Intensive care medicine
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Intensive care medicine · Aug 1997
Comparative Study Clinical TrialHypercarbia during tracheostomy: a comparison of percutaneous endoscopic, percutaneous Doppler, and standard surgical tracheostomy.
Tracheostomy is one of the most commonly performed surgical procedures in the critical care setting. The early use of tracheostomy as a method of primary airway management has been proposed as a means to decrease pulmonary morbidity and to shorten the number of ventilator, intensive care unit, and hospital days. We set out to (1) determine whether hypercarbia occurs during tracheostomy of the critically ill patient and (2) determine the extent to which the partial pressure of carbon dioxide in arterial blood (PaCO2) rises during percutaneous endoscopic, percutaneous Doppler, and standard surgical tracheostomy. ⋯ Continuous bronchoscopy during percutaneous tracheostomy contributes significantly to early hypoventilation, hypercarbia, and respiratory acidosis during the procedure. Percutaneous tracheostomy, when performed using the Doppler ultrasound method to position the endotracheal tube, significantly reduces CO2 retention when compared to PET. Because of a possible rise in intracranial pressure, the potential for hypercarbia should be considered when choosing the method of tracheostomy in the critically ill and/or head-injured patient, where hypercarbia may be detrimental. If PET is to be performed, steps to minimize occult hypercarbia, such as using the smallest bronchoscope available, minimizing suctioning during bronchoscopy, and minimizing the length of time the bronchoscope is in the endotracheal tube, should be undertaken.
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Intensive care medicine · Aug 1997
Randomized Controlled Trial Clinical TrialBlood pressure and heart rate changes during apnoea testing with or without CO2 insufflation.
To determine changes of blood pressure and heart rate during apnoea testing for brain death without (A) and with (B) artificial CO2 augmentation. ⋯ HR varied less than BP. The possibility of a marked relative rise of fall of BP in group (A) was equal; in group (B) there was a lower change of rising BP. The chances for a rise or fall in HR were equal for the two groups. There was a tendency for less variation of cardiovascular parameters in group (B).
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Intensive care medicine · Aug 1997
Comparative StudyComparison between cardiac output measured by thermodilution technique and calculated by O2 and modified CO2 Fick methods using a new metabolic monitor.
To calculate cardiac ouptut from dual oximetry with carbon dioxide production (VCO2) and oxygen consumption (VO2) measured by a new metabolic monitor, and to compare these values with measurements made simultaneously using the thermodilution method during the steady state condition. ⋯ In stable patients, cardiac output measurements obtained from dual oximetry with VO2 and VCO2 measured by this new metabolic monitor, show good correlation with measurements made using the thermodilution method. The values of cardiac output calculated from VCO2 are more accurate and precise than values from VO2. The validity of these measurements in hemodynamically unstable patients and during various modes of mechanical ventilation seems warranted.
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Intensive care medicine · Aug 1997
Randomized Controlled Trial Clinical TrialImprovement of internal jugular vein cannulation using an ultrasound-guided technique.
To determine whether ultrasound guidance can help operators to improve the results of jugular vein access in the ICU. ⋯ Ultrasound guidance improved the success rate of jugular vein cannulation in ICU patients. Our results suggest that ultrasound guidance should be used when the internal jugular vein has not been successfully cannulated within 3 min by the external landmark-guided technique.
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Intensive care medicine · Aug 1997
Comparative Study Clinical Trial Controlled Clinical TrialDistribution of inhaled nitric oxide during sequential and continuous administration into the inspiratory limb of the ventilator.
The concentrations of nitric oxide (NO) in the ventilatory circuits and the patient's airways were compared between sequential (SQA) and continuous (CTA) administration during inspiratory limb delivery. ⋯ CTA did not provide homogenous mixing of NO with the tidal volume and resulted in fluctuating INSP-NOMeas. In contrast, SQA delivered stable and predictable NO concentrations during controlled mechanical ventilation with a constant inspiratory flow and was economical compared to CTA. However, SQA did not provide stable and predictable NO concentrations during pressure support ventilation.