Tadao Nishimura

Endoscopic examination of obstructive sleep apnea syndrome patients during drug-induced sleep.

Sixty patients diagnosed with obstructive sleep apnea syndrome (OSAS) underwent uvulopalatopharyngoplasty (UPPP). The effects of surgery were studied based on endoscopic findings during drug-induced sleep and determination of the apnea-hypopnea index (AHI) before and after the operation. Changes in the form of the airway during sleep in the recumbent position were observed, and the role of upper airway endoscopy in the diagnosis and surgical treatment of OSAS was determined. The site of airway obstruction during sleep induced by i.v. injection of 10 mg of diazepam was classified into five types, and changes in AHI and the site of airway obstruction were compared before and after surgery. Changes in airway morphology during sleep in the supine and recumbent positions were also compared before surgery. The postoperative improvement rate was 74.4% for the soft palatal type of obstruction, 76.2% for the tonsillar type, 53.3% for the circumferential palatal type and 34.0% for the mixed type. Treatment produced excellent or good effects for the soft palatal and tonsillar types of obstruction. However, many patients with the circumferential palatal and mixed types of obstruction showed only some improvement or no change. Good airway morphology was maintained in the recumbent position by patients with the soft palatal type of obstruction. With the circumferential palatal and mixed types of obstruction, improvement can be expected from operations which include surgical treatment of the posterior pharyngeal wall or lateral funiculus, or with midline laser glossectomy. A good operative outcome can be predicted in patients showing improvement of apnea in the recumbent position preoperatively.

Genetic Characteristics and Clonal Dissemination of β-Lactamase-Negative Ampicillin-Resistant Haemophilus influenzae Strains Isolated from the Upper Respiratory Tract of Patients in Japan

ABSTRACT We evaluated the recent prevalence of antimicrobial-resistant Haemophilus influenzae isolated from the upper respiratory tracts (URT) of patients in Japan. Mutations in the ftsI gene, which encodes penicillin binding protein 3 (PBP3), and the clonal dissemination of the resistant strains were also investigated. A total of 264 H. influenzae isolates were collected from patients with URT infections. According to the criteria of the Clinical and Laboratory Standards Institute for the susceptibility of H. influenzae to ampicillin (AMP), the isolates were distributed as follows: 161 (61.0%) susceptible strains (MIC ≤ 1 μg/ml), 37 (14.0%) intermediately resistant strains (MIC = 2 μg/ml), and 66 (25.0%) resistant strains (MIC ≥ 4 μg/ml). According to PCR-based genotyping, 172 (65.1%) of the isolates had mutations in the ftsI gene and were negative for the β-lactamase (bla) gene. These 172 isolates were thus defined as genetically β-lactamase-negative ampicillin-resistant (gBLNAR) strains. The ftsI mutant group included 98 (37.1%) strains with group I/II mutations in the variable mutated region (group I/II gBLNAR) and 74 (28.0%) strains with group III mutations in the highly mutated region (group III gBLNAR). Eighty-seven (33.0%) of the isolates were genetically β-lactamase-negative ampicillin-susceptible (gBLNAS) strains. The group III gBLNAR strains showed resistance to β-lactams. Only five strains (1.9%) were positive for a bla gene encoding TEM-type β-lactamase. The three clusters consisting of 16 strains found among the 61 BLNAR strains (MIC ≥ 4 μg/ml and without the bla gene) showed identical or closely related DNA restriction fragment patterns. Those isolates were frequently identified among strains with a MIC to AMP of 16 μg/ml. The current study demonstrates the apparent dissemination and spread of a resistant clone of H. influenzae among medical centers in Japan. The gBLNAR strains show a remarkable prevalence among H. influenzae isolates, with the prevalence increasing with time. This fact should be taken into account when treating URT infections.

Posture of patients with sleep apnea during sleep

The relationship between sleep apnea syndrome (SAS) and posture during sleep has been noted and the beneficial effect of an optimal posture on sleep apnea has been empirically indicated. We investigated this effect in a group of subjects that included obese patients and found that the apnea-hypopnea index (AHI) may be normalized in the lateral position, even among patients severely affected with apnea. Among those with intermediate or lower AHI values, sleeping in a lateral position markedly improved the symptoms, with AHI even approaching the normal range in many patients. A tendency was noted for AHI to rise regardless of posture but in proportion to the increase in body mass index (BMI). In other words, the improvement due to changes in posture became increasingly insignificant with increase in BMI.

Anatomy of oral respiration: morphology of the oral cavity and pharynx.

The anatomical states of the oral cavity and pharynx during mouth breathing in children with adenoid hypertrophy and in adults confirmed the speculation that mouth breathing is disadvantageous compared with nose breathing. In addition, comparison of the anatomical state between wakefulness and sleep in normal adults showed slight depression of the tongue root and slight narrowing of the oropharynx and hypopharynx during sleep. Obstructive sleep-disordered breathing occurs due to a variety of factors, such as paranasal sinus disease, tonsil and adenoid hypertrophy, hypertrophy and morphological abnormalities of the soft palate and palatine uvula, low-set soft palate, micrognathia, macroglossia, obesity and tongue root depression. Narrowing or obstruction of the middle pharynx and hypopharynx is more marked in patients with obstructive sleep-disordered breathing than in normal people and is especially marked during sleep. Therefore, morphological (i.e. anatomical) changes during mouth breathing may provide useful information for evaluating the pathology of snoring and sleep apnea.

Obesity and obstructive sleep apnea syndrome

We investigated the influence of obesity on upper airway obstruction, especially the relationship between obesity and the type of obstruction. The site of obstruction was identified by means of endoscopic examination and dynamic MRI during sleep. Many obese patients have the circumferential type of obstruction.

Carnosine-like immunoreactivity in human olfactory mucosa.

By means of immunohistochemical techniques it is demonstrated for the first time ever that carnosine (beta-alanyl-L-histidine)-like immunoreactivity (LI) is localized in the olfactory receptor neuron in human olfactory mucosa. Carnosine-LI was found in all regions of the receptor cells, i.e. in dendrites, olfactory vesicles, soma and axons. Supporting cells and basal cells were not immunoreactive. The present results suggest that carnosine play a major role in the human olfactory neuron and supports the concept that this peptide is a putative neurotransmitter in vertebrate olfactory systems.

Two cases of sleep apnea syndrome caused by primary hypothyroidism.

Two cases of sleep apnea syndrome caused by primary hypothyroidism are reported. The first patient was a 66-year-old man who complained of sleep apnea; his apnea-hypopnea index (AHI) was 50.8, as assessed by all-night monitoring. Hypothyroidism was subsequently suspected when he showed delayed recovery from general anesthesia following surgery involving uvulopalatopharyngoplasty. Hypothyroidism was diagnosed on the basis of blood tests His snoring and apnea improved after 2 months of levothyroxine sodium administration and the AHI fell from 50.8 to 13.0. The second patient was a 73-year-old man with an AHI of 41.3, as assessed by all-night monitoring. Hypothyroidism was diagnosed on the basis of blood tests and was suspected because of his slow speech. He was similarly treated with levothyroxine sodium. The AHI did not decrease after 4 months of treatment. His desaturation rate (rate of O2 saturation < 90%) improved however, from 56.6% to 31.9%, and the symptoms of hypothyroidism also improved markedly. In both patients, elevated creatine phosphokinase, a dull facial expression, peripheral edema and slow speech were recognized, and these symptoms were suggestive of hypothyroidism. The type of sleep apnea was mainly obstructive in both patients.

Laser midline glossectomy and lingual tonsillectomy as treatments for sleep apnea syndrome.

Preservation treatments for sleep respiratory disorders, such as the use of a dental device and the technique of nasal continuous positive air pressure, cause discomfort to the patient and are not radical treatments. Therefore, we performed operative therapy instead. Laser midline glossectomy was performed to treat constriction at the root of the tongue in 16 patients diagnosed with sleep apnea syndrome. We also tried lingual tonsil excision using the Harmonic Scalpel in three patients with stenosis at the base of the tongue.

Obstructive sleep apnea syndrome in children.

Obstructive sleep apnea syndrome (OSAS) in children is often caused by obstruction of the upper airway due to hypertrophy of the adenoids and palatine tonsils. Between October 1988 and December 1991, 50 children (34 males, 16 females) visited our department due to attacks of sleep apnea and underwent adenotomy or adeno-tonsillectomy. Respiratory monitoring during sleep was performed before and after operation, and the usefulness of the surgery was evaluated. Before operation, 27/ 50 children (54.0%) were diagnosed as having OSAS. Their age distribution showed peaks at the ages of 4 and 5 years and the male:female ratio was 2:1. Concerning the degree of improvement in clinical symptoms after surgery, marked effects were observed in 40/50 patients (80.0%), moderate effects in 7 (14.0%) and slight effects in 3 (6.0%). Concerning the degree of improvement in the apnea index after surgery in the 27 patients with OSAS, marked effects were observed in 22 patients (81.50%), moderate effects in 2 (7.4%), slight effects in 1 (3.7%) and no change in 2 (7.4%).

Application of lingual tonsillectomy to sleep apnea syndrome involving lingual tonsils.

In sleep apnea syndrome, surgical treatment is applied in obstructive-type cases and some mixed-type cases. If the obstructive part is in the root of the tongue, forward transfer of the tongue, lingual tonsillectomy and laser midline glossectomy are applied. In this study, we demonstrate the surgical technique of lingual tonsillectomy using an ultrasonic coagulating dissector (SonoSurg) with a blade tip shape developed in our department. We conclude that lingual tonsillectomy using SonoSurg, which we have frequently used, should be the first choice of treatment for snoring and sleep apnea caused by hypertrophy of the lingual tonsils from the viewpoints of effectiveness, prevention of hemorrhage, safety and handling.