Cardiovascular effects of polymethylmethacrylate or cardiovascular effects of conscious sedation?

Cardiovascular Effects of Conscious Sedation? We read with interest the article by Kaufmann et al about the cardiovascular effects of polymethylmethacrylate (PMMA) injection during percutaneous vertebroplasty (PV). The authors compared patients’ vital signs before with those during and after PMMA injection: no significant differences were noted between preinjection mean arterial pressure (MAP) and that during, 5 minutes after, and 10 minutes after PMMA injection. The authors concluded that there were no clinically relevant generalized systemic cardiovascular effects related to PMMA injection during PV. We retrospectively reviewed charts of 33 consecutive patients who underwent 48 PVs at our institution: systolic and diastolic blood pressure, heart rate (HR), and systemic arterial oxygen saturation were recorded from before, during, 10 minutes after, and 20 minutes after PMMA injection. Conscious sedation was administered by an experienced interventionalist (G.D.B.) and titrated for effect. Our results differ substantially from those reported by Kaufmann and colleagues: a significant difference was noted between preinjection MAP and MAP during, 10 minutes after, and 20 minutes after PMMA injection using the paired Student t test (P .04, 0.03, 0.02). On the other hand, no significant differences were noted between MAP during PMMA injection and MAP 10 and 20 minutes after PMMA injection. We hypothesize a role for the routinely administered sedatives and narcotics (meperidine and midazolam), whose effects (in particular for meperidine) are widely known: meperidine anesthesia results in a moderate reduction in blood pressure and a marked depression in cardiac output.