Paul R. Phipps

Regional deposition of saline aerosols of different tonicities in normal and asthmatic subjects

Nonisotonic aerosols are frequently used in the diagnosis and therapy of lung disease. The purpose of this work was to study the difference in the pattern of deposition of aerosols containing aqueous solutions of different tonicities. 99mTechnetium-diethyltriaminepentaacetic acid (99mTc-DTPA)-labelled saline aerosols, with mass median aerodynamic diameter 3.7-3.8 microns and geometric standard deviation 1.4, were inhaled under reproducible breathing conditions on two occasions. Hypotonic and hypertonic solutions were used in 11 normals subjects, isotonic and hypertonic solutions in 9 asthmatics. The regional deposition was quantified by a penetration index measured with the help of a tomographic technique. There was a small but significant increase (6.7%) in the penetration index of the hypotonic as compared to the hypertonic aerosols in the normal subjects. The region that was markedly affected was the trachea. The differences in the penetration of the isotonic and hypertonic aerosols in the asthmatics appeared to be strongly dependent on the state of the airways at the time of the study. These findings can be interpreted in terms of effects of growth or shrinkage of nonisotonic aerosols, as well as of airway narrowing, on regional deposition of aerosols. Tonicity of aerosols appears to affect their deposition both through physical and physiological mechanisms. This should be taken into account when interpreting the effects of inhaled aqueous solutions of various tonicities in patients in vivo.

Return of Voice for Ventilated Tracheostomy Patients in Icu: A Randomized Controlled Trial of Early-targeted Intervention*

Objectives:A cuffed tracheostomy tube facilitates prolonged mechanical ventilation and weaning but usually leads to prolonged voicelessness, which can be one of the most negative experiences of hospitalization. No randomized trials have examined the effects of targeted early communication intervention for the restoration of voice in ventilated tracheostomy patients in the ICU. Design:A prospective randomized clinical trial. Setting:The trial was conducted in the ICU of an urban tertiary level hospital. Patients:Thirty adult participants enrolled, with 15 randomly allocated to the intervention and control groups. Interventions:The early intervention group received early cuff deflation and insertion of an in-line speaking valve during mechanical ventilation. The control group received standard cuff deflation and a speaking valve during self-ventilation. A speech-language pathologist provided all treatments. Measurements and Main Results:The primary outcome measure was time from tracheostomy insertion to phonation. Early intervention significantly hastened return to phonation (median difference = 11 d; hazard ratio = 3.66; 95% CI, 1.54–8.68) with no significant effect on duration of tracheostomy cannulation (hazard ratio = 1.40; 95% CI, 0.65–3.03), duration of mechanical ventilation in days from tracheostomy insertion (hazard ratio = 1.19; 95% CI, 0.58–2.51), length of stay in ICU (hazard ratio = 1.16; 95% CI, 0.54–2.52), or time to return to oral intake (hazard ratio = 2.35; 95% CI, 0.79–6.98). Adverse events were low and equal in both groups. There was no significant change in measures of quality of life. Conclusions:Focused early intervention for communication during mechanical ventilation allows the restoration of phonation significantly sooner than standard treatment, with no increase in complications in a small patient cohort. Although these results are favorable, further research is needed to determine whether the effects on any of the secondary outcomes are statistically significant and clinically important.

A rapid method for the evaluation of diagnostic radioaerosol delivery systems

The effective delivery (ED) in MBq/min of a 100 MBq/ml nebuliser solution was defined as the rate of delivery of droplets in the respirable size range (aerodynamic diameter below 3.3 μm) to the mouthpiece of the aerosol delivery system (ADS). Wasted delivery (WD) was defined as the rate of delivery of droplets above 3.3 μm. ED and WD were measured on four types of commercially available ADS. The aerosols were sampled at the mouthpiece of each system and droplet size distribution measured with a seven stage cascade impactor. The effect of ambient air humidity on the droplet size produced by the Cadema delivery system was also evaluated. The ED values ranged from 6 to 15 MBq/min and WD values from 0.01 to 15 MBq/min. Two ADS produced low ED and WD values (6.1–9.0 and 0.01–0.07 MBq/min, respectively) due to a low output, while another produced higher ED and WD values [11.3±0.2 (SD) and 15.4±0.5 (SD) MBq/min, respectively] due to a larger droplet size. The Cadema delivery system gave the optimum characteristics of high ED [13.9±0.8 (SD) MBq/min] and low WD [1.24±0.61 (SD) MBq/min] values. The mass median aerodynamic diameter (MMAD) of the Cadema ADS fell by 22% (P< 0.01) as the ambient dilution air was dried from a high relative humidity (RH) (88%–100%) to a low RH (12%–17%). The variability of both MMAD and geometric standard deviation (σg) was increased with dry dilution air (P< 0.01).

A clinical audit of the management of patients with a tracheostomy in an Australian tertiary hospital intensive care unit: Focus on speech-language pathology

Speech-language pathologists manage communication and swallowing disorders, both of which can occur in patients after tracheostomy insertion. An audit on the incidence and timing of speech-language pathology intervention for adults with tracheostomies has not previously been published. Data were retrospectively extracted from the medical records of all patients who were tracheostomized at Royal Prince Alfred Hospital, NSW, Australia, from October 2007 for 1 year. Extracted data included diagnosis, date and type of tracheostomy, time to speech-language pathologist involvement, time to phonation, and time to oral intake. Among the 140 patients (mean age 58 years, range 16–85), diagnoses were neurological (32%), head and neck (25%), cardiothoracic (24%), respiratory (6%), and other (13%). Speech-language pathology was involved with 78% of patients, with initial assessment on average 14 days after tracheostomy insertion (14 days to 166 days). Median time from tracheostomy insertion to phonation was 12 days (range 1–103). Median time from tracheostomy insertion to oral intake was 15 days (range 1–142). Only 20% of patients returned to verbal communication within 1 week after tracheostomy insertion. Further research into access to and timing of speech-language pathology intervention in the critical care setting is warranted.

Quality of life improves with return of voice in tracheostomy patients in intensive care: An observational study.

PURPOSE To measure patient-reported change of mood, communication-related quality of life, and general health status with return of voice among mechanically ventilated tracheostomy patients admitted to the intensive care unit (ICU). MATERIALS AND METHODS A prospective observational study in a tertiary ICU was conducted. Communication-related quality of life was measured daily using the Visual Analogue Self-Esteem Scale. General health status was measured weekly using the EuroQol-5D. RESULTS Aspects of communication self-esteem that significantly improved with the return of voice were ability to be understood by others (P = .006) and cheerfulness (P = .04), both with a median difference from before to after return of voice of 1 on the 5-point scale. Return of voice was not associated with a significant improvement in confidence, sense of outgoingness, anger, sense of being trapped, optimism, or frustration. Reported general health status did not significantly improve. CONCLUSIONS Return of voice was associated with significant improvement in patient reported self-esteem, particularly in being understood by others and in cheerfulness. Improved self-esteem may also improve quality of life; however, further research is needed to confirm this relationship. Early restoration of voice should be investigated as a way to improve the experience of ICU for tracheostomy patients.