-
[show abstract]
[hide abstract]
ABSTRACT: ObjectiveTo perform spectral analysis of noise generated by equipments and activities in a level III neonatal intensive care unit (NICU)
and measure the real time sequential hourly noise levels over a 15 day period.
MethodsNoise generated in the NICU by individual equipments and activities were recorded with a digital spectral sound analyzer to
perform spectral analysis over 0.5–8 KHz. Sequential hourly noise level measurements in all the rooms of the NICU were done
for 15 days using a digital sound pressure level meter. Independent sample t test and one way ANOVA were used to examine the
statistical significance of the results. The study has a 90% power to detect at least 4 dB differences from the recommended
maximum of 50 dB with 95 % confidence.
ResultsThe mean noise levels in the ventilator room and stable room were 19.99 dB (A) sound pressure level (SPL) and 11.81 dB (A)
SPL higher than the maximum recommended of 50 dB (A) respectively (p < 0.001). The equipments generated 19.11 dB SPL higher
than the recommended norms in 1–8 KHz spectrum. The activities generated 21.49 dB SPL higher than the recommended norms in
1–8 KHz spectrum (p< 0.001). The ventilator and nebulisers produced excess noise of 8.5 dB SPL at the 0.5 KHz spectrum.
ConclusionNoise level in the NICU is unacceptably high. Spectral analysis of equipment and activity noise have shown noise predominantly
in the 1–8 KHz spectrum. These levels warrant immediate implementation of noise reduction protocols as a standard of care
in the NICU.
The Indian Journal of Pediatrics 04/2012; 75(3):217-222. · 0.52 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: There is a need to develop an affordable and reliable tool for hearing screening of neonates in resource constrained, medically underserved areas of developing nations. This study valuates a strategy of health worker based screening of neonates using a low cost mechanical calibrated noisemaker followed up with parental monitoring of age appropriate auditory milestones for detecting severe-profound hearing impairment in infants by 6 months of age.
A trained health worker under the supervision of a qualified audiologist screened 425 neonates of whom 20 had confirmed severe-profound hearing impairment. Mechanical calibrated noisemakers of 50, 60, 70 and 80 dB (A) were used to elicit the behavioural responses. The parents of screened neonates were instructed to monitor the normal language and auditory milestones till 6 months of age. This strategy was validated against the reference standard consisting of a battery of tests - namely, auditory brain stem response (ABR), otoacoustic emissions (OAE) and behavioural assessment at 2 years of age. Bayesian prevalence weighted measures of screening were calculated.
The sensitivity and specificity was high with least false positive referrals for 70 and 80 dB (A) noisemakers. All the noisemakers had 100 per cent negative predictive value. 70 and 80 dB (A) noisemakers had high positive likelihood ratios of 19 and 34, respectively. The probability differences for pre- and post- test positive was 43 and 58 for 70 and 80 dB (A) noisemakers, respectively.
In a controlled setting, health workers with primary education can be trained to use a mechanical calibrated noisemaker made of locally available material to reliably screen for severe-profound hearing loss in neonates. The monitoring of auditory responses could be done by informed parents. Multi-centre field trials of this strategy need to be carried out to examine the feasibility of community health care workers using it in resource constrained settings of developing nations to implement an effective national neonatal hearing screening programme.
The Indian journal of medical research 02/2012; 135:170-6. · 1.84 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To examine the effectiveness and cost of implementing a noise reduction protocol in a level III neonatal intensive care unit (NICU).
A prospective longitudinal study was done in a level III NICU, wherein a noise reduction protocol that included behavioral and environmental modification was implemented. The noise levels were measured sequentially every hour for 15 days before and after this intervention. The statistical significance of the reduction in noise levels after implementation of the protocol was tested by paired sample student's t-test. Cost was calculated using the generalized cost effectiveness model of the World Health Organisation. The present study has 80% power with 95% confidence to measure 2 dB differences between groups for the maximum recommended of 50 dB.
The protocol in the present study reduced noise levels in all the rooms of the NICU to within 60 dB with high statistical significance (p< 0.001). The extent of noise reduction in the rooms of the NICU was as follows: ventilator room by 9.58 dB (95% confidence interval: 6.73-12.42, p < 0.001), stable room by 6.54 dB (95% confidence interval: 2.92-4.16, p < 0.001), isolation room by 2.26 dB (95% confidence interval: 1.21-3.30, p < 0.001), pre-term room by 2.37 dB(95% confidence interval: 1.22-3.51, p < 0.001) and extreme preterm room by 2.09 dB (95% confidence interval: 1.14-3.02, p < 0.001). The intervention was most cost-effective in the ventilator room, requiring Rs. 81.09 to reduce 1 dB and least effective in the extreme pre-term room requiring Rs. 371.61 to reduce 1 dB.
The high efficacy and affordability of noise reduction protocols justify the need for implementation of these measures as a standard of care in neonatal intensive care units.
The Indian Journal of Pediatrics 05/2009; 76(5):475-8. · 0.52 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To perform spectral analysis of noise generated by equipments and activities in a level III neonatal intensive care unit (NICU) and measure the real time sequential hourly noise levels over a 15 day period.
Noise generated in the NICU by individual equipments and activities were recorded with a digital spectral sound analyzer to perform spectral analysis over 0.5 - 8 KHz. Sequential hourly noise level measurements in all the rooms of the NICU were done for 15 days using a digital sound pressure level meter . Independent sample t test and one way ANOVA were used to examine the statistical significance of the results. The study has a 90 % power to detect at least 4 dB differences from the recommended maximum of 50 dB with 95 % confidence.
The mean noise levels in the ventilator room and stable room were 19.99 dB (A) sound pressure level (SPL) and 11.81 dB (A) SPL higher than the maximum recommended of 50 dB (A) respectively ( p < 0.001). The equipments generated 19.11 dB SPL higher than the recommended norms in 1 - 8 KHz spectrum. The activities generated 21.49 dB SPL higher than the recommended norms in 1 - 8 KHz spectrum ( p< 0.001). The ventilator and nebulisers produced excess noise of 8.5 dB SPL at the 0.5 KHz spectrum.
Noise level in the NICU is unacceptably high .Spectral analysis of equipment and activity noise have shown noise predominantly in the 1 - 8 KHz spectrum. These levels warrant immediate implementation of noise reduction protocols as a standard of care in the NICU.
The Indian Journal of Pediatrics 04/2008; 75(3):217-22. · 0.52 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To determine the weighted incidence of hearing impairment in a standardized population of at risk and not at risk neonates seeking care at a tertiary level hospital in India.
A prospective study of a nonrandomized cohort of 1769 neonates (1490: Not at risk; 279: At risk) from a total of 8192 neonates (6509: Not at risk; 1683: At risk) who sought care at St John's medical College hospital from 1st September 2002 to 31st March 2006 were screened for hearing impairment using transient evoked otoacoustic emissions. Weighting was performed using the expected value of 10 % at risk and 90 % not at risk infants in a typical tertiary care level center in India derived from the National Neonatology and Perinatology database 2002-2003. Z test and 95 % confidence interval was used to determine the external validity of the results. P less than 0.05 was considered as statistically significant. The power of the study is 90 %.
The incidence of hearing impairment in infants screened was 10 per 1769 infants screened (1490: Not at risk; 279: At risk) which is 5.65 per 1000 screened. 279 at risk infants were screened and 3 were detected to have hearing impairment which is an incidence of approximately 10.75 per 1000 screened. Of the 1490 not at risk infants screened 7 had hearing impairment that is 4.70 per 1000 screened. If this was extrapolated to a standardized population consisting of 10 % at risk and 90 % not at risk then the incidence would be 5.60 per 1000 screened with a 95 % confidence interval of 4.13-7.06. This narrow 95 % confidence interval with a p equal to 0.001 indicates that this value may be close to the caseload in a typical tertiary care center.
In this study the incidence of hearing impairment is 3 per 279 in at risk infants screened and 7 per 1490 in not at risk infants screened. The weighted incidence in a standardized population of neonates seeking care at tertiary level center in India is 5.60 per 1000 as per this study. This high incidence calls for all pediatricians to consider incorporating a basic hearing screen for all the neonates using cost effective and appropriate technology. Initial screening may be performed using behavioral observation techniques and confirmation by otoacoustic emissions.
The Indian Journal of Pediatrics 07/2007; 74(6):545-9. · 0.52 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: ObjectiveTo determine the weighted incidence of hearing impairment in a standardized population of at risk and not at risk neonates
seeking care at a tertiary level hospital in India.
MethodsA prospective study of a nonrandomized cohort of 1769 neonates (1490: Not at risk; 279: At risk) from a total of 8192 neonates
(6509: Not at risk; 1683: At risk) who sought care at St John’s medical College hospital from 1st September 2002 to 31st March 2006 were screened for hearing impairment using transient evoked otoacoustic emissions. Weighting was performed using
the expected value of 10 % at risk and 90 % not at risk infants in a typical tertiary care level center in India derived from
the National Neonatology and Perinatology database 2002–2003. Z test and 95 % confidence interval was used to determine the
external validity of the results. P less than 0.05 was considered as statistically significant. The power of the study is
90 %.
ResultsThe incidence of hearing impairment in infants screened was 10 per 1769 infants screened (1490: Not at risk; 279: At risk)
which is 5.65 per 1000 screened. 279 at risk infants were screened and 3 were detected to have hearing impairment which is
an incidence of approximately 10.75 per 1000 screened. Of the 1490 not at risk infants screened 7 had hearing impairment that
is 4.70 per 1000 screened. If this was extrapolated to a standardized population consisting of 10 % at risk and 90 % not at
risk then the incidence would be 5.60 per 1000 screened with a 95 % confidence interval of 4.13–7.06. This narrow 95 % confidence
interval with a p equal to 0.001 indicates that this value may be close to the caseload in a typical tertiary care center.
ConclusionIn this study the incidence of hearing impairment is 3 per 279 in at risk infants screened and 7 per 1490 in not at risk infants
screened. The weighted incidence in a standardized population of neonates seeking care at tertiary level center in India is
5.60 per 1000 as per this study. This high incidence calls for all pediatricians to consider incorporating a basic hearing
screen for all the neonates using cost effective and appropriate technology. Initial screening may be performed using behavioral
observation techniques and confirmation by otoacoustic emissions.
The Indian Journal of Pediatrics 01/2007; 74(6):545-549. · 0.52 Impact Factor
