Carabini et al. authored an insightful article on caring for patients undergoing complex spine surgery.1 Their discussion and referenced studies on the predictive ability of pulse pressure variation in prone-positioned patients during volume expansion merit attention. The referenced studies have limitations, particularly regarding their relevance to patients with higher BMI, poor pulmonary compliance, and abdominal obesity.
Reference 30 was a non-randomized, crossover study with patients in the prone position experiencing increased blood pressure during volume expansion, with pulse pressure variationexceeding 15% predicting this response. The study’s population had an average body mass index (BMI) of 22, and the ventilation settings, including a positive end-expiratory pressure (PEEP) range of 0 to 3 cm H2O, raise concerns about applicability. Moreover, the observed rise in plateau pressure during prone positioning raises questions about generalizing these findings to patients with abdominal obesity, where abdominal compression is common and increases in plateau...
