Bacteriologic response to oral cephalosporins: are established susceptibility breakpoints appropriate in the case of acute otitis media?

Bacteriologic response to cefuroxime axetil and cefaclor administered for 10 days was evaluated in acute otitis media (AOM) in patients aged 6-36 months. Middle ear fluid culture was obtained by tympanocentesis before treatment, on day 4 or 5 after initiation of treatment, and if clinical relapse occurred before day 17. Bacteriologic failure was observed in 32% of patients receiving cefaclor versus 15% of patients receiving cefuroxime axetil (P = .009). Failure rates increased with increasing MIC: For Streptococcus pneumoniae, 0.5 microg/mL (established as cutoff value for cefuroxime by the National Committee for Clinical Laboratory Standards [NCCLS]) discriminated between success and failure. For Haemophilus influenzae, high failure rates were observed for cefaclor, even with low MICs (< or = 1.0 microg/mL), and with both drugs they tended to increase with increasing MIC, even for values below the cutoff suggested by the NCCLS (8.0 and 4.0 microg/mL for cefaclor and cefuroxime, respectively). Thus, for AOM caused by H. influenzae, lower susceptibility cutoff levels for MICs should be established.

Impaired bacteriologic response to oral cephalosporins in acute otitis media caused by pneumococci with intermediate resistance to penicillin.

BACKGROUND: Penicillin resistance of Streptococcus pneumoniae, one of the most common causes of acute otitis media, has recently increased and is now highly prevalent in many regions. However, its contribution to clinical failure still must be proved. Because the role of antibiotics in acute otitis media is to eradicate the pathogens present in the middle ear fluid, we conducted a randomized controlled study to determine bacterial eradication of pathogens in acute otitis media by two commonly used oral cephalosporins, cefuroxime axetil (30 mg/kg/day) and cefaclor (40 mg/kg/day). METHODS: Patients 6 to 36 months old with pneumococcal otitis media seen in the Pediatrics Emergency Room were studied. An initial middle ear fluid culture was obtained at enrollment, and a second culture was obtained on Day 4 or 5 during treatment. Follow-up was done also on Days 10, 17 and 42 after initiation of treatment. In cases of clinical relapse a third culture was obtained. RESULTS: In total 78 patients were enrolled, 41 in the cefuroxime axetil group and 37 in the cefaclor group. Of the 78 S. pneumoniae isolates 31 (40%) were intermediately penicillin-resistant (MIC 0.125 to 1.0 microgram/ml). Of the 47 patients with penicillin-susceptible organisms 3 (6%) had bacteriologic failure vs. 4 of 19 (21%) and 7 of 11 (64%) of those with MIC of 0.125 to 0.25 microgram/ml and 0.38 to 1.0 microgram/ml, respectively (P < 0.001). For intermediately resistant pneumococci, in 7 of 12 (58%) of those receiving cefaclor the isolate was not eradicated vs. only 4 of 19 (21%) of those receiving cefuroxime axetil (P = 0.084). MIC to the administered cephalosporin of > 0.5 microgram/ml was associated with bacteriologic failure. Clinical failure was observed in 9 of 14 (64%) patients with bacteriologic failure vs. 10 of 52 (19%) patients with bacteriologic eradication (P = 0.003). CONCLUSION: Intermediately penicillin-resistant S. pneumoniae is associated with an impaired bacteriologic and clinical response of acute otitis media to cefaclor and cefuroxime axetil. This effect was more pronounced with cefaclor than with cefuroxime axetil.

Antibiotic for cesarean section: the case for 'true' prophylaxis.

OBJECTIVES: To assess prospectively the efficiency and safety of two extended spectrum cephalosporins used as pre-operative prophylaxis in nonelective cesarean sections, and compare the results to those of a third group of patients that received cefamezine post cord clamping. METHODS: Two hundred and forty one patients undergoing a nonscheduled cesarean section were assigned to receive either cefonicid or ceftriaxone prior to skin incision. These patients were followed prospectively for infectious and fetal complications. The outcome of these patients was also compared with another group of 194 patients that received cefamezine prophylaxis post cord clamping, and whose data were collected retrospectively. Chi-square analysis of variance were performed with P < 0.05 considered significant. RESULTS: There were no significant differences in the febrile complications among the two groups of patients that received pre-operative prophylaxis. However, these patients had significantly less wound infections (P = 0.008) and a significantly shorter hospital stay (P < 0.001) than the patients who received their prophylactic antibiotics post cord clamping. CONCLUSIONS: Extended-spectrum cephalosporins, when given pre-operatively, are both effective and safe, and may have an advantage over intra-operative first generation cephalosporins in the reduction of post cesarean section infectious morbidity.

Cystic hygroma of the parotid gland.

Cystic hygroma of the parotid gland is an uncommon benign congenital neoplasm that presents as an asymptomatic soft fluctuant mass. Cervical ultrasonography, computerized tomography (CT) and magnetic resonance imaging (MRI) are used to assess the size and extent of the lesion and to assist in planning the surgical approach. Ultrasonography may demonstrate a multilocular cystic mass containing septa of variable thicknesses. Extension of the mass into deeper structures is more accurately assessed by CT or MRI. A CT scan may show thin-walled cystic masses filled with material of density close to that of water. The use of contrast medium can demonstrate the relationship of the lesion to the surrounding structures. Magnetic resonance imaging is superior to CT in defining the nature and extent of the lesion.

Oral ciprofloxacin in the management of chronic suppurative otitis media without cholesteatoma in children: preliminary experience in 21 children.

The current medical management of children with chronic suppurative otitis media without cholesteatoma unresponsive to local treatment and oral antibiotics is intravenous antibiotic therapy in the hospital setting. We studied the efficacy and toxicity of oral ciprofloxacin in chronic suppurative otitis media. Twenty-one children received oral ciprofloxacin, 30 mg/kg/day. Ear discharge was positive for bacteria resistant to other oral medications and susceptible to the quinolones. The mean duration of treatment was 16.7 days. In 18 children suppuration ceased and 3 failed their first course. During a mean follow-up of 15.4 months, 6 children remained free of ear, nose and throat problems. Otorrhea recurred in 12 children. Ear cultures were positive for organisms susceptible to amoxicillin in 5 of them. In 7 cases Pseudomonas aeruginosa was again isolated from otorrhea. Repeated antibiotic therapy was advocated only in 3 (2 responded to ciprofloxacin; 1 failed ciprofloxacin and was cured by ceftazidime). Adverse clinical effects were not observed. Transient neutropenia was observed in 1 child. There was no change in the height percentile. The results of this study show that children with chronic suppurative otitis media without cholesteatoma can be effectively treated with oral ciprofloxacin. This novel approach may prevent hospitalization.

Successful treatment of malignant external otitis with oral ciprofloxacin: report of experience with 23 patients.

Twenty-three consecutive patients with malignant external otitis (MEO) were treated with oral ciprofloxacin, 1.5-2.25 g/day for 6 weeks. Treatment was combined with local surgical debridement. Patients were discharged early for ambulatory follow-up. Few minor side effects were reported, and full compliance with the study drug was observed. In 21 patients cure was achieved; in 2 the response was not adequate. Oral ciprofloxacin is an effective, convenient, nontoxic, economically justified alternative to the combination intravenous therapy previously advocated.

Ciprofloxacin treatment of malignant external otitis.

The Ear, Nose, and Throat department of the Meir Hospital treated 91 patients with malignant external otitis during the past 16 years. The last 23 patients with malignant external otitis were treated with ciprofloxacin 750 mg twice daily, combined with local excision of the aural lesion. The records of 61 of our previous 68 patients who underwent surgery and were hospitalized and treated with an intravenous extended-spectrum penicillin and gentamicin for six to eight weeks, were analyzed. Twenty-one of 23 patients treated with ciprofloxacin were cured; therapy failed in two patients. Treatment averaged 16.8 days of hospitalization, and bacteriologic eradication was achieved after an average of 7.04 days, as compared with 49 and 15.3 days, respectively, in the group of patients with the intravenous treatment. The mean peak concentrations of ciprofloxacin in serum varied between 2.5 and 3.7 micrograms/ml, and the drug concentrations in different ear tissues were 0.2 to 13 micrograms/g. The treatment with ciprofloxacin was well tolerated with no significant side effects, whereas serious side effects were noted in 45.9 percent of the previous intravenously treated group. The concentrations of the drug in serum and ear tissues were higher than the average minimal inhibitory concentration for Pseudomonas aeruginosa. Use of ciprofloxacin treatment, combined with local excision of the aural lesion, will bring about healing of malignant external otitis in the majority of cases. Ciprofloxacin can be given on an ambulatory basis after a relatively short period of hospitalization.

Survival of early monocular deprivation effects in cortical cells of kittens following prolonged dark rearing.

To study whether early visual experience survives the absence of consequent visual stimulation during development, experimental kittens were reared in the dark for 5-13.5 months following monocular deprivation (MD) periods of 2-11 weeks which were initiated at the time of natural eye opening (MD-dark). For comparison, experimental kittens, normally reared after equivalent MD periods (MD-bino.), were also studied. Cats raised with permanent MD, dark-reared cats and normal cats, served as controls. The proportion of responsive cells was considerably reduced by the dark-rearing. It was especially reduced for the MD-dark kittens following monocular deprivation limited to the first postnatal month (58.3% responsive cells) in comparison to the equivalent group of MD-bino. kittens (80.5%). This is also in keeping with the diminution in cortical responsiveness obtained in the kittens which were dark-reared from birth (55.5%). The responsiveness level found in the normal control cats was 87.3%. It was found that the duration of the MD period prior to the dark-rearing period was directly related to the ocular dominance (OD) distribution of cortical cells. The susceptibility period to MD in both MD-dark and MD-bino. groups ends at approximately 3 months of age; the lower limit for the susceptibility period is at approximately 1-2 weeks after natural eye opening. The main period of sensitivity within this period of time is the first 4 postnatal weeks following natural eye opening. It is concluded that once the effect of monocular deprivation has been established, it will survive for the rest of the cat's life, even under conditions of complete absence of consequent visual stimulation. Furthermore, a certain degree of consolidation of the MD effect takes place in the light (i.e. in MD-bino. cats) despite their return to normal binocular vision. A somewhat opposite occurrence takes place in the dark (in MD-dark cats) with a tendency for masking of the MD effect previously induced in the light to be found.

Ocular dominance of cortical cells in cats dark-reared into maturity after short postnatal monocular deprivation.

We studied the preservation of the early monocular deprivation effect by rearing kittens in complete darkness for long periods (9.5 to 20 months) after a monocular deprivation period of 4 weeks that was initiated at the age of 1 month (MDDR cats). For comparison, four groups of kittens were used: monocularly deprived as those described above and then reared in normal light conditions (MDN), monocularly deprived at the age of 1 month (MD), and dark-reared (DR) or normally light-reared (NOR) from birth. Recordings from the visual cortex of MDDR and MDN cats showed that there was a clear preference for cells driven only by the experienced eye compared with the deprived eye. This preference was found whether, subsequent to the monocular deprivation period, these cats were dark- or light-reared (P less than 0.005 for MDDR and MDN compared with NOR cats). The difference between the MDDR, MDN, and MD groups of cats was reflected in the proportions of binocularly driven cells; the largest number of binocularly driven cells was found in the MDDR cats. There was no bias toward either eye in the ocular dominance distribution of cortical cells in cats that were reared in total darkness (DR) or in the light under normal conditions (NOR). We thus conclude that the long-term dark period during development did not erase the effect of early monocular deprivation on the cat visual cortex provided that the latter lasted 4 weeks prior to the dark period.

Deafferentation of the visual cortex: the effect on cortical cells in normal and in early monocularly deprived cats.

The optic tract was unilaterally transected and receptive field mapping and unit recordings were made for cells in the boundary of areas 17-18 in the deafferented and in the intact visual cortex of adult cats monocularly deprived during the critical developmental period. Three groups of adult animals served as controls: normal cats, early monocularly deprived (MD) cats, and optic tract transected cats. In contrast to the activity found in the intact hemisphere, the deafferented hemisphere of the experimental group was almost completely unresponsive. The ocular dominance distribution in the intact hemisphere of the experimental group (75.0% cells monocularly driven by the normal eye) was similar to that of the control MD cats (78.1%). This indicates that cutting the optic tract after the critical period does not affect the ocular dominance distribution of cortical cells induced in the intact hemisphere by early monocular deprivation. The reduction found in the proportion of visually responsive cells and the orientation and direction selective cells in the intact hemisphere of the experimental group, is mainly due to the isolation of the fellow hemisphere from its direct visual input, and the subsequent inactivation of the callosal pathway interconnecting the two visual areas.

The effects of early visual experience followed by prolonged dark rearing on visual cortex cells of cats.

Five groups of kittens (N = 13) were dark reared for 9.5-20 months following normal binocular exposure of 0-85 days after natural eye opening and 1 month of monocular deprivation. For comparison, kittens monocularly deprived (MD) for 10 months (N = 2) and normal adult cats (N = 13) served as controls. The ocular dominance distribution of cortical cells showed a clear (although small) bias in the first group of kittens which received the minimal exposure. A striking effect was obtained in the proportion of visually unresponsive cells (55.1%) in this first group of cats. Concerning orientation and direction selectivity, the highest proportions of nonselective cells, 16.1% and 33.3%, were obtained in the first two groups of cats respectively. It was concluded that periods of monocular deprivation shorter than that used in the present study (4 weeks) and without any previous visual experience would be ineffective if followed by a year or more of total absence of visual experience. Prolonged dark rearing therefore, masks the effect of prior monocular deprivation to a large extent. In addition, the results emphasize the fact that the age factor is more important than the duration of the monocular visual experience.