Population pharmacokinetic model of cefazolin in total hip arthroplasty.

Cefazolin is an antibiotic recommended for infection prevention in total hip arthroplasty (THA). However, the dosing regimen necessary to achieve therapeutic concentrations in obese patients remains unclear. The aim of this study was to conduct a population analysis of cefazolin pharmacokinetics (PK) and assess whether cefazolin administration should be weight adapted in THA. Adult patients undergoing THA surgery received an injection of 2000 mg of cefazolin, doubled in the case of BMI > 35 kg/m2 and total body weight > 100 kg. A population PK study was conducted to quantify cefazolin exposure over time compared to the therapeutic concentration threshold. A total of 484 cefazolin measurements were acquired in 100 patients, of whom 29% were obese. A 2-compartment model best fitted the data, and creatinine clearance determined interpatient variability in elimination clearance. Our PK simulations using a 2000 mg cefazolin bolus showed that cefazolin concentrations remained above the threshold throughout surgery, regardless of weight or renal function. A 2000 mg cefazolin single injection without adaptation to weight or renal function and without intraoperative reinjection was efficient in maintaining therapeutic concentrations throughout surgery. The optimal target concentration and necessary duration of its maintenance remain unclear.

Double-blind, randomised, controlled study of post-operative pain in children undergoing radiofrequency tonsillotomy versus laser tonsillotomy.

INTRODUCTION: In the last decade tonsillotomy has come into vogue again, whereas the number of tonsillectomies is decreasing rapidly. Currently, most tonsils are reduced by utilise electrosurgery, radiofrequency or carbon dioxide laser. However, it is not clear whether radiofrequency tonsillotomy is as effective as laser or other surgical techniques in respect of post-operative pain and haemorrhage. MATERIAL AND METHODS: A prospective, randomised, double-blinded, controlled, clinical study was conducted in the otorhinolaryngology department of Ludwig Maximilians University, Munich, Germany. Twenty-six children with tonsillar hypertrophy were included. Exclusion criteria were: history of peritonsillar abscess, previous tonsil surgery, tonsillitis within two weeks, pain before surgery, psychiatric illness, asymmetrical tonsils, chronic analgesic usage, bleeding disorders and other surgical procedures during the same operation. Tonsillotomy was performed on one side with radiofrequency and on the other side with a carbon dioxide laser. All procedures were performed by a single surgeon, under general anaesthesia. A visual analogue scale was used to measure patients' pain on each side, administered by a 'blinded' nurse on the three post-operative mornings and evenings, within the hospital. RESULTS: There was no difference in post-operative pain scores or haemorrhage, comparing laser versus radiofrequency tonsillotomy. Patient's overall reported pain was very modest compared with post-tonsillectomy pain. No haemorrhage or other adverse effects were observed.

[S1 guideline on the "diagnosis and treatment of snoring in adults"]. / S1-Leitlinie "Diagnostik und Therapie des Schnarchens des Erwachsenen".

Due to the frequency of this phenomenon and the often considerable distress caused to the affected person, competent advice, diagnosis and treatment of snoring in adults is of particular importance. The aim of this guideline is to promote high-quality medical care for patients affected by this problem. According to the three-level concept of the AWMF, it corresponds to an S1 guideline. Prior to any therapeutic intervention, relevant sleep medical history, clinical examination, as well as a mandatory objective diagnostic measure are performed. Snoring is only treated if the patient asks for it. In general, invasive methods should be viewed critically and the patient should be advised correspondingly. In the case of surgical therapy, minimally invasive techniques are preferred. Reducing body weight (in the case of overweight snorers), abstinence from alcohol, nicotine and sleep medication, as well as maintaining a healthy sleep-wake cycle can be recommended from a sleep-medicine perspective, although convincing clinical studies are not yet available. Since evidence for the effectiveness of muscle stimulation or various methods for toning and training of the muscles of the floor of mouth is not available, these methods are not recommended. Snoring can be successfully treated with the use of an intraoral device; however, careful patient selection is important. Avoiding a supine position during sleep can be helpful in some cases. Only limited data is available on the success rates of the surgical approaches and long term data is often lacking, and not all techniques have been sufficiently evaluated from a scientific point of view. Nasal surgery is only indicated if the patient suffers from nasal obstruction. Extensive data supports the effectiveness of laser-assisted resection of excessive soft palate tissue (laser-assisted uvuloplasty, LAUP). In principle, however, such resections can be performed using other techniques. Placebo-controlled studies were able to prove the effectiveness of radiofrequency surgery of the soft palate. A reduction in snoring could also be achieved in many cases by means of soft palate implants with minimal post-operative morbidity. The indication for tonsillectomy and uvulopalatopharyngoplasty should be made cautiously due to the comparatively high morbidity associated with these procedures.

[Sarcoidosis of lymph nodes in the submandibular compartment]. / Lymphknotensarkoidose der Submandibularisloge.

Sarcoidosis is a granulomatous systemic disease of unknown etiology. Besides the landmark pulmonary lesions, extrathoracic manifestations of the disease can also occur. We report the case of a 53-year-old woman with an obscure swelling of both submandibular compartments. The radiological and pathohistological evaluations confirmed the uncommon diagnosis of sarcoidosis of the submandibular compartment. The tumor in each compartment consisted of a huge lymph node conglomerate respectively displacing the submandibular gland. The major salivary glands and the thorax were not involved.

[Guideline: Treatment of obstructive sleep apnea in adults]. / Leitlinie: Therapie der obstruktiven Schlafapnoe des Erwachsenen.

The current guideline discusses conservative and surgical therapy of obstructive sleep apnea (OSA) in adults from the perspective of the ear, nose and throat specialist. The revised guideline was commissioned by the German Society of Ear-Nose-Throat, Head-Neck Surgery (DG HNO KHC) and compiled by the DG HNO KHC's Working Group on Sleep Medicine. The guideline was based on a formal consensus procedure according to the guidelines set out by the German Association of Scientific Medical Societies (AWMF) in the form of a"S2e guideline". Research of the literature available on the subject up to and including December 2008 forms the basis for the recommendations. Evaluation of the publications found was made according to the recommendations of the Oxford Centre for Evidence-Based Medicine (OCEBM). This yielded a recommendation grade, whereby grade A represents highly evidence-based studies and grade D those with a low evidence base.

[Local botulinum toxin A for treating chronic sialorrhea]. / Lokale Botulinumtoxin-A-Therapie bei chronischer Sialorrhö.

BACKGROUND: Sialorrhea and drooling interfere with oral communication and nutrition, posing problems for hygiene, nursing, and social interactions. Therapeutic efforts such as swallowing therapy, systemic medications, operations, and irradiation are often insufficient or accompanied by side effects. MATERIALS AND METHODS: Ten patients with therapy-resistant sialorrhea of various etiologies were treated between 2002 and 2007 with sonography-guided botulinum toxin A (BTA) injections into the parotid and submandibular glands bilaterally. Therapeutic success was evaluated using established symptom scores, and the glandular tissue size was sonographically measured before and 3 months after injections. RESULTS: All 10 patients benefited from the BTA therapy, as shown by significant reduction of the troublesome sialorrhea. The effect lasted 6-28 weeks. On one occasion, transient xerostomia occurred. Sonographic measurements revealed no morphologic changes. CONCLUSION: BTA is an effective and safe treatment for chronic sialorrhea. The effect is reversible. It causes no sonographically detectable changes.

[Snoring: therapeutic options]. / Massnahmen gegen primäres Schnarchen. Endlich Ruhe im Schlafzimmer!

Primary snoring is mainly the bed partner's problem and not that of the snorer. The request for treatment arises from how annoying the snoring is and how sensitive the bed partner is to noise. In addition to a thorough medical history and an ENT examination, a polysomnography should be always performed to differentiate between primary snoring, upper airway resistance and obstructive sleep apnoea syndromes. Primarily weight loss and avoidance of alcohol in the evening as well as devices and surgery are used in the treatment of snoring.

[Use of pharyngeal pressure measurement to localize the source of snoring]. / Einsatz der ösophagopharyngealen Druckmessung zur Topodiagnostik des Schnarchens.

BACKGROUND: Depending on age and gender up to 60 % of the population snore regularly. As simple snoring is more a social than a medical problem, unlike OSAS, CPAP-therapy or multilevel surgery are not appropriate therapies for snoring. But alternative therapies, such as laser-assisted uvulopalatoplasty (LAUP) or uvulopalatopharyngoplasty (UPPP) address distinct sites of the pharynx. Therefore a correct identification of the snoring-source should optimise the selection of patients and improve the outcome of therapy. As there is no commonly recommended tool for identifying the snoring-source, the use of a new technique, based on pharyngeal pressure measurement, was tested. METHODS: 25 patients with suspected OSAS had standard polysomnography recordings during two nights with esophagopharyngeal pressure measurement on the second night. The pressure probe had 5 pharyngeal and 1 esophageal transducers. The curves of the pharyngeal pressure were examined for quick pressure changes superimposed on the slow pressure-changes caused by breathing. The appearance of these quick pressure changes was documented for each transducer throughout the whole night. RESULTS: The average (+/- SD) Apnea-Hypopnea-Index in the patients was 28.3 +/- 24.8. 17 patients (68 %) had an AHI of more than 10. All patients showed heavy snoring. 23 patients (92 %) showed a high frequency, sawtooth-pattern, superimposed on the slow breathing rhythm in at least one channel and in association with snoring. 91 % of the patients showed a sawtooth pattern in more than one channel, but the pattern was always more pronounced in one channel compared to others. The sawtooth-pattern of the highest amplitude was seen in the pressure curves from the velum in 56 % of the patients, from the tonsils in 24 %, and from the tonguebase in 12 % of the patients. CONCLUSIONS: Quick pressure changes from distinctive pharyngeal pressure transducers during snoring are common in OSAS patients and may indicate the source of snoring. Further investigations have to show whether this assumption is correct, and whether the quick pressure changes are also apparent in simple snorers.

[Respiratory sleep disorders: benefit from laser-surgery]. / Lasertherapie bei schlafbezogenen Atemstörungen. Am Schnarchzapfen sägen.

Laser-assisted surgery is a valid option for the treatment of respiratory sleep disorders and complements established therapies. Laser-surgery of the inferior turbinates can improve nasal obstruction and amend or eliminate primary snoring. LAUP is as well an ambulant therapeutic method for snoring, but it is leading to strong post-operative pain and should exclusively be applied to patients with small tonsils or who already underwent tonsillectomy. OSAS can be worsened by LAUP and should therefore be excluded before the operation. In childhood OSAS laser tonsillotomy leads to a distinct improvement of sleep-disordered breathing with normalisation of the sleeping profile; it is less painful than tonsillectomy and a part of the tonsil is left to continue to exercise its function in the immune system.

Pulse trains produced by phase-modulation of ultrashort optical pulses: tailoring and characterization.

In this paper, creation of pulse doublets and pulse trains by spectral phase modulation of ultrashort optical pulses is investigated. Pulse doublets with specific features are generated through step-like and triangular spectral phase modulation, whereas sequences of pulses with controllable delay and amplitude are produced via sinusoidal phase modulations. A temporal analysis of this type of tailored pulses is exposed and a complete characterization with the SPIDER technique (Spectral Phase Interferometry for Direct Electric-field Reconstruction) is presented.

Allergic rhinitis does not constitute a risk factor for obstructive sleep apnea syndrome.

Obstructive sleep apnea syndrome (OSAS) is a condition characterized by recurrent episodes of obstruction of the upper airway. The aim of this study was to evaluate whether nasal obstruction due to allergic rhinitis constitutes a risk factor for OSAS. Patients (n = 119) presenting typical symptoms of sleep apnea were tested for OSAS using polysomnography. Additionally all patients were tested in vivo and in vitro (including nasal eosinophilic cationic protein) for allergic rhinitis. Examination for allergic rhinitis revealed that 88.3% of all patients had no allergic rhinitis, whereas only 11.7% were diagnosed as allergic. No significant differences in sleeping parameters were observed between allergic and non-allergic patients. Comparison of parameters indicative of relevant OSAS (apnea-hypopnea index [AHI] > 10) revealed that 60% of non-allergic patients had relevant OSAS, compared to only 50% of allergic patients. Investigation of allergic subgroups revealed similar results: no significant differences in sleeping parameters or elevated rates of relevant OSAS parameters were observed, especially in perennial allergic rhinitis due to house dust mites. No elevated rates of allergic rhinitis were observed in the studied cohort of patients suffering from sleep apnea or OSAS. Furthermore, no significant differences in sleeping behavior or polysomnography parameters were found on comparing allergic and non-allergic patients. In summary, our data rule out allergic rhinitis as a major risk factor for OSAS.

[Obstructive sleep apnea syndrome. Which therapy for which patients]. / Obstruktives Schlafapnoesyndrom. Welche Therapie für welchen Patienten?

Obstructive sleep apnea syndrome is defined by the American Academy of Sleep Medicine as a combination of at least five obstructive events per hour of sleep and such other symptoms as daytime sleepiness, ischemic heart disease and stroke. In addition to weight reduction, the use of oral appliances, and continuous positive airway pressure (CPAP), a number of surgical interventions such as uvulopalatopharyngoplasty and maxillomandibular advancement are also available for the treatment of sleep apnea. Since no prolongation of life has yet been shown for most of the therapeutic options, treatment needs to be individualized on the basis of symptoms, clinical findings and compliance.

[Influence of nasal obstruction on sleep-associated breathing disorders]. / Nasenatmungsbehinderung und schlafbezogene Atmungsstörungen. Eine kurze Ubersicht.

BACKGROUND: The influence of nasal obstruction on sleep associated breathing disorders (SABD) and the controversial effects of surgical treatment are discussed. RESULTS: Complete nasal obstruction caused by nasal packing increases SABD, but varies from patient to patient and depends on age and individual anatomy. Especially patients with preexisting obstructive sleep apnea syndrome (OSAS) can develop severe complications. Some authors found a higher frequency of SABD in patients with nasal obstruction due to anatomical alterations, i.e. septal deviation, while others denied this connection. Major causes for the development of SABD in nasal obstruction include certain reflex mechanisms, increased negative inspiration pressure with a tendency for pharyngeal collapse, and transition to transoral breathing. Intermittent dilatation of the nasal valve using stents or tapes will lead to a decrease of nasal airway resistance and might also result in an improvement of SABD according to some studies, while others did not find any improvement. The results of controversial operative treatment in nasal airway obstruction are also described and include complete healing of high degree OSAS, improvement of sleep quality, and elimination of snoring. On the other hand, surgery might also be completely unsuccessful or even induce OSAS. CONCLUSION: As the effect of any kind of nasal operation on SABD is unpredictable from our present knowledge, the decision whether or not nasal surgery is indicated should depend on the individual situation of the patient. If OSAS is suspected, preoperative and post-operative polysomnography should be performed.