Globus pharyngeus due to a lymphangiomatous polyp arising from the tonsil

INTRODUCTION

Lymphangiomatous polyp of the tonsil is generally accepted as a hamartomatous lesion. Its differential diagnosis includes fibroepithelial polyp, squamous papilloma, angiofibroma, haemangioma, arteriovenous malformation, hamartoma and lymphangioma.

CASE REPORT

A 33-year-old man presented with 2 months history of feeling of foreign body sensation in the throat. Examination revealed a nodular red coloured polyp on the left tonsil. Histologically, the polyp was covered by squamous epithelium and is composed of numerous vascular channels containing lymphocytes and eosinophilic material, in a fibrous stroma. Immunohistochemically, the endothelial cells were positive toward CD31 and D2-40.

DISCUSSION

The characteristic histological features of a lymphangiomatous polyp are benign vascular proliferation with variable fibrous, adipose and lymphoid stromal components. Nested intraepithelial epidermotropism of lymphocytes can be observed. The vascular channels are typically thin-walled and contain eosinophilic proteinaceous material and lymphocytes. There is no reported incidence of recurrent or malignant transformation.

A Comparison of the GlideScope® with the Macintosh Laryngoscope for Tracheal Intubation in Patients with Simulated Difficult Airway

We compared the use of the GlideScope® and the conventional Macintosh laryngoscope in a simulated difficult airway. The primary hypothesis was that time to intubation would be shorter using the GlideScope® than using the Macintosh laryngoscope.

After obtaining approval from the ethics committee and written informed consent, we recruited 60 ASA 1 and 2 patients to our randomized controlled trial. Group G (n=30) had tracheal intubation performed using the GlideScope® and Group M (n=30) were intubated using a Macintosh laryngoscope. We simulated a difficult airway in each patient by having an experienced assistant provide in-line manual stabilization of the head and neck. We recorded the best laryngeal view; difficulty of the tracheal intubation; time taken for successful tracheal intubation; manoeuvre needed to aid tracheal intubation and complications associated with the tracheal intubation.

The median Cormack and Lehane grade was significantly better in Group G than Group M. Group G had a significantly shorter intubation time than group M (mean 41.8s±SD 20.2 vs mean 56.2s±26.6, P<0.05).

The GlideScope® improved the laryngeal view and decreased time for tracheal intubation time when compared with the Macintosh laryngoscope in patients with simulated difficult airway. The GlideScope® may be a good alternative for managing the difficult airway but clinical trials evaluating its use on patients with an actual difficult airway are needed.

Comparative study of new autologous material, bone-cartilage composite graft, for ossiculoplasty with Polycel® and Titanium

OBJECTIVE

Ossiculoplasty is a surgical procedure that recreates sound transmission of the middle ear in conductive hearing loss. Various materials have been used for ossicular reconstruction, but the most ideal material for ossiculoplasty remains controversial. The purpose of this study was to introduce a novel method of autologous ossiculoplasty, bone-cartilage composite graft (BCCG) and to compare its surgical results with different types of ossiculoplastic prostheses.

STUDY DESIGN

A retrospective study was performed in a tertiary referral centre.

METHODS

Data of 275 patients who received ossiculoplasty using the three different materials of BCCG, Polycel^® and titanium were analysed according to type of ossiculoplasty: partial or total ossicular replacement prosthesis (PORP or TORP). Hearing results, complication rates and clinical parameters including age, sex, past history, preoperative diagnosis and surgery type were compared among different groups.

RESULTS

Ossiculoplasty with BCCG showed satisfactory hearing outcomes and the lowest complication rate among the three different materials. In particular, its extrusion rate was 0%.

CONCLUSION

We propose that the BCCG technique is a useful alternative method for ossiculoplasty, with proper patient selection.

Clinical and biochemical factors that affect DPOAE expressions in children with middle ear effusion

OBJECTIVES

To evaluate the clinical and biochemical characteristics of middle ear effusion (MEE) that affect distortion product otoacoustic emissions (DPOAE) responsiveness and to investigate the possible role of DPOAE as a tool to know the characteristics of MEE preoperatively.

STUDY DESIGN AND SETTING

Prospective analysis of children with MEE effusion in a tertiary referral center. DPOAE results were compared with other audiologic tests, the character, amount of MEE, the amount of total protein, and TNF-alpha in the effusion.

RESULTS

The negative DPOAE with MEE group had much more thick mucous fluid in their middle ears than that of positive DPOAE with MEE group. The levels of total protein and TNF-alpha in MEE were significantly higher in the negative DPOAE group than those of the positive DPOAE group (P < 0.01).

CONCLUSIONS AND SIGNIFICANCE

The measurement of DPOAE in the children with MEE may predict the amount and the characteristics of MEE, which may help to decide the treatment methods.

Serum heat shock protein 70 and its correlation with clinical characteristics in patients with sudden sensorineural hearing loss

OBJECTIVES

Previous studies have reported that in cochlear cells, heat shock protein (HSP)70 is expressed after ototoxic stimuli. We performed this study to investigate the possibility of HSP70 being found in circulation and to observe its possible clinical role in patients with sudden sensorineural hearing loss (SSNHL).

METHODS

A total of 67 patients with SSNHL and age-sex matched normal controls were included in this study. Their serum HSP70 levels were measured with highly sensitive enzyme-linked immunoadsorbent assay (ELISA) test and confirmed with Western blot immunoassay. Clinical variables including initial and final audiometric findings and accompanying symptoms were analyzed to find the possible clinical value of serum HSP70 level in the patients with SSNHL.

RESULTS

Serum HSP70 levels were significantly higher in the patients with SSNHL than those of normal controls by ELISA test (P < .01), and their presence were confirmed as strong bands in the Western blot assay. There was significant correlation between serum HSP70 levels and the recovery of HL in the patients with SSNHL (P < .01).

CONCLUSION

This is the first report showing elevated serum HSP70 levels in the patients with SSNHL compared with normal controls. We suggest that serum HSP70 levels might have a clinical role for predicting prognosis of HL in the patients with SSNHL.

A BIS-guided study of sevoflurane requirements for adequate depth of anaesthesia in Caesarean section

Caesarean section carries a high risk of awareness, especially in the period prior to neonatal delivery. We investigated the concentration of sevoflurane required to maintain bispectral index (BIS) < 60 until delivery occurred. We enrolled 23 parturients into an up-down sequential allocation study. The median effective end-tidal concentration (EC(50)) of sevoflurane was defined as that which maintained BIS < 60 between skin incision and delivery in 50% of patients. This was calculated using Dixon and Massey's method. Receiver operating characteristic curve analysis was used to establish BIS response probability thresholds. The EC(50) for sevoflurane was 1.22% (1.08-1.33, 95% CI). The probability of maintaining BIS < 60 was < 55% at a concentration of < 1.1%; this increased to 80% at concentrations of 1.2-1.3%. We conclude that sevoflurane concentrations of at least 1.2-1.3% should be administered in uncomplicated Caesarean section, so as to minimise the risk of awareness and recall.

General anesthesia for cesarean section in a Singapore maternity hospital: a retrospective survey

We conducted a retrospective study of all cases of cesarean section at the KK Women's and Children's Hospital over a one-year period from September 1, 2002 to August 31, 2003, with the aim of evaluating current anesthetic practice. These cases were identified using hospital databases and relevant data was extracted from clinical notes. There were 14244 deliveries during the study period with a cesarean section rate of 25.2% (3583 cases). Of these, 20.4% (732 cases) were performed under general anesthesia. Maternal request was the chief reason for general anesthesia, especially among elective cases. Regional block failure accounted for 16% of the general anesthesia cases performed or 4.0% of the total regional techniques attempted. Regional block failure rate was highest for emergency cases in which an indwelling labor epidural catheter was used to provide surgical anesthesia via a bolus top-up. General anesthesia still has a definite place for cesarean delivery despite the predominant use of regional techniques in our institution.

Immunohistochemical localization of urea transporters A and B in the rat cochlea

Urea is present in the inner ear, and when it is administered, induces rapid changes in the volume and osmolality of the inner ear fluid. However, the regulating mechanisms are unknown. Two groups of urea transporters (UTs), the renal urea transporter (UT-A) and the erythrocyte urea transporter (UT-B) have been cloned recently. The aims of the current study were to investigate the cellular localization of UTs in the cochlea of male Sprague-Dawley rats by immunohistochemistry. Both UT-A1 and UT-B were expressed in the inner and outer pillar cells, inner and outer hair cells, Boettcher's cells, and Deiters' cells in the organ of Corti. Immunoreactivity for UT-A3 was localized only in the mesothelial cells underlying the basilar membrane. In the stria vascularis, UT-A1 was expressed only in the marginal cells, whereas UT-B was expressed only in the basal cells. In the spiral ganglion, most cells had strong UT-A1 immunoreactivity whereas UT-B was not expressed. In the spiral limbus, UT-B was expressed in the interdental cells whereas UT-A was not expressed. In the crista ampullaris, UT-A1 was expressed in the dark cells, and UT-B expressed in the apical membrane of supporting cells in the neuroepithelium. The distribution of UT-A and UT-B in the inner ear suggests that the cells that surround the inner ear fluids may be involved in urea transport and thus play an important role in fluid homeostasis in the inner ear. The expression of UT-A and UT-B in the hair cells raises the possibility that UTs may be involved in volume regulation in these cells and mediate hair cell turgor.

Superoxide dismutase in pediatric palatine tonsils and adenoids and its related clinical parameters

PURPOSE

The objective of this study was to investigate a protective system of pediatric palatine tonsils and adenoids against superoxide radicals (O(2)(-)) and to evaluate the clinical factors including otitis media with effusion that are related to both the expression and activities of copper zinc superoxide dismutases (CuZnSODs).

DESIGN

CuZnSODs in the palatine tonsils and adenoids were studied using immunohistochemistry and reverse-transcription polymerase chain reaction.

RESULTS

Immunohistochemistry showed that CuZnSODs distribute in the crypt epithelium, mucous membrane, mantle zone, and extrafollicular area of the pediatric adenoids as well as in the palatine tonsils. Otitis media with effusion and paranasal sinusitis were related to CuZnSODs expression in the pediatric adenoids. In addition, the frequency of tonsillitis and presence of recent tonsillitis were significantly related to CuZnSODs expression in the pediatric tonsils (P <.05).

CONCLUSIONS

In both the pediatric palatine tonsils and adenoids, the mechanism of tissue protection against infection and frequent inflammatory reactions may be closely related to CuZnSODs expression. There may be close relationship between the increased level of O(2)(-) that leads to an increase in CuZnSODs in the pediatric adenoid tissue and the development of otitis media.

Effects of testosterone in the treatment of immune-mediated sensorineural hearing loss

Testosterones have beneficial effects not only on the modulation of expression of autoimmunity of B/W mice, but on other unrelated models such as autoimmune thyroiditis as well. This study was performed to evaluate the effect of testosterone in the treatment of immune-mediated sensorineural hearing loss (IMSNHL). To induce IMSNHL, 29 female Wistar rats were sensitized with bovine inner ear antigen three times weekly. Fourteen of 29 rats were injected subcutaneously three times a week with 250 microg of testosterone propionate from 1 week prior to the first sensitization to 1 week following the second booster sensitization. An auditory brain-stem response (ABR) test was performed prior to each antigen challenge and at 1, 2, 3, 4, 6 and 8 weeks following sensitization. On ABR testing, the testosterone-treated animals showed better results than the control animals with IMSNHL in the degree of hearing loss (10 to 20 dB vs. 10 to 40 dB) and incidence of hearing loss over 20 dB (25.0% vs. 53.3%). None of testosterone-treated animals showed a hearing loss over 20 dB, whereas 40% of the control animals with IMSNHL revealed hearing loss over 20 dB. These results suggest that testosterone propionate may be effective in the prevention of and early recovery from IMSNHL and may be used in the future as a one treatment modality for IMSNHL.

Prognostic value of otoacoustic emissions in children with middle ear effusion

The amplitude and frequency spectra of otoacoustic emissions are influenced by the condition of the middle ear. These are noninvasive measurements of cochlear function that are accurate, rapid, and simple to perform. In this study, prognostic value of otoacoustic emissions in children with middle ear effusion (MEE) was investigated. A total of 49 children aged 3.5 to 11.2 years with MEE were included. Spontaneous otoacoustic emission, transient evoked otoacoustic emission (TEOAE), and distortion product (DP) otoacoustic emission measurements were performed on each ear before medical treatment and were compared according to the responsiveness of medical treatment (medicine responder vs medicine nonresponder groups). Responses of spontaneous otoacoustic emissions and DP audiogram showed no significant difference between the 2 groups but TEOAE response was significantly decreased in medicine nonresponders ( P > 0.05). Positive responses of the DP Input-Output function curve in geometric mean frequencies at 5 and 6 kHz using a primary tone of 55 dB SPL were significantly detected in medicine responders ( P > 0.01). The sensitivity, specificity, and predictive values of TEOAE and the DP I-O function curve in geometric mean frequency at 6 kHz using a primary tone of 55 dB SPL showed the high prognostic value of these tests in terms of predicting response to medical treatment in the patients with MEE. This suggests that otologists may have to be more aggressive in their treatment of children with MEE who showed no response.

Influence of human leukocyte antigen in the pathogenesis of Ménière's disease in the South Korean population

In order to study the associations of Ménière's disease (MD) with human leukocyte antigen (HLA) alleles in the South Korean population, we examined the distribution of HLA class I and II alleles in 39 MD patients and 199 healthy controls. The frequencies of HLA-Cw*0303 (relative risk (RR) = 2.5; p < 0.02) and -Cw*0602 (RR = 3.7; p < 0.03) were significantly increased in patients with MD compared to controls. However, HLA-B44 (RR = 0.2, p < 0.004) and -Cw*0102 (RR = 0.3; p < 0.03) were significantly decreased in patients compared to controls. When the association between hearing level and the presence of HLA alleles was evaluated, the frequencies of HLA-B13 (RR = 7.4; p < 0.004), -B39 (RR = 45.7; p < 0.003), -Cw*0303 (RR = 4.5; p < 0.02) and -Cw*0602 (RR = 6.5; p < 0.02) were significantly increased and those of -B44 (RR = 0.1; p < 0.02) and -Cw*0102 (RR = 0.1; p < 0.03) were significantly decreased in MD patients with hearing losses (stages II-IV) compared to controls. The frequency of HLA-B13 was significantly higher in MD patients with hearing loss (stages II-IV) than in those with normal hearing (stage I). In terms of HLA-DRB1, -DQA1 and -DQB1 allele frequencies, a significantly higher frequency of DRB1*15 was seen in the patients (RR = 2.4; p < 0.03). These results suggest that some HLA alleles may be a useful genetic marker for predicting prognosis in South Korean patients with MD.

Effect of middle-ear effusion on otoacoustic emissions

Because otoacoustic emissions (OAEs) are transmitted from the cochlea to the ear canal via the middle ear, the transmission properties of the middle ear directly influence OAEs' characteristics. In general, middle-ear effusion (MEE) reduces measured emission amplitudes and sometimes eliminates the response entirely. The purpose of this study was to establish the relationship between the conduction of the middle ear and OAEs' properties and to elucidate the effect of middle-ear effusion on detecting OAEs. Spontaneous otoacoustic emissions (SOAEs), transiently evoked otoacoustic emissions (TEOAEs) and distortion product otoacoustic emissions (DPOAEs) were recorded from 44 normal ears and 32 ears with middle-ear effusion. DPOAEs were collected in two basic forms consisting of distortion product audiograms (DP grams) and input-output (I-O) functions, elicited by two primary tones F1 and F2 and varying geometric mean frequencies between 1-6 kHz. The results of air and bone conduction hearing levels in pure tone audiogram were also analysed. In 21 ears out of 32 otitis media with effusion (OME) ears, SOAEs were absent. In the 28 ears with middle-ear effusion, the response and wave reproducibility were diminished, and in the 17 ears with middle-ear effusion, the DP gram was diminished or eliminated. In particular, I-O function curves at 3 kH and 4 kHz were diminished by the primary tones of 45 and 55 dB under the condition of MEE. The SOAEs, TEOAEs and DPOAEs (DP gram and I-O function curve) are highly reliable and useful tests for monitoring changes in middle-ear condition in children with OME and in predicting the course of OME.

Effects of antibiotics and steroid on middle ear mucosa in rats with experimental acute otitis media

The prevention of mucosal changes induced by experimental pneumococcal otitis media by means of antibiotics has been demonstrated previously. However, the effect of combined antibiotic and steroid therapy on the middle ear mucosa in acute otitis media (AOM) has not been determined. The right middle ears of 27 rats were inoculated with a log-phase type 3 Streptococcus pneumoniae, with the left ears serving as controls. Penicillin G was administered to nine rats and penicillin G and dexamethasone in combination were administered to nine rats after bacterial challenge; the remaining nine rats were not treated. Three animals from each group were sacrificed on Days 4, 7 and 14 after challenge. Tympanic membranes and middle ear mucosa were examined using otomicroscopy and light microscopy. Structural changes were diminished in both the antibiotic-treated and antibiotic + steroid-treated groups, compared with those in the untreated infected controls. The antibiotic + steroid-treated group showed the most marked decrease in structural change, especially in the mucosal metaplasia to the secretory epithelium. The results suggest that combination therapy with antibiotics and steroid in AOM is the most effective at reducing the treatment period and preventing persistent mucosal changes, which may decrease the risk of development of secretory otitis media as a sequela of AOM.

Effect of inhibitor of tumor necrosis factor-alpha on experimental otitis media with effusion

Tumor necrosis factor (TNF)-alpha is important in the pathogenesis of otitis media with effusion (OME). The purpose of this study was to determine the effect of TNF-alpha antagonist on the outcome of lipopolysaccharide (LPS)-induced OME in rats. Otitis media was induced by injecting Pseudomonas aeruginosa LPS transtympanically. Another (combination) group was pretreated with TNF-alpha antagonist, soluble TNF receptor type I (sTNF RI), before transtympanic injection of LPS. Saline and phosphate-buffered saline solutions were used as controls. Twelve hours after the transtympanic injection, otoscopic examination and aspiration of middle ear effusion (MEE) were done. The temporal bones in each group were examined histopathologically, and the vascular permeability of the middle ear mucosa was measured by the Evans blue vital dye technique. In the LPS and combination groups, MEE developed in 90% and 0% of ears, respectively. The combination group showed less inflammation, less mucosal thickening, and significantly decreased vascular permeability as compared to the LPS group. Transtympanic administration of sTNF RI appears to suppress the development of LPS-induced OME. This study suggests that TNF-alpha antagonist, along with antibiotics, may have an adjunctive role in the future treatment of MEE.

Different distribution of HLA class II alleles according to response to corticosteroid therapy in sudden sensorineural hearing loss

OBJECTIVE

To investigate the association of HLA class II alleles with the susceptibility to sudden sensorineural hearing loss and with the results of corticosteroid treatment in the Korean population.

DESIGN

HLA-DRB1, -DQA1, -DQB1, and -DPB1 genotyping by the sequence-specific oligonucleotide probes method in 41 patients with sudden sensorineural hearing loss and in 206 healthy control subjects. Initial hearing levels at the onset of hearing loss and final hearing levels after treatment were evaluated for the association with HLA class II alleles.

SETTING

Tertiary care referral center, ambulatory and hospitalized care.

SUBJECTS

Forty-one patients (24 men and 17 women; mean age, 49.2 years) were compared with 206 controls. Patients were divided into 2 groups according to their response to corticosteroid therapy (good response vs nonresponse).

RESULTS

The frequencies of HLA-DRB1, -DQA1, -DQB1, and -DPB1 alleles were not significantly different between patients and controls (P>.05). When an association between the results of corticosteroid treatment and the frequency of HLA alleles was evaluated, the frequencies of HLA-DRB1*14 (relative risk [RR] = 3.5, P<.02), -DQA1*03 (RR = 4.2, P<.02), and -DQA1*05 (RR = 3.1, P<.03) were significantly increased, but HLA-DQA1*01 (RR = 0.2, P<.004) and -DQB1*06 (RR = 0.2, P<.009) were decreased in the group nonresponsive to corticosteroid therapy, compared with the controls. The distribution of HLA-DQA1*01 (P<.04), -DQB1*06 (P<.02), and -DQA1*03 (P<.003) was significantly different between the responsive and the nonresponsive groups. HLA-DQA1 allelic combination analysis showed that the frequencies of DQA1*03 and *05 had a high RR value in patients with sudden sensorineural hearing loss (RR = 4.1, P<.003) and in patients in the nonresponsive group (RR = 8.9, P<.001), compared with the controls.

CONCLUSION

The presence of HLA class II alleles may be a useful genetic marker in forecasting a prognosis in Korean patients with sudden sensorineural hearing loss.

Effect of tumor necrosis factor-alpha on experimental otitis media with effusion

OBJECTIVES/HYPOTHESIS

Up to the present, many reports have demonstrated that local immune response is associated with maintenance and persistence of effusion in the middle ear cavity. Resulting retention of inflammatory cells and mediators in the middle ear results in ongoing effusion. The purpose of this study was to clarify the role of tumor necrosis factor in experimental otitis media with effusion, which was induced by transtympanic injection of tumor necrosis factor in the rats.

STUDY DESIGN

Four groups were designed in two experiments. The purpose of experiment 1 was to confirm that transtympanic injection of TNF-alpha produces the middle ear effusion. In experiment 2, TNFsolRI was used to evaluate the possibility as an inhibitor in otitis media with effusion.

METHODS

The histopathological changes were observed under light microscope, and the changes in microvascular permeability were examined using Evans blue vital dye technique.

RESULTS

Middle ear effusion was developed in 70% of specimens, and histopathological changes, such as subepithelial edema and marked infiltration of neutrophils, were present in 100% at 24 hours after administration of tumor necrosis factor-alpha through transtympanic approach. Extravasation of Evans blue dye was found in all specimens injected by tumor necrosis factor-alpha, which was qualified using a fluorescence microscope and quantified using a spectrophotometer. These histopathological findings and changes in microvascular permeability were significantly reduced by tumor necrosis factor soluble receptor type I.

CONCLUSIONS

Neutrophil infiltration, subepithelial edema, increased microvascular permeability, and resultant effusion were indirectly proved to be induced by tumor necrosis factor-alpha. We hope that this study may contribute to understanding the role of tumor necrosis factor-alpha in otitis media with effusion and clarifying the future role of tumor necrosis factor soluble receptor type I in preventing otitis media with effusion.

The clinical evaluations of pathophysiology for congenital middle ear cholesteatoma

PURPOSE

Congenital middle ear cholesteatoma (CMEC) is less common than the acquired variety. Many theories have been put forward to explain the pathophysiology of CMEC; however, none of them have been convincingly proven thus far. This clinical study was performed to analyze the case reviews; assess the characteristic features of CMEC, and evaluate the correlation between those features and the pathophysiology of CMEC.

METHODS

The medical records of patients who underwent otologic procedures at the hospitals of the Catholic University, Seoul, Korea, from January 1993 to November 1998 have been reviewed.

RESULTS

Of the 14 patients, 3 had cystic lesions isolated to the anterosuperior quadrant of the mesotympanum. The lesions were easy to remove and did not affect the patients' hearing. Eleven patients had more extensive disease with posterior mesotympanum involvement; the lesions were large, were often too extensive to indicate a formative site, and caused ossicular damage.

CONCLUSION

CMEC manifests in 2 distinctive forms according to the formation site. This distinctive formation site suggests that the pathophysiology of posterior lesions may be different from that of anterior ones. For early diagnosis of CMEC, a screening program should be established for children to prevent more extensive disease.

Obstetric admissions to the intensive therapy unit of a tertiary care institution

INTRODUCTION

Between 0.1% and 0.9% of women develop pregnancy complications which require admission to an intensive therapy unit. The aim of this study was to review all obstetric admissions to the intensive therapy unit at the KK Women's and Children's Hospital from 1998 to 1999 with respect to indications for admission, interventions employed and clinical outcome.

METHOD

The medical records of all obstetric patients admitted to the intensive therapy unit during the 2-year period were analysed retrospectively. Subjects were included if they were admitted during pregnancy up to 42 days postpartum.

RESULTS

There were 31,725 deliveries in our hospital during the study period of which there were 239 admissions to the intensive therapy unit. Of these, 42% were Malays, 41% Chinese, 12% Indians and 5% other races. 65% stayed 1 day, 24% 2 days, 7% 3 days and 4% more than 3 days. The patients' ages ranged from 18 to 44 years. The indications for admission were hypertension (50%), haemorrhage (24%), respiratory insufficiency (10%), neurological problems (11%) and sepsis (3%). Intervention-wise, 43% of patients required vasoactive infusions, 35% had arterial line placement, 22% central venous pressure monitoring, 21% ventilatory support and 2% pulmonary artery catheter placement. The maternal mortality and stillbirth rates were 1.3% and 3.7% of intensive therapy unit admissions, respectively.

CONCLUSION

The admission rate to the intensive therapy unit in our institution was 0.73% of all deliveries during the 2-year study period. Hypertensive disease and haemorrhage were the predominant admitting diagnoses.

Distribution of HLA-A, -B and -DRB1 alleles in patients with sudden sensorineural hearing loss

This study was performed to investigate the association between human leukocyte antigen (HLA) and susceptibility to sudden sensorineural hearing loss in the Korean population. HLA-A and HLA-B typing using a standard microlymphocytotoxicity technique and HLA-DRB1 genotyping were performed in 35 patients with sudden sensorineural hearing loss and in 206 healthy controls. Prednisone (usual dose 60 mg/day) was administered for 6 days and tapered for an additional 4-6 days. Both initial hearing levels at the onset of deafness and final hearing levels after treatment were examined and evaluated for association with HLA alleles. The frequency of HLA-DRB1*14 was increased in patients with sudden sensorineural hearing loss compared with controls (relative risk [RR] = 2.7, p = 0.016). The frequencies of HLA-A2, -A31, -B52, -B61, -DRB1*04, -DRB1*11 and -DRB1*12 were slightly higher than in the controls, but did not reach statistical significance. When an association between the treatment results and HLA alleles was also evaluated, the frequency of HLA-DRB1*04 was found to be increased in the patients who did not respond to steroid treatment compared with both patients who responded well to steroid (50%, vs 16%, p = 0.034) and controls (RR = 3.0, p = 0.046). These results suggest that there is an association between HLA-DRB1*14 and disease susceptibility and that the presence of HLA-DRB1*04 may be an useful marker for predicting a poor prognosis in Korean patients with sudden sensorineural hearing loss.

Effects of platelet-derived growth factor-AA on the healing process of tympanic membrane perforation

PURPOSE

Platelet-derived growth factor basic 30-kD disulfide-bonded dimer of A and B chains (PDGF-AA, PDGF AB, PDGF-BB) and a cytokine, promoting wound healing by its mitogenicity for fibroblast and by stimulating the production of fibronectin and hyaluronic acid. This article investigates the effect of PDGF on the healing process of tympanic membrane (TM) perforation.

MATERIALS AND METHODS

The pars tensa of the posterior aspect of the TM of rats was excised and treated with 2 microg of PDGF-AA or placebo. The animals were killed at 3, 5, 7, 9, 11, 15, and 28 days after operation. The healing process of TM perforation was observed with a telescope and light microscope. The temporal bones were also immunohistochemically examined for PDGF-alpha receptor (PDGF-R(alpha)) and fibronectin.

RESULTS

All PDGF-AA-treated TM were completely closed by 5 days after surgery, whereas some of the placebo-treated TM were not closed at 15 postoperative days. PDGF-AA induced the most prominent proliferation of the connective tissue by 9 postoperative days, after which the growth of the connective tissue decreased. By the 4th postoperative week, the PDGF-treated TM were slightly thicker than normal TM. An intense expression of fibronectin was detected in the connective tissue layer of the TM that were treated with PDGF-AA. PDGF-R(alpha) was expressed in the epithelial layer of both the PDGF-treated and control TM.

CONCLUSION

These results show that PDGF-AA speeds up the healing process of TM defect, improves the rate of healing, and prevents atrophic changes in the healed TM by promoting the connective tissue growth. The use of PDGF-AA can be an effective alternative to surgery for managing TM perforations.

Streptococcal toxic shock-like syndrome in a post-myomectomy patient

We report on a healthy 34-year-old woman who received an elective myomectomy for uterine fibroid, and postoperatively developed fatal streptococcal toxic shock-like syndrome. We discuss the series of events that led to this life-threatening disease and its pathophysiology, and suggest areas in which management might have been improved.

Sedation for the conduct of lumbar epidural anaesthesia: a study using subanaesthetic dose of ketamine in combination with midazolam

We gave sedation for the conduct of lumbar epidural analgesia using intravenous ketamine 0.3 mg.kg-1 with intravenous midazolam 2 mg. Forty adult Chinese females undergoing major gynaecological laparotomies had epidural catheter inserted before general anaesthesia, 20 of whom were given ketamine and midazolam (study group) and the other 20 acted as control. During the conduct of the epidural, the pain and anxiety scores in the study group were significantly less than the control group (P < 0.05). Patients were significantly more sedated in the study group (P < 0.05). All the patients in the study group were satisfied and would consent to future epidural versus 75% in the control group (significant at P < 0.05). Ninety per cent of patients in the study group had amnesia but none in the control group. Pain experienced during the epidural was the reason for refusal of future epidural. We did not observe any emergence phenomenon or cardiovascular stimulation. There was a statistically significant decrease in the pulse oximetry oxygen saturation (SpO2) in the study group but none required oxygen supplementation. We concluded that pain caused by the conduct of epidural did decrease the patient's acceptance rate to future epidural, and the combined use of intravenous ketamine 0.3 mg.kg-1 and midazolam 2 mg provided adequate sedation, analgesia, anxiolysis and amnesia to significantly increase the acceptance rate without any significant side effects.

Antigen diffusion from the perilymphatic space of the cochlea

The diffusion pattern of horseradish peroxidase (HRP) injected into the scala tympani of the cochlear basal turn of guinea pigs was studied to test whether antigen presented in this manner can gain access to the endolymphatic sac. By two hours, HRP reaction product was found throughout the cochlea, with the greatest amounts in the spiral ligament, spiral limbus, basilar membrane, and organ of Corti. In several cochleas, very weak labeling was seen in the stria vascularis. HRP reaction product was maximal in the basal turn. By two hours, HRP reaction product was also observed in the endolymphatic sac lumen, epithelial cells, subepithelial tissue, and perisaccular connective tissue. It was more common in the proximal portion. At this time, macrophages within the lumen already appeared to have phagocytosed the HRP. By 72 hours after injection, the inner ear was cleared of HRP. The results of this study support the hypothesis that antigen in the scala tympani gains access to the endolymphatic sac lumen, where it may be presented by macrophages to the systemic immune system. Antigen most likely does not gain access to the endolymphatic space in the cochlea, but it gets to the endolymphatic sac through the perilymph and the perisaccular tissue.

Continuous spinal analgesia--initial experiences with differential sensory block and labour pain relief

This report describes the use of microcatheters to provide continuous spinal analgesia for the relief of labour pain. Bupivacaine 0.025% was administered through a 28G spinal microcatheter resulting in a differential block which provided effective labour pain relief. Conduction by the smaller pain fibres from the uterus were blocked, while relatively sparing the larger A fibres. Motor power, sense of touch, and discrimination between blunt and sharp objects were therefore left relatively intact. Patients were thus spared the discomfort of motor paralysis and an intense sensory block. No patient had hypotension (blood pressure fall greater than 20%). However one patient suffered a severe post-dural puncture headache which required an epidural blood patch. Continuous intra-thecal spinal analgesia is a potential alternative to continuous epidural analgesia in the relief of labour pain.

General anaesthesia vs sedation for minor gynaecological procedures--a comparative study

Sedation using combined intravenous midazolam and fentanyl is a popular technique for minor gynaecological procedures. However, it is fraught with inconsistency in efficacy and has a greater tendency to perioperative oxygen desaturation. Fifty female ASA I patients scheduled for minor gynaecological procedures were given intravenous midazolam and fentanyl before surgery started. Intraoperative excessive movement that interfered with surgery and failure to maintain a patient airway were noted. Perioperative oxygen saturation was monitored with the pulse oximeter. In another group of 50 female ASA I patients, intravenous thiopentone was given and anaesthesia maintained with 67% nitrous oxide in 33% oxygen and 0.5% of isoflurane via a face mask. Results showed that 10% of the sedated patients had excessive movements that interfered with surgery, of which 6% needed a general anaesthetic. Twenty-two percent of the sedated patients needed maintenance of airway perioperatively. Perioperative oxygen desaturation was profound in incidence and degree in the sedated patients whereas no patient who received general anaesthesia desaturated. The perioperative incidence of desaturation in the sedated patients was 46%. Intraoperatively, 28% (p < 0.001) of the sedated patients had oxygen saturation in the range of 85 to 90% and 18% of them (p < 0.01) had oxygen saturation of less than 85%. Postoperatively 8% of the sedated patients had oxygen saturation of 85 to 90%. We conclude that general anaesthesia is more efficacious and safer than sedation in patients scheduled for minor gynaecological procedures. The same minimum standard of monitoring applied to general anaesthesia should be used for sedated patients.

Difficult intubation: a prospective study

Difficult intubation has been much discussed in the anaesthetic literature. The incidence of difficult intubation (11:560) was higher in obstetric patients (6:277) as compared to gynaecological patients (5:283) in our hospital. We tested the Mallampati's classification as a predictor of difficult intubation in 277 obstetric and 283 gynaecological patients. We recommend that Mallampati's classification can be used reliably (p less than 0.05) to predict difficult intubation in obstetric but not in gynaecological patients.