[Use of high-flow nasal cannula for non-invasive ventilation in children]. / Utilización de cánulas nasales de alto flujo para la ventilación no invasiva en niños.

OBJECTIVE: To analyse the efficacy and tolerance of non-invasive mechanical ventilation (NIMV) via high-flow oxygen therapy nasal cannulae in children after withdrawal of mechanical ventilation and/or with moderate respiratory insufficiency. PATIENTS AND METHODS: A prospective observational clinical study including 34 children between 9 months and 17 years treated with NIMV via high-flow oxygen therapy nasal cannulae. The following variables were analysed: age, sex, respiratory rate, heart rate, oxygen saturation, blood gases, clinical improvement, tolerance, onset of complications and treatment failure. RESULTS: NIMV was used in 13 children after withdrawal of mechanical ventilation and in 21 with respiratory failure. A high percentage (82.3%) of patients improved clinically and/or allowed the mechanical ventilation to be withdrawn, but there were no significant changes in respiratory rate, heart rate, pH, pCO(2) or saturation. NIMV was not effective in 6 patients (17.6%) and required change to a nasal or buconasal mask (5 patients) or intubation (1 patient). Two patients (5.9%) required change of interface to a nasal or buconasal mask, one had nasal erosion, and another, although improved clinically, showed excessive leakage. The duration of treatment was 48 hours (range 1 to 312 hours). CONCLUSIONS: Non-invasive mechanical ventilation via high-flow oxygen therapy nasal cannulae is effective and well tolerated in a high percentage of children after withdrawal of mechanical ventilation or with moderate respiratory insufficiency.

[The effect of helium on ventilator parameters: in vitro study with a Servoi ventilator]. / Efecto del helio sobre los parámetros de los respiradores en ventilación mecánica: estudio in vitro con el respirador Servoi.

OBJECTIVE: To analyze the changes in respiratory parameters in a Servoi ventilator with heliox. MATERIAL AND METHODS: In vitro study with a Servoi (Maquet) ventilator in volume controlled (VC), pressure controlled (PC) and volume control regulated by pressure (VCPR) modes connected to an artificial lung. A heliox tank with a fixed concentration of helium 70 % and oxygen 30 % was connected to the air inlet of the ventilator. The ventilator was set in VC mode with tidal volumes of 30, 50, 100, 250 and 500 ml; in PC mode with pressure of 20 and 30 cmH(2)O and in VCPR mode with tidal volume of 150 ml. In each case FiO(2) of 21, 30, 40, 50, 60, 70, 80, 90 and 100 % was used. The FiO(2), inspired and expired tidal volume and inspiratory pressure measured by the ventilator and a pitot spirometer (Datex_S5) were compared. RESULTS: In VC and VCPR modes the increase in helium produced a progressive decrease in the pressure needed to administrate the set volume. Heliox also produced a decrease in the tidal volume measured by the spirometer and the tidal expired volume measured by the respirator. In PC mode, heliox produced a progressive increase in the inspired tidal volume, increasing the differences between inspired and expired tidal volumes. CONCLUSIONS: Heliox used with Servoi ventilator produces a decrease in inspiratory pressures in VC and VCPR modes, and an increase in inspiratory tidal volume in PC mode. In all modes heliox reduced the expired tidal volume measured by the ventilator and the spirometer. These changes should be borne in mind if heliox is used with this ventilator.

[Experience with high-flow nasal cannula oxygen therapy in children]. / Experiencia con la oxigenoterapia de alto flujo en cánulas nasales en niños.

OBJECTIVE: To analyze the efficacy of a high-flow oxygen therapy system in children with moderate respiratory failure and/or high oxygen requirements. PATIENTS AND METHODS: We performed a prospective, observational clinical study of patients treated with a high-flow oxygen therapy system via nasal cannulae. The following variables were analyzed: clinical severity score, respiratory rate, heart rate, clinical improvement, oxygen saturation, blood gases, complications, and the need for ventilation after starting the treatment. RESULTS: Eighteen treatments were studied in 16 patients (two girls and 14 boys) aged between 2 and 156 months. With the high-flow oxygen therapy system, respiratory rate slightly decreased from 34.5 bpm to 32.2 bpm (p<0.04) and O2 saturation increased from 90.2% to 93.5% (p<0.02). Fourteen patients showed a clinical improvement and/or tolerated the change from the previous respiratory assistance. The duration of treatment was 3 days (range: 6 hours to 25 days). Mild complications (initial irritability and excessive humidity) were observed in two patients, but treatment interruption was not required. No secondary respiratory tract infections were observed. The system was withdrawn in four patients, due to lack of improvement in two patients, deterioration after initial improvement in one patient, and failure of the system's temperature regulation in one patient. CONCLUSIONS: The high-flow oxygen therapy system is effective in a large percentage of children with high oxygen requirements and/or moderate respiratory failure.

[Necrotizing fasciitis due to Streptococcus pyogenes]. / Fascitis necrosante por Streptococcus pyogenes.

Necrotizing fasciitis is a severe infection, with systemic involvement and tissue necrosis. The clinical course is rapid and often fatal. Although this entity is uncommon, early recognition and treatment is essential to improve prognosis. Necrotizing fasciitis should be suspected when there are symptoms of toxicity and there is severe pain, frequently out of proportion to the clinical findings. In addition, in the last few years the incidence of invasive disease due to Streptococcus pyogenes in children has increased. Treatment is based on life support, aggressive debridement, and antimicrobial therapy. Intravenous immunoglobulin (IVIG) as adjunctive therapy seems useful and reduces mortality. The case of an infant with necrotizing fasciitis of four extremities is presented.