658
gonorrhϾ resistant to penicillin G by disc diffusion sensitivity testing. Between April 27 and May 6 he received erythromycin, 500 mg by mouth four times daily, with little decrease in his urethral symptoms. On May 8 he was again treated with 1 g of probenecid and 4.8 megaunits of procaine penicillin G. Smears and cultures were still positive on May 10, at which time he received 4 g of spectinomycin intramuscularly. Bacteriological and symptomatic cure were confirmed on May 14.
USE OF NASAL CONTINUOUS POSITIVE AIRWAY PRESSURE TO TREAT SEVERE RECURRENT APNŒA IN VERY PRETERM
INFANTS* PETER M. DUNN
BRIAN D. SPEIDEL
University of Bristol, Department of Child Health, Southmead Hospital, Bristol BS10 5NB
MATERIALS AND METHODS
The isolation and identification of N. gonorrhϾ were performed by standard laboratory methods. A gonococcal agar plate (G.C. agar base, Difco Laboratories, Detroit, Michigan)
containing 1% haemoglobin (Difco Laboratories), supplemented with ’Iso-Vitalex’ enrichment (B.B.L. Division of Becton, Dickinson and Company, Cockeysville, Maryland), vancomycin, colistin, and nystatin, was inoculated and incubated for 18 h in a candle jar containing 3-7% carbon dioxide at 36°C. Tubes of cystine tryptic agar (Difco Laboratories) media containing 1% each of glucose, maltose, sucrose, and lactose were prepared, and a heavy inoculum of bacteria was placed on the surface of the medium. Identification procedures included direct fluorescent-antibody procedure colonial morphology,3 oxidase reaction (tetramethyl-p-phenylenediamine dihydrochloride, Eastman Kodak Company, Rochester, N.Y.) and gram stain. RESULTS
The direct
fluorescent-antibody procedure,
colonial
morphology, oxidase reaction, and gram-stain morphology all corroborated the identification of the isolate as N. gonorrhϾ. This organism, however, failed to ferment any of the sugars. Further, the 10 fJ-g penicillin G disc produced no detectable zone of growth inhibition. As a consequence of these findings, the organism was forwarded to the venereal disease control unit at the Center for Disease Control, Atlanta, Georgia, which confirmed our observations.4 Utilisation of the chromogenic cephalosporin test for &bgr;-lactamase5 suggested the mechanism of resistance to be the production of a
penicillinase enzyme. DISCUSSION
The isolation of a
penicillinase-producing strain of N. number of important questions gonorrhϾ poses regarding therapeutic recommendations for the treatment of gonorrhoea. How widely disseminated is this resistant organism? Does penicillin G remain the drug of choice in the treatment of gonorrhoea? Is the developa
ment
of resistance R-factor mediated? Should antimicro-
susceptibility testing be done on strains of N. gonorrhϾ acquired from patients not cured by currently recommended penicillin G therapy? Studies under way at our institution should help answer these and other important questions. bial
We thank F. Moore, T. Waller, J. Bettinger, and C. Presley laboratory assistance, and Betty Corbin for secretarial assistance. Requests for reprints should be addressed to V. G. H.
for
REFERENCE S 1. Khan, W., Ross, R., Rodriguez, W., Controni, G., Saz, A. K. J. Am. med. Ass. 1974, 229, 298. 2. White, L. A., Kellog, D. S., Jr. Appl. Microbiol. 1965, 13, 171. 3. Kellog, D. S., Jr., Cohen, I. R., Norins, I. C., Schroeter, A. L., Reising, G. J. Bact. 1968, 95, 596. 4. Center for Disease Control Morbid. Mortal. wkly Rep. 1976, 25, 261. 5. O’Callaghan, C. H., Morris, A., Kirby, S. M., Shindler, A. H. Antimicrob. Ag Chemother. 1972, 1, 283.
Nasal continuous positive airway pressure (C.P.A.P.) of 2-3 mm Hg abolished or reduced the incidence of severe apnœic attacks in 5 very preterm newborn infants. It is postulated that C.P.A.P. provides a respiratory drive by reflexly stimulating the infant’s pulmonary stretch receptors.
Summary
INTRODUCTION
INFANTS of very short
gestational
apnceic attacks.Although these may
age
are
prone to
in association with a variety of disorders, often no explanationis found other than immaturity. The condition has a high mortality2 and is likely to be a possible cause of hypoxic brain damage among survivors.3 4Although individual apnœic attacks frequently respond to superficial stimulation, positive pressure ventilation may be required for refractory cases. The use of a raised ambient oxygen has been advocatedS but is often ineffective and may expose the infant to the risk of hyperoxia between attacks and consequent retrolental fibroplasia. Theophylline has also been recommendedbut we have not ourselves been overimpressed by its effectiveness. Continuous positive airway pressure (C.P.A.P.) has been used by us in the treatment of severe respiratory distress syndrome of the newborn since 197I.7 Besides improving arterial oxygenation, C.P.A.P. also affects the pattern of breathing in this condition.s The typically irregular respiration rapidly becomes regular with little breath-to-breath variation. In addition, we found that sudden withdrawal of C.P.A.P. often led to immediate apncea which in turn, was usually abolished by the reapplication of C.P.A.P. We have applied this effect of C.P.A.P. to the management of apnoeic attacks of immaoccur
turity. PATIENTS AND METHODS
The effect of C.P.A.P. on the frequency of apnceic attacksm 5 preterm infants was studied. An apnreic attack was defined as the absence of breathing for a period of more than 20 s Attacks were monitored using a 4-electrode transthoracic impedance pneumograph8 and the diagnosis was confirmed b’ direct observation and the need for intervention. A chart was kept of the frequency of attacks. In 2 infants a polarographic intra-arterial oxygen electrode (G. D. Searle Ltd.) was usedto provide a continuous recording of arterial oxygen tension (Pao2). The catheter was inserted into an umbilical arten until the oxygen electrode tip was in the lower aorta. The accuracy of this in-vivo Pa02 recording was regularly checked against the in-vitro Pa02 of intermittent blood-samples withdrawn through the catheter. The environmental oxygen level was recorded using a continuous-reading oxygen analyser, Ihc infants were nursed in servo-controlled incubators set to mair tain abdominal skin temperature at 36.5°C. C.P,A.P, was applied through bilateral soft-rubber nasopharyngeal ca:’Y eters.
The clinical details of the infants *Based
on a
paper given
to
the Neonatal
tal, London, on Feb. 5, 1976.
are
given in table i. The’
Society,
St.
Thomas Hosp-
659 TABLE ;—CLINICAL DATA OF THE
TABLE
II-FREQUENCY
5
INFANTS
OF APNOEIC ATTACKS
birth-weight was 1202 g at a mean gestational age of 28 wk. All were considered to be in grave danger of dying because of the frequency and severity of their apnoeic attacks. The age at which C.P.A.P. was started ranged from 7 h to 27 days. The airway pressure used was 2-3 mm Hg. The mean environmental oxygen of the infants before starting c.P.A.P. was 32%; folmean
lowing establishment on C.P.A.P. this was reduced to 24%. RESULTS
The frequency of apnoeic attacks in each case before and after starting C.P.A.P. is shown in table 11. In 2 cases the attacks were abolished while in 3 they were greatly reduced in frequency. The mean number of 3.66 attacks/h for the whole group before treatment fell to The average 0.23/h after starting C.P.A.P. (P
gonorrhϾ resistant to penicillin G by disc diffusion sensitivity testing. Between April 27 and May 6 he received erythromycin, 500 mg by mouth four times daily, with little decrease in his urethral symptoms. On May 8 he was again treated with 1 g of probenecid and 4.8 megaunits of procaine penicillin G. Smears and cultures were still positive on May 10, at which time he received 4 g of spectinomycin intramuscularly. Bacteriological and symptomatic cure were confirmed on May 14.
USE OF NASAL CONTINUOUS POSITIVE AIRWAY PRESSURE TO TREAT SEVERE RECURRENT APNŒA IN VERY PRETERM
INFANTS* PETER M. DUNN
BRIAN D. SPEIDEL
University of Bristol, Department of Child Health, Southmead Hospital, Bristol BS10 5NB
MATERIALS AND METHODS
The isolation and identification of N. gonorrhϾ were performed by standard laboratory methods. A gonococcal agar plate (G.C. agar base, Difco Laboratories, Detroit, Michigan)
containing 1% haemoglobin (Difco Laboratories), supplemented with ’Iso-Vitalex’ enrichment (B.B.L. Division of Becton, Dickinson and Company, Cockeysville, Maryland), vancomycin, colistin, and nystatin, was inoculated and incubated for 18 h in a candle jar containing 3-7% carbon dioxide at 36°C. Tubes of cystine tryptic agar (Difco Laboratories) media containing 1% each of glucose, maltose, sucrose, and lactose were prepared, and a heavy inoculum of bacteria was placed on the surface of the medium. Identification procedures included direct fluorescent-antibody procedure colonial morphology,3 oxidase reaction (tetramethyl-p-phenylenediamine dihydrochloride, Eastman Kodak Company, Rochester, N.Y.) and gram stain. RESULTS
The direct
fluorescent-antibody procedure,
colonial
morphology, oxidase reaction, and gram-stain morphology all corroborated the identification of the isolate as N. gonorrhϾ. This organism, however, failed to ferment any of the sugars. Further, the 10 fJ-g penicillin G disc produced no detectable zone of growth inhibition. As a consequence of these findings, the organism was forwarded to the venereal disease control unit at the Center for Disease Control, Atlanta, Georgia, which confirmed our observations.4 Utilisation of the chromogenic cephalosporin test for &bgr;-lactamase5 suggested the mechanism of resistance to be the production of a
penicillinase enzyme. DISCUSSION
The isolation of a
penicillinase-producing strain of N. number of important questions gonorrhϾ poses regarding therapeutic recommendations for the treatment of gonorrhoea. How widely disseminated is this resistant organism? Does penicillin G remain the drug of choice in the treatment of gonorrhoea? Is the developa
ment
of resistance R-factor mediated? Should antimicro-
susceptibility testing be done on strains of N. gonorrhϾ acquired from patients not cured by currently recommended penicillin G therapy? Studies under way at our institution should help answer these and other important questions. bial
We thank F. Moore, T. Waller, J. Bettinger, and C. Presley laboratory assistance, and Betty Corbin for secretarial assistance. Requests for reprints should be addressed to V. G. H.
for
REFERENCE S 1. Khan, W., Ross, R., Rodriguez, W., Controni, G., Saz, A. K. J. Am. med. Ass. 1974, 229, 298. 2. White, L. A., Kellog, D. S., Jr. Appl. Microbiol. 1965, 13, 171. 3. Kellog, D. S., Jr., Cohen, I. R., Norins, I. C., Schroeter, A. L., Reising, G. J. Bact. 1968, 95, 596. 4. Center for Disease Control Morbid. Mortal. wkly Rep. 1976, 25, 261. 5. O’Callaghan, C. H., Morris, A., Kirby, S. M., Shindler, A. H. Antimicrob. Ag Chemother. 1972, 1, 283.
Nasal continuous positive airway pressure (C.P.A.P.) of 2-3 mm Hg abolished or reduced the incidence of severe apnœic attacks in 5 very preterm newborn infants. It is postulated that C.P.A.P. provides a respiratory drive by reflexly stimulating the infant’s pulmonary stretch receptors.
Summary
INTRODUCTION
INFANTS of very short
gestational
apnceic attacks.Although these may
age
are
prone to
in association with a variety of disorders, often no explanationis found other than immaturity. The condition has a high mortality2 and is likely to be a possible cause of hypoxic brain damage among survivors.3 4Although individual apnœic attacks frequently respond to superficial stimulation, positive pressure ventilation may be required for refractory cases. The use of a raised ambient oxygen has been advocatedS but is often ineffective and may expose the infant to the risk of hyperoxia between attacks and consequent retrolental fibroplasia. Theophylline has also been recommendedbut we have not ourselves been overimpressed by its effectiveness. Continuous positive airway pressure (C.P.A.P.) has been used by us in the treatment of severe respiratory distress syndrome of the newborn since 197I.7 Besides improving arterial oxygenation, C.P.A.P. also affects the pattern of breathing in this condition.s The typically irregular respiration rapidly becomes regular with little breath-to-breath variation. In addition, we found that sudden withdrawal of C.P.A.P. often led to immediate apncea which in turn, was usually abolished by the reapplication of C.P.A.P. We have applied this effect of C.P.A.P. to the management of apnoeic attacks of immaoccur
turity. PATIENTS AND METHODS
The effect of C.P.A.P. on the frequency of apnceic attacksm 5 preterm infants was studied. An apnreic attack was defined as the absence of breathing for a period of more than 20 s Attacks were monitored using a 4-electrode transthoracic impedance pneumograph8 and the diagnosis was confirmed b’ direct observation and the need for intervention. A chart was kept of the frequency of attacks. In 2 infants a polarographic intra-arterial oxygen electrode (G. D. Searle Ltd.) was usedto provide a continuous recording of arterial oxygen tension (Pao2). The catheter was inserted into an umbilical arten until the oxygen electrode tip was in the lower aorta. The accuracy of this in-vivo Pa02 recording was regularly checked against the in-vitro Pa02 of intermittent blood-samples withdrawn through the catheter. The environmental oxygen level was recorded using a continuous-reading oxygen analyser, Ihc infants were nursed in servo-controlled incubators set to mair tain abdominal skin temperature at 36.5°C. C.P,A.P, was applied through bilateral soft-rubber nasopharyngeal ca:’Y eters.
The clinical details of the infants *Based
on a
paper given
to
the Neonatal
tal, London, on Feb. 5, 1976.
are
given in table i. The’
Society,
St.
Thomas Hosp-
659 TABLE ;—CLINICAL DATA OF THE
TABLE
II-FREQUENCY
5
INFANTS
OF APNOEIC ATTACKS
birth-weight was 1202 g at a mean gestational age of 28 wk. All were considered to be in grave danger of dying because of the frequency and severity of their apnoeic attacks. The age at which C.P.A.P. was started ranged from 7 h to 27 days. The airway pressure used was 2-3 mm Hg. The mean environmental oxygen of the infants before starting c.P.A.P. was 32%; folmean
lowing establishment on C.P.A.P. this was reduced to 24%. RESULTS
The frequency of apnoeic attacks in each case before and after starting C.P.A.P. is shown in table 11. In 2 cases the attacks were abolished while in 3 they were greatly reduced in frequency. The mean number of 3.66 attacks/h for the whole group before treatment fell to The average 0.23/h after starting C.P.A.P. (P
