Daniel Rodenstein

Tracheobronchial Foreign Bodies: Presentation and Management in Children and Adults

STUDY OBJECTIVES To compare the clinical and management aspects of tracheobronchial aspirated foreign body (AFB) removal in children and adults; to assess the influence of the operators experience on the outcome of the procedure. DESIGN A retrospective review of a 20-year experience (from 1976 to 1996). SETTING A 900-bed university hospital. PATIENTS Eighty-four children up to 8 years old (the child group) and 28 adult patients (the adult group). RESULTS The peak incidence of foreign body aspiration occurred during the second year of life in the child group and during the sixth decade in the adult group. The symptoms at presentation were similar in both age groups, but the diagnosis was significantly delayed in the adults. The AFBs were lodged preferentially in the right bronchial tree only in the adults; a central location was predominant (but not at all exclusive) in the children. Atelectasis was more common in the adults, and air trapping was more common in the children. The most frequent procedure was rigid bronchoscopy; when a flexible bronchoscope was used, it was always in the adult patients. When the operator was less experienced, a failed first attempt at bronchoscopy and the need for a second procedure were significantly more frequent. CONCLUSIONS At presentation, the symptoms seen with AFBs do not differ according to the age of the patient; however, the delay to diagnosis, the location of the AFBs, and the radiographic images differ between child and adult populations. The removal of AFBs in patients of all ages can be performed by the same operators. Because the outcome associated with these procedures improves when the operator is experienced, the removal of AFBs should be performed in medical centers that are capable of acquiring and maintaining the necessary expertise.

Pharyngeal shape and dimensions in healthy subjects, snorers, and patients with obstructive sleep apnoea.

To characterise the relation between pharyngeal anatomy and sleep related disordered breathing, 17 men with complaints of snoring were studied by all night polysomnography. Ten of them had obstructive sleep apnoea (mean (SD) apnoea-hypopnoea index 56.3 (41.7), age 52 (10) years, body mass index 31.4 (5.3) kg/m2); whereas seven were simple snorers (apnoea-hypopnoea index 6.7 (4.6), age 40 (17) years, body mass index 25.9 (4.3) kg/m2). The pharynx was studied by magnetic resonance imaging in all patients and in a group of eight healthy subjects (age 27 (6) years, body mass index 21.8 (2.2) kg/m2, both significantly lower than in the patients; p less than 0.05). On the midsagittal section and six transverse sections equally spaced between the nasopharynx and the hypopharynx several anatomical measurements were performed. Results showed that there was no difference between groups in most magnetic resonance imaging measurements, but that on transverse sections the pharyngeal cross section had an elliptic shape with the long axis oriented in the coronal plane in normal subjects, whereas in apnoeic and snoring patients the pharynx was circular or had an elliptic shape but with the long axis oriented in the sagittal plane. It is suggested that the change in pharyngeal cross sectional shape, secondary to a reduction in pharyngeal transverse diameter, may be related to the risk of developing sleep related disordered breathing.

Acoustic analysis of snoring sound in patients with simple snoring and obstructive sleep apnoea

Snoring, a symptom which may indicate the presence of the obstructive sleep apnoea syndrome (OSA), is also common in the general population. Recent studies have suggested that the acoustic characteristics of snoring sound may differ between simple snorers and OSA patients. We have studied a small number of patients with simple snoring and OSA, analysing the acoustic characteristics of the snoring sound. Seventeen male patients, 10 with OSA (apnoea/hypopnoea index (AHI) 26.2 events x h(-1)) and seven simple snorers (AHI 3.8 events x h(-1)), were studied. Full night polysomnography was performed and the snoring sound power spectrum was analysed. Spectral analysis of snoring sound showed the existence of two different patterns. The first pattern was characterized by the presence of a fundamental frequency and several harmonics. The second pattern was characterized by a low frequency peak with the sound energy scattered on a narrower band of frequencies, but without clearly identified harmonics. The seven simple snorers and two of the 10 patients with OSA (AIH 13 and 14 events x h(-1), respectively) showed the first pattern. The rest of the OSA patients showed the second pattern. The peak frequency of snoring was significantly lower in OSA patients, with all but one OSA patient and only one simple snorer showing a peak frequency below 150 Hz. A significant negative correlation was found between AHI and peak and mean frequencies of the snoring power spectrum (p<0.0016 and p<0.0089, respectively). In conclusion, this study demonstrates significant differences in the sound power spectrum of snoring sound between subjects with simple snoring and obstructive sleep apnoea patients.

Acceptance and long-term compliance with nCPAP in patients with obstructive sleep apnoea syndrome

Previous studies have generally shown poor effective long-term compliance with nasal continuous positive airway pressure (nCPAP) in patients with obstructive sleep apnoea syndrome (OSAS). We performed a retrospective study of patients treated with nCPAP for more than one year. Compliance was defined as the average number of hours of nCPAP use per day, where hours of use were obtained from the built-in time counter of the nCPAP device, after deduction of the 10% difference between effective use and time counters previously shown by others. We present data on the first 95 patients for whom results were available. The follow-up period was 784 +/- 366 (mean +/- SD) days for the whole group. Compliance was 5 +/- 1.8 h. For a subgroup of 36 patients, we had data on two consecutive follow-up periods (673 +/- 235 and 390 +/- 147 days for the first and second period, respectively). Compliance remained stable (5.2 +/- 1.5 and 5 +/- 2.3 h, respectively). For the whole group, a significant correlation was found between compliance and sleep fragmentation expressed as the movement arousal index (r = 0.226). During a similar 3 year period, 155 patients with a confirmed diagnosis of OSAS were offered a nCPAP trial. CPAP was actually delivered for home use to 117 patients (76%). During this same 3 year period, only 21 patients out of a total of 192 followed-up in our institution quit treatment, mainly due to intolerance or cure. These results indicate that in a nonselected group of obstructive sleep apnoea syndrome patients a high and stable compliance with nasal continuous positive pressure can be achieved, contradicting recent results of other series.

Compliance with nasal CPAP in obstructive sleep apnea patients

Continuous positive airway pressure (CPAP) is currently the treatment of choice for the majority of patients with obstructive sleep apnea (OSA). After a CPAP trial, the initial acceptance rate is 70-80%. Patients who derive no subjective benefit from such a trial are poor candidates for home treatment with CPAP because they are likely to exhibit lower adherence and compliance rates. About 90% of OSA patients provided with CPAP apparatus will adhere to long-term CPAP treatment. Patients abandoning CPAP do so during the first few months of home therapy, a period during which close monitoring and support is warranted. Because of the strong correlation between the machine run time and effective pressure delivered at the nasal mask (90-95%), the time-counter of the CPAP device is sufficient to monitor compliance in clinical practice, allowing for early intervention in cases of suboptimal use. Longterm acceptors of CPAP display a satisfactory compliance (5-6.5 h of average daily use) which compares favourably with compliance with treatment in other chronic diseases. Lower acceptance and compliance rates have been reported in North America as compared to Europe. This could be related to cultural differences or different routines of prescription and follow-up.

Noninvasive ventilation for acute respiratory failure: a prospective randomised placebo-controlled trial

The aim of the present study was to clarify whether the known effects of noninvasive positive-pressure ventilation (NPPV) in patients with respiratory failure are real or due to placebo effects and whether early application of NPPV in the emergency department leads to rapid improvement of the patients condition and outcome. A prospective randomised placebo-controlled study was conducted in 20 patients with severe acute respiratory failure (ARF) secondary to an acute exacerbation of chronic obstructive pulmonary disease (COPD) or acute pulmonary oedema, not improving under conventional medical therapy and on the edge of intubation. Patients received either conventional medical therapy plus two-level NPPV (bi-level NPPV) or conventional medical therapy plus “placebo” NPPV. The main outcome measures involved the need for endotracheal intubation in the bi-level NPPV arm and in the placebo arm after crossing over to active NPPV. Morbidity, length of stay, mortality and the effect of the ventilatory mode on clinical, arterial-blood gas parameters, and the sternocleidomastoid muscles electromyogram (EMG) activity were also measured. The 10 patients in the active NPPV group rapidly improved and none needed intubation. Placebo NPPV resulted in no change in the clinical condition of patients that continued to worsen and the 10 patients were crossed over to active NPPV. Three patients were intubated. No differences in terms of morbidity, length of stay or mortality between the two groups were observed. Active NPPV (but not placebo NPPV) led to a rapid and significant improvement in the clinical parameters, pH and the carbon dioxide tension in arterial blood and to a decrease in respiratory frequency and sternocleidomastoid EMG activity. Early application of bi-level noninvasive positive-pressure ventilation in patients with severe acute respiratory failure, due to chronic obstructive pulmonary disease and acute pulmonary oedema, leads to a rapid improvement in clinical status and blood gases. Noninvasive positive-pressure ventilation had no placebo effect.

An Official American Thoracic Society Clinical Practice Guideline: Sleep Apnea, Sleepiness, and Driving Risk in Noncommercial Drivers. An Update of a 1994 Statement

BACKGROUND Sleepiness may account for up to 20% of crashes on monotonous roads, especially highways. Obstructive sleep apnea (OSA) is the most common medical disorder that causes excessive daytime sleepiness, increasing the risk for drowsy driving two to three times. The purpose of these guidelines is to update the 1994 American Thoracic Society Statement that described the relationships among sleepiness, sleep apnea, and driving risk. METHODS A multidisciplinary panel was convened to develop evidence-based clinical practice guidelines for the management of sleepy driving due to OSA. Pragmatic systematic reviews were performed, and the Grading of Recommendations, Assessment, Development, and Evaluation approach was used to formulate and grade the recommendations. Critical outcomes included crash-related mortality and real crashes, whereas important outcomes included near-miss crashes and driving performance. RESULTS A strong recommendation was made for treatment of confirmed OSA with continuous positive airway pressure to reduce driving risk, rather than no treatment, which was supported by moderate-quality evidence. Weak recommendations were made for expeditious diagnostic evaluation and initiation of treatment and against the use of stimulant medications or empiric continuous positive airway pressure to reduce driving risk. The weak recommendations were supported by very low-quality evidence. Additional suggestions included routinely determining the driving risk, inquiring about additional causes of sleepiness, educating patients about the risks of excessive sleepiness, and encouraging clinicians to become familiar with relevant laws. DISCUSSION The recommendations presented in this guideline are based on the current evidence, and will require an update as new evidence and/or technologies becomes available.

Proposal for a systematic analysis of polygraphy or polysomnography for identifying and scoring abnormal events occurring during non-invasive ventilation

Non-invasive ventilation (NIV) is recognised as an effective treatment for chronic hypercapnic respiratory failure. Monitoring NIV during sleep may be preferable to daytime assessment. This paper reports the findings of an international consensus group which systematically analysed nocturnal polygraphic or polysomnographic tracings recorded with either volume-cycled or pressure-cycled ventilators. A systematic description of nocturnal respiratory events which occur during NIV is proposed: leaks, obstruction at different levels of the upper airway (glottis and/or pharynx), with or without decrease of respiratory drive and asynchrony.

Targeted hypoglossal neurostimulation for obstructive sleep apnoea: a 1-year pilot study

Continuous positive airway pressure (CPAP) is an effective but cumbersome treatment for obstructive sleep apnoea (OSA). Noncompliant patients need alternative therapies. We studied a tongue neurostimulation approach: targeted hypoglossal neurostimulation (THN) therapy with the aura6000™ System. A multi-contact electrode positioned around the main trunk of the twelfth nerve connected to an implanted pulse generator stimulates segments of the nerve, activating dilator muscles. The primary objective was to improve the polysomnographically determined apnoea/hypopnoea index (AHI) at 3 months, and maintain the improvement after 12 months of treatment. 13 out of 14 operated patients were successfully implanted. At 12 months, the AHI decreased from 45±18 to 21±17, a 53% reduction (p<0.001). The 4% oxygen desaturation index fell from 29±20 to 15±16 and the arousal index from 37±13 to 25±14, both p<0.001. The Epworth sleepiness scale decreased from 11±7 to 8±4 (p=0.09). THN was neither painful nor awakened patients, who all complied with therapy. There were two transient tongue paresis. The present study represents the longest study of any hypoglossal neurostimulation reported to date. We conclude that THN is safe and effective to treat OSA in patients not compliant with CPAP.

Postoperative pain and side effects after uvulopalatopharyngoplasty, laser-assisted uvulopalatoplasty, and radiofrequency tissue volume reduction in primary snoring.

Objectives We compared, in a prospective study, the side effects and the postoperative complications of three procedures commonly used for the treatment of primary snoring.