Modes of pressure delivery and patient-ventilator interaction.

Differences between assist-control pressure and volume ventilation are minimal provided that peak inspiratory flow delivered at early inspiration matches patient demand Ventilation at constant flow and controlled tidal volume allow instantaneous analysis of the patient-ventilator interactions and the mechanical properties of the respiratory system. The cycle-per-cycle variability of peak inspiratory flow, which is permitted in pressure-limited modes, may allow better patient comfort. We do not know if one mode (pressure controlled or volume controlled) is superior to the other in terms of outcomes.

[False low oximetry reading caused by patent blue vital dye during breast surgery]. / Falsa desaturación provocada por colorante durante la cirugía de mama.

Patent blue vital (patent blue V; Laboratoire Guerbet, France) is used to identify the sentinel node during surgery for invasive breast cancer. Detecting the sentinel node that first drains the primary tumor reduces the need for total breast and wide axillary node removal, with the problems that such radical surgery involves. Like other dyes, patent blue V can interfere with accurate pulse oximeter reading, leading to underestimation of real values. We report the case of a 31-year-old woman who underwent lumpectomy and removal of the sentinel node. After intradermal injection of patent blue V dye into the left breast (100 mg administered because the sentinel node was difficult to locate) a drop in peripheral oxyhemoglobin saturation from 99% to 93% was detected by the pulse oximeter. When arterial blood gas analysis showed normal values and other causes were ruled out, the diagnosis was false low oximetry reading due to patent blue V dye.

[Varicella-zoster virus infection in children with Hodgkin's disease in advanced stages III and IV]. / Infección por virus varicela zoster en enfermedad de Hodgkin de niño en estadios avanzados III y IV.

Over a 10-year period, among 22 children with Hodgkin's disease (stages III and IV), 10 (45.5%) developed varicella-zoster virus (VZV) infection, varicella in 8 cases (36.4%) and herpes zoster (HZ) in 3 (13.6%) (one patient had varicella and six months later). Three patients with varicella had significant pneumonitis, one of them showed clinical evidence of dissemination and died. Two patients had localized HZ and one had disseminated HZ without visceral involvement. All cases of VZV infections occurred in the first year of treatment: the primary infection presented while patients were under induction therapy and the secondary one after radiotherapy.