Biomedical subjects

R W Riley

Publications and source records attributed to R W Riley.

At least 37 records · Page 2Linked to original sources

PubMed1999

A comparative model: reaction time performance in sleep-disordered breathing versus alcohol-impaired controls.

OBJECTIVES/HYPOTHESIS: Patients with sleep-disordered breathing have reaction time deficits that may lead to catastrophic accidents and loss of life. Although safety guidelines do not exist for unsafe levels of sleepiness, they have been established for unsafe levels of alcohol consumption. Since reaction time performance is altered in both, we prospectively used seven measures of reaction time performance as a comparative model in alcohol-challenged normal subjects with corresponding measures in subjects with sleep-disordered breathing. STUDY DESIGN: Institutional Review Board-approved, nonrandomized prospective controlled study. METHODS: Eighty healthy volunteers (29.1+/-7.5 y of age, 56.3% female subjects) performed four reaction time trials using a psychomotor test at baseline and at three subsequent rising alcohol-influenced time points. The same test without alcohol was given to 113 subjects (47.2+/-10.8 y of age, 19.3% female subjects) with mild to moderate sleep-disordered breathing. RESULTS: Mean blood alcohol concentrations (BACs) in the alcohol-influenced subjects at baseline and three trials were 0, 0.057, 0.080, and 0.083 g/dL. The sleep-disordered subjects had mean respiratory disturbance indices of 29.2 events per hour of sleep. On all seven reaction time measures, their performance was worse than that of the alcohol subjects when BACs were 0.057 g/dL. For three of the measures, the sleep-disordered subjects performed as poorly as or worse than the alcohol subjects when alcohol levels were 0.080 g/dL. These results could not be explained by sex or age differences. CONCLUSION: The data demonstrate that sleep-disordered subjects in this study (with a mean age of 47 y) with mild to moderate sleep-disordered breathing had worse test reaction time performance parameters than healthy, nonsleepy subjects (with a mean age of 29 y) whose BAC is illegally high for driving a commercial motor vehicle in California. This comparative model points out the potential risks of daytime sleepiness in those with sleep-disordered breathing relative to a culturally accepted standard of impairment.

Adult↗

PubMed1999

A comparison of Asian and white patients with obstructive sleep apnea syndrome.

OBJECTIVE: To evaluate the possible differences between Asian and white patients with obstructive sleep apnea syndrome. METHODS: A retrospective review of Asian and white patients during a 12-month period was conducted. Patients with respiratory disturbance index (RDI) > or = 15 based on polysomnography were included in the study. Variables examined include age, sex, body mass index (BMI), RDI, lowest oxygen saturation (LSAT), and cephalometric analysis data. RESULTS: Fifty-eight Asian patients (53 men) and 293 white patients (260 men) were studied. The Asians were younger (44.1 +/- 9.8 vs. 47.5 +/- 11.6 y, P = .02), and the mean BMI (kg/m2) was 26.6 +/- 3.7 in the Asians and 30.7 +/- 5.9 in the whites (P < .001). The mean RDI was similar (56.6 +/- 34.9 vs. 55.6 +/- 26.9, P = NS), but the mean LSAT was lower in the whites (77.7 +/- 9.9% vs. 70.0 +/- 15.6%, P < .001). Based on the cephalometric data, the Asians have maxillomandibular protrusion, narrower cranial base angle, larger posterior airway space, and more superiorly positioned hyoid bone compared with the whites. CONCLUSIONS: Although male gender was found to be an important risk factor for obstructive sleep apnea syndrome in both Asian and white patients, obesity may be a less significant risk factor in the Asians because the majority of our Asian patients were nonobese. There was also variability in the craniomandibular factors that contributed to obstructive sleep apnea syndrome in the two groups.

Adolescent↗

PubMed1999

Overview of phase I surgery for obstructive sleep apnea syndrome.

It is well established that obstructive sleep apnea syndrome is associated with increased morbidity and mortality. Surgical therapy has been demonstrated to be a viable treatment option for cure. Thorough presurgical evaluation with the identification of the type of airway abnormality is mandatory to allow for the utilization of a surgical protocol that results in improved clinical outcomes. Phase I surgical protocol is designed to apply specific surgical procedures to alleviate the obstruction(s) present. Following a logical, stepwise surgical approach in airway reconstruction will minimize surgical interventions and avoid unnecessary operations. The incorporation of a risk-management protocol will minimize treatment complications while achieving cure.

Female↗

PubMed1999

Overview of phase II surgery for obstructive sleep apnea syndrome.

Maxillomandibular advancement is an extremely effective surgical procedure for the treatment of obstructive sleep apnea syndrome. When properly executed, it is associated with minimal morbidity and is well accepted by patients. It is a treatment option that achieves long-term care.

Aged↗

PubMed1998

Surgical management of the hypopharyngeal airway in sleep disordered breathing.

The etiology of sleep disordered breathing is collapse or obstruction of the upper airway during sleep. This obstruction may be localized to one or two areas or may encompass the entire upper airway passages to include the nasal cavity, nasopharynx, oropharynx, hypopharynx, and larynx. The presurgical evaluation, which includes polysomnography, a comprehensive head and neck physical examination, fiberoptic nasopharyngoscopy, and lateral cephalometric analysis is essential in directing surgical therapy in a site specific approach. The surgical procedures available to address hypopharyngeal and base of the tongue collapse include inferior sagittal mandibular osteotomy and gengioglossus advancement, hyoid myotomy and suspension, laser midline glossectomy, lingualplasty, partial glossectomy, and maxillomandibular advancement surgery. The Riley-Powell-Stanford Surgical Protocol has proven to be an effective and safe method for controlling upper airway collapse in sleep disordered breathing.

Airway Obstruction↗

PubMed1998

Long-term results of surgical management of sleep disordered breathing: are our patients really benefiting?

The etiology of sleep disordered breathing (SDB), which includes upper airway resistance syndrome (UARS) and obstructive sleep apnea syndrome (OSAS), is collapse or obstruction of the upper airway during sleep. Surgical management was the first treatment modality available for SDB. Since the introduction of the tracheotomy to treat OSAS, there have been numerous procedures discovered to address the various sites of obstruction of the upper airway. This article reviews the long-term surgical results and may improve one's insight into the successes of surgical therapy for SDB.

Airway Obstruction↗

PubMed1998

Radiofrequency volumetric tissue reduction for treatment of turbinate hypertrophy: a pilot study.

OBJECTIVES: Ideal treatment for nasal obstruction caused by turbinate hypertrophy remains in question. Medical therapy is often ineffective. Surgical procedures have associated morbidity including pain, bleeding, crusting, adhesion, infection, and dryness. Radiofrequency has recently been shown to be safe and effective in volumetric tissue reduction of the tongue in the animal model and of the palate in human beings. We prospectively evaluate the safety and effectiveness of radiofrequency volumetric tissue reduction (RFVTR) for the treatment of nasal obstruction caused by inferior turbinate hypertrophy. METHODS: Twenty-two consecutive patients with nasal obstruction and associated inferior turbinate hypertrophy refractory to medical therapy were evaluated for RFVTR. The study design limited the region of treatment to the anterior third of the inferior turbinate. The procedures were performed in an ambulatory facility with patients under local anesthesia. Clinical examinations, patient questionnaires, and visual analog scales were used to assess treatment outcomes. RESULTS: No adverse effects were encountered, including bleeding, crusting, dryness, infection, adhesion, or a worsening of obstruction. Mild edema was noted in all patients but was of short duration (24 to 48 hours). Posttreatment discomfort was well controlled with acetaminophen. Eight weeks after treatment, nasal breathing improved in 21 of 22 patients, with a 58.5% reduction in severity and a 56.5% decrease in the frequency of nasal obstruction. CONCLUSION: The results of this study demonstrate that RFVTR of the hypertrophic inferior turbinate is associated with minimal adverse effects. Furthermore, this new treatment modality achieves subjective improvement in patients with symptoms of nasal obstruction. However, because of the small sample size and short follow-up, future investigations are needed to fully evaluate the use of RFVTR in the treatment of nasal obstruction caused by turbinate hypertrophy.

Adolescent↗

PubMed1998

Surgical management of obstructive sleep apnea syndrome.

This article discusses the history of operative management of obstructive sleep apnea syndrome and reviews a protocol for surgical intervention. An overview of diagnostic procedures and evaluation is also presented, and emerging technology for the management of this disorder is touched on.

Clinical Trials as Topic↗

PubMed1998

Radiofrequency volumetric tissue reduction of the palate in subjects with sleep-disordered breathing.

STUDY OBJECTIVES: To evaluate pain, swallowing, speech, edematous response, tissue shrinkage, sleep, snoring, and safety (energy limits and adverse effects) following radiofrequency (RF) treatment to the palate in 22 subjects with sleep-disordered breathing. DESIGN: This investigation is a prospective nonrandomized study. Polysomnography, radiographic imaging, and infrared thermography, along with questionnaires and visual analog scales, were used to evaluate the effects of RF treatment to the palate. SETTING: Treatments were delivered on an outpatient basis at Stanford University Medical Center. PATIENTS: Twenty-two healthy patients (18 men), with a mean age of 45.3+/-9.1 years, were enrolled. All were snorers seeking treatment and met predetermined criteria: a respiratory disturbance index < or = 15, oxygen saturation > or = 85%, and a complaint of daytime sleepiness. INTERVENTION: RF was delivered to the submucosa of the palate with a custom-fabricated electrode for a mean duration of 141+/-30 s with a mean of 3.6+/-1.2 treatments per patient. Reduction of their snoring scores determined the end point of the study. RESULTS: Neither speech nor swallowing was adversely affected. Pain was of short duration (0 to 48 h) and was controlled with acetaminophen. There were no infections. Although there was documented edema at 24 to 48 h, there were no clinical airway compromises. Polysomnographic data showed improvement in esophageal pressure measurements of the mean nadir and the 95th percentile nadir (p=0.031, p=0.001) respectively, as well as the mean sleep efficiency index (p=0.002). Radiographic imaging showed a mean shrinkage of 5.5+/-3.7 mm (p< or =0.0001). Subjective snoring scores fell by a mean of 77% (8.3+/-1.8 to 1.9+/-1.7, p=0.0001) accompanied by improved mean Epworth sleepiness scores (8.5+/-4.4 to 5.2+/-3.3, p=0.0001). CONCLUSION: The results of this investigation allowed the formulation of safety parameters for RF in this defined population with mild sleep-disordered breathing. There was a documented tissue reduction and improvement in symptoms in all subjects. However, given the small sample size and short-term follow-up, these results should be confirmed by further investigation.

Ambulatory Surgical Procedures↗

PubMed1997

Obstructive sleep apnea surgery: risk management and complications.

BACKGROUND: Hypoxemia, hypertension, airway obstruction, and death have been associated with surgery for obstructive sleep apnea syndrome (OSAS). Patient analysis was undertaken to identify potential factors that could affect risk-management outcome. METHODS: One hundred eighty-two consecutively treated patients with OSAS undergoing 210 procedures were evaluated. Fifty-four factors were analyzed. RESULTS: Group characteristics included a mean age of 48.2 years, a mean respiratory disturbance index of 42.3, and a mean low oxyhemoglobin desaturation (LSAT) of 77.5%. Surgery included a combination of uvulopalatopharyngoplasty (162 patients; 77%) and maxillofacial procedures (173 patients; 82%). Patients with a respiratory disturbance index greater than 40 and an LSAT less than 80% (117 patients; 64%) were maintained on nasal continuous positive airway pressure. Thirty-nine patients (18.6% had difficult intubations. There was a positive correlation (p > 0.001) of difficult intubations, neck circumference (> 45.6 cm) and skeletal deficiency (Sella-Nasion-Point B < 75 degrees). All tubes were removed with the patient awake in the operating room with two transient episodes of airway obstruction. One hundred forty-eight of the patients (70.5%) required postoperative intravenous antihypertensive medications. Patients with a preoperative history of hypertension had a significantly increased risk (p > 0.01) of requiring intraoperative and postoperative intravenous antihypertensive medications. The mean hospital stay was 2.2 days (SD +/- 0.9). Analgesia was achieved with intravenous morphine sulfate or meperidine HCl (intensive care unit) and oral oxycodone (non-intensive care unit). There were no significant oxyhemoglobin desaturations, irrespective of severity of OSAS or obesity (mean LSAT day 1, 94.8% (SD +/- 2.4); mean LSAT day 2, 95.5% (SD +/- 1.6)). Complications included postoperative bleeding (n = 4), infection (n = 5), seroma (n = 3), arrhythmia (n = 4), angina (n = 1), and loss of skeletal fixation (n = 1). CONCLUSION: Intraoperative airway risks can be reduced by use of fiberoptic intubation in patients with increased neck circumference and skeletal deficiency. Patients with OSAS are at a significantly increased risk for hypertension. Nasal continuous positive airway pressure eliminated the postoperative risk of hypoxemia, which allowed the use of adequate parenteral or oral analgesics.

Female↗

PubMed1997

Radiofrequency volumetric reduction of the tongue. A porcine pilot study for the treatment of obstructive sleep apnea syndrome.

STUDY OBJECTIVE: To investigate, in an animal model, the feasibility of radiofrequency (RF) volumetric tongue reduction for the future purpose of determining its clinical applications in obstructive sleep apnea syndrome (OSAS). DESIGN: The study was performed in three stages, one in vitro bovine stage and two in vivo porcine stages. The last stage was a prospective investigation with histologic and volumetric analyses to establish outcomes. SETTING: Laboratory and operating room of veterinary research center. PARTICIPANTS: A homogeneous population of porcine animal models, including seven in stage 2 and 12 in stage 3. INTERVENTION: RF energy was delivered by a custom-fabricated needle electrode and RF generator to the tongue tissue of both the in vitro and in vivo models. MEASUREMENTS AND RESULTS: Microultransonic crystals were used to measure three-dimensional changes (volumetric reduction). Lesion size correlated well with increasing RF energy delivery (Sperman correlation coefficient of 0.986; p = 0.0003). Histologic assessments done serially over time (1 h through 3 weeks) showed a well-circumscribed lesion with a normal healing progression and no peripheral damage to nerves. Volumetric analysis documented a very mild initial edematous response that promptly tapered at 24 h. At 10 days after RF, a 26.3% volume reduction was documented at the treatment site (circumscribed by the microultrasonic crystals). CONCLUSION: RF, in a porcine animal model, can safely reduce tongue volume in a precise and controlled manner. Further studies will validate the use of RF in the treatment of OSAS.

Animals↗

PubMed1995

Obstructive sleep apnea. Trends in therapy.

The National Commission on Sleep Disorders Research, in its report to Congress, concluded that the primary care community generally does not understand sleep disorders. Obstructive sleep apnea carries a risk of substantial morbidity and mortality. Excessive daytime sleepiness results from fragmented sleep and microarousals associated with apneic events. It causes poor work performance and increases the incidence of automobile accidents due to driving while drowsy. The commission estimates that the loss of productivity in the United States from excessive daytime sleepiness is more than $20 billion per year. Obstructive sleep apnea is strongly associated with hypertension, myocardial infarction, and stroke. Risk factors for obstructive sleep apnea include male sex, obesity, older age, craniofacial anomalies, and familial risk. Treatment is based on documenting the disorder by polysomnography. Medical management of the syndrome includes weight loss and nasal continuous positive airway pressure. A network of follow-up and support is necessary to maintain compliance. Surgical treatment is reserved for those for whom nasal airway pressure treatment fails. A surgical protocol is presented that demonstrates efficacy equal to nasal airway pressure treatment. Primary care physicians should assume the responsibility of identifying patients at risk for obstructive sleep apnea and refer them appropriately.

Humans↗

PubMed1994

Obstructive sleep apnea and the hyoid: a revised surgical procedure.

Obstructive sleep apnea syndrome results from a loss of muscular activity of pharyngeal dilators and airway collapse at the hypopharynx-base of tongue or the oropharynx-soft palate. The hyoid arch and its muscle attachments strongly affect hypopharyngeal airway patency and resistance. On the basis of these concepts and previous experience, a modified hyoid suspension procedure is presented. Fifteen consecutively treated surgical patients underwent an isolated modified hyoid suspension procedure to correct hypopharyngeal obstruction. Oropharyngeal-palatal obstruction had previously been corrected or was thought not to be a component of the obstruction. Treatment outcomes were based on objective polysomnographic data and subjective clinical correction of excessive daytime sleepiness. The polysomnographic data included analysis of the respiratory disturbance index and lowest oxyhemoglobin desaturation. On the basis of these criteria, 12 of 15 patients (75%) had correction of their excessive daytime sleepiness and marked improvement in their sleep disorder breathing. The mean preoperative respiratory disturbance index was 44.7 +/- 22.6, and the lowest oxyhemoglobin desaturation was 82% +/- 6%. The postoperative respiratory disturbance index and lowest oxyhemoglobin desaturation were 12.8 +/- 6.9 and 86% +/- 5%, respectively. The modified hyoid suspension procedure appears to offer significant adjunctive treatment for hypopharyngeal obstruction in obstructive sleep apnea syndrome.

Adult↗

PubMed1993

Obstructive sleep apnea syndrome: a surgical protocol for dynamic upper airway reconstruction.

A surgical protocol for dynamic upper airway reconstruction in the treatment of obstructive sleep apnea syndrome is presented. Two hundred thirty-nine consecutively treated patients were evaluated. All patients underwent a presurgical evaluation that included a physical examination, fiberoptic pharyngoscopy, cephalometric analysis, and polygraphic monitoring. The goal of the presurgical evaluation was to document sleep apnea and isolate the area of obstruction. The treatment was then directed to the obstructive site. The surgical protocol included two phases. Phase 1 was a conservative approach and included uvulopalatopharyngoplasty and/or mandibular osteotomy with genioglossus advancement-hyoid myotomy and suspension. Polysomnography was repeated at 6 months and patients with unsuccessful surgical results were offered maxillary-mandibular advancement osteotomy. Results were based on the postoperative polysomnograms, and included assessing changes in both sleep architecture and sleep-disordered breathing. The surgical results were compared with results in patients who were using nasal continuous positive airway pressure. The surgical success rate for the 239 patients entered into phase 1 therapy was 61% (145 patients). Twenty-four patients who failed phase 1 treatment elected phase 2 treatment. The surgical success rate of this phase was 100%.

Cephalometry↗

PubMed1993

Obstructive sleep apnea syndrome: a review of 306 consecutively treated surgical patients.

Three hundred six consecutively treated surgical patients with obstructive sleep apnea syndrome were evaluated from a group of 415 patients. One hundred nine patients were excluded because they failed to obtain a postoperative polysomnogram or were lost to followup. All patients received a physical examination, cephalometric analysis, fiberoptic examination, and polysomnography before treatment to document OSAS and determine the areas of obstruction. A two-phase surgical protocol was used for the reconstruction of the upper airway. Phase I surgery consisted of a uvulopalatopharyngoplasty (UPPP) for palatal obstruction and genioglossus advancement with hyoid myotomy-suspension for base of tongue obstruction. Failures of phase I were offered phase 2 reconstruction, which consisted of maxillary-mandibular advancement osteotomy. One hundred twenty-one patients were treated with nasal continuous positive airway pressure (CPAP) before surgery and this was the primary method of evaluating surgical success. Results were reported on the polysomnogram performed a minimum of 6 months after surgery and compared to the preoperative polysomnogram and the second night nasal CPAP study. The polysomnographic results included respiratory disturbance index (RDI), lowest oxyhemoglobin saturation (LSAT), and sleep architecture parameters. Surgery was considered a success if it was equivalent to nasal CPAP or the postoperative RDI was less than 20 with normal oxygenation. The overall success rate, which included patients that dropped from the protocol, was 76.5%, with a mean followup of 9.3 months (SD, 6.7). The preoperative RDI, nasal CPAP RDI, and postoperative RDI were 55.8 (SD, 26.7), 7.2 (SD, 5.4), and 9.2 (SD, 7.5), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

Maxillary, mandibular, and hyoid advancement for treatment of obstructive sleep apnea: a review of 40 patients.

Forty patients with documented obstructive sleep apnea syndrome (OSAS) were evaluated following maxillary and mandibular osteotomies (MMO). All patients were evaluated before and after surgery by a physical examination, fiberoptic pharyngoscopy, cephalometric analysis, and polysomnography. Ninety-seven percent of the patients responded to the surgical treatment, based on the polysomnogram. The present indications for MMO are severe OSAS, morbid obesity, and severe mandibular deficiency.

Adolescent↗

PubMed1990

Maxillofacial surgery and nasal CPAP. A comparison of treatment for obstructive sleep apnea syndrome.

Nasal continuous positive airway pressure (CPAP) is the primary therapy for obstructive sleep apnea syndrome (OSAS). Recent reports have indicated, however, that there is a small but significant number of failures related to patient compliance. Primary surgical treatment, which has been uvulopalatopharyngoplasty (UPPP), has declined because of poor results. A reviewed of UPPP failures has shown that while UPPP eliminated palatal obstruction, it failed to eliminate base of tongue obstruction. Maxillofacial surgery has been reported as treatment of OSAS by correcting base of tongue obstruction. Thirty patients with severe OSAS were evaluated to compare nasal CPAP and maxillofacial surgery. The goal was to determine if our surgical protocol was as effective as nasal CPAP. All patients initially underwent baseline diagnostic polysomnography to document OSAS. A nasal CPAP study was performed to determine the appropriate positive end-expiratory pressure. The patients in this study were using nasal CPAP, but they found it unacceptable as long-term treatment and elected surgery. Maxillofacial surgery consisted of maxillary, mandibular, and hyoid advancement. Polysomnography was performed six months following surgery and compared with the night 2 CPAP results. The parameters included in the investigation were the respiratory disturbance index (RDI), lowest SaO2, number of SaO2 falls below 90 percent, total sleep time (TST), REM sleep percent, stage 3-4 sleep percent, and wake after sleep onset. The mean RDI before treatment was 72.0 (SD 25.7). After completing therapy, the RDI from surgery and CPAP was 8.8 (SD 6.0) and 8.6 (SD 4.1), respectively. The mean low SaO2 prior to treatment was 61.0 (SD 13.5), and the CPAP results and postsurgical results were 86.2 (SD 5.5) and 86.1 (SD 4.2), respectively. An analysis of variance was used to examine the results, and there was no statistical difference between nasal CPAP and surgery for all respiratory variables.

Adult↗

PubMed1990

Maxillofacial surgery and obstructive sleep apnea syndrome.

Maxillofacial surgery has proven to be an effective method for controlling OSA syndrome, and its results are as effective as those obtained with nasal CPAP. The presurgical evaluation, which includes polysomnography, physical examination, fiberoptic pharyngoscopy, and cephalometric analysis, is essential in directing surgical therapy. With phased reconstruction of the upper airway there is an excellent chance of correcting the obstructive process and eliminating the associated problems of OSA syndrome.

Adult↗