegia with nystagmus, ataxic gait, and confusion. The full triad is absent in up to 90%, so the Caine criteria — two of ataxia, confusion, and ophthalmoplegia — are what you act on. MRI may show hyperintensity in the periventricular thalamus, mammillary bodies, and periaqueductal gray, but a normal scan does not rule it out. Replace magnesium as well; deficiency blunts recovery.

Correct sodium slowly - Rapid correction of hyponatremia is the usual cause of central pontine myelinolysis. Restore volume first and let the sodium come up gradually.

Treat her as a full stomach - Ongoing vomiting means NPO status is meaningless. Aspiration prophylaxis with sodium citrate 30 mL PO, famotidine 20 mg IV or pantoprazole 40 mg IV, and metoclopramide 10 mg IV, with rapid sequence induction if a general is needed.

Know what antiemetics she is already on - Pyridoxine plus doxylamine is first line; second line is promethazine 12.5 to 25 mg, prochlorperazine 25 mg PR every 12 hours, dimenhydrinate or diphenhydramine, then metoclopramide or ondansetron. Refractory cases get chlorpromazine 25 to 50 mg IV or IM, or methylprednisolone 16 mg every 8 hours. Check the chart before stacking another dopamine antagonist.

Look for the forceful-vomiting injuries - Esophageal rupture and pneumothorax have both been reported from repeated retching. Chest pain, subcutaneous emphysema, or unexplained dyspnea earns a chest film before positive-pressure ventilation.

Make sure it is actually HG - Vomiting starting after 9 weeks points elsewhere: preeclampsia, HELLP, and acute fatty liver of pregnancy show up in the late second or third trimester. Thyroid studies, lipase, and liver function tests sort the differential, and an obstetric ultrasound rules out molar pregnancy, multiple gestation, and ectopic pregnancy.

The fetal picture is largely reassuring - Studies have not shown an association between hyperemesis and perinatal or neonatal mortality, and congenital anomaly rates are not increased. Data on low birth weight and prematurity conflict.

Hyperemesis gravidarum (HG) is intractable vomiting in pregnancy severe enough to cause weight loss — commonly 5% or more of pre-pregnancy weight — with volume depletion and ketonuria or ketonemia. It sits at the severe end of the nausea and vomiting of pregnancy spectrum, affecting roughly 0.3% to 3% of pregnancies, starting around 5 to 6 weeks and usually settling by week 20; about 10% of affected patients carry it the whole pregnancy. Increased placental mass from a molar or multiple gestation raises the risk.

What matters perioperatively is the downstream damage rather than the vomiting itself: hemoconcentration, prerenal acute kidney injury, derangement of potassium, magnesium, calcium, sodium and bicarbonate, and thiamine depletion that can tip into Wernicke encephalopathy.