Non-surgical external jugular vein catheterization using an ear vein access in piglets.

The objective of this study was to investigate the feasibility of external jugular vein catheterization through an ear vein in piglets. Forty-six sevoflurane-midazolam anaesthetized piglets were included. External jugular vein catheterization was conducted through the ear vein using the Seldinger technique. Part 1 (n = 27): optimal puncture site was based on the deltoid tuberosity as a landmark to reach the external jugular vein. The final position of the catheter was verified in 25 piglets using computer tomography. Catheterization time was recorded and patency of the catheter assessed by repeated blood sampling for up to 4 h. Part 2 (n = 19): ear vein catheterization was without taking into account any landmarks. Functionality for blood sampling was evaluated as described in part 1. Catheter advancement was possible in 25/27 and 18/19 piglets in parts 1 and 2, respectively. Median (range) time required for successful catheterization was 1.95 (1-10) min (n = 38). The deltoid tuberosity was a good landmark to reach the external jugular vein. But blood sampling was also possible through catheters ending slightly cranial to the external jugular vein. Despite successful catheter advancement, blood sampling was not possible from one catheter in each part of the study (total: two piglets). One of these catheters presented luminal damage, while the other one presented as normal after being removed from the animal. Summarizing, central vein catheterization through the ear vein was feasible in 93.5% and repeated blood sampling was possible in 89.1% of the piglets (n = 46).

Effects of moderate and severe arterial hypotension on intracerebral perfusion and brain tissue oxygenation in piglets.

BACKGROUND: Hypotension is common in anaesthetised children, and its impact on cerebral oxygenation is unknown. The goal of the present study was to investigate the effects of moderate systemic arterial hypotension (mHT) and severe hypotension (sHT) on cerebral perfusion and brain tissue oxygenation in piglets. METHODS: Twenty-seven anaesthetised piglets were randomly allocated to a control group, mHT group, or sHT group. Cerebral monitoring comprised a tissue oxygen partial pressure ( [Formula: see text] ) and laser Doppler (LD) perfusion probe advanced into the brain tissue, and a near-infrared spectroscopy sensor placed over the skin measuring regional oxygen saturation (rSO2). Arterial hypotension was induced by blood withdrawal and i.v. nitroprusside infusion [target MAP: 35-38 (mHT) and 27-30 (sHT) mm Hg]. Data were analysed at baseline, and every 20 min during and after treatment. RESULTS: Compared with control, [Formula: see text] decreased equally with mHT and sHT [mean (SD) after 60 min: control: 17.1 (6.4); mHT: 6.4 (3.6); sHT: 7.2 (4.3) mm Hg]. No differences between groups were detected for rSO2 and LD during treatment. However, in the sHT group, rSO2 increased after restoring normotension [from 49.3 (9.5) to 58.9 (8.9)% Post60]. sHT was associated with an increase in blood lactate [from 1.5 (0.4) to 2.4 (0.9) mmol L-1], and a decrease in bicarbonate [28 (2.4) to 25.8 (2.6) mmol L-1] and base excess [4.7 (1.9) to 2.0 (2.7) mmol L-1] between baseline and 60 min after the start of the experiment. CONCLUSIONS: Induction of mHT and sHT by hypovolaemia and nitroprusside infusion caused alterations in brain tissue oxygenation in a piglet model, but without detectable changes in brain tissue perfusion and regional oxygen saturation.

Systematic review of the neurocognitive outcomes used in studies of paediatric anaesthesia neurotoxicity.

BACKGROUND: Neurotoxicity of anaesthetics in developing brain cells is well documented in preclinical studies, yet results are conflicting in humans. The use of many and different outcome measures in human studies may contribute to this disagreement. METHODS: We conducted a systematic review to identify all measures used to assess long-term neurocognitive outcomes following general anaesthesia (GA) and surgery in children. The quality of studies was assessed according to the Newcastle-Ottawa Scale (NOS) for observational studies. PubMed/MEDLINE, EMBASE, Cinahl, Web of Science, and the Cochrane Library were searched for studies investigating neurocognitive outcome after GA in children <18 yr. RESULTS: Sixty-seven studies were identified from 19 countries during 1990-2017. Most assessments were performed within cognition, sensory-motor development, academic achievement or neuropsychological diagnosis. Few studies assessed other outcomes (magnetic resonance imaging, serum-biomarkers, mortality, neurological examination, measurement of head circumference, impairment of vision). Rating according to the NOS rewarded a mean of six stars out of nine. Some concerns prevail regarding potential inter-rater variability because of equivocal description of rating criteria. Specific features such as stability over lifetime and inter-relations of outcomes (e.g. prediction of subsequent development or diagnosis of neuropsychological conditions) are discussed. The importance of validity and reliability of the various test instruments are described. The studies vary immensely in important characteristics. CONCLUSIONS: Future observational studies should be more consistent in the choice of study population, age at exposure, follow-up, indication for and type of surgery, and outcomes. Assessment of sensory-motor development seems feasible in young children (age <4 yr), and intelligence/cognition in older children.

Effectiveness of tip rotation in fibreoptic bronchoscopy under different experimental conditions: an in vitro crossover study.

Background: Proper manipulation of fibreoptic bronchoscopes is essential for successful tracheal intubation or diagnostic bronchoscopy. Failure of proper navigation and rotation of the fibrescope may lead to difficulties in advancing the fibrescope and might also be responsible for (unnecessary) difficulties and delays in fibreoptic tracheal intubation, with subsequent hypoxaemia. The present study, therefore, aimed to assess the effectiveness of tip rotation in flexible bronchoscopes in different experimental conditions. Methods: Five differently sized pairs of fibrescopes (outer diameters of 2.2, 2.4, 3.5, 4.2, and 5.2 mm) were inserted into paediatric airway manikins via an appropriately sized laryngeal mask and were turned clockwise or anticlockwise at the fibrescope body or cord to 45, 90, and 180°, with the cord held either straight or bent. The primary outcome measure was the ratio of rotation measured at the tip over the rotation performed with the fibrescope body or cord. Results: Overall, the 'body' turn was significantly less effective when a bent cord was present (mean difference ranging from 29.8% (95% confidence interval 8.8-50.9) to 117.4% (93.6-141.2). This difference was diminished when the 'cord' turn was performed. Smaller fibrescopes, with outer diameters of 2.2 and 2.4 mm, were inferior with respect to the transmission of 'body' rotation to the tip. Conclusions: 'Cord' turning of the fibrescope appears to be more effective in rotating the tip than a turn of the fibrescope 'body' only. Straightening the fibrescope cord and combined 'body' and 'cord' turning are recommended.