Know what to do second, when the plan you already have stops working. Obstetric anesthesia is the one setting in perioperative medicine where two coupled patients can deteriorate within minutes, and where the decisive skill is rarely choosing the first plan. It is recognizing that the labor epidural will not extend, that the spinal is inadequate before incision, that a normal blood pressure in a young woman conceals a hemorrhage already in progress. This reference covers maternal and fetal physiology, labor analgesia, anesthesia for cesarean delivery, obstetric emergencies, and coexisting disease in the sequence a clinician meets them, teaching mechanism before management so that decisions under pressure follow from understanding rather than recall. Every chapter carries the Peripartum Contingency Atlas: a repeating block naming the situation, the primary plan, the earliest signature that it is failing, the fallback, and the red line. What this reference gives you at the point of care: • Maternal and uteroplacental physiology worked through mechanism by mechanism, so hypotension, apnea tolerance, and altered laboratory values become predictions rather than surprises • Labor analgesia from segmental anatomy to programmed intermittent bolus, with inadequate blocks diagnosed by pattern instead of adjusted blindly • Spinal, epidural extension, and general anesthesia for cesarean delivery, including the predictors of extension failure and the declared decision point that prevents an emergency induction • Postpartum hemorrhage managed on trend and quantitative loss, with the fibrinogen thresholds that fall earliest and uterotonic contraindications settled in advance • Preeclampsia, amniotic fluid embolism, maternal arrest, and perimortem delivery, each with the timing that determines survival • Thrombocytopenia and anticoagulation decisions built from the evidence behind the thresholds, including catheter removal scheduling • The Master Peripartum Contingency Index consolidating one hundred contingency arcs by failure signature, red line, phase of care, and presenting emergency Put the reasoning in place before the night you need it.
