Safe and reliable sound threshold measures with direct vibration of the ossicular chain

OBJECTIVES: The aim of the study was to evaluate the safety and feasibility of piezoelectric malleus vibration audiometer (MVA), which presents micromechanical vibrations to the umbo membranae tympani. STUDY DESIGN: Phase I study performed in a tertiary referral center (University Hospital). METHODS: The coupling rod of the MVA was moved slowly through the outer ear canal toward the eardrum with a micromanipulator. Coupling was completed when the rod tip touched the umbo membranae tympani. Basic audiologic measures of sound threshold obtained with direct stimulation of the malleus are presented. We used MANOVA (multivariate repeated measures ANOVA) to investigate the repeatability of MVA thresholds from one day to the other and when decoupling and retracting the coupling rod 2 mm off the umbo. We also selected the MANOVA to test for unwanted bone-conduction threshold shifts after MVA application. We assessed normality of the data by quantile-quantile plots of the residuals. RESULTS: Twenty-eight male and 10 female subjects with normal hearing, 22.2 to 34.6 years old (median age, 27.2 yr) underwent an examination. Thirty-six subjects underwent MVA, because 2 of the 38 subjects who volunteered for the study have not undergone the procedure due to the external auditory canal anatomy preventing application of the MVA. The results show that it is possible to safely and reliably measure thresholds of direct vibration of the ossicular chain. Using pure tone audiograms, no pure tone bone- and/or air-conduction threshold shifts occurred after the procedure. None of the subjects reported any other ear-related symptoms such as vertigo, tinnitus, or dizziness. Geometric mean vibratory displacements at threshold ranged from 0.55 nm at 250 Hz to 0.03 nm at 6 kHz. MANOVA demonstrated a repeatability of MVA thresholds. CONCLUSION: Malleus vibration audiometry will not allow exact linkage of actual implantable hearing aid. But the present study demonstrates that MVA can provide an audiometric tool for assessing ossicular function and integrity prior to implantation of an electronic hearing amplifier.     

Microsurgical free flap reconstruction outcomes in head and neck cancer patients after surgical extirpation and intraoperative brachytherapy

OBJECTIVES: The management of recurrent or persistent head and neck cancer poses a challenging problem. Salvage surgery for these individuals consists of ablative surgery, interstitial brachytherapy, and microsurgical free flap reconstruction. This study reviews complications after such reconstruction. METHODS: We reviewed 139 consecutive head and neck cancer patients undergoing free flap reconstruction from January 1994 to May 2002. These included 66 patients with recurrent head and neck cancer undergoing intraoperative brachytherapy (IOBT) and free flap reconstruction and 73 undergoing free flap reconstructions only. A total of 142 reconstructions were performed, with three patients in IOBT group receiving two free flap reconstructions per patient, giving us a total of 69 reconstructions in the IOBT group versus 73 in the non-IOBT group. Nine patients were excluded from the IOBT group because of nonsynchronous use of brachytherapy and reconstruction, and 10 patients were excluded from the other group because they had prior radiotherapy or surgical treatment, leaving us with a total of 123 reconstructions, 60 in the IOBT group and 63 in the non-IOBT group. The IOBT group patients received iodine Vicryl seed implants, palladium seed implants, or both, to deliver an average dose of 79.3 +/- 31.8 Gy (mean +/- 1SD) to the surgical bed. RESULTS: All patients were followed for evidence of local wound complications. The IOBT group showed multiple complications in 23 (38.33%) of 60 reconstructions, the most common being wound dehiscence in 11. This, when compared with the non-IOBT group complications (15.87%), was found to be statistically significant (chi test, P <.01). CONCLUSION: IOBT increases the rate of complications in patients undergoing microvascular free tissue transfer. This, however, should not deter or alter the aggressiveness of cancer therapy used for managing recurrent head and neck cancer.     

Airway colonisation in long-term mechanically ventilated patients

Objective To evaluate the impact of continuous subglottic suctioning and semi-recumbent body position on bacterial colonisation of the lower respiratory tract.Design A randomised controlled trial.Setting The ten-bed medical ICU of a French university hospital.Patients Critically ill patients expected to require mechanical ventilation for more than 5 days.Interventions Patients were randomly assigned to receive either continuous suctioning of subglottic secretions and semi-recumbent body position or to receive standard care and supine position.Measurements and results Oropharyngeal and tracheal secretions were sampled daily and quantitatively cultured. All included patients were followed up from day 1 (intubation) to day 10, extubation or death. Ninety-seven samples of oropharynx and trachea were analysed (40 for the suctioning group and 57 for the control group). The median bacterial counts in trachea were 6.6 Log₁₀ CFU/ml (interquartile range, IQR, 4.4–8.3) in patients who received continuous suctioning and 5.1 Log₁₀ CFU/ml (IQR 3.6–5.5) in control patients. Most of the patients were colonised in the trachea after 1 day of mechanical ventilation (75% in the suctioning group, 80% in the control group). No significant difference was found in the daily bacterial counts in the oropharynx and in the trachea between the two groups of patients.Conclusion Tracheal colonisation in long-term mechanically ventilated ICU patients was not modified by the use of continuous subglottic suctioning and semi-recumbent body position.     

Corticotropin-releasing hormone (CRH) in psychiatry: from stress to psychopathology

Corticotropin-releasing hormone (CRH) plays a central role in the adaptation of the organism to stress. It serves as the main regulating hormone of the hypothalamic pituitary adrenal (HPA) axis, which is activated within seconds after exposure to acute stress. Furthermore, it acts as a neurotransmitter in numerous other brain regions. Globally, CRH leads to a number of metabolic, neuroendocrine and autonomic adaptations, which are vitally important for an adequate reaction to acute stress, but can lead to pathological somatic and psychological effects in chronic stress situations. The adequate functioning of CRH is a delicate equilibrium, which can be permanently disturbed by early experiences of physical or sexual abuse, leading to psychopathology in adulthood. This review discusses the physiological functions of CRH as the stress response hormone. Subsequently, the emerging data on the disruptive effects of early trauma on the CRH system are summarized. The third part is devoted to CRH and HPA axis abnormalities in major depression and other psychiatric disorders. This rapidly accumulating evidence will change our understanding of psychopathology, and might challenge the established classification of psychiatric disorders.     

The effect on cartilage of different forms of application of postmenopausal estrogen therapy: comparison of oral and transdermal therapy

The effect on urine C-telopeptides of type II collagen (uCTX-II) of oral and transdermal estradiol treatment was compared using samples from two randomized, double-blind, placebo-controlled trials. A total of 171 healthy, Danish postmenopausal women, 45-65 years of age completed the 2-year study periods. The uCTX-II marker assessed cartilage degradation, and this response was compared with the effect on urine C-telopeptides of type I collagen (uCTX-I), considered a specific marker of bone resorption. Doses in the oral estradiol treatment groups (continuous combined therapy) were 1 mg 17-beta-estradiol+1 mg drosperinone or 1 mg 17-beta-estradiol+2 mg drosperinone or 1 mg 17-beta-estradiol+3 mg drosperinone or placebo. Doses in the transdermal estradiol treatment groups (continuous combined therapy) were 45 microg 17-beta-estradiol+30 levonorgestrel or 45 microg 17-beta-estradiol+40 microg levonorgestrel or placebo. The effect of oral and transdermal estradiol therapy on cartilage degradation was reflected as a decrease of 19-30% in uCTX-II (P=0.02 and P=0.003 vs. placebo) after 1 year of treatment. uCTX-I decreased 70% (P<0.0001 vs. placebo) reflecting a pronounced effect on bone resorption that was consistent with a 2-year increase in spine and hip BMD of 7-8% and 4-6%, respectively. The results indicate that different regimens of postmenopausal HRT both have an effect on cartilage and bone thus protecting against osteoporosis and osteoarthritis (OA). However, long-term clinical trials are needed to further investigate this issue.