U. Brandenburg

Surgical maxillofacial treatment of obstructive sleep apnea.

&NA; Obstructive sleep apnea is the most common sleeprelated breathing disorder, with a surprisingly high prevalence. The treatment of choice is nasal continuous positive airway pressure (CPAP) ventilation during sleep, which has to be applied throughout the patients whole life. Because of various underlying pathomechanisms in patients with certain craniofacial disorders—narrow posterior airway space and maxillary‐mandibular deficiency— surgical therapy by craniofacial osteotomies seems possible. A series of 38 consecutive patients were treated by 10‐mm maxillomandibular advancement by retromolar sagittal split osteotomy and Le Fort I osteotomy, respectively. Obstructive sleep apnea syndrome was improved considerably in all patients; there was no significant difference compared to the results under nasal CPAP. In 37 of 38 patients, the postoperative apnea‐hypopnea index was reduced clearly to under 10 per hour, oxygen saturation rose, and sleep quality improved. This was achieved by maxillomandibular advancement of 10 mm without secondary refinements in all but 2 patients. In one patient, the apnea‐hypopnea index could only be reduced to 20 per hour, probably because of insufficient maxillary advancement. These results indicate that successful surgical treatment is possible in a high percentage of selected patients with certain craniofacial characteristics. In addition to cardiorespiratory polysomnography, there should be routine cephalometric evaluation of all patients. Maxillomandibular advancement should be offered as an alternative therapy to all patients with maxillary and/or mandibular deficiency or dolichofacial type in combination with narrow posterior airway space. (Plast. Reconstr. Surg. 99: 619, 1997.)

Mandibular setback for surgical correction of mandibular hyperplasia — does it provoke sleep-related breathing disorders?

The question has arisen as to whether mandibular setback may possibly cause sleep-related breathing disorders (SRBD). To evaluate the possible effects of mandibular setback on posterior airway space (PAS), 16 consecutive patients were examined prospectively. All patients underwent surgical mandibular setback using bilateral sagittal split osteotomy. Polysomnographic evaluation for SRBD was performed according to the Marburg graded diagnostic protocol before and after surgery. Cephalometric analysis was performed preoperatively, and 1 week, 3 months, and 1 year postoperatively, with particular attention to pharyngeal changes. PAS decreased considerably in all patients. Nevertheless, the preoperative PAS was enlarged in all patients with mandibular hyperplasia compared to normal subjects. Despite the pharyngeal narrowing, there was no evidence of postoperative SRBD in any of these patients. SRBD as a consequence of mandibular setback may be rare; nevertheless, the pharyngeal airway does decrease.

Morphology of the viscerocranium in obstructive sleep apnoea syndrome - cephalometric evaluation of 400 patients

The aim of this study was the cephalometric evaluation of patients with obstructive sleep apnoea in order to see whether certain craniofacial characteristics exist. Additional to known skeletal facial parameters cephalometric analysis has been used to establish pharyngeal dimensions. Surprisingly, many patients with obstructive sleep apnoea (nearly 40%) showed certain craniofacial characteristics which apparently predispose to pharyngeal obstruction and to obstructive sleep apnoea. More than one third of 400 patients prove to have pharyngeal narrowing combined with more or less distinct maxillary and mandibular deficiency. Cephalometric evaluation helps to identify sleep apnoea patients, in whom maxillomandibular advancement surgery might be effective in the treatment of obstructive sleep apnoea. According to our results, an indication for surgical treatment by maxillomandibular advancement exists in patients with maxillary and especially mandibular deficiency combined with pharyngeal narrowing.

Long-term follow-up after surgical treatment of obstructive sleep apnoea by maxillomandibular advancement

Obstructive sleep apnoea (OSA) is a common disorder with potentially serious consequences. If maxillary and mandibular deficiency, often in combination with a narrow posterior airway space is present, therapy of OSA by maxillomandibular osteotomy is possible. However, long-term follow-up of patients undergoing these procedures is lacking. We present the results of 15 OSA patients (1 female and 14 males), who underwent maxillomandibular advancement surgery with a follow-up of at least 2 yrs. Polysomnography was performed before surgery, after 6-12 weeks, and 1 and 2 yrs postoperatively. Mean apnoea/hypopnoea index (AHI) decreased from 51.4 events.h-1 before therapy to 5.0 events.h-1 6 weeks postoperatively, and was 8.5 events.h-1 after 2 yrs. Oxygen saturation significantly increased following surgery. After 2 yrs, the AHI was < 10 events.h-1 in 12 out of 15 subjects. No significant changes were found comparing the 6-12 weeks versus the 2 year follow-up data. The significant increase in stage 3/4 non-rapid eye movement (NREM) sleep and decrease in stage 1 NREM sleep, indicative of the restoration of normal physiological sleep structure, persisted in 14 of the 15 subjects 2 yrs postoperatively. Three patients, however, did not show satisfactory improvement 2 yrs postoperatively; two showed obstructive and one central respiratory events. This study demonstrates that maxillomandibular advancement is successful in a high percentage of patients carefully selected by cephalometric and polysomnographic investigation. Postoperative success has proved to be stable over a period of 2 yrs. Further preoperative evaluation seems necessary in patients with predominantly mixed or central apnoeas.

Arousal in patients with gastro-oesophageal reflux and sleep apnoea

Nocturnal gastro-oesophageal reflux has been observed in patients with obstructive sleep apnoea (OSA). Negative intrathoracic pressure during apnoeas and arousal have been suggested as the underlying mechanisms. In order to evaluate this hypothesis, the coincidence and sequence in time of arousal, apnoea and reflux events were analysed. Fifteen patients with OSA or heavy snoring were studied by means of standard polysomnograpy with parallel recording of 24-h oesophageal pH. Reflux events during the day were present in all patients, five of whom had symptoms of reflux. In three of these and in five other patients, a total of 69 nocturnal reflux events were found. In 68 events, arousal was found with the reflux event. Only one reflux without arousal was found (sleep stage 2). Seventeen events occurred during wakefulness after sleep onset. The percentage of time with a pH of <4 during wakefulness after sleep onset was significantly higher than the percentage of time with a pH of <4 during total sleep time (p<0.05). In 37 of the 52 reflux events which occurred during sleep, either an apnoea or a hypopnoea was found prior to the event. The investigation of sequence in time did not prove a causal relation between respiratory events and reflux events. The results indicate that gastro-oesophageal reflux and obstructive sleep apnoea are two separate disorders, which both have a high prevalence in obese patients.

Sleep fragmentation and daytime vigilance in patients with OSA treated by surgical maxillomandibular advancement compared to CPAP therapy

Impaired vigilance is a frequent daytime complaint of patients with obstructive sleep apnoea (OSA). To date, continuous positive airway pressure (CPAP) is a well established therapy for OSA. Nevertheless, in patients with certain craniofacial characteristics, maxillomandibular advancement osteotomy (MMO) is a promising surgical treatment. Twenty‐four male patients with OSA (pretreatment respiratory disturbance index (RDI) 59.3 SD±24.1 events/h) participated in this investigation. The mean age was 42.7±10.7 years and the mean body mass index was 26.7±2.9 kg/m2. According to cephalometric evaluation, all patients had a narrow posterior airway space, more or less due to severe maxillary and mandibular retrognathia. All patients except two were treated first with CPAP for at least 3 months and afterwards by MMO. Two patients only tolerated a CPAP trial for 2 nights. Polysomnographic investigation and daytime vigilance were assessed before therapy, with CPAP therapy and 3 months after surgical treatment. Patients’ reports of impaired daytime performance were confirmed by a pretreatment vigilance test using a 90‐min, four‐choice reaction‐time test. The test was repeated with effective CPAP therapy and postoperatively. Daytime vigilance was increased with CPAP and after surgical treatment in a similar manner. Respiratory and polysomnographic patterns clearly improved, both with CPAP and after surgery, and showed significant changes compared to the pretreatment investigation. The RDI decreased significantly, both with CPAP (5.3±6.0) and postoperatively (5.6±9.6 events/h). The percentages of non‐rapid eye movement Stage 1 (NREM 1) sleep showed a marked decrease (with CPAP 8.2±3.6% and after MMO 8.2±4.4% vs. 13.3±7.4% before treatment), whereas percentages of slow wave sleep increased significantly from 8.0±6.1% before therapy to 18.2±12.8 with CPAP and 14.4±7.3% after MMO. The number of awakenings per hour time in bed (TIB) was significantly reduced after surgery (2.8±1.3), compared to both preoperative investigation (baseline 4.2±2.0 and CPAP 3.4±1.5). Brief arousals per hour TIB were reduced to half with CPAP (19.3±20.0) and after MMO (19.7±13.6), compared to baseline (54.3±20.0). We conclude that the treatment of OSA by MMO in carefully selected cases has positive effects on sleep, respiration and daytime vigilance, which are comparable to CPAP therapy.

A new design of a polysomnography-based multi-center treatment study for the restless legs syndrome

Periodic limb movements (PLM) cause sleep disorders and daytime symptoms and are frequently associated with restless legs syndrome (RLS). Treatment of RLS with increased PLM during sleep (PLMS) has been evaluated in studies limited in size, methodology and study length. This long-term, placebo-controlled, multi-center, study with polysomnography (PSG) recordings has been designed in order to assess efficacy and safety parameters of pergolide treatment in RLS. This novel approach for a study was created to assure consistently high quality of sleep recording and analysis. Using defined criteria, 21 sleep centers were approved for the study after a pilot phase. Seventeen centers with 16 different PSG systems randomized 100 patients. Digital sleep recordings from 4 visits (baseline, 6 weeks, 6 months, 1 year) were submitted to one central evaluation center following previously defined standardized operating procedures. Visual scoring of all recordings was performed by one independent scorer. Reliability of scoring was evaluated for 20 randomly selected baseline recordings. The mean epoch by epoch agreement for sleep stages was 88% (range 81-96%), mean arousal re-scoring differed by 0.5 (range: -16 to 20), and mean PLM index re-scoring differed by 0.1 (range: -1.5 to 2.1). Using one scorer with a demonstrated high reliability in PSG scoring for all sleep recordings was very effective in terms of study cost, study duration, and data quality.

LANGZEITREGISTRIERUNG UND ZEITREIHENANALYSE IN DER INNEREN MEDIZIN

Zum ThemaLangzeitregistrierungen gehören heute in den verschiedensten Fächern zum Repertoire der Diagnostik in der Inneren Medizin: Langzeit-EKG, Langzeit-Blutdruck, Oximetrie, ösophageale pH-metrie, Langzeit-EEG und Polysomnographie mit ihren Begleitparametern. Das Monitoring von Vitalparametern in der internistischen Intensivmedizin stellt einen zweiten großen Bereich der Langzeitregistrierungen dar. Allen Langzeitregistrierungen gemeinsam ist die anfallende Datenflut. Diese muß auf die für die Diagnostik wesentliche Information reduziert werden. Mit der heute vorhandenen und verbreiteten Computertechnik stehen die technischen Voraussetzungen zur Lösung dieser Aufgaben zur Verfügung.Die Werkzeuge der Zeitreihenanalyse dienen der Datenreduktion, der Analyse und der Visualisierung. Das Ziel der Zeitreihenanalyse besteht darin, pathophysiologische Muster korrekt zu erkennen, übersichtlich darzustellen und beim intensivmedizinischen Monitoring die richtigen Alarme auszulösen. Die Praxis zeigt, daß dieses Ziel erst teilweise erreicht ist. Weiterhin wird versucht mit Methoden der Zeitreihenanalyse den Übergang von physiologischer Regulation und Funktion zu pathologischer Dysfunktion zu untersuchen, um eine Trennung bzw. Therapieempfehlung nicht an willkürlich festgelegte Grenzwerte zu knüpfen. Hier soll die physiologische Variabilität der Signale mit in die Bewertung einbezogen werden.

Führt die Velopharyngoplastik als sprachverbessernde Maßnahme bei Gaumenspalten zur obstruktiven Schlafapnoe

ZusammenfassungDie Velopharyngoplastik zur Therapie der velopharyngealen Insuffizienz kann die Entstehung schlafbezogener Atmungsstörungen in Einzelfällen verursachen. Ziel dieser Untersuchung war die Frage, inwieweit und wie häufig Anzeichen für schlafbezogene Atmungsstörungen nach Velopharyngoplastik erkennbar sind. Im Sinne einer Stufendiagnostik gemäß den Empfehlungen der Deutschen Gesellschaft für Schlafmedizin und Schlafforschung wurden bei 25 Patienten zum Teil präoperativ, in jedem Fall postoperativ die nächtliche Sauerstoffsättigung, Herzfrequenz und Schnarchgeräusche aufgezeichnet. Bei auffälligenpathologischen Befunden schloß sich eine kardiorespiratorische Polygraphie an. Bei den 25 untersuchten Patienten waren bislang allenfalls passagere schlafbezogene Atmungsstörungen feststellbar; in keinem Fall konnten bleibender schlafbezogene Atmungsstörungen als Folge der Velopharyngoplastik nachgewiesen werden. Gerechtfertigt erscheinen die Forderung nach einem pulsoxymetrischen Monitoring in der unmittelbarenpostoperativen Phase sowie eine entsprechende präoperative Aufklärung. Auch wenn die Gefahr schlafbezogener Atmungsstörungen nach Velopharyngoplastik gering erscheint, sollten diese vorläufigen Ergebnisse an einem größeren Kollektiv polysomnographisch überprüft werden, um bessere Rückschlüsse zu treffen und im Einzelfall gegenmaßnahmen ergreifen zu können.SummaryVelopharyngoplasty performed to correct velopharyngeal insufficiency in cleft palate patients may cause obstructive sleep apnea in individual cases. The aim of this study was to answer the question following velopharyngoplasty to what extent and with what frequency can signs of breathing disturbances during sleep be observed. Following the recommendations of the German Sleep Society, a step-by-step procedure was adopted. In 25 patients, in some cases before the operation and in all cases following surgery, nightly oxygen saturation, heart rate, and snoring were recorded. When observable pathological signs surfaced, a cardiorespiratory polygraph was taken. Up to this point only quickly passing signs of sleep related breathing disturbances have been observed. In not a single case could lasting sleep related breathing disturbances as a result of velopharyngoplasty be proven. Nevertheless, the call for pulseoxymetric monitoring in the immediate postoperative phase together with corresponding pre-operative observation is, legitimate. Even if at this point the danger of sleep related breathing disturbances following velopharyngoplasty appears to be minimal, these preliminary results should be polysomnographically studied within the framework of a much larger test study in order to reach still more reliable conclusions and in order to intercede if necessary with counter measures in the rare individual case of breathing disturbance during sleep following velopharyngoplasty.Velopharyngoplasty performed to correct velopharyngeal insufficiency in cleft palate patients may cause obstructive sleep apnea in individual cases. The aim of this study was to answer the question, following velopharyngoplasty to what extent and with what frequency can signs of breathing disturbances during sleep be observed. Following the recommendations of the German Sleep Society, a step-by-step procedure was adopted. In 25 patients, in some cases before the operation and in all cases following surgery, nightly oxygen saturation, heart rate, and snoring were recorded. When observable pathological signs surfaced, a cardiorespiratory polygraph was taken. Up to this point only quickly passing signs of sleep related breathing disturbances have been observed. In not a single case could lasting sleep related breathing disturbances as a result of velopharyngoplasty be proven. Nevertheless, the call for pulse oximetric monitoring in the immediate postoperative phase together with corresponding pre-operative observation is legitimate. Even if at this point the danger of sleep related breathing disturbances following velopharyngoplasty appears to be minimal, these preliminary results should be polysomnographically studied within the framework of a much larger test study in order to reach still more reliable conclusions and in order to intercede if necessary with counter measures in the rare individual case of breathing disturbance during sleep following velopharyngoplasty.

Auswertung von Biosignalen des Schlafs unter besonderer Berücksichtigung von Nicht-EEG-Parametern

Die Funktionen des menschlichen Korpers im Schlaf geraten zunehmend in den Blickpunkt klinischen Interesses, da die Bedeutung von schlafbezogenen Storungen fur die am Tage gefundenen Erkrankungen zunehmend erkannt wird. Die klinisch besonders bedeutsamen schlafbezogenen Atmungsstorungen machen deutlich, das neben der Aufzeichnung des konventionellen Polysomnogramms mit EEG, EOG und EMG gerade auch die sog. Nicht-EEG-Signale uberwacht werden mussen. Unter diesen nehmen die Atmungsparameter mit Atemflus, Atmungsanstrengung und Blutgasen eine herausragende Rolle ein, was durch die hohe Pravalenz schlafbezogener Atmungsstorungen begrundet ist. Aber auch das EKG, das EMG der Beine und der arterielle Blutdruck zahlen zu den Parametern, die bei einer umfassenden Polysomnographie heute nicht mehr fehlen durfen (Kurtz 1988, 1990; Penzel et al. 1991a).