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Biomedical subjects

R C Raphaely

Publications and source records attributed to R C Raphaely.

11 recordsLinked to original sources

Pulmonary mechanics in infants after cardiac surgery.

OBJECTIVE: To determine pulmonary mechanical characteristics in neonates after cardiac surgery. DESIGN: A prospective study. SETTING: A 23-bed, pediatric ICU in a 280-bed children's hospital. PATIENTS: Twenty-six infants on the first post-operative day after cardiac surgery. METHODS: Pulmonary mechanics measurements were made during spontaneous breathing, using the esophageal balloon technique and a pneumotachometer. The least mean square method of analysis was used to calculate mechanics. Infants who tolerated withdrawal of mechanical ventilation (group 1) were compared with those infants with respiratory failure (group 2). RESULTS: Spontaneous respiratory rate, tidal volume, and minute ventilation were similar in groups 1 and 2. Lung compliance was decreased, with no difference between groups. Total lung resistance (34.3 +/- 21.6 cm H2O/L.sec in group 1 vs. 136.8 +/- 105.8 cm H2O/L.sec in group 2, p = .002) and resistive work of breathing (33.4 +/- 29.9 g.cm/kg in group 1 vs. 212.9 +/- 173.8 g.cm/kg in group 2, p = .001) were significantly higher in group 2. All infants with a total lung resistance greater than 75 cm H2O/L.sec exhibited respiratory failure (resistance greater than 75 cm H2O/L.sec correlated with respiratory failure, r2 = .73, odds ratio of 70 [confidence interval, 4.4 to 3240], p less than .001). CONCLUSIONS: Increased lung resistance identifies neonates with respiratory failure after cardiac surgery. Pulmonary mechanics testing may be useful in timing withdrawal of mechanical ventilation.

Airway Resistance

Descriptive analysis of critical care units in the United States.

OBJECTIVE: To gather data about available technology, staffing, administrative policies, and bed capacities of ICUs in the United States. DESIGN AND SETTING: On January 15, 1991, survey instruments were mailed to the administrators of 4,233 hospitals to gather information from the medical director of the institutions' respective ICUs for the purpose of developing a database on ICUs in the United States. The sampling frame for this study was based on all American Hospital Association (AHA) hospitals that stated they have ICUs. MEASUREMENTS: Census questionnaires solicited information on types of hospitals, types of ICUs, number of ICU beds open and closed, technology available to the unit, organizational structure and management of the ICU, as well as the staffing and certification of unit personnel. MAIN RESULTS: Data were obtained on 32,850 ICU beds with 25,871 patients from 2,876 separate ICUs in 1,706 hospitals in the United States. Census responses came from units in all sizes of hospitals within all ten census regions in the country, all states, and all types of hospital sponsorship (federal, state, and local government, private nonprofit and private for profit). The census response rate was 40% of the AHA hospitals that stated that they have ICUs, with specific ICU data on 38.7% of the nation's ICUs. The number of ICUs per hospital increases with overall hospital size. The smallest hospitals (less than 100 beds) usually had only one ICU. As hospital size increased, the single, all inclusive medical/surgical/coronary care units diminished, and in hospitals with greater than 300 beds, specialization of units became prevalent. In absolute terms, hospitals had the following number of ICUs: 1.04 +/- 0.20 (less than or equal to 100 beds); 1.30 +/- 0.65 (101 to 300 beds); 2.37 +/- 1.58 (301 to 500 beds); and 3.34 +/- 2.21 (greater than 500 beds). ICU beds averaged, nationally, 8.09% of hospital-licensed beds with a median of 6.98%. Generally, medical units, pediatric units, coronary care units (CCUs), and medical/surgical/CCUs reported an average of 10 beds per unit. Neonatal units averaged 21 beds, and surgical units averaged 12 beds. The average ICU size, nationally, was 11.7 +/- 7.8 beds per unit. Available technology within hospitals and individual units was increased as hospital size increased; surgical units tended to have more available technology than other unit types. A wide range of organizational arrangements within hospitals determines where the ICU appears in an organizational chart and to whom unit management is accountable. Thirty-six percent of the units were located organizationally within the hospital's department of medicine, while 23% were considered "free standing," having no departmental affiliation. Although units must have a medical director, the perception as to whether this director supervises the day-to-day operation was different in larger vs. smaller hospitals. In hospitals with less than or equal to 100 beds, 72% of the units were perceived to be supervised by the medical director, whereas in larger hospitals (greater than 500 beds), 81% of units were supervised. Study results indicated that medical directors in pediatric, neonatal, and burn units most often were perceived to supervise the unit. Presently, 63% of all ICUs responding are directed by an internist. The next largest group to direct ICUs were surgeons, followed by pediatricians. Pediatrician involvement tended to be exclusive in pediatric and neonatal units. Surgeons directed most surgical and neurologic units and were involved in 21% of mixed medical/surgical units. Internists predominated in medical units and in CCUs, as well as in combined medical/surgical/CCUs. Direction by anesthesiologists, although relatively infrequent, predominated in the surgical unit. Critical care medicine certification of the medical director and attending staff of the ICU increased as hospital size increased, although only 44% of all units stated that thei

Allied Health Personnel

Undergraduate education in critical care medicine.

OBJECTIVE: To review the current status and future needs of medical students with respect to education in critical care medicine. DATA SOURCES: Literature review and questionnaire administered at the 1990 Educational and Scientific Symposium of the Society of Critical Care Medicine. MEASUREMENTS AND MAIN RESULTS: Medical students are presently not required to master even the basic aspects of critical care medicine before licensing. The results of the questionnaire demonstrated that critical care medicine professionals believe a critical care core curriculum should be established and its completion should be made a requirement for graduation from medical school. A reference set of critical care medicine learning objectives and a strategy for their implementation are presented. CONCLUSIONS: There is a gap between what student physicians are required to learn and what they need to know to effectively initiate critical care interventions and to appropriately refer patients to ICUs. This gap can and should be remedied with wide implementation of a critical care core curriculum.

Accreditation

Endotracheal tube leak pressure and tracheal lumen size in swine.

Endotracheal tube "leak" is often estimated in children to judge the fit of uncuffed endotracheal tubes within the trachea. Twenty-five swine were intubated with uncuffed tracheal tubes to determine whether a more sensitive measurement of leaks could be devised and whether leak pressure estimates fit between tracheal tube and trachea. We compared leak pressure measurement using a stethoscope and aneroid manometer with a technique using a microphone, pressure transducer, and recorder, and found no differences between the two methods. The tracheas were then removed and slides prepared of tracheal cross-sectional specimens. Regression analysis revealed a linear relationship between tracheal lumen size and tracheal tube size for both low leak pressure (y = -0.4 + 0.79x, r = 0.88, P less than 0.05) and high leak pressure (y = -2.9 + 0.71x, r = 0.92, P less than 0.05) groups. We conclude that leak testing with a stethoscope and aneroid manometer is sensitive and accurate, and that tracheal tube leak pressure accurately portrays fit between tube and trachea.

Animals

Pathophysiology, treatment and outcome following severe head injury in children.

The pathophysiology and outcome following severe head injury in 85 children are presented. The commonest initial CT diagnosis was of acute brain swelling. This swelling was associated with an increased white matter density on the CT scan which decreased to normal concomitant with recovery and increased ventricular size. CBF measurements in 6 of these patients revealed an increased blood flow despite a decreased CMRO2 and clinical coma. This CT pattern of diffuse swelling is believed to be due to acute cerebrovascular congestion and hyperemia and not to edema. Because of this, all children were treated with endotracheal intubation and controlled hyperventilation as part of the initial management. Mass lesions were uncommon, 20%. ICP was monitored in 40 children. The ICP rose above 20 Torr despite therapy in 80% of children with decerebrate or flaccid coma and in only 20% of children with spontaneous motor function. The ICP was at its highest between the second and fifth day. Aggressive therapy to control the ICP, with barbiturates if necessary, was successful in 80% of the patients. The overall results were useful recovery in 87.5% of the children, 3.5% were left vegetative or severely disabled and 9% died.

Adolescent

Successful treatment of varicella pneumonia with prolonged extracorporeal membrane oxygenation in a child with leukemia.

A 5-year-old boy with acute lymphoblastic leukemia in complete continuous remission developed life-threatening varicella pneumonia and acute respiratory insufficiency (ARI). The child recovered after 92 hours of partial venoarterial perfusion with a membrane oxygenator. Functional asplenia developed. Serial pulmonary function tests after perfusion indicate moderately severe restrictive lung disease which has slightly improved during an 18 month period.

Acute Disease

Optimum levels of CPAP for tracheal extubation of newborn infants.

Arterial oxygen tension and functional residual capacity were studied in 16 intubated, spontaneously breathing newborn infants recovering from respiratory disease. Studies were made at 2 cm H2O continuous positive airway pressure, at zero end expiratory pressure, and following extubation. The study showed that PaO2 and FRC at 2 cm H2O CPAP were the same as observed following extubation, but that both values were significantly lower at ZEEP.

Humans