Explaining unexplained hypoglycemia: How LC-MS/MS can help.

Explaining hypoglycaemia, especially in patients without diabetes mellitus, is challenging. Here we present a case, where the added value for clinical diagnosis of insulin determination with liquid chromatography-mass spectrometry (LC-MS/MS) is shown. By the use of LC-MS/MS the different insulin analogues can be identified. The confirmation of an insulin analogue present during hypoglycaemia facilitated in our case the discussion with the patient and his family about what happened.

Sustainable neonatal CLABSI surveillance: consensus towards new criteria in the Netherlands.

BACKGROUND: Central line-associated bloodstream infections (CLABSI) are a main focus of infection prevention and control initiatives in neonatal care. Standardised surveillance of neonatal CLABSI enables intra- and interfacility comparisons which can contribute to quality improvement. To date, there is no national registration system for CLABSI in neonatal care in the Netherlands and several criteria are used for local monitoring of CLABSI incidence rates. To achieve standardised CLABSI surveillance we conducted a consensus procedure with regard to nationwide neonatal CLABSI surveillance criteria (SC). METHODS: A modified Delphi consensus procedure for the development of nationwide neonatal CLABSI SC was performed between January 2016 and January 2017 in the Netherlands. An expert panel was formed by members of the Working Group on Neonatal Infectious Diseases of the Section of Neonatology of the Dutch Paediatric Society. The consensus procedure consisted of three expert panel rounds. RESULTS: The expert panel achieved consensus on Dutch neonatal CLABSI SC. Neonatal CLABSI is defined as a bloodstream infection occurring more than 72 h after birth, associated with an indwelling central venous or arterial line and laboratory confirmed by one or more blood cultures. In addition, the blood culture finding should not be related to an infection at another site and one of the following criteria can be applied: 1. a bacterial or fungal pathogen is identified from one or more blood cultures; 2. the patient has clinical symptoms of sepsis and 2A) a common commensal is identified in two separate blood cultures or 2B) a common commensal is identified by one blood culture and C-reactive protein level is above 10 mg/L in the first 36 h following blood culture collection. CONCLUSIONS: The newly developed Dutch neonatal CLABSI SC are concise, specified to the neonatal population and comply with a single blood culture policy in actual neonatal clinical practice. International agreement upon neonatal CLABSI SC is needed to identify best practices for infection prevention and control.

Surveillance of catheter-related bloodstream infections in haemato-oncology patients: comparison of two definitions.

In the Netherlands, the PREZIES surveillance is used for registration and surveillance of central venous catheter (CVC) -related bloodstream infections (CRBSI). We investigated how this Dutch definition correlated with internationally used definitions for CRBSI, central line-associated bloodstream infections (CLABSI) and mucosal barrier injury laboratory-confirmed bloodstream infections (MBI-LCBI). We determined that the Dutch PREZIES definition of CRBSI is appropriate for surveillance control of CVC care bundle use in haemato-oncology patients managed with multi-lumen CVCs.

Surveillance-embedded genomic outbreak resolution of methicillin-susceptible Staphylococcus aureus in a neonatal intensive care unit.

We observed an increase in methicillin-susceptible Staphylococcus aureus (MSSA) infections at a Dutch neonatal intensive care unit. Weekly neonatal MSSA carriage surveillance and cross-sectional screenings of health care workers (HCWs) were available for outbreak tracing. Traditional clustering of MSSA isolates by spa typing and Multiple-Locus Variable number tandem repeat Analysis (MLVA) suggested that nosocomial transmission had contributed to the infections. We investigated whether whole-genome sequencing (WGS) of MSSA surveillance would provide additional evidence for transmission. MSSA isolates from neonatal infections, carriage surveillance, and HCWs were subjected to WGS and bioinformatic analysis for identification and localization of high-quality single nucleotide polymorphisms, and in-depth analysis of subsets of isolates. By measuring the genetic diversity in background surveillance, we defined transmission-level relatedness and identified isolates that had been unjustly assigned to clusters based on MLVA, while spa typing was concordant but of insufficient resolution. Detailing particular subsets of isolates provided evidence that HCWs were involved in multiple outbreaks, yet it alleviated concerns about one particular HCW. The improved resolution and accuracy of genomic outbreak analyses substantially altered the view on outbreaks, along with apposite measures. Therefore, inclusion of the circulating background population has the potential to overcome current issues in genomic outbreak inference.

Worldwide practices on flexible endoscope reprocessing.

Background: Endoscopy related infections represent an important threat for healthcare systems worldwide. Recent outbreaks of infections with multidrug resistant micro-organisms have highlighted the problems of contaminated endoscopes. Endoscopes at highest risk for contamination have intricate mechanisms, multiple internal channels and narrow lumens that are especially problematic to clean. In light of raised awareness about the necessity for meticulous reprocessing of all types of endoscopes, a call for international collaboration is needed. An overview is presented on current practices for endoscope reprocessing in facilities worldwide. Method: An electronic survey was developed and disseminated by the International Society for Antimicrobials and Chemotherapy. The survey consisted of 50 questions aimed at assessing the reprocessing of flexible endoscopes internationally. It covered three core elements: stakeholder involvement, assessment of perceived risks, and reprocessing process. Results: The survey received a total of 165 completed responses from 39 countries. It is evident that most facilities, 82% (n = 136), have a standard operating procedure. There is, however a lot of variation within the flexible endoscope reprocessing practices observed. The need for regular training and education of reprocessing practitioners were identified by 50% (n = 83) of the respondents as main concerns that need to be addressed in order to increase patient safety in endoscope reprocessing procedures. Conclusion: This international survey on current flexible endoscope reprocessing identified a large variation for reprocessing practices among different health care facilities/countries. A standardised education and training programme with a competency assessment is essential to prevent reprocessing lapses and improve patient safety.

An international survey of cleaning and disinfection practices in the healthcare environment.

BACKGROUND: Antimicrobial resistance has become an urgent global health priority. Basic hygiene practices and cleaning and disinfection of the hospital environment are key in preventing pathogen cross-transmission. AIM: To our knowledge no studies have assessed the worldwide differences in cleaning and disinfection practices in healthcare facilities. The electronic survey described here was developed in order to evaluate differences in healthcare facility cleaning practices around the world. METHODS: The International Society of Antimicrobial Chemotherapy (ISAC, formerly ISC), Infection Prevention and Control work group developed a survey with 30 multiple-choice questions. The questions were designed to assess the current cleaning practices in healthcare settings around the world. FINDINGS: A total of 110 healthcare professionals, representing 23 countries, participated in the online survey. In 96% of the facilities a written cleaning policy was present. Training of cleaning staff occurred in 70% of the facilities at the start of employment. Cleaning practices and monitoring of these practices varied. CONCLUSIONS: The survey enabled assessment and recognition of widely differing global practices in approaches to environmental cleaning and disinfection. Development of guideline recommendations for cleaning and disinfection could improve practices and set minimum standards worldwide.

Spread of carbapenem-resistant international clones of Acinetobacter baumannii in Turkey and Azerbaijan: a collaborative study.

Epidemic clones of Acinetobacter baumannii, described as European clones I, II, and III, are associated with hospital epidemics throughout the world. We aimed to determine the molecular characteristics and genetic diversity between European clones I, II, and III from Turkey and Azerbaijan. In this study, a total of 112 bloodstream isolates of carbapenem-resistant Acinetobacter spp. were collected from 11 hospitals across Turkey and Azerbaijan. The identification of Acinetobacter spp. using conventional and sensitivity tests was performed by standard criteria. Multiplex polymerase chain reaction (PCR) was used to detect OXA carbapenemase-encoding genes (bla OXA-23-like, bla OXA-24-like, bla OXA-51-like, and bla OXA-58-like). Pulsed-field gel electrophoresis (PFGE) typing was used to investigate genetic diversity. The bla OXA-51-like gene was present in all 112 isolates, 75 (67 %) carried bla OXA-23-like, 7 (6.2 %) carried bla OXA-58-like genes, and 5 (4.5 %) carried bla OXA-24-like genes. With a 90 % similarity cut-off value, 15 clones and eight unique isolates were identified. The largest clone was cluster D, with six subtypes. Isolates from clusters D and I were widely spread in seven different geographical regions throughout Turkey. However, F cluster was found in the northern and eastern regions of Turkey. EU clone I was grouped within J cluster with three isolates found in Antalya, Istanbul, and Erzurum. EU clone II was grouped in the U cluster with 15 isolates and found in Kayseri and Diyarbakir. The bla OXA-24-like gene in carbapenemases was identified rarely in Turkey and has been reported for the first time from Azerbaijan. Furthermore, this is the first multicenter study in Turkey and Azerbaijan to identify several major clusters belonging to European clones I and II of A. baumannii.

Effectiveness of a multimodal hand hygiene improvement strategy in the emergency department.

BACKGROUND: Hand hygiene (HH) is essential in preventing nosocomial infection. The emergency department (ED) is an open portal of entry for pathogens into the hospital system, hence the important sentinel function of the ED personnel. The main objective of this study was to assess the effect of a multimodal improvement strategy on hand hygiene compliance in the ED. METHODS: Our study was a prospective before-and-after study to determine the effect of a multimodal improvement strategy on the compliance of HH in the ED according to the My 5 Moments of Hand Hygiene defined by the World Health Organization. Interventions such as education, reminders, and regular feedback on HH performance and role models were planned during the 3 intervention weeks. RESULTS: In total, 57 ED nurses and ED physicians were observed in this study, and approximately 1,000 opportunities for handrubs were evaluated during the 3 intervention periods. HH compliance increased significantly from baseline from 18% (74/407) to 41% (77/190) after the first intervention and stabilized to 50% (99/200) and 46% (96/210) after the second and third interventions, respectively. CONCLUSIONS: Implementing a multimodal HH improvement program significantly improved the HH compliance of ED personnel.

Estimation of extravascular lung water using the transpulmonary ultrasound dilution (TPUD) method: a validation study in neonatal lambs.

Increased extravascular lung water (EVLW) may contribute to respiratory failure in neonates. Accurate measurement of EVLW in these patients is limited due to the lack of bedside methods. The aim of this pilot study was to investigate the reliability of the transpulmonary ultrasound dilution (TPUD) technique as a possible method for estimating EVLW in a neonatal animal model. Pulmonary edema was induced in 11 lambs by repeated surfactant lavages. In between the lavages, EVLW indexed by bodyweight was estimated by TPUD (EVLWItpud) and transpulmonary dye dilution (EVLWItpdd) (n = 22). Final EVLWItpud measurements were also compared with EVLWI estimations by gold standard post mortem gravimetry (EVLWIgrav) (n = 6). EVLWI was also measured in two additional lambs without pulmonary edema. Bland-Altman plots showed a mean bias between EVLWItpud and EVLWItpdd of -3.4 mL/kg (LOA ± 25.8 mL/kg) and between EVLWItpud and EVLWIgrav of 1.7 mL/kg (LOA ± 8.3 mL/kg). The percentage errors were 109 and 43 % respectively. The correlation between changes in EVLW measured by TPUD and TPDD was r2 = 0.22. Agreement between EVLWI measurements by TPUD and TPDD was low. Trending ability to detect changes between these two methods in EVLWI was questionable. The accuracy of EVLWItpud was good compared to the gold standard gravimetric method but the TPUD lacked precision in its current prototype. Based on these limited data, we believe that TPUD has potential for future use to estimate EVLW after adaptation of the algorithm. Larger studies are needed to support our findings.

Manual cleaning of hospital mattresses: an observational study comparing high- and low-resource settings.

BACKGROUND: Hospital-associated infections (HAIs) are more frequently encountered in low- than in high-resource settings. There is a need to identify and implement feasible and sustainable approaches to strengthen HAI prevention in low-resource settings. AIM: To evaluate the biological contamination of routinely cleaned mattresses in both high- and low-resource settings. METHODS: In this two-stage observational study, routine manual bed cleaning was evaluated at two university hospitals using adenosine triphosphate (ATP). Standardized training of cleaning personnel was achieved in both high- and low-resource settings. Qualitative analysis of the cleaning process was performed to identify predictors of cleaning outcome in low-resource settings. FINDINGS: Mattresses in low-resource settings were highly contaminated prior to cleaning. Cleaning significantly reduced biological contamination of mattresses in low-resource settings (P < 0.0001). After training, the contamination observed after cleaning in both the high- and low-resource settings seemed comparable. Cleaning with appropriate type of cleaning materials reduced the contamination of mattresses adequately. Predictors for mattresses that remained contaminated in a low-resource setting included: type of product used, type of ward, training, and the level of contamination prior to cleaning. CONCLUSION: In low-resource settings mattresses were highly contaminated as noted by ATP levels. Routine manual cleaning by trained staff can be as effective in a low-resource setting as in a high-resource setting. We recommend a multi-modal cleaning strategy that consists of training of domestic services staff, availability of adequate time to clean beds between patients, and application of the correct type of cleaning products.

A cross-sectional observational study about media and infection control practices: are photographic portrayals of healthcare workers setting a bad example?

BACKGROUND: Attempts to increase compliance with infection control practices are complex and are - in part - based on attempts to change behaviour. In particular, the behaviour of significant peers (role models) has been shown to be a strong motivator. While role models within the working environment are obviously the most important, some experts suggest that media and public display cannot be ignored. The aim of this present study was to examine the display of technique recommended by current infection control guidelines including the "bare below the elbow" principle, which is considered a basic requirement for good infection control in many countries, in sets of professional stock photos. FINDINGS: From 20 random photo-stock websites we selected pictures with search terms "doctor and patient" and "nurse and patient". In all selected photos a doctor or nurse and a patient were presented, healthcare workers (HCWs) were wearing white coats or uniforms, and their arms were visible. Each photo was evaluated with regard to: closure of white coat, sleeve length, personal clothing covered, hairstyle and presence of a wristwatch, bracelet and/or ring. Overall, 1600 photos were evaluated. The most common mistakes were with regard to HCWs' white coats/uniforms. Eighty-nine percent of the photos containing doctor's images were considered incorrect while 28 % of nurse-containing photos were incorrect. CONCLUSIONS: The results seem to reflect the real world with only 40 % displaying correct behaviour with doctors being worse than nurses. It seems that the stereotypical image of a doctor does not agree with the current infection control guidelines. If we aim for higher compliance rates of HCWs, we need to change the social image of doctors and improve production, selection and display of stock photo images.

Mechanical vs. manual cleaning of hospital beds: a prospective intervention study.

BACKGROUND: Cleaning regimens for hospital beds were evaluated in the context of a rising prevalence of highly resistant micro-organisms and increasing financial pressure on healthcare systems. Dutch hospitals have to choose between standardized, mechanical bed-washers advised in national guidance and manual cleaning. AIM: To evaluate the quality of mechanical and manual bed-cleaning regimens. METHODS: The multi-faceted analysis of bed-cleaning regimens consisted of three steps. In Step 1, the training of the domestic service team was evaluated. In Step 2, the cleaning quality of manual and mechanical regimens was assessed. Soiled beds, obtained at random, from different departments were evaluated using microbiological analysis (N = 40) and ATP (N = 20). ATP and microbiological contamination were measured in five predetermined locations on all beds. In Step 3, manual cleaning was introduced over a two-month pilot study at the surgical short-stay unit, and beds from other departments were processed according to the 'gold standard' mechanical cleaning. ATP levels were evaluated in three locations on 300 beds after cleaning. FINDINGS: Training was found to improve the quality of cleaning significantly. Mechanical cleaning resulted in significantly lower ATP levels than manual cleaning. CONCLUSIONS: Mechanical cleaning shows less variation and results in consistently lower ATP levels than manual cleaning.

Teacher characteristics, social classroom relationships, and children's social, emotional, and behavioral classroom adjustment in special education.

The goal of this study was to explore relations between teacher characteristics (i.e., competence and wellbeing); social classroom relationships (i.e., teacher-child and peer interactions); and children's social, emotional, and behavioral classroom adjustment. These relations were explored at both the individual and classroom levels among 414 children with emotional and behavioral disorders placed in special education. Two models were specified. In the first model, children's classroom adjustment was regressed on social relationships and teacher characteristics. In the second model, reversed links were examined by regressing teacher characteristics on social relationships and children's adjustment. Results of model 1 showed that, at the individual level, better social and emotional adjustment of children was predicted by higher levels of teacher-child closeness and better behavioral adjustment was predicted by both positive teacher-child and peer interactions. At the classroom level, positive social relationships were predicted by higher levels of teacher competence, which in turn were associated with lower classroom levels of social problems. Higher levels of teacher wellbeing were directly associated with classroom adaptive and maladaptive child outcomes. Results of model 2 showed that, at the individual and classroom levels, only the emotional and behavioral problems of children predicted social classroom relationships. At the classroom level, teacher competence was best predicted by positive teacher-child relationships and teacher wellbeing was best predicted by classroom levels of prosocial behavior. We discuss the importance of positive teacher-child and peer interactions for children placed in special education and suggest ways of improving classroom processes by targeting teacher competence.

Developmental links between disobedient behavior and social classroom relationships in boys with psychiatric disorders in special education.

In mainstream education, positive relationships with teachers and peers have been found to positively influence children's behavioral development. However, high levels of classroom behavior problems may hinder the formation of such positive relationships. Therefore, findings from mainstream education cannot be generalized to special education. The present study investigated the developmental links between disobedience and positive as well as negative relationships with teachers and peers among boys in restrictive special educational settings. At three assessment waves across one school year, teacher-reports of teacher-child closeness and conflict, and peer-reports of peer acceptance, rejection and disobedience were collected among 340 boys (mean age = 10.1 years, SD = 1.58, range = 5-13) with psychiatric disorders receiving special education. Autoregressive cross-lagged models were fitted to explore the nature of these developmental links. The impact of boys' age was examined using multiple group analyses. Findings supported the importance of teacher-child conflict, but not closeness, and positive and negative peer relationships for the development of boys' disobedience, with a stronger effect of negative than positive relationships. However, teacher-child and peer relationships were not longitudinally related and the effect of boys' age was minimal. This study extends prior research by suggesting that, despite differences in educational setting and severity of behavior problems between children in mainstream and special education, reducing negative classroom interactional patterns is most important in preventing the development of problematic classroom behavior in boys with severe social-emotional and behavioral difficulties.

Influence of lung injury on cardiac output measurement using transpulmonary ultrasound dilution: a validation study in neonatal lambs.

BACKGROUND: Transpulmonary ultrasound dilution (TPUD) is a promising method for cardiac output (CO) measurement in severely ill neonates. The incidence of lung injury in this population is high, which might influence CO measurement using TPUD because of altered lung perfusion. We evaluated the influence of lung injury on the accuracy and precision of CO measurement using TPUD in an animal model. METHODS: In nine neonatal lambs, central venous and arterial catheters were inserted and connected to the TPUD monitor. Repeated lavages with warmed isotonic saline were performed to gradually induce lung injury. CO measurements with TPUD (COtpud) were compared with those obtained by an ultrasonic transit-time flow probe around the main pulmonary artery (COufp). An increase in oxygenation index was used as an indicator of induced lung injury during the experiment. Post-mortem lung injury was confirmed by histopathological examination. RESULTS: Fifty-five sessions of three paired CO measurements were analysed. The mean COufp was 1.53 litre min(-1) (range 0.66-2.35 litre min(-1)), and the mean COtpud was 1.65 litre min(-1) (range 0.78-2.91 litre min(-1)). The mean bias (standard deviation) between the two methods was 0.13 (0.15) litre min(-1) with limits of agreement of ±0.29 litre min(-1). The overall percentage error was 19.1%. The accuracy and precision did not change significantly during progressive lung injury. Histopathological severity scores were consistent with heterogeneous lung injury. The capability to track changes in CO using TPUD was moderate to good. CONCLUSIONS: The accuracy and precision of CO measurement using TPUD is not influenced in the presence of heterogeneous lung injury in an animal model.

Cardiac output measurement with transpulmonary ultrasound dilution is feasible in the presence of a left-to-right shunt: a validation study in lambs.

BACKGROUND: Cardiac output (CO) monitoring remains complex in newborns as most of the current technologies fail to accurately measure systemic blood flow in the presence of shunts. We validated CO measurements using transpulmonary ultrasound dilution (TPUD) in a neonatal lamb model with a left-to-right shunt. METHODS: Regular arterial and central venous catheters were inserted into seven lambs (3.5-8.3 kg). A surgically constructed left-to-right aorto-pulmonary Gore-Tex(®) shunt was intermittently opened and closed, while CO was manipulated by creating haemorrhagic hypotension. CO measurements with TPUD (COtpud) were compared with those obtained by an ultrasonic transit-time flow probe positioned around the main pulmonary artery (COufp). RESULTS: We performed 72 sessions of three paired CO measurements. The mean COufp was 1.00 litre min(-1) (range 0.47-1.75 litre min(-1)) and mean COtpud 1.05 litre min(-1) (range 0.54-1.87 litre min(-1)). With an open shunt, the mean Qp/Qs ratio was 1.8 (range 1.3-2.6). A comparison between COufp and COtpud showed a mean bias (sd) of 0.03 (0.09) and 0.07 (0.10) litre min(-1), respectively, for measurements with a closed and an open shunt. The percentage error was 18% and 20% for measurements with a closed and an open shunt. Polar plot analysis showed good trending ability for both closed and open shunt groups. CONCLUSIONS: TPUD is a reliable technology to measure CO in the presence of a left-to-right shunt.

Cardiac output can be measured with the transpulmonary thermodilution method in a paediatric animal model with a left-to-right shunt.

BACKGROUND: The transpulmonary thermodilution (TPTD) technique for measuring cardiac output (CO) has never been validated in the presence of a left-to-right shunt. METHODS: In this experimental, paediatric animal model, nine lambs with a surgically constructed aorta-pulmonary left-to-right shunt were studied under various haemodynamic conditions. CO was measured with closed and open shunt using the TPTD technique (CO(TPTD)) with central venous injections of ice-cold saline. An ultrasound transit time perivascular flow probe around the main pulmonary artery served as the standard reference measurement (CO(MPA)). RESULTS: Seven lambs were eligible for further analysis. Mean (sd) weight was 6.6 (1.6) kg. The mean CO(MPA) was 1.21 litre min(-1) (range 0.61-2.06 l min(-1)) with closed shunt and 0.93 litre min(-1) (range 0.48-1.45 litre min(-1)) with open shunt. The open shunt resulted in a mean Q(p)/Q(s) ratio of 1.8 (range 1.6-2.4). The bias between the two CO methods was 0.17 litre min(-1) [limits of agreement (LOA) of 0.27 litre min(-1)] with closed shunt and 0.14 litre min(-1) (LOA of 0.32 litre min(-1)) with open shunt. The percentage errors were 22% with closed shunt and 34% with open shunt. The correlation (r) between the two methods was 0.93 (P<0.001) with closed shunt and 0.86 (P<0.001) with open shunt. The correlation (r) between the two methods in tracking changes in CO (ΔCO) during the whole experiment was 0.94 (P<0.0001). CONCLUSIONS: The TPTD technique is a feasible method of measuring CO in paediatric animals with a left-to-right shunt.

Effects of midazolam and morphine on cerebral oxygenation and hemodynamics in ventilated premature infants.

BACKGROUND: Midazolam sedation and morphine analgesia are commonly used in ventilated premature infants. OBJECTIVES: To evaluate the effects of midazolam versus morphine infusion on cerebral oxygenation and hemodynamics in ventilated premature infants. METHODS: 11 patients (GA 26.6-33.0 weeks, BW 780-2,335 g) were sedated with midazolam (loading dose 0.2 mg/kg, maintenance 0.2 mg/kg/h) and 10 patients (GA 26.4-33.3 weeks, BW 842-1,955 g) were sedated with morphine (loading dose 0.05 mg/kg, maintenance 0.01 mg/kg/h). Changes in oxyhemoglobin (Delta cO2Hb) and deoxyhemoglobin (Delta cHHb) were assessed using near infrared spectrophotometry. Changes in cHbD (= Delta cO(2)Hb - Delta cHHb) reflect changes in cerebral blood oxygenation and changes in concentration of total hemoglobin (Delta ctHb = Delta cO2Hb + Delta cHHb) represent changes in cerebral blood volume (DeltaCBV). Changes in cerebral blood flow velocity (DeltaCBFV) were intermittently measured using Doppler ultrasound. Heart rate (HR), mean arterial blood pressure (MABP), arterial oxygen saturation (saO2) and transcutaneous measured pO2 (tcpO2) and pCO2 (tcpCO2) were continuously registered. Statistical analyses were carried out using linear mixed models to account for the longitudinal character study design. RESULTS: Within 15 min after the loading dose of midazolam, a decrease in saO2, tcpO2 and cHbD was observed in 5/11 infants. In addition, a fall in MABP and CBFV was observed 15 min after midazolam administration. Immediately after morphine infusion a decrease in saO2, tcpO2 and cHbD was observed in 6/10 infants. Furthermore, morphine infusion resulted in a persistent increase in CBV. CONCLUSIONS: Administration of midazolam and morphine in ventilated premature infants causes significant changes in cerebral oxygenation and hemodynamics, which might be harmful.

Effects of rapid versus slow infusion of sodium bicarbonate on cerebral hemodynamics and oxygenation in preterm infants.

BACKGROUND: Sodium bicarbonate (NaHCO3) is often used for correction of metabolic acidosis in preterm infants. The effects of NaHCO3 administration on cerebral hemodynamics and oxygenation are not well known. Furthermore, there is no consensus on infusion rate of NaHCO3. OBJECTIVES: To evaluate the effects of rapid versus slow infusion of NaHCO3 on cerebral hemodynamics and oxygenation in preterm infants. METHODS: Twenty-nine preterm infants with metabolic acidosis were randomized into two groups (values are mean +/-SD): In group A (GA 30.5 +/- 1.7 weeks, b.w. 1,254 +/- 425 g) NaHCO3 4.2% was injected as a bolus. In group B (GA 30.3 +/- 1.8 weeks, b.w. 1,179 +/- 318 g) NaHCO3 4.2% was administered over a 30-min period. Concentration changes of oxyhemoglobin (cO2Hb) and deoxyhemoglobin (cHHb) were assessed using near infrared spectrophotometry. Changes in HbD (= cO2Hb - cHHb) represent changes in cerebral blood oxygenation and changes in ctHb (= cO2Hb + cHHb) reflect changes in cerebral blood volume. Cerebral blood flow velocity was intermittently measured using Doppler ultrasound. Longitudinal data analysis was performed using linear mixed models (SAS procedure MIXED), to account for the fact that the repeated observations in each individual were correlated. RESULTS: Administration of NaHCO3 resulted in an increase of cerebral blood volume which was more evident if NaHCO3 was injected rapidly than when infused slowly. HbD and cerebral blood flow velocity did not show significant changes in either group. CONCLUSION: To minimize fluctuations in cerebral hemodynamics, slow infusion of sodium bicarbonate is preferable to rapid injection.