摘要:

The synthetic inotropic agent, dobutamine, has reportedly increased cardiac output in adults after cardiopulmonary bypass with minimal side effects. Its use in children, after surgical correction of congenital heart disease, was tested by infusing the drug at 1, 4, 7, and 10 μg/kg min in 11 children. While significant increases in cardiac index above control (23, 23, and 16% at 4, 7, and 10 μg/kg min, respectively) were observed, this was achieved at the expense of significant increases in heart rate (15, 24, and 10%). This increase in heart rate (47% in one child) necessitated discontinuing the infusion in 4 subjects. There were also significant increases in systolic and mean blood pressure with no change in stroke volume or peripheral vascular resistance.The authors conclude that in children, dobutamine is an effective inotropic agent acting principally by stimulating β1-receptors in the myocardium producing a predominantly chronotropic effect without significant changes in peripheral vascular resistance. Given the intrinsically higher heart rate of children, the levels of tachycardia produced by the drug in some instances reach unacceptable levels and as such, may make dobutamine unsuitable for use in children after cardiopulmonary bypass.

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

There are few reports of the application of high PEEP (PEEP ≥ 15 cm H2O) in infants and children. Data concerning cardiac index (CI), pulmonary venous admixture (Qsp/Qt), and arterial mixed venous oxygen content difference (avDO2) during mechanical ventilation with high PEEP have not been reported. Fourteen infants and children were treated with high levels of PEEP; 8 of these patients were monitored with pulmonary artery catheters. Cardiopulmonary data were obtained from these 8 patients and pulmonary barotrauma data were tabulated from all 14 patients. At highest PEEP, CI = 3.6 ± 0.6 L/min M2, avDO2= 4.45 ± 0.83 ml/dl and Qsp/Qt = 16.7 ± 3.1%. One patient experienced severe cardiac depression unresponsive to therapy; it resolved when PEEP was lowered. Pulmonary barotrauma was a frequent complication. Pneumothorax occurred in 6 patients. No patient died from pulmonary barotrauma. We conclude that PEEP ≥ 15 cm H2O can be used in infants and children to decrease Qsp/Qt toward normal; CI and avDO2can usually be maintained in an acceptable range. Patients should be frequently monitored for pulmonary barotrauma.

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

The transcutaneous oxygen sensor (PtcO2), which has been used to predict PaO2in neonates, recently has been shown to follow changes in oxygen delivery, rather than PaO2during shock and hypoxia in dogs. Six preterminal patients were continuously monitored with PtcO2and monitored hemodynamically at frequent intervals during cardiac decompensation, arrest, and cardiopulmonary resuscitation (CPR). The weighted mean correlation coefficients between PtcO2and O2delivery as well as between PtcO2and cardiac output were 0.94 and 0.96, respectively. Five patients died of severe ARDS and 1 patient died intraoperatively of hemorrhagic shock. Four patients were monitored 1–7 days before shock occurred. The correlation between PtcO2and PaO2was 0.91 during periods of normal cardiac output in the preterminal period. During cardiac decompensation, the cardiac output, PtcO2, and mixed venous oxygen tension (PvO2), all fell simultaneously. When a PtcO2of 25 torr was reached, the PtcO2fell below the PvO2. This also corresponded to a decrease in VO2. The mean VO2was 142 ± 24 ml/min M2for PtcO2values >25 torr, and 75 ± 15 ml/min M2for PtcO2<25 torr (p<0.01). A PtcO2of >40 torr corresponded to normal cardiac index, O2delivery, VO2, PvO2, and arterial pH (pHa) while a PtcO2, oftcO2of

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

The effect of coronary artery disease (CAD) on hemodynamic response to infrarenal aortic cross-clamping was studied in 25 patients undergoing either aortofemoral bypass or abdominal aortic aneurysmectomy. Ten patients had evidence of CAD and 15 did not. Systemic, pulmonary artery (PAP), and pulmonary capillary wedge pressures (PCWP), thermodilution cardiac output, and heart rate were measured immediately before, and 2 and 5 min after infrarenal aortic cross-clamping. Heart rate decreased and arterial pressures and pulmonary and systemic vascular resistances increased in both CAD and non CAD groups after aortic clamping. Cardiac index decreased after clamping in both groups and was significantly lower in the patients with CAD. However, PCWP decreased after clamping in patients without CAD as compared to a significant increase in the patients with CAD. The significantly lower cardiac index (1.8–1.9 L/min M2) and increased PCWP (13–15 torr) in patients with preexisting CAD scheduled for aortofemoral surgery may suggest that this subgroup is at greater risk for myocardial dysfunction immediately after aortic cross-clamping.

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

The esophageal obturator airway (EOA) has been approved since 1973 as an adjunct for artificial ventilation. Description of the tube and contraindications to its use are presented. The two primary complications are tracheal intubation and esophageal perforation. A case report of esophageal perforation after EOA use is presented and a brief review of the previously reported cases is correlated with this case report. The true incidence of this complication has never been accurately studied but estimates vary between 0 and 2%. Possible factors contributing to this complication are discussed and recommendations regarding proper inflation are given. Because early diagnosis and treatment is essential, helpful historical, clinical, and radiographic findings that are presented should help to increase the index of suspicion of this complication. Increased familiarity with the EOA by physicians in the emergency department and the ICU is also necessary for early diagnosis and treatment.

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

A new technique is described for selective lung ventilation of patients with predominantly unilateral pulmonary pathology. Separate ventilators were used to inflate each lung via a double lumen endobronchial tube and no attempt was made to synchronize them. In three of the four cases, there was considerable improvement in respiratory function and radiographic appearance. In no case was there any cardiovascular depression. The use of a new endobronchial tube, the “broncho-cath”, suitable for this technique is also described.

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

The authors have developed a new method for independent lung ventilation (ILV). After lung isolation with a double-lumen endotracheal tube, one ventilator with two subunits controls independent lung tidal volume (VT) and PEEP to each lung. A modified bird Mark 2 ventilator serves as a pneumatically powered timer activating two sets of parallel inspiratory-expiratory flow cartridges. Intermittent mandatory ventilation (IMV) with PEEP or controlled mechanical ventilation (CMV) with PEEP can be provided. This ventilator has been successfully used to treat patients with severe unilateral disease. Desirable qualities include simplicity of operation, availability of parts, and low cost.

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

A lightweight and nondirectional PEEP adaptor for use with a T-piece system is described. It delivers PEEP up to 35 cm H2O at constant levels regardless of changes in the direction of the valve. It is suitable for manual ventilation during transportation and is also capable of being used under CPAP conditions. This makes it especially useful in pediatric critical care.

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

The pneumatic power supply (PPS) has been used as the driving device for the pneumatic blood pump during the resuscitation of more than 15 hypovolemic patients. The device has been found to be safe and easy to use. By virtue of its semiautomatic function, members of the resuscitation team are free to perform other duties. Previously, these individuals would have been required to maintain an adequate driving pressure in the infusion pumps.

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

The measurement of hypopharyngeal FIO2, is a simple and rapid method for evaluating oxygen delivery systems in clinical practice. Hypopharyngeal FIO2measurements were compared to other established methods of inspired gas measurement, namely, tracheal gas sampling and exhaled gas analysis. Hypopharyngeal sampling compared favorably with these methods. Furthermore, arterial blood gas samples from patients receiving oxygen by aerosol mask correlated with the hypopharyngeal measurements but not with the delivery system's settings.In normal, healthy subjects, the authors studied variables known to influence FIO2. Using nasal prongs as well as an aerosol mask system, the authors studied the interaction of the wall flow rates, the concentration (Venturi) settings (in the case of the aerosol mask), and the subject's respiratory rate. Under these controlled conditions of tidal breathing, the hypopharyngeal FIO2was directly related to the total flow of gas from the delivery system and the concentration of the Venturi setting but inversely related to the respiratory rate.Hypopharyngeal gas sampling offers a simple method for evaluating and correcting a patient's inspired oxygen concentration.

ISSN:0090-3493    

出版商:OVID    

年代:1980

数据来源: OVID