Hypotension (MeSH: D007022)

Blood pressure is routinely monitored during anesthesia in children, but blood pressure alone may not accurately reflect blood flow to vital organs. This is particularly important in infants and young children, in whom normal cardiovascular values vary with age. The CARFLOW study is a prospective observational study of 100 children aged 0-5 years undergoing anesthesia and surgery. The purpose is to investigate how blood flow in the common carotid artery, measured non-invasively using Doppler ultrasound, relates to blood pressure and cardiac output during anesthesia. Carotid artery blood flow will be measured before and during anesthesia and compared with blood pressure recorded as part of routine monitoring. In children who are intubated, cardiac output will also be measured non-invasively using a capnodynamic method. The main questions are whether changes in blood pressure are associated with changes in carotid artery blood flow, how carotid artery blood flow relates to cardiac output, and whether reference values for carotid artery blood flow during anesthesia can be established for young children. All clinical decisions and treatment will follow routine clinical practice. Measurements performed as part of the study will not be used to guide treatment.

This study compares two methods of identifying the correct intervertebral level before performing spinal anesthesia in women undergoing elective cesarean delivery. In current practice, anesthesiologists locate the puncture site by feeling anatomical landmarks on the lower back (palpation of Tuffier's line). Ultrasound imaging offers an alternative in which the spine is scanned and the intended level is marked on the skin before the needle is inserted. It is not yet clear whether this additional step improves the success of the procedure or affects the mother's blood pressure and heart rate after the block. Sixty pregnant women scheduled for elective cesarean section will be randomly assigned to one of two groups. In one group, the puncture level will be determined by preprocedural ultrasound marking; in the other, by conventional landmark palpation. All other aspects of anesthetic care, including drug doses, will be identical in both groups. The main outcome is the proportion of patients in whom the subarachnoid space is entered successfully at the first attempt with a single skin puncture, producing a block adequate for surgery. Additional outcomes include the number of needle passes, procedure duration, changes in maternal blood pressure and heart rate, vasopressor requirement, sensory block level, and complications such as headache or back pain within 24 hours after surgery.