Browsing by Author "Horn, Alan"

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    Open Access
    Anaesthetic method and short-term outcomes of preterm infants delivered by caesarean section in a tertiary hospital in South Africa
    (2021) Stander, Raphaella; Horn, Alan; Tooke Lloyd
    Background. There are inconsistent published data describing the influence of anaesthetic type during caesarean section (CS), on outcomes of preterm neonates. Objectives. To describe indications and type of anaesthesia in preterm neonates and to describe short-term outcomes, comparing spinal anaesthesia (SA) to general anaesthesia (GA). Methods. Data were collected retrospectively on preterm babies born at 28 – 35 weeks' gestation by CS, between 1 January and 30 Sep 2014 at Groote Schuur Hospital, Cape Town, South Africa. Babies with missing data were excluded. The largest group of babies with similar indications for delivery were identified from the theatre register. Baseline characteristics and short-term outcomes for this group were extracted from an existing prospective data base, and compared between those delivered under SA and GA. Results. Data were available for 226 deliveries, having excluded 23 with incomplete data. Most babies (75%) were delivered under SA. The most common indication for CS was ‘cardiotocograph abnormalities,' in 139 deliveries. Within this group, SA was more frequent (81.7% vs. 12.9%) while GA was associated with lower Apgar scores (p < 0.001) and more intubation at birth (p = 0.004). There was no difference in mortality when comparing SA with GA. Conclusion. Our data suggest a sedative effect of maternal GA on preterm babies delivered by CS, and the need for staff with advanced resuscitation skills. This study provides novel baseline data in our setting, but these data need to be validated in a prospective study.
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    Early clinical signs in neonates with hypoxic ischemic encephalopathy predict an abnormal amplitude-integrated electroencephalogram at age 6 hours
    (BioMed Central Ltd, 2013) Horn, Alan; Swingler, George; Myer, Landon; Linley, Lucy; Raban, Moegammad; Joolay, Yaseen; Harrison, Michael; Chandrasekaran, Manigandan; Rhoda, Natasha; Robertson, Nicola
    BACKGROUND: An early clinical score predicting an abnormal amplitude-integrated electroencephalogram (aEEG) or moderate-severe hypoxic ischemic encephalopathy (HIE) may allow rapid triage of infants for therapeutic hypothermia. We aimed to determine if early clinical examination could predict either an abnormal aEEG at age 6 hours or moderate-severe HIE presenting within 72 hours of birth. METHODS: Sixty infants [greater than or equal to] 36 weeks gestational age were prospectively enrolled following suspected intrapartum hypoxia and signs of encephalopathy. Infants who were moribund, had congenital conditions that could contribute to the encephalopathy or had severe cardio-respiratory instability were excluded. Predictive values of the Thompson HIE score, modified Sarnat encephalopathy grade (MSEG) and specific individual signs at age 3-5 hours were calculated. RESULTS: All of the 60 infants recruited had at least one abnormal primitive reflex. Visible seizures and hypotonia at 3-5 hours were strongly associated with an abnormal 6-hour aEEG (specificity 88% and 92%, respectively), but both had a low sensitivity (47% and 33%, respectively). Overall, 52% of the infants without hypotonia at 3-5 hours had an abnormal 6-hour aEEG. Twelve of the 29 infants (41%) without decreased level of consciousness at 3-5 hours had an abnormal 6-hour aEEG (sensitivity 67%; specificity 71%). A Thompson score [greater than or equal to] 7 and moderate-severe MSEG at 3-5 hours, both predicted an abnormal 6-hour aEEG (sensitivity 100 vs. 97% and specificity 67 vs. 71% respectively). Both assessments predicted moderate-severe encephalopathy within 72 hours after birth (sensitivity 90%, vs. 88%, specificity 92% vs. 100%). The 6-hour aEEG predicted moderate-severe encephalopathy within 72 hours (sensitivity 75%, specificity 100%) but with lower sensitivity (p = 0.0156) than the Thompson score (sensitivity 90%, specificity 92%). However, all infants with a normal 3- and 6-hour aEEG with moderate-severe encephalopathy within 72 hours who were not cooled had a normal 24-hour aEEG. CONCLUSIONS: The encephalopathy assessment described by the Thompson score at age 3-5 hours is a sensitive predictor of either an abnormal 6-hour aEEG or moderate-severe encephalopathy presenting within 72 hours after birth. An early Thompson score may be useful to assist with triage and selection of infants for therapeutic hypothermia.
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    Neonatal Sepsis And Antibiotic Sensitivity Patterns At A South African Tertiary Nursery – Evolution Over A 15 Year Period
    (2019) Naidoo, Nayestha; Harrison, Michael; Horn, Alan
    Background Neonatal infection is an important cause of morbidity and mortality in babies. The causative pathogens and their antibiotic susceptibility patterns should be monitored so that treatment regimens can be adjusted to maintain efficacy and avoid selection of resistant organisms. Objectives To compare the incidence of culture positive neonatal sepsis; and to describe the pathogens and antibiotic resistance profiles for significant organsims over a 15-year period in a tertiary nursery in Cape Town. Methods Retrospective blood culture data for 12 months were collected at three time points over a 15-year period. Blood cultures from 2004, 2013 and 2017 were analysed. All neonates with growth on blood cultures were included. Results During 2004 a total of 817 (43.3% of total admissions) blood cultures were taken, 171 (9.1% of total admissions) were culture positive. The most common invasive organisms were Klebsiella pneumoniae (31.8% of invasive organisms), S.aureus (26.1%) and enterococcus species (7.3%). There were 102 contaminants (12.5% of total cultures) of which 7.8% were due to Coagulase-negative Staphylococcus (CONS). In 2013 a total of 1070 (46.8% of total admissions) blood cultures were taken, 124 (5.4% of total admissions) were culture positive. Common invasive organisms were Klebsiella pneumoniae (53.8% of invasive organisms), E. coli (12.8%) and S. aureus (10.3% ). Forty-six blood cultures were deemed contaminated (4.3% of all cultures) and of these 2.1% were due to CONS. In 2017, there were 581 blood cultures taken (26.5% of total admissions), 56 were culture positive (2.6% of total admissions). Commonly occuring invasive organisms were Klebsiella pneumoniae (32.4% of invasive organisms), Group B streptococcus (16.2%) and Acinetobacter (13.5%). Twenty-nine blood cultures were considered contaminated (5.6% of cultures) of which 1.7% were CONS. The gram-negative organisms showed an increasing resistance to penicillin, ampicillin and aminoglycosides but remained sensitive to carbapenems. Conclusions The initial reduction in positive blood cultures from 2004 to 2013 was primarily due to the reduction of contaminants, probably reflecting improved blood sampling techniques. The large reduction in Gram-negative organisms from 2013 to 2017 suggests improved infection control measures , but gram-negative organisms remained prominent in all three cohorts. Emergence of resistant organisms is concerning and in keeping with other nurseries worldwide. These data illustrate the need for antibiotic stewardship, infection control measures and ongoing surveillance.
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    Retinopathy of Prematurity in a cohort of neonates at Groote Schuur Hospital
    (2016) Keraan, Qaunitah; Joolay, Yaseen; Horn, Alan
    Background: Screening for Retinopathy of Prematurity (ROP) is recommended to prevent possible blindness. Prior to 2016, resource limitations precluded routine ROP screening at Groote Schuur Hospital (GSH). Previous pilot studies at GSH did not detect ROP requiring treatment. However, improved survival of very low birth weight infants may affect the prevalence of ROP. Objectives: The study objectives were to: i) Determine the prevalence and severity of ROP in a prospective cohort of premature infants; ii) Describe the association with pre-specified potential risk factors; iii) Assess the feasibility of screening for ROP in our resource-limited setting. Methods Infants with a birth weight of < 1251 g or gestational age < 31 weeks admitted to the GSH neonatal unit from November 2012 to May 2013 were screened. A paediatric ophthalmologist examined the infants at 4 weeks chronological age or 32 weeks corrected gestational age, with follow-up examinations as indicated. Results: Screening was performed in 135 of 191 eligible infants. A total of 313 ROP examinations were performed; 38.5% of infants required a single examination and 16.3% required more than four. The mean gestational age and weight at birth were 30.1 ± 1.9 weeks and 1056 ± 172 g respectively. Seventy-four infants were female (54.8%). Only black (57.0%) and coloured (42.9%) infants were represented. ROP was diagnosed in 40 (29.6%) infants: Eight (5.9%) infants had clinically significant ROP. No infants had stage 4 or 5 ROP. No infants weighing more than 1250 g required treatment. Two infants received laser treatment. Infants with ROP had a lower mean gestational age and lower mean birth weight than those without ROP: 29.2 ± 1.6 vs. 30.5 ± 1.9 weeks (P < 0.002) and 988 ± 181 g vs. 1085 ± 160 g (P = 0.001) respectively. Infants with ROP were more likely to have received a blood transfusion (P < 0.002); to have late onset sepsis (P = 0.024); and to have receive d exclusive breast milk feeds (P = 0.005). There were no significant differences in the level of respiratory support, the need for oxygen therapy, the occurrence of apnoea, early sepsis or severe intraventricular haemorrhage in infants with ROP compared to no ROP. On multivariate analysis, only gestational age was independently associated with ROP was gestational age (RR 0.85; 95% CI 95% 0.740 - 0.988; p=0.03). When gestational age was excluded in post-hoc analysis, birth weight (RR 0.99; 95% CI 0.997 - 0.999; P=0.03) and blood transfusions (RR 1.71; 95% CI 1.0 27 - 2.859; P=0.03) were independently associated with ROP. Infants <1000 g had a 2.5 times higher risk of having ROP than their larger counterparts (95% CI 1.05 - 5.90, P=0.03). ROP screening was completed in 91.1% (123/135) of infants. Conclusion Clinically significant ROP was found in this study. In contrast to previous studies conducted in this setting, two patients received laser treatment. Extensive resources were required for successful screening. The strong association with birth weight and gestational age suggests that infants with lower birth weights and gestational ages should be prioritized for screening in our resource-limited setting.
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    The effect of device position and use of transparent covers on the irradiance distribution of LED phototherapy devices
    (2021) Ismail, Mugammad Taib; Horn, Alan
    Background Effective phototherapy reduces neonatal jaundice and its complications. Irradiance increases as the distance of the light source decreases from a single phototherapy light. There are limited studies of the effect of distance and positional changes on different LED light designs on achieving effective phototherapy. Objectives To describe and compare the effect of distance, angle and plastic barriers on three different LED lights of different design. Methods Comparisons were made using a Servolite LED light, a General Electric (GE) Lullaby and a Ningbo David LED phototherapy light. Measurements were done according to methods described by the International Electrotechnical Communission (IEC). The effective irradiated area was measured on a grid measuring 60 x 30 cm subdivided into 5 x 5 cm squares. Measurements were done for the following scenarios: light placed at the manufacturers' recommended distance, 20 cm closer, 20 cm further, at an angle, through clear plastic and through scuffed perspex. Results When the lights were placed closer to the irradiated surface than the manufacturers' recommendations, the maximum irradiance increased, but the median irradiance and uniformity ratio decreased. When the lights were angled at 45 the median irradiance was decreased. A decrease in the median irradiance was also seen when phototherapy lights passed through scuffed plastic and food grade plastic. Conclusion Our study demonstrated that placing LED lights closer than the manufacturers recommendations, the use of transparent barriers and the use of lights at an angle, compromised phototherapy irradiance and distribution. Only the GE light met IEC standards.