Nurse-driven intranasal dexmedetomidine administration as sedation for non-invasive procedures in children: a single centre audit.

The purpose of this study is to audit the efficacy and safety of intranasal dexmedetomidine sedation for non-invasive procedural sedation in children provided by nurses of the procedural sedation (PROSA) team in the University Hospitals Leuven. Efficacy (successful sedation as sole sedative) and safety (cardiorespiratory monitoring, saturation) were assessed. In this audit, prospectively recorded data were extracted from the medical files in 772 patients between 4 weeks to 18 years old, who underwent sedation with intranasal dexmedetomidine (2-4 µg/kg) by the nurse-driven PROSA team, following pre-screening on risk factors. Ninety-one percent of the patients were successfully sedated (single dose, monotherapy), 60 patients (7.8%) needed an additional intervention during sedation, 37 (4.8%) needed an extra dose of intranasal dexmedetomidine, and 14 (1.8%) received an additional other sedative. Successful sedation rates were higher in younger children, and medical imaging was the most common indication. Sedation failed in 12 (1.6%) patients, with 10 of them failed to fall asleep. Adverse events were limited in number (n = 13, 1.7%) and severity: 4 patients had a low heart rate (one received atropine), one had an irregular heart rate, and 7 desaturation events were described. Hypotension was treated with normal saline in one case. CONCLUSIONS: In this nurse-driven PROSA setting, intranasal dexmedetomidine is effective and safe for non-invasive procedural sedation in an a priori low risk group of paediatric patients. WHAT IS KNOWN: • Procedural sedation outside the operating theatre or intensive care units is increasingly used, including sedation performed by non-anaesthesiologists or nurses. This resulted in the development of procedural sedation and analgesia (PROSA) teams. • Off-label use of intranasal dexmedetomidine in children is increasing, with a limited number of audits on this practice, its safety and efficacy. WHAT IS NEW: • In an audit on 772 procedures, nurse-driven intranasal dexmedetomidine administration as sedation for non-invasive procedures in children within a structured framework was safe and effective. • Imaging (CT, MRI) was the most common procedural indication in our study, but also nuclear imaging techniques were included.

Exercise-induced right ventricular dysfunction is associated with ventricular arrhythmias in endurance athletes.

AIMS: Intense exercise places disproportionate strain on the right ventricle (RV) which may promote pro-arrhythmic remodelling in some athletes. RV exercise imaging may enable early identification of athletes at risk of arrhythmias. METHODS AND RESULTS: Exercise imaging was performed in 17 athletes with RV ventricular arrhythmias (EA-VAs), of which eight (47%) had an implantable cardiac defibrillator (ICD), 10 healthy endurance athletes (EAs), and seven non-athletes (NAs). Echocardiographic measures included the RV end-systolic pressure-area ratio (ESPAR), RV fractional area change (RVFAC), and systolic tricuspid annular velocity (RV S'). Cardiac magnetic resonance (CMR) measures combined with invasive measurements of pulmonary and systemic artery pressures provided left-ventricular (LV) and RV end-systolic pressure-volume ratios (SP/ESV), biventricular volumes, and ejection fraction (EF) at rest and during intense exercise. Resting measures of cardiac function were similar in all groups, as was LV function during exercise. In contrast, exercise-induced increases in RVFAC, RV S', and RVESPAR were attenuated in EA-VAs during exercise when compared with EAs and NAs (P < 0.0001 for interaction group × workload). During exercise-CMR, decreases in RVESV and augmentation of both RVEF and RV SP/ESV were significantly less in EA-VAs relative to EAs and NAs (P < 0.01 for the respective interactions). Receiver-operator characteristic curves demonstrated that RV exercise measures could accurately differentiate EA-VAs from subjects without arrhythmias [AUC for ΔRVESPAR = 0.96 (0.89-1.00), P < 0.0001]. CONCLUSION: Among athletes with normal cardiac function at rest, exercise testing reveals RV contractile dysfunction among athletes with RV arrhythmias. RV stress testing shows promise as a non-invasive means of risk-stratifying athletes.

Fetal and maternal analgesia/anesthesia for fetal procedures.

For many prenatally diagnosed conditions, treatment is possible before birth. These fetal procedures can range from minimal invasive punctions to full open fetal surgery. Providing anesthesia for these procedures is a challenge, where care has to be taken for both mother and fetus. There are specific physiologic changes that occur with pregnancy that have an impact on the anesthetic management of the mother. When providing maternal anesthesia, there is also an impact on the fetus, with concerns for potential negative side effects of the anesthetic regimen used. The question whether the fetus is capable of feeling pain is difficult to answer, but there are indications that nociceptive stimuli have a physiologic reaction. This nociceptive stimulation of the fetus also has the potential for longer-term effects, so there is a need for fetal analgesic treatment. The extent to which a fetus is influenced by the maternal anesthesia depends on the type of anesthesia, with different needs for extra fetal anesthesia or analgesia. When providing fetal anesthesia, the potential negative consequences have to be balanced against the intended benefits of blocking the physiologic fetal responses to nociceptive stimulation.

Regional anesthesia outside the operating room: indications and techniques.

PURPOSE OF REVIEW: Regional anesthesia is not only performed in the operating room. There are indications for the use of these techniques for pain relief in the emergency department and for anesthesia support of procedures outside the operating room. In this review, we will provide an overview of the indications for the regional techniques performed in the out-of-operating room environment. RECENT FINDINGS: In the emergency department, patients may experience significant pain, and adequate analgesia is not always provided. Regional analgesia is effective and indicated for many trauma situations including hip fracture, reduction of shoulder dislocation, treatment of upper limb fractures and multiple rib fractures.Ultrasound guidance makes the performance of regional blocks more accessible and safer for use in the emergency department setting.For therapeutic procedures outside the operating room, regional anesthesia is possible for uterine artery embolization and for postoperative analgesia after implantation of cervical brachytherapy needles. SUMMARY: Regional anesthesia is a valuable option for analgesia in trauma patients, enabling improved pain control in the emergency department and has benefits in the anesthetic management of therapeutic procedures outside the operating room. For many blocks, ultrasound guidance is useful.

Aprotinin reduces cardiac troponin I release and inhibits apoptosis of polymorphonuclear cells during off-pump coronary artery bypass surgery.

OBJECTIVES: In addition to blood-sparing effects, aprotinin may have cardioprotective and anti-inflammatory effects during cardiopulmonary bypass-assisted cardiac surgery. In this study, the authors examined whether aprotinin had cardioprotective and/or anti-inflammatory effects in patients undergoing off-pump coronary artery bypass grafting. DESIGN: A prospective randomized clinical trial. SETTING: University hospital. PARTICIPANTS: Fifty patients were randomized to control (n = 25) or aprotinin treatment (n = 25) groups. INTERVENTIONS: Aprotinin was given as a loading dose (2 x 10(6) KIU) followed by a continuous infusion at 5 x 10(5) KIU/h until skin closure. MEASUREMENTS AND MAIN RESULTS: Blood samples for cardiac troponin I; interleukin-6, interleukin-8, and interleukin-10; tumor necrosis factor alpha; and elastase were taken after anesthesia induction, completion of revascularization, and 6 hours, 12 hours, and 24 hours after revascularization. Blood samples were taken to assess for apoptosis in polymorphonuclear cells. Baseline plasma levels for cardiac troponin I did not differ between groups but were significantly lower in aprotinin-treated patients at the time of revascularization (p = 0.03) and 6 hours (p = 0.004) and 24 hours (p = 0.03) later. Aprotinin significantly reduced apoptosis in polymorphonuclear cells compared with control-treated patients (p = 0.04). There were no differences in plasma cytokine or elastase levels between groups. CONCLUSIONS: The authors conclude that aprotinin reduces perioperative cardiac troponin I release and attenuates apoptosis in polymorphonuclear cells but has no significant effects on plasma cytokine levels in patients undergoing off-pump coronary artery bypass graft surgery.

Feasibility of in utero telemetric fetal ECG monitoring in a lamb model.

OBJECTIVES: If fetal ECG (fECG) devices could be miniaturized sufficiently, one could consider their implantation at the time of fetal surgery to allow permanent monitoring of the fetus and timely intervention in the viable period. We set up an experiment to evaluate the feasibility of in utero direct fECG monitoring and telemetric transmission using a small implantable device in a lamb model. METHODS: A 2-lead miniature ECG sensor (volume 1.9 cm(3); weight 3.9 g) was subcutaneously implanted in 2 fetal lambs at 122 days gestation (range 119-125; term 145 days). The ECG sensor can continuously register and transmit fECG. The signal is captured by an external receiving antenna taped to the maternal abdominal wall. We developed dedicated software running on a commercial laptop for on-line analysis of the transmitted fECG signal. This was a noninterventional study, i.e. daily readings of the fECG signal were done without clinical consequences to the observations. RESULTS: fECG could be successfully registered, transmitted by telemetry and analyzed from the moment of implantation till term birth in one case (24 days). In the second case, unexplained in utero fetal death occurred 12 days after implantation. In this subject, agonal fECG changes were recorded. CONCLUSION: An implanted miniature (<2 ml) ECG sensor can be used to retrieve, process and transmit continuously a qualitative fECG signal in third-trimester fetal lambs. The telemetric signal could be picked up by an external antenna located within a 20-cm range. In this experiment, this was achieved through taping the external receiver to the maternal abdomen. Any acquired signal could be transmitted to a commercially available laptop that could perform on-line analysis of the signal.

Anesthesia for fetal surgery.

PURPOSE OF REVIEW: To look at different anesthetic approaches to different surgical techniques used in fetal procedures and the influence of maternal and fetal factors on anesthetic management. RECENT FINDINGS: Fetal surgery is evolving rapidly in the field of mainly ex-utero intrapartum treatment procedures, where new indications are found and new anesthetic techniques are developed, enabling the use of locoregional anesthesia. Further development of anesthetic techniques focuses on minimizing the risks for the mother and preserving the normal neurodevelopment of the fetus. SUMMARY: Open fetal surgery remains a major invasive procedure for mother and fetus both, requiring general anesthesia with adequate invasive monitoring. Minimal invasive fetal procedures can be performed with local anesthesia alone or, for the more complex fetoscopic procedures, with a neuraxial locoregional technique. Fetal anesthesia and analgesia can then be provided by different routes. Ex-utero intrapartum treatment procedures are open fetal procedures, but they can be performed with locoregional anesthesia, when uterine relaxation can be achieved without volatile anesthetics with the use of intravenous nitroglycerin.

Exercise cardiac magnetic resonance to differentiate athlete's heart from structural heart disease.

Aims: The distinction between left ventricular (LV) dilation with mildly reduced LV ejection fraction (EF) in response to regular endurance exercise training and an early cardiomyopathy is a frequently encountered and difficult clinical conundrum. We hypothesized that exercise rather than resting measures would provide better discrimination between physiological and pathological LV remodelling and that preserved exercise capacity does not exclude significant LV damage. Methods and results: We prospectively included 19 subjects with LVEF between 40 and 52%, comprising 10 ostensibly healthy endurance athletes (EA-healthy) and nine patients with dilated cardiomyopathy (DCM). In addition, we recruited five EAs with a region of subepicardial LV. Receiver operating characteristic fibrosis (EA-fibrosis). Cardiac magnetic resonance (CMR) imaging was performed at rest and during supine bicycle exercise. Invasive afterload measures were obtained to enable calculations of biventricular function relative to load (an estimate of contractility). In DCM and EA-fibrosis subjects there was diminished augmentation of LVEF (5 ± 6% vs. 4 ± 3% vs. 14 ± 3%; P = 0.001) and contractility [LV end-systolic pressure-volume ratio, LVESPVR; 1.4 (1.3-1.6) vs. 1.5 (1.3-1.6) vs. 1.8 (1.7-2.7); P < 0.001] during exercise relative to EA-healthy. Receiver-operator characteristic curves demonstrated that a cut-off value of 11.2% for ΔLVEF differentiated DCM and EA-fibrosis patients from EA-healthy [area under the curve (AUC) = 0.92, P < 0.001], whereas resting LVEF and VO2max were not predictive. The AUC value for LVESPVR ratio was similar to that of ΔLVEF. Conclusions: Functional cardiac evaluation during exercise is a promising tool in differentiating healthy athletes with borderline LVEF from those with an underlying cardiomyopathy. Excellent exercise capacity does not exclude significant LV damage.

Fetal pain perception and pain management.

This paper gives an overview of current science related to the concept of fetal pain. We have answered three important questions: (1) does fetal pain exist? (2) does management of fetal pain benefit the unborn child? and (3) which techniques are available to provide good fetal analgesia?

Preterm rabbit lung tissue mechanics: maturational changes and effect of antenatal steroids.

AIM: Describe lung tissue and central airway mechanics using forced oscillation in preterm rabbits at different gestational ages and after maternal administration of betamethasone (BM). METHODS: One hundred twelve fetuses from 54 does were studied. Ventilation was done using a Flexivent (Scireq, Montreal, Canada). Resistance (Rrs), compliance/bodyweight (Crs/bw), Newtonian resistance (Rn), tissue damping (G(L)), and elastance (H(L)) were assessed. Maturational changes were studied in normal controls at days 27-31. The effect of BM (0.05 mg/kg on days 25 and 26) or placebo was studied in preterm fetuses at days 27, 28, and 29. RESULTS: In unmanipulated control fetuses, Rrs decreased and Crs/bw increased with advancing gestation. Rn remained stable while G(L) and H(L) decreased. After day 29 no differences in pulmonary mechanics were observed. At 28 days Rrs and Crs/bw in BM and placebo fetuses were better compared to controls. At 29 days, Crs/bw and Rrs were higher, respectively, lower in control fetuses than BM or placebo exposed pups. CONCLUSION: Maturational changes in preterm rabbits occur mainly up to day 29 of gestation and are largely due to changes in tissue mechanics. Maternal BM injection improves lung mechanics at 28 days but placebo has equal effects.