Endoscopic intratracheal carbon dioxide measurements during pediatric flexible bronchoscopy

Background: CO2 monitoring is recommended for thoracic telescopic procedures and for spontaneous breathing general anesthesia in children. During flexible bronchoscopy (FB) in children, the various currently available methods of CO2 measurements are limited. The CO2 falls and increases have been reported in FB but it is unknown whether airway lesions predispose to CO2 change. The aim of this study was to describe and validate endoscopic intratracheal CO2 measurements in children undergoing FB under spontaneously breathing GA. Methods: Endtidal CO2 (PECO2) measurements at the start (Start-CO2) and end (End-CO2) of FB on 100 consecutive children were performed using a newly designed endoscopic intratracheal method. To validate the method blood gas sampling was simultaneously performed in 28 children and results analyzed using the Bland and Altman method, intraclass correlation and 95% range for repeatability. Results: End-CO2 and CO2-change (End-CO2 minus Start-CO2) were significantly different in children with airway lesions (CO2 change: no lesion = 3 mmHg, extrathoracic airway lesion = 4.5, intrathoracic airway lesion = 8, P = 0.038). There was no significant difference in Start-CO2 values among the groups. CO2-change in those aged > 12 months was similar to those >12 months. Intratracheal CO2 measurements were comparable with arterial blood values in the Bland and Altman plots. The intraclass correlation was 0.69 and 95% range for repeatability was 3.7-4.17 mmHg. Conclusions: Midtracheal PECO2 provides a useful estimate of PaCO2 for monitoring the respiratory status of children undergoing FB. The presence of airway lesions rather than age is associated with significant increased PCO2 rise.

A Bronchoscopic scoring system for airway secretions - Airway cellularity and microbiological validation

There is currently no validated scoring system for quantification of airway secretions in children. A user friendly, valid scoring system of airway secretions during flexible bronchoscopy (FB) would be useful for comparative purposes in clinical medicine and research. The objective of this study was to validate our bronchoscopic secretion (BS) scoring system by examining the relationship between the amount of secretions seen at bronchoscopy with airway cellularity and microbiology. In 106 children undergoing FIB, the relationship of BS grades with bronchocalveolar lavage (BAL) cellularity and infective state (bacterial and viral infections) were examined using receptor operator curves (ROC). BAL was obtained according to European Respiratory Society guidelines; first lavage for microbiology and second lavage for cellularity Area under the ROC was significant for total cell count (TCC) and neutrophil % but not for lymphocyte %. BS grade significantly related to infection positive state (chi(2)(trend) = 5.85, P = 0,016). The area under the ROC for infection positive state versus BS grade was 0.645, 95% Cl 0.527-0.763. The BS scoring system is a valid method for quantifying airway secretions in children undergoing bronchoscopy The system related well to airway cellularity and neutrophilia, as well as to an airway infective state. However, the system is only complementary to cell counts and cultures and cannot replace these laboratory quantification techniques.

Quantification of the magnification and distortion effects of a pediatric flexible video-bronchoscope

Background: Flexible video bronchoscopes, in particular the Olympus BF Type 3C160, are commonly used in pediatric respiratory medicine. There is no data on the magnification and distortion effects of these bronchoscopes yet important clinical decisions are made from the images. The aim of this study was to systematically describe the magnification and distortion of flexible bronchoscope images taken at various distances from the object. Methods: Using images of known objects and processing these by digital video and computer programs both magnification and distortion scales were derived. Results: Magnification changes as a linear function between 100 mm ( x 1) and 10 mm ( x 9.55) and then as an exponential function between 10 mm and 3 mm ( x 40) from the object. Magnification depends on the axis of orientation of the object to the optic axis or geometrical axis of the bronchoscope. Magnification also varies across the field of view with the central magnification being 39% greater than at the periphery of the field of view at 15 mm from the object. However, in the paediatric situation the diameter of the orifices is usually less than 10 mm and thus this limits the exposure to these peripheral limits of magnification reduction. Intraclass correlations for measurements and repeatability studies between instruments are very high, r = 0.96. Distortion occurs as both barrel and geometric types but both types are heterogeneous across the field of view. Distortion of geometric type ranges up to 30% at 3 mm from the object but may be as low as 5% depending on the position of the object in relation to the optic axis. Conclusion: We conclude that the optimal working distance range is between 40 and 10 mm from the object. However the clinician should be cognisant of both variations in magnification and distortion in clinical judgements.

Australian and New Zealand practice in intensive care (ANZPIC II: The spectrum of practice in the diagnosis and management of pneumonia in patients requiring mechanical ventilation

This study of ventilated patients investigated current clinical practice in 476 episodes of pneumonia (48% community-acquired pneumonia, 24% hospital-acquired pneumonia, 28% ventilator-associated pneumonia) using a prospective survey in 14 intensive care units (ICUs) within Australia and New Zealand. Diagnostic methods and confidence, disease severity, microbiology and antibiotic use were assessed. All pneumonia types had similar mortality (community-acquired pneumonia 33%, hospital-acquired pneumonia 37% and ventilator-associated pneumonia 24%, P = 0.15) with no inter-hospital differences (P = 0.08-0.91). Bronchoscopy was performed in 26%, its use predicted by admission hospital (one tertiary: OR 9.98, CI 95% 5.11-19.49, P < 0.001; one regional: OR 629, CI 95% 3.24-12.20, P < 0.001), clinical signs of consolidation (OR 3.72, CI 95% 2.09-662, P < 0.001) and diagnostic confidence (OR 2.19, CI 95% 1.29-3.72, P = 0.004). Bronchoscopy did not predict outcome (P = 0.11) or appropriate antibiotic selection (P = 0.69). Inappropriate antibiotic prescription was similar for all pneumonia types (11-13%, P = 0.12) and hospitals (0-16%, P = 0.25). Blood cultures were taken in 51% of cases. For community-acquired pneumonia, 70% received a third generation cephalosporin and 65% a macrolide. Third generation cephalosporins were less frequently used for mild infections (OR 0.38, CI 95% 0.16-0.90, P = 0.03), hospital-acquired pneumonia (OR 0.40, CI 95% 0.23-0.72, P < 0.01), ventilator-associated pneumonia (OR 0.04, CI 95% 0.02-0.13, P < 0.001), suspected aspiration (OR 0.20, CI 95% 0.04-0.92, P = 0.04), in one regional (OR 0.26, CI 95% 0.07-0.97, P = 0.05) and one tertiary hospital (OR 0.14, CI 95% 0.03-0.73, P = 0.02) but were more commonly used in older patients (OR 1.02, CI 95% 1.01-1.03, P = 0.01). There is practice variability in bronchoscopy and antibiotic use for pneumonia in Australian and New Zealand ICUs without significant impact on patient outcome, as the prevalence of inappropriate antibiotic prescription is low. There are opportunities for improving microbiological diagnostic work-up for isolation of aetiological pathogens.

Involuntary glottal closure during inspiration in muscle tension dysphonia

Objective/Hypothesis: The purpose of this study was to examine respiratory function in a group of patients with muscle tension dysphonia (MTD) Design: Cross-sectional analytical study. Methods: Participants included 15 people with a diagnosis of MTD referred to speech pathology for management of their voice disorder, fiberoptic evidence of glottal or supraglottic constriction during phonation with or without posterior chink, or bowing combined and deviation in perceptual voice quality. A second group of 15 participants with no history of voice disorder served as healthy controls,. Baseline pulmonary function test measures included forced expiratory volume in the first second (FEV1), FVC, FEF25 to 75, FIF50, FEV1/FVC, ratio and FEF50/FIF50 ratio. Hypertonic saline challenge test measures included FEV1 and FIF50 after provocation, close response slope, and provocation dose. Results: Compared with healthy controls, participants with MTD demonstrated a higher prevalence of glottal constriction during inspiration after provocation with nebulized hypertonic saline as demonstrated by a reduction in FIF50 after the hypertonic saline challenge. There was no significant difference between the MTD and healthy control groups in baseline pulmonary function testing. Participants with MTD demonstrated a higher prevalence than healthy controls of abnormal glottic closure during inspiration similar to paradoxical vocal fold movement (PVFM). This suggests that they either had previously undiagnosed coexisting PVFM or that the condition of MTD could be expanded to include descriptions of aberrant glottic function during respiration. This study enhances the understanding of PVFM and MTD by combining research advances made in the fields of otolaryngology and respiratory medicine.

Successful use of recombinant factor VII in massive hemoptysis due to community-acquired pneumonia

Recombinant activated factor VII (rFVIIa) is a powerful hemostatic agent developed for use in hemophilia. It has been used increasingly in life-threatening hemorrhage in a variety of other settings in which conventional medical or surgical therapy is unsuccessful. This report describes the successful use of rFVIIa for pulmonary hemorrhage due to a focal bleeding source in a regional hospital where bronchial artery embolization or surgery were not available. rFVIIa may be a useful temporizing measure in the unstable patient with pulmonary hemorrhage without coagulopathic bleeding when conventional treatment. is not immediately available.