THE SURGICAL TREATMENT OF PULMONARY EMPHYSEMA. (17/158)

Emphysema may be focal or multifocal. In either type an area of disease may enlarge and reduce the function of adjacent lung.Thirty patients who required treatment for emphysema and its complications are described. Fifteen patients with focal emphysema that did not constitute a space-occupying lesion required operation because of recurrent pneumothorax or infection in the affected area. The results were excellent. Ten patients with focal emphysema and progressive "space occupation" complained of moderate but increasing dyspnea. Removal of the enlarging lesion resulted in marked improvement. Five patients with multifocal emphysema and progressive space occupation in one focal area suffered from severe dyspnea and poor general health. The space-occupying lesion was removed by lobectomy. The results, measured by pulmonary function tests and subjective improvement, were rewarding in most cases. No patient with multifocal emphysema but without a space-occupying lesion under-went operation.  (+info)

Upper airway afferents are sufficient to evoke the early components of respiratory-related cortical potentials in humans. (18/158)

Repeated inspiratory occlusions in humans elicit respiratory-related cortical potentials, the respiratory counterpart of somatosensory-evoked potentials. These potentials comprise early components (stimulus detection) and late components (cognitive processing). They are considered as the summation of several afferent activities from various part of the respiratory system. This study assesses the role of the upper airway as a determinant of the early and late components of the potentials, taking advantage of the presence of a tracheotomy in patients totally or partially deafferented. Eight patients who could breathe either through the mouth or through a tracheotomy orifice (whole upper airway bypassed) were studied (4 quadriplegic patients with phrenic pacing, 4 patients with various sources of inspiratory pump dysfunction). Respiratory-related evoked potentials were recorded in CZ-C3 and CZ-C4. They were consistently present after mouth occlusions, with a first positive P1 and a first negative N1 components of normal latencies (P1: 40.4 +/- 6.1 ms in CZ-C3 and 47.6 +/- 7.6 ms in CZ-C4; N1: 84.4 +/- 27.1 ms in CZ-C3 and 90.2 +/- 17.4 ms in CZ-C4) and amplitudes. Tracheal occlusions did not evoke any cortical activity. Therefore, in patients with inspiratory pump dysfunction, the activation of upper airway afferents is sufficient to produce the early components of the respiratory-related evoked cortical potentials. Per contra, in this setting, pulmonary afferents do not suffice to evoke these components.  (+info)

Immediate post-operative effects of tracheotomy on respiratory function during mechanical ventilation. (19/158)

INTRODUCTION: Tracheotomy is widely performed in the intensive care unit after long-term oral intubation. The present study investigates the immediate influence of tracheotomy on respiratory mechanics and blood gases during mechanical ventilation. METHODS: Tracheotomy was performed in 32 orally intubated patients for 10.5 +/- 4.66 days (all results are means +/- standard deviations). Airway pressure, flow and arterial blood gases were recorded immediately before tracheotomy and half an hour afterwards. Respiratory system elastance (Ers), resistance (Rrs) and end-expiratory pressure (EEP) were evaluated by multiple linear regression. Respiratory system reactance (Xrs), impedance (Zrs) and phase angle (phirs) were calculated from Ers and Rrs. Comparisons of the mechanical parameters, blood gases and pH were performed with the aid of the Wilcoxon signed-rank test (P = 0.05). RESULTS: Ers increased (7 +/- 11.3%, P = 0.001), whereas Rrs (-16 +/- 18.4%, P = 0.0003), Xrs (-6 +/- 11.6%, P = 0.006) and phi rs (-14.3 +/- 16.8%, P = <0.001) decreased immediately after tracheotomy. EEP, Zrs, blood gases and pH did not change significantly. CONCLUSION: Lower Rrs but also higher Ers were noted immediately after tracheotomy. The net effect is a non-significant change in the overall Rrs (impedance) and the effectiveness of respiratory function. The extra dose of anaesthetics (beyond that used for sedation at the beginning of the procedure) or a higher FiO2 (fraction of inspired oxygen) during tracheotomy or aspiration could be related to the immediate elastance increase.  (+info)

Tracheotomy in bulbar poliomyelitis. (20/158)

Tracheotomy was performed on 181 of 351 patients with bulbar poliomyelitis. The essential indication for tracheotomy was secretional obstruction of the respiratory tract that could not be relieved by postural drainage and aspiration. Comparison of mortality rates in this series with those of previous series in which tracheotomy was not done in the presence of similar indications, suggests that the procedure may be life-saving in a considerable percentage of cases. Outside the respirator the tracheotomy can be done with or without the aid of the bronchoscope or endotracheal anesthesia tube. When done inside the opened respirator the Bennett flow-sensitive positive pressure machine should be used to supply oxygen to the patient while the respirator is not operating.  (+info)

Ventilator-associated pneumonia: issues related to the artificial airway. (21/158)

Pooling of contaminated secretions above the cuff of the endotracheal tube predisposes patients to ventilator-associated pneumonia (VAP). Subglottic secretion drainage requires a special endotracheal tube that has a separate lumen that opens in the subglottic region above the tracheal tube. A recent meta-analysis of the 5 randomized clinical trials that evaluated the efficacy of removing these secretions found that this technique significantly reduces the incidence of VAP. One cost-effectiveness analysis showed savings of dollar 4,900 per episode of VAP prevented. Greatest benefit is derived by patients requiring fewer than 10 days of mechanical ventilation and not exposed to antibiotic therapy. Maintaining the intracuff pressure between 25 and 30 cm H2O is mandatory to guarantee effective drainage and safety. While silver-coated endotracheal tubes reduce pseudomonas pneumonia in intubated dogs and delay airway colonization in intubated patients, evaluation of studies with a variety of case mixes is warranted to identify subsets likely to benefit from the technique before it is implemented on a large scale. A patient who has a colonized airway and who undergoes percutaneous tracheotomy has an increased risk of VAP, particularly due to Pseudomonas aeruginosa, in the week following the procedure. As many studies suggest that incidence of VAP is highly dependent on the strategies of airway management, health care workers should be alerted to issues related to the artificial airway.  (+info)

Factors associated with failure of weaning from long-term mechanical ventilation after cardiac surgery. (22/158)

The purpose of this prospective, quantitative, comparative study, conducted at the 55 bed cardiothoracic intensive care unit of the Heart Institute (InCor), University of Sao Paulo Medical School, was to identify factors involved in the weaning of patients who require long-term (> 10 days) mechanical ventilation after cardiac surgery. The subjects included all patients who underwent open-heart surgery with cardiopulmonary bypass during a 10 month period from April 2000 to January 2001 (n = 946). From this group, 52 (5.7%) patients who required a tracheotomy for the management of long-term mechanical ventilation after cardiac surgery with cardiopulmonary bypass were selected. Pre-, intra- and postoperative data from patients who were not successfully weaned after reintubation and who underwent an elective tracheotomy were compared. Parameters of respiratory mechanics such as respiratory complications, oxygenation, and cardiac, renal, and neurological function were evaluated. Weaning success was defined as the ability of a patient to tolerate 48 hours without pressure or flow support from a mechanical ventilator. A patient was considered to have failed weaning if they died or remained under ventilation for more than 8 weeks. Of the 52 patients studied, 25 were successfully weaned, 21 died, and 6 remained ventilated for more than 8 weeks. We found significant statistical differences (P < 0.05) between the groups with respect to success or failure in LVEF (P = 0.0035), the need for vasoactive agents (P = 0.0018), and renal failure (P = 0.002). Parameters of respiratory mechanics and oxygenation (eg, static airway compliance, airway resistance) did not influence the success or failure of weaning. There was a significant difference in relation to the presence of pneumonia (P = 0.0086) between the two groups. Although neurological complications were more frequent in patients in the weaning success group, the failure group had lower GCS scores, which is indicative of worse prognoses. It is concluded that cardiac dysfunction, the need for dialysis, and pneumonia are determinants for weaning failure in patients undergoing long-term mechanical ventilation after cardiac surgery.  (+info)

Temporal dynamics and latency patterns of receptor neuron input to the olfactory bulb. (23/158)

Odorants are first represented in the brain by distributed patterns of activity in the olfactory bulb (OB). Although neurons downstream of sensory inputs respond to odorants with temporally structured activity, sensory inputs to glomeruli are typically described as static maps. Here, we imaged the temporal dynamics of receptor neuron input to the OB with a calcium-sensitive dye in the olfactory receptor nerve terminals in anesthetized mice. We found that diverse, glomerulus- and odorant-dependent temporal dynamics are present even at this initial input stage. Instantaneous spatial patterns of receptor input to glomeruli changed both within and between respiration cycles. Glomerular odorant responses differed in amplitude, latency, rise time, and degree of modulation by sniffing in an odorant-specific manner. Pattern dynamics within the first respiration cycle recurred in a similar manner during consecutive cycles. When sniff rate was increased artificially, pattern dynamics were preserved in the first sniff but were attenuated during subsequent sniffs. Temporal response properties were consistent across individuals on a coarse regional scale and on a fine scale of individual glomeruli. Latency and magnitude of glomerular inputs were only weakly correlated and might therefore convey independent odorant information. These data demonstrate that glomerular maps of primary sensory input to the OB are temporally dynamic. These dynamics may contribute to the representation of odorant information and affect information processing in the central olfactory system of rodents.  (+info)

Foreign body aspiration through tracheotomy: a case report. (24/158)

A 70 year-old man, with a 7-year tracheotomy because of a laryngeal tumor, had an accident during daily canulla cleansing procedure, aspirating a piece of the cleaning brush. Chest radiograph showed metallic foreign body at the right inferior bronchus. Rigid bronchoscopy was performed under general anesthesia, with no resistance in passing the tube through the glottis. The foreign body was easily removed and the patient had no complications. After leaving the hospital, the patient was sent to the ENT service where he used to be followed up.  (+info)