ABSTRACT
Systolic pressure variation (SPV) is the cyclic change in systolic blood pressure secondary to positive-pressure ventilation. It is normally a good indicator of intravascular volume and often can be substituted for central venous pressure monitoring, but the reliability of SPV for this use depends on the multiple determinants of intrathoracic pressure remaining constant. We present a case in which an intrabronchial tumor caused dynamic hyperinflation of one lung. This situation, in turn, caused a marked increase in SPV but, more importantly, it increased variability of the SPV despite normal intravascular volume. We discuss the physiology of SPV and the implications of this case for the use of SPV as a monitor of intravascular volume.
Subject(s)
Blood Pressure , Bronchial Neoplasms/diagnosis , Leiomyoma/diagnosis , Lung Volume Measurements , Adult , Bronchial Neoplasms/complications , Bronchial Neoplasms/surgery , Diagnosis, Differential , Female , Humans , Hypovolemia/diagnosis , Leiomyoma/complications , Leiomyoma/surgery , Lung/pathology , Meningeal Neoplasms/complications , Meningeal Neoplasms/surgery , Meningioma/complications , Meningioma/surgery , Respiratory Mechanics , SystoleABSTRACT
PURPOSE: Ureteroscopy for treating urolithiasis in prepubertal children has become more common with the advent of smaller instruments. We reviewed our experience with ureteroscopy for urolithiasis in this cohort of patients as well as the literature using this treatment modality in children. MATERIALS AND METHODS: Between 1994 and 2000 we performed 27 ureteroscopic stone extractions in 25 children. Ureteroscopy was done in a manner similar to that in adults. Ureteral dilation was performed when necessary to access the ureter. A stent was placed postoperatively if there was significant ureteral trauma. RESULTS: Of the 25 children 13 were male and 12 were female. Average age was 9.2 years (range 3 to 14). Stones were 2 to 12 mm. in greatest diameter (average 6). Of the 27 procedures the ureteral orifice was dilated before stone treatment in 15 (56%), while in 19 (70%) a stent was placed afterward. No intraoperative and 2 postoperative complications were identified. Overall 92% of the children were rendered stone-free after 1 procedure and 100% were stone-free after 2. CONCLUSIONS: Ureteroscopy for urolithiasis in prepubertal children is safe and effective. Routine ureteral dilation and ureteral stent placement are not always necessary in these patients.
