An elevated respiratory quotient predicts complications after cardiac surgery under extracorporeal circulation: an observational pilot study.

Following cardiac surgery, hyperlactatemia due to anaerobic metabolism is associated with an increase in both morbidity and mortality. We previously found that an elevated respiratory quotient (RQ) predicts anaerobic metabolism. In the present study we aimed to demonstrate that it is also associated with poor outcome following cardiac surgery. This single institution, prospective, observational study includes all those patients that were consecutively admitted to the intensive care unit (ICU) after cardiac surgery with cardiopulmonary bypass, that had also been monitored using pulmonary artery catheter. Data were recorded at admission (H0) and after one hour (H1) including: oxygen consumption ([Formula: see text]), carbon dioxide production ([Formula: see text]), RQ ([Formula: see text]), lactate levels and mixed venous oxygen saturation ([Formula: see text]). The primary endpoint was defined as mortality at 30 days. Comparison of the area under the curve (AUC) for receiver operating characteristic curves was used to analyze the prognostic predictive value of RQ, lactate levels and [Formula: see text], in terms of patient outcome. We studied 151 patients admitted to the ICU between May 2015 and February 2016. Seventy eight patients experienced a worse than expected outcome in the post-operative period, and among those seven died. RQ at H1 in non-survivors ([Formula: see text]) was higher than in survivors ([Formula: see text]; p = 0.02). The AUC for RQ to predict mortality was 0.77 (IC95% [0.70-0.84]), with a threshold value of 0.76 (sensitivity 64%, specificity 100%). By comparison, the AUC for lactate levels was significantly superior (AUClact 0.89, IC95% [0.83-0.93], p = 0.02). In this study, elevated RQ appeared to be predictive of mortality after cardiac surgery with CPB.

Extracorporeal life support for massive pulmonary embolism during pregnancy.

Massive pulmonary embolism is a leading cause of death during pregnancy. While the prevention of thromboembolic disease during the peripartum period is codified, there is no consensus regarding its treatment. We report two cases of pregnant women who had massive pulmonary embolisms (PE) and shock treated with veno-arterial extracorporeal life support (ECLS) and heparin therapy.Haemodynamic and oxygenation parameters were rapidly restored. The patients completely recovered and the pregnancies continued. The patients did not develop pulmonary hypertension. ECLS can be considered as a successful treatment option of massive pulmonary embolism during pregnancy.

Fluoroscopic guidance of Arndt endobronchial blocker placement for single-lung ventilation in small children.

BACKGROUND: Thoracoscopic surgery may require single-lung ventilation (SLV) in infants and small children. A variety of balloon-tipped endobronchial blockers exist but the placement is technically challenging if the size of the tracheal tube does not allow the simultaneous passage of the fibreoptic scope and the endobronchial blocker. This report describes a technique for endobronchial blocker insertion using fluoroscopic guidance in children undergoing SLV. METHODS: After approval from the local Medical Ethics Committee and parental consent, 18 patients aged 2 years or younger scheduled for thoracic surgery requiring SLV were prospectively included. Following induction of anesthesia, a 5 Fr endobronchial blocker (Cook) Arndt endobronchial blocker) was inserted first into the trachea under direct laryngoscopy. Correct placement in the main bronchus was assessed by fluoroscopy and tracheal intubation next to the endobronchial blocker. Optimal position and balloon inflation was verified using a fibreoptic scope. The duration and number of insertion attempts as well as age, weight and size of the tracheal tube were recorded. RESULTS: Eighteen patients were studied. Median (range) age and weight were 12 (0.2-24) months and 11.2 (4-15) kg, respectively. SLV was successfully achieved in all patients using a 5 Fr endobronchial blocker outside a 3.5-4.5 mm ID tracheal tube within 11.2 (+/-2.2) min. No side effects were observed during the procedure. CONCLUSION: Fluoroscopic-guided insertion of extraluminal endobronchial blocker is an effective and reliable tool to place Arndt endobronchial blockers in small children.

Comparative study of propofol and midazolam effects on somatosensory evoked potentials during surgical treatment of scoliosis.

OBJECTIVE: Studies of the effects on lower-limb cortical somatosensory evoked potentials (CSEP) during total intravenous anesthesia are sparse for propofol and are lacking for midazolam. This study was designed to compare the effects of propofol and midazolam on CSEP under total intravenous anesthesia during intraoperative monitoring for surgical treatment of scoliosis. METHODS: CSEPs were recorded in two groups of 15 patients during posterior instrumentation for treatment of idiopathic scoliosis. The anesthesia used the combination of atracurium, alfentanil, and an hypnotic agent (propofol for Group I or midazolam for Group II). The main characteristics of the CSEPs (P40 latency and N34-P40 and P40-N50 amplitudes) were recorded using ankle posterior tibial nerve stimulation. The CSEPs were recorded before induction, 10, 70, 100, 130, and 160 minutes after induction, and before the wake-up test. The statistical analysis involved analysis of variance for repeated measures. Both groups were homogeneous before induction. RESULTS: Neither CSEP deterioration during risk-associated surgical procedures nor postoperative clinical abnormalities were observed. Both propofol and midazolam induced increases in P40 latencies, with the increases being greater and more regular for the propofol-treated group. The amplitude values changed with time for both groups, decreasing mainly after induction; in the midazolam-treated group, the amplitudes were smaller but more stable. Propofol modified the morphological characteristics of the response by decreasing the late P60 component amplitude; the W-shaped CSEP morphological pattern was maintained with midazolam. CONCLUSION: This study demonstrates the appropriate use of either propofol or midazolam in scoliosis monitoring. Preoperative small-amplitude CSEPs might favor the use of propofol anesthesia.

[Neuromonitoring and anesthesia in surgery of the spine]. / Neuromonitorage et anesthésie dans la chirurgie du rachis.

The authors report the main effects of anaesthetic drugs that are used alone or in association with anaesthetic protocols on somatosensory evoked potentials (SEP) and on motor evoked potentials (MEP). In the first part of the article, the effects are analysed on SEPs and MEPs that are obtained from non-invasive methods; in the second part, the effects of anaesthesia are analysed with respect to invasive methods of EP recordings. The current increase of invasive techniques of neuromonitoring by SEPs and MEPs is in relation with the weak effect of anaesthetics on evoked responses. Total intravenous anaesthesia (TIVA) provides stable anaesthesia for non-invasive SEP neuromonitoring only if bolus is avoided. With TIVA and other anaesthetic techniques, the introduction of repetitive stimulation provides new possibilities for non-invasive MEP neuromonitoring.