RESUMEN
OBJECTIVES: Auto-inhalation of nitric oxide (NO) produced in the upper airways may have physiologic effects on lung function. For intubated patients, the upper airway source of NO is eliminated, but the hospital compressed air source from the environment is contaminated with varying levels of NO, creating an "occult" form of NO therapy. We examined the physiologic significance of occult inhaled NO in ventilator-dependent pediatric patients. We hypothesized that very low levels of NO contamination in inspired gas improve PaO2 in ventilator-dependent children. STUDY DESIGN: Inspired NO levels at the mouth were measured by chemiluminescence in 4 pediatric subjects with normal lungs and 3 with parenchymal lung disease. Subjects were sequentially ventilated with first standard hospital gas (H1), switched to pure nitrogen-oxygen at a similar FIO2 but with no NO contamination (A2), hospital gas again (H2), the nitrogen-oxygen (A2) to control for time and sequence, and finally the nitrogen-oxygen mixture with supplemental NO in an amount equal to the NO previously measured in hospital gas (A2 + NO). Inhaled NO levels and PaO2 were recorded 15 minutes into each of the 5 steps. Two patients were studied a second time, remote from their first examination. RESULTS: NO levels in inhaled hospital gas mixtures ranged from 13 to 79 ppb (mean H1 = 53.3 +/- 23.7 ppb, mean H2 = 53.2 +/- 20.7 ppb, mean A2 + NO = 45 +/- 15.3 ppb; P < .0001). Removing NO from ventilator gas decreased PaO2 in all subjects, whereas replacing NO in artificial gas restored PaO2 to baseline values (P < .0001). CONCLUSION: Concentrations of NO in hospital compressed air are variable and have physiologic effects. The long-term implications of these findings remain to be defined.
Asunto(s)
Óxido Nítrico/administración & dosificación , Oxígeno/sangre , Respiración Artificial , Insuficiencia Respiratoria/terapia , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Intercambio Gaseoso Pulmonar/efectos de los fármacos , Intercambio Gaseoso Pulmonar/fisiología , Insuficiencia Respiratoria/sangre , Insuficiencia Respiratoria/etiología , Resultado del TratamientoRESUMEN
OBJECTIVE: To test the hypothesis that a pretransport Pediatric Risk of Mortality (PRISM) score underestimates the requirement for both intensive care and interventions during pediatric interhospital transport. DESIGN: Prospective, descriptive study. SETTING: All children were treated in a regional hospital and then transported to a pediatric tertiary care center by a pediatric critical care specialty team. PATIENTS: Children (n = 156) with a median age of 1.3 yrs (range newborn to 18 yrs). INTERVENTIONS: None related to the study. MEASUREMENTS AND MAIN RESULTS: Two sets of Pediatric Risk of Mortality scores were calculated: one from data collected over the telephone at the time of the referral (Referral PRISM), and one from both the referring hospital's records and from data collected by the transport team on arrival at the referring hospital and before the team provided any intervention (Team PRISM). The admission area used on arrival at the tertiary care center (intensive care unit [ICU] vs. non-ICU) and the number of major clinical interventions performed by both the referring hospital staff and the transport team were recorded. The Therapeutic Intervention Scoring System was used to assess the cumulative level of medical care provided up to 8 hrs after admission to the pediatric tertiary care hospital. No patient died during transport. The overall in-hospital mortality rate was 5.1%. Median Therapeutic Intervention Scoring System scores were higher for patients admitted to the ICU (16 vs. 4, p < .001). Whereas median PRISM scores were significantly higher in those children admitted to the ICU (4 vs. 0, p < .001), 58 (75%) of 77 ICU admissions had a Team PRISM score of < or = 10. Forty-four (71%) of 62 children who required at least one major intervention at some time during the transport process and 15 (63%) of 24 children who required at least one major intervention by the transport team had a Team PRISM score of < or = 10. Referral PRISM scores underestimated Team PRISM scores. CONCLUSIONS: PRISM scores determined before interhospital transfer of pediatric patients underestimated the requirement for intensive care and the performance of major interventions in the pretransport setting. Many patients with low PRISM scores required intensive care on admission to the receiving hospital and major interventions during the transport process, and, therefore, were not at "low risk" for clinical deterioration. The PRISM score should not be used as a severity of illness measure or triage tool for pediatric interhospital transport.
Asunto(s)
Unidades de Cuidado Intensivo Pediátrico , Mortalidad , Transferencia de Pacientes , Adolescente , Niño , Preescolar , Cuidados Críticos , Humanos , Lactante , Recién Nacido , Pronóstico , Factores de Riesgo , Índice de Severidad de la EnfermedadRESUMEN
The safety and risks of percutaneous infraclavicular subclavian vein catheterization, when performed by nonsurgical staff, were studied prospectively in 100 consecutive patients. The overall success rate was 92% (with one attempt, 45%; with two attempts, 85%). The procedure was performed under emergency conditions in 35% of the patients, with a success rate of 88.6%. The success rate was significantly lower in younger patients. Hemodynamic status, respiratory status, and level of expertise of the individual performing catheterization did not affect success rate. Most of the failures (six of eight) were related to presumed thrombosis from prior cannulation of the superior vena cava. Mean duration of catheterization was 7.5 +/- 5.8 days (+/- SD). Minor complications (n = 24) included hematomas, minor bleeding from subclavian artery puncture, and transient premature ventricular ectopic beats. Major complications (n = 6) were pneumothoraces (n = 4) and catheter-related infection (n = 2). The number of attempts made to catheterize the vessel and the level of expertise of the operator had the greatest effect on complication rates. No mortality was associated with this procedure. We have found percutaneous infraclavicular subclavian vein catheterization to be a rapid alternative to surgical cutdown for venous access during cardiopulmonary resuscitation. Pediatric residents can be trained, under direct supervision, to perform this procedure with a high success rate and a low complication rate.