Effect of hyperextension of the neck (rose position) on cerebral blood oxygenation in patients who underwent cleft palate reconstructive surgery: prospective cohort study using near-infrared spectroscopy.

OBJECTIVES: To facilitate the best approach during cleft palate surgery, children are positioned with hyperextension of the neck. Extensive head extension may induce intraoperative cerebral ischemia if collateral flow is insufficient. To evaluate and monitor the effect of cerebral blood flow on cerebral tissue oxygenation, near-infrared spectroscopy has proved to be a valuable method. The aim of this study was to evaluate and quantify whether hyperextension affects the cerebral tissue oxygenation in children during cleft palate surgery. MATERIALS AND METHODS: This prospective study included children (ASA 1 and 2) under the age of 3 years old who underwent cleft palate repair at the Wilhelmina Children's Hospital, in The Netherlands. Data were collected for date of birth, cleft type, date of cleft repair, and physiological parameters (MAP, saturation, heart rate, expiratory CO2 and O2, temperature, and cerebral blood oxygenation) during surgery. The cerebral blood oxygenation was measured with NIRS. RESULTS: Thirty-four children were included in this study. The majority of the population was male (61.8%, n = 21). The mixed model analyses showed a significant drop at time of Rose position of - 4.25 (69-74 95% CI; p < 0.001) and - 4.39 (69-74 95% CI; p < 0.001). Postoperatively, none of the children displayed any neurological disturbance. CONCLUSION: This study suggests that hyperextension of the head during cleft palate surgery leads to a significant decrease in cerebral oxygenation. Severe cerebral desaturation events during surgery were uncommon and do not seem to be of clinical relevance in ASA 1 and 2 children. CLINICAL RELEVANCE: There was a significant drop in cerebral oxygenation after positioning however it is not clear whether this drop is truly significant physiologically in ASA 1 and 2 patients.

The effect of intrathecal bupivacaine/morphine on quality of recovery in robot-assisted radical prostatectomy: a randomised controlled trial.

Robot-assisted radical prostatectomy causes discomfort in the immediate postoperative period. This randomised controlled trial investigated if intrathecal bupivacaine/morphine, in addition to general anaesthesia, could be beneficial for the postoperative quality of recovery. One hundred and fifty-five patients were randomly allocated to an intervention group that received intrathecal 12.5 mg bupivacaine/300 µg morphine (20% dose reduction in patients > 75 years) or a control group receiving a subcutaneous sham injection and an intravenous loading dose of 0.1 mg.kg-1 morphine. Both groups received standardised general anaesthesia and the same postoperative analgesic regimen. The primary outcome was a decrease in the Quality of Recovery-15 (QoR-15) questionnaire score on postoperative day 1. The intervention group (n = 76) had less reduction in QoR-15 on postoperative day 1; median (IQR [range]) 10% (1-8 [-60% to 50%]) vs. 13% (5-24 [-6% to 50%]), p = 0.019, and used less morphine during the admission; 2 mg (1-7 [0-41 mg]) vs. 15 mg (12-20 [8-61 mg]), p < 0.001. Furthermore, they perceived lower pain scores during exertion; numeric rating scale (NRS) 3 (1-6 [0-9]) vs. 5 (3-7 [0-9]), p = 0.001; less bladder spasms (NRS 1 (0-2 [0-10]) vs. 2 (0-5 [0-10]), p = 0.001 and less sedation; NRS 2 (0-3 [0-10]) vs. 3 (2-6 [0-10]), p = 0.005. Moreover, the intervention group used less rescue medication. Pruritus was more severe in the intervention group; NRS 4 (1-7 [0-10]) vs. 0 (0-1 [0-10]), p = 0.000. We conclude that despite a modest increase in the incidence of pruritus, multimodal pain management with intrathecal bupivacaine/morphine remains a viable option for robot-assisted radical prostatectomy.

Differences in Blood Pressure in Infants After General Anesthesia Compared to Awake Regional Anesthesia (GAS Study-A Prospective Randomized Trial).

BACKGROUND: The General Anesthesia compared to Spinal anesthesia (GAS) study is a prospective randomized, controlled, multisite, trial designed to assess the influence of general anesthesia (GA) on neurodevelopment at 5 years of age. A secondary aim obtained from the blood pressure data of the GAS trial is to compare rates of intraoperative hypotension after anesthesia and to identify risk factors for intraoperative hypotension. METHODS: A total of 722 infants ≤60 weeks postmenstrual age undergoing inguinal herniorrhaphy were randomized to either bupivacaine regional anesthesia (RA) or sevoflurane GA. Exclusion criteria included risk factors for adverse neurodevelopmental outcome and infants born at <26 weeks of gestation. Moderate hypotension was defined as mean arterial pressure measurement of <35 mm Hg. Any hypotension was defined as mean arterial pressure of <45 mm Hg. Epochs were defined as 5-minute measurement periods. The primary outcome was any measured hypotension <35 mm Hg from start of anesthesia to leaving the operating room. This analysis is reported primarily as intention to treat (ITT) and secondarily as per protocol. RESULTS: The relative risk of GA compared with RA predicting any measured hypotension of <35 mm Hg from the start of anesthesia to leaving the operating room was 2.8 (confidence interval [CI], 2.0-4.1; P < .001) by ITT analysis and 4.5 (CI, 2.7-7.4, P < .001) as per protocol analysis. In the GA group, 87% and 49%, and in the RA group, 41% and 16%, exhibited any or moderate hypotension by ITT, respectively. In multivariable modeling, group assignment (GA versus RA), weight at the time of surgery, and minimal intraoperative temperature were risk factors for hypotension. Interventions for hypotension occurred more commonly in the GA group compared with the RA group (relative risk, 2.8, 95% CI, 1.7-4.4 by ITT). CONCLUSIONS: RA reduces the incidence of hypotension and the chance of intervention to treat it compared with sevoflurane anesthesia in young infants undergoing inguinal hernia repair.

Perioperative hospital mortality at a tertiary paediatric institution.

BACKGROUND: Research in postoperative mortality is scarce. Insight into mortality and cause of death might improve and innovate perioperative care. The objective for this study was to report the 24-hour and 30-day overall, and surgery and anaesthesia-related, in-hospital mortality at a tertiary paediatric hospital. METHODS: All patients <18 yr old who underwent anaesthesia with or without surgery between January 1, 2006, and December 31, 2012, at the Wilhelmina Children's Hospital, Utrecht, The Netherlands, were included in this retrospective cohort study. Causes of death within 30 days were identified and tabulated into four major categories according to principal cause. RESULTS: A total of 45,182 anaesthetics were administered during this 7-yr period. The all-cause 24-hour hospital mortality was 13.1 per 10,000 anaesthetics (95% CI: 9.9-16.8) and the all-cause 30-day in-hospital mortality was 41.6 per 10,000 anaesthetics (95% CI: 35.9-48.0). In total five patients were partially contributable to anaesthesia (30-day mortality: 1.1/10,000, 95% CI: 0.4-2.6) and four patients were partially contributable to surgery (30-day mortality: 0.9/10,000, 95% CI: 0.2-2.3). Mortality was higher in neonates and infants, children with ASA physical status III and IV, and emergency- and cardiothoracic surgery. CONCLUSIONS: Neonates and infants, children with ASA physical status III or poorer, and emergency- and cardiothoracic surgery are associated with a higher postoperative mortality. Anaesthesia- or surgery-related complications contribute to mortality in only a small amount of the deaths, indicating the relative safety of paediatric surgical and anaesthetic procedures.

Near-infrared light to aid peripheral intravenous cannulation in children: a cluster randomised clinical trial of three devices.

Intravenous cannulation can be difficult in children. Recently, new devices using near-infrared light to make blood vessels visible have become available. We aimed to evaluate the effectiveness of three such devices in facilitating peripheral intravenous cannulation in children. In this cluster randomised clinical trial, daily operating rooms at a tertiary childrens' hospital were randomised to the use of the VeinViewer®, AccuVein® AV300, VascuLuminator Vision® or to a control group. We included 1913 children between birth and 18 years scheduled for elective surgery. Suitable veins for cannulation were more easily visible with the VeinViewer (307/322 (95.3%)) and AccuVein (239/254 (94.1%)) devices than with VascuLuminator (229/257 (89.1%)) (p = 0.03). However, success at the first attempt was not significantly different among groups, ranging from 73.1% to 75.3% (p = 0.93). We conclude that although vein visibility is enhanced, near-infrared devices do not improve cannulation.

General anesthesia as a possible GABAergic modulator affects visual processing in children.

Gamma-Aminobutyric Acid (GABA) inhibitory interneurons play an important role in visual processing, as is revealed by studies administering drugs in human and monkey adults. Investigating this process in children requires different methodologies, due to ethical considerations. The current study aimed to investigate whether a new method, being general anesthesia using Sevoflurane, can be used to trace the effects of GABAergic modulation on visual brain functioning in children. To this aim, visual processing was investigated in children aged 4-12 years who were scheduled for minor urologic procedures under general anesthesia in day-care treatment. In a visual segmentation task, the difference in Event-Related Potential (ERP) response to homogeneous and textured stimuli was investigated. In addition, psychophysical performance on visual acuity and contrast sensitivity were measured. Results were compared between before and shortly after anesthesia. In two additional studies, effects at 1 day after anesthesia and possible effects of task-repetition were investigated. ERP results showed longer latency and lower amplitude of the Texture Negativity (TN) component shortly after compared to before anesthesia. No effects of anesthesia on psychophysical measurements were found. No effects at 1 day after anesthesia or of repetition were revealed either. These results show that GABAergic modulation through general anesthesia affects ERP reflections of visual segmentation in a similar way in children as benzodiazepine does in adults, but that effects are not permanent. This demonstrates that ERP measurement after anesthesia is a successful method to study effects of GABAergic modulation in children.

Difficult arterial cannulation in children: is a near-infrared vascular imaging system the answer?

BACKGROUND: Arterial cannulation is a common anaesthetic procedure that can be challenging and time-consuming in small children. By visualizing the position of the radial artery, near-infrared vascular imaging systems (NIRVISs) might be of assistance in arterial cannulation. The present study evaluates the effectiveness of an NIRVIS in arterial cannulation in infants. METHODS: An observational study was conducted in patients up to 3 yr old, undergoing arterial cannulation before cardiothoracic surgery. Arterial cannulation was performed as usual in 38 patients, and subsequently with the NIRVIS in 39 patients. RESULTS: The time to successful cannulation was 547 s (171-1183) without and 464 s (174-996) with the NIRVIS (P=0.76) and the time to first flashback of blood was 171 s (96-522) and 219 s (59-447), respectively (P=0.38). There was a tendency in favour of the NIRVIS in success at first attempt: 12/38 and 7/39, respectively (P=0.29) and in the number of punctures: 6 (2-12) and 3 (1-7), respectively (P=0.10). CONCLUSIONS: The present study did not show a significant clinical improvement when NIR light was used during arterial cannulation in small children. There is a large difference between time to first flashback of blood and time to successful cannulation, indicating that inserting the cannula, and not localizing the artery, is the main difficulty in arterial cannulation in children.

Medication discontinuity errors in the perioperative period.

BACKGROUND: Inappropriate withdrawal or continuation of medication in the perioperative period is associated with an increased risk for adverse events. To reduce this risk, it is important that patients take their regular medication as prescribed. We evaluated this treatment objective by studying the frequency and reasons for errors related to medication discontinuity in the perioperative period. METHODS: Patients scheduled for non-cardiac surgery were included in this cross-sectional study. Perioperative medication intake was assessed at the holding area of the operation theatre complex and on the ward during the first 24 h after surgery. Medication intake data were obtained from medical records and by questioning patients and compared with pre-operative instructions. RESULTS: The study included 701 patients, of whom 485 (69%) used regular medication. Medication was incorrectly taken or discontinued before surgery in 27% of the patients. In 57% of these patients, the reason for incorrect intake was an unclear or a falsely understood instruction before surgery. Post-operative medication errors occurred in 26% of the patients. CONCLUSION: Medication errors occur frequently in the perioperative period, even in the era of an electronic medication file. Errors in prescription, administration and intake of medication are not easily solved because no single health care professional is responsible for adequate intake of medication in surgical patients. The anaesthesiologist should take on a more prominent role in regulating perioperative medication intake in surgical patients.

Early transection of a central venous catheter in a sedated ICU patient.

We report transection and embolization to the heart of a subclavian venous catheter in an immobilized and mechanical ventilated patient. The catheter tip was retrieved using a percutaneous method via the left femoral vein. Mechanical compression of the subclavian venous catheter at the costoclavicular area is termed pinch-off syndrome. It can be recognized by intermittent difficulties with drug injection, and chest wall swelling at the insertion site. The diagnosis can be confirmed by chest radiography with or without contrast administration. A more lateral approach of the subclavian vein is advocated to prevent compression.

Interobserver variation in duplex scanning of infrainguinal arterial bypass grafts.

OBJECTIVE: to determine the degree of interobserver variation of color-flow duplex scanning of infrainguinal arterial bypass grafts. METHODS: two experienced vascular technologists randomly assessed bypass grafts in 32 consecutive patients, using a color-flow duplex scan. In pre-defined segments the highest peak systolic velocity (PSV(max)) and end-diastolic velocity (EDV) were measured and a peak systolic velocity ratio (PSV ratio) was calculated. Results were analyzed as continuous variables (Bland and Altman plots and Intraclass Correlation Coefficient=ICC) and also as categorical data (weighted Kappa coefficient) for the PSV ratio 1-2.5, > or =2.5-4, > or =4.0. RESULTS: the ICC for the PSV(max), PSV ratio and EDV indicated "almost perfect" agreement for all three parameters. However, the Bland and Altman plots showed impressive interobserver variation for the higher values of all three parameters. For the PSV ratio categories a weighted kappa of 0.31 was calculated, indicating only fair agreement. Substantial variation was found for the categories with PSV ratios > or =2.5-4.0 and > or =4.0. CONCLUSION: though performing accurately for the lower values of the assessed parameters, duplex scanning shows considerable interobserver variation for the clinically significant higher values. Particularly in the PSV ratio interval > or =2.5-4.0, most relevant for clinical decision-making, the interobserver variability is unacceptable.

Comparison of OPS imaging and conventional capillary microscopy to study the human microcirculation.

Orthogonal polarization spectral (OPS) imaging is a new clinical technique for observation of the microcirculation of organ surfaces. For validation purposes, we compared OPS images of the nailfold skin with those obtained from conventional capillary microscopy at rest and during venous occlusion in 10 male volunteers. These images were computer analyzed to provide red blood cell velocity and capillary diameters of the same nailfold capillaries at rest and during venous occlusion. Results showed that OPS images provided similar values for red blood cell velocity and capillary diameter as those obtained from capillary microscopy images. OPS imaging, however, provided significantly better image quality, as shown by comparison of image contrast between OPS imaging and capillary microscopy. This made image analysis better and easier to perform. It is anticipated, therefore, that OPS imaging will become a new and powerful technique in the study of the human microcirculation in vivo because it can be used on human internal organs.

Interobserver and intraobserver reproducibility of peripheral blood and oxygen pressure measurements in the assessment of lower extremity arterial disease.

INTRODUCTION: Peripheral blood pressure measurements play a prominent role in the diagnosis and follow-up of patients with peripheral vascular diseases. Toe pressure of the hallux (TP1) and second toe (TP2) and transcutaneous oxygen pressure (TCPO2) measurements are becoming more important. The ankle/brachial pressure index (ABPI) is known to be a reliable parameter, but the toe pressure and TCPO2 are evaluated less thoroughly. Therefore, we evaluated the reproducibility of TP1, TP2, TCPO2, ABPI, ankle pressure (AP), and brachial pressure (BP). PATIENTS AND METHODS: In 54 patients with various stages of peripheral vascular disease, the intraobserver and interobserver reproducibility of BP, AP, ABPI, TP1, TP2, and TCPO2 was investigated by calculating the repeatability coefficient (RC) and the intraclass correlation coefficient (ICC) and by using Bland-Altman plots. RESULTS: The intraobserver and interobserver reproducibility at 1 day and after 1 week of BP, AP, ABPI, and TP1 was substantial and comparable (ICC range, 0.80-0.99), except for the BP after 1 week. The TP2 and TCPO2 were less reproducible (ICC range, 0.62-0.98). The interobserver RC of BP was 31 mm Hg; of AP, 44 mm Hg; of ABPI, 27%; of TP1, 41 mm Hg; of TP2, 67 mm Hg; and of TCPO2; 30 mm Hg. The difference plot showed that the observer variability was equally distributed across the range of pressure in all measurements. CONCLUSION: The BP, AP, ABPI, and TP1 have a substantial intraobserver and interobserver reproducibility, whereas TP2 and TCPO2 show worse reproducibility. Especially when low values (or values around a cutoff value) are measured, the RC should be taken into account, and repetition of the measurement is advocated.

The diagnosis of deep venous thrombosis using laser Doppler skin perfusion measurements.

Compression ultrasonography (CUS) falls short in the diagnosis of deep venous thrombosis in asymptomatic patients and thrombi limited to the calf veins. Alternatively, laser Doppler fluxmetry (LDF) may be useful for this purpose, as it can measure the peripheral vasoconstriction response upon an increase in venous pressure, which is hypothetically preactivated upon venous damming by a thrombus. We investigated the merits of LDF in the diagnosis of DVT. In 81 outpatients, referred with clinically suspected unilateral DVT, skin perfusion in the symptomatic and contralateral legs was measured in the big toe by measuring resting flux (RF) before and during an increase in venous pressure by inflating an ankle cuff to 50 mm Hg. The percentage of LDF reduction (LDFr) was used as a parameter to detect DVT and compared with an independent gold standard (a combination of CUS, D-dimer testing, and 3-month clinical follow-up). The prevalence of DVT was 31%. LDFr in symptomatic legs with DVT [24%; interquartile range (IQR) 8-44%] was significantly (P < 0.001) lower than in symptomatic legs without DVT (60%; IQR 44-70%). Assessment of the diagnostic accuracy of LDF yielded an area under the ROC curve of 0.79. The optimum cutoff value resulted in a sensitivity and a specificity of 80 and 72%, respectively. LDFr is reduced in legs with DVT, supporting the hypothesis of preactivation of the peripheral vasoconstriction response. The diagnostic value of LDF measurements is not likely to surpass that of CUS in symptomatic patients, but may be of additional use in situations where CUS is less sensitive.

Impaired vascular function in women with pre-eclampsia observed with orthogonal polarisation spectral imaging.

OBJECTIVE: To investigate in vivo the function of the microcirculation of the skin in pregnancy and pregnancy complicated with pre-eclampsia. DESIGN: Case-control study. SETTING: Academic Medical Centre. PARTICIPANTS: A group of 10 women with pre-eclampsia and a healthy control group of 10 pregnant women. METHODS: The microcirculation of the skin of the finger at rest and during venous occlusion was studied with laser Doppler fluxmetry and orthogonal polarisation spectral imaging. By inflating a cuff around the upper arm to a pressure of 50 mmHg, causing venous occlusion, the local sympathetic veno-arteriolar reflex was provoked. With laser Doppler fluxmetry the blood flow of the skin at a depth of 1-2mm was measured at rest and during venous occlusion. Orthogonal polarisation spectral imaging was used to assess red blood cell velocity at rest and during venous occlusion of the nutritive capillaries of the skin. RESULTS: Laser Doppler fluxmetry showed no significant difference between the normotensive group and the group with pre-eclampsia. Using orthogonal polarisation spectral imaging, venous occlusion produced a significantly greater decrease in red blood cell velocity in the control group than in the women with pre-eclampsia: (84% (81-88)(median and interquartile range) vs 58% (45-88), P = 0.0029). No differences in absolute red blood cell velocities were observed between groups either at rest or during venous occlusion. CONCLUSION: This study shows an impaired local veno-arteriolar reflex in pre-eclampsia at the nutritive, but not at the therrmoregulatory, level of the microcirculation of the skin.

The usefulness of a laser Doppler in the measurement of toe blood pressures.

OBJECTIVE: The purpose of this study was to evaluate the clinical value and reproducibility of laser Doppler (LD) versus photoplethysmography (PPG) in the measurement of the systolic toe blood pressure. METHODS: Toe blood pressure was measured in 60 patients in different stages of peripheral vascular disease with simultaneous digital sampling of PPG and two LD signals, each with a different filter setting (3 second [LD(3)] and 0.03 second [LD(0.03)]), and cuff pressure. These measurements were repeated after 1 week. The signals were analyzed with previous results ignored. The agreement of the PPG and LD pressures and reproducibility after 1 week were assessed by calculating the intraclass correlation coefficient (ICC). The agreement variation across the range of pressure values was visually explored by means of difference plots. RESULTS: In 19 legs with a very low pressure only LD could adequately measure the pressure, whereas PPG did not. The ICCs between PPG and LD(3) and LD(0.03) were 0.95 or more. The ICCs of the 1-week reproducibility of the PPG, LD(3), and LD(0.03) pressures were 0.92, 0.88, and 0.86, respectively. The variation was equally distributed across the range of pressures in all three methods. CONCLUSION: LD is a reliable alternative to PPG to measure toe blood pressures. Furthermore, LD is able to measure low pressures, which is relevant in the assessment of the presence of critical ischemia.

Optimisation of the non-invasive assessment of critical limb ischaemia requiring invasive treatment.

OBJECTIVE: to assess the optimal cut-off values of toe blood pressure (TBP) and transcutaneous oxygen pressure (TcpO(2)) in the supine and sitting positions, in order to accurately detect the presence of severe leg ischaemia requiring invasive treatment. METHODS: in 49 consecutive patients (65 legs) with severe ischaemia according to clinical symptoms of Fontaine III or IV and a lowered ankle blood pressure, TBP and TcpO(2)were measured in the supine and sitting positions. Treatment within 6 weeks after the diagnosis was classified as either conservative or invasive (revascularisation or amputation). RESULTS: of the 65 legs, 38 (58%) required invasive treatment. The mean ankle pressure for this group was 70 mmHg. The optimal cut-off value for TBP was 38 mmHg and for TcpO(2)35 mmHg. A TBP of

Influence of repetitive finger puncturing on skin perfusion and capillary blood analysis in patients with diabetes mellitus.

BACKGROUND: Frequent puncturing of fingers to check blood glucose in patients with type 1 diabetes might alter skin perfusion and, hence, influence the representativeness of the blood sample. We investigated the influence of repetitive puncturing on skin microcirculatory perfusion using laser Doppler fluxmetry and on the preanalytical phase of capillary blood analysis for small molecules (glucose) and large particles (cholesterol). METHODS: In 49 patients with long-standing (mean, 21 years) type 1 diabetes, with a mean puncture frequency of three times daily for a mean duration of 13 years, laser Doppler skin perfusion was measured in a finger at a frequently punctured site and compared with a similar site of another finger of the same hand, which was never punctured. In the supine position with the hand level with the heart, resting flux (RF), peak flux (PF), and the microcirculatory reserve capacity (MRC; PF - RF) were assessed. Subsequently, blood samples for capillary whole blood glucose and cholesterol analyses were taken from the same sites. RESULTS: No significant differences were found between the puncture and control sites in mean RF (2.3 vs 2.0 V; P = 0.14, paired-samples t-test), PF (3.3 vs 3.1 V; P = 0.24), MRC (1.0 vs 1.0 V; P = 0.65), glucose (10.2 vs 10.2 mmol/L; P = 0.69), or cholesterol (5.1 vs 5.2 mmol/L; P = 0.26). Power calculation for a RF of 2.0 V and the SD and n of this study indicate a power (beta) of 80% to detect a 25% change in RF at P <0.05. CONCLUSIONS: Repetitive finger puncturing in diabetics appears not to injure local skin microcirculatory perfusion nor to influence results of capillary blood analysis for glucose and cholesterol.