Pseudoxanthoma elasticum and obstetric epidural analgesia: Report of a case

peer reviewedPseudoxanthoma elasticum is a rare inherited disorder of the elastic tissue characterised by multisystem manifestations. Skin, eyes, gastro-intestinal system and cardiovascular system are the major affected systems. We describe the anaesthetic management of a parturient affected by this disease

Effect of an intubation dose of rocuronium on Spectral Entropy and Bispectral Index (TM) responses to laryngoscopy during propofol anaesthesia

Background. The spectral entropy of the electroencephalogram has been proposed to monitor the depth of anaesthesia. State Entropy (SE) reflects the level of hypnosis. Response Entropy (RE), computed from electroencephalogram and facial muscle activity, reflects the response to nociceptive stimulation. We evaluated the effect of rocuronium on Bispectral Index (TM) (BIS) and entropy responses to laryngoscopy. Methods. A total of 25 patients were anaesthetized with propofol using a target-controlled infusion. At steady state, they randomly received 0.6 mg kg(-1) rocuronium (R) or saline (S). After 3 min, a 20 s laryngoscopy was applied. BIS, RE and SE were recorded continuously and averaged over 1 min during baseline, at steady state, 2 min after R or S administration (R/S+2) and 0, 1, 2 and 3 min after laryngoscopy (L0, L1, L2, L3). Results. At R/S+2, the RE-SE gradient was higher in Group S than in Group R. Laryngoscopy provoked an increase in BIS, RE and SE. Comparing R/S+2 and L0 values in Groups R and S, BIS increased from 43 (6) to 49 (8) and 42 (9) to 51 (15), SE increased from 43 (7) to 50 (8) and 41 (10) to 55 (12), and RE increased from 46 (8) to 54 (9) and 47 (12) to 66 (15), respectively. BIS and SE did not differ between groups. At L0, RE and RE-SE were higher in Group S [66 (15) and 11 (4), respectively] than in Group R [54 (9) and 4 (2), respectively]. Conclusions. Rocuronium alters the RE-SE gradient and the RE and RE-SE responses to laryngoscopy. Muscle relaxation may confound interpretation of entropy monitoring

Blood glucose concentration profile after 10 mg dexamethasone in non-diabetic and type 2 diabetic patients undergoing abdominal surgery

BACKGROUND: Dexamethasone prevents postoperative nausea and vomiting but may increase blood glucose. We compared blood glucose concentrations after dexamethasone in non-diabetic and type 2 diabetic patients undergoing surgery and looked for any association with preoperative glycosylated haemoglobin [HbA (1c)] and BMI. METHODS: Sixty three patients were enrolled: 32 were non-diabetic (Group ND) and 31 type 2 diabetic (Group D) without insulin treatment. Anaesthesia was induced using i.v. anaesthetic agents and maintained with sevoflurane. All patients received 10 mg dexamethasone at induction. Blood glucose concentrations were measured at induction and then every 60 min for 240 min. Data were analysed using anova. Effects of HbA (1c) and BMI were investigated using linear correlation and logistic regression. RESULTS: Blood glucose concentrations increased significantly over time and peaked at 120 min after 10 mg dexamethasone in both groups. The magnitude of increase was comparable between the groups [mean (SD) 29 (19) and 35 (19)% of baseline in Group D and Group ND, respectively]. Maximum concentrations were higher in Group D [8.97 (1.51) mmol litre(-1), range 6.67-12.94 mmol litre(-1)] than in Group ND [7.86 (1.00) mmol litre(-1), range 5.78-10.00 mmol litre(-1)]. There was a significant correlation between the maximum concentrations and BMI (R(2)=0.21) or HbA (1c) (R(2)=0.26). Logistic regression analysis revealed that the higher the BMI, the lower the HbA (1c) threshold associated with an increased probability (>0.5) of observing blood glucose levels higher than 8.33 mmol litre(-1) during 240 min after dexamethasone administration. Similarly, the higher the HbA (1c), the lower the BMI threshold associated with the same probability. CONCLUSIONS: After 10 mg dexamethasone, blood glucose levels increase in non-diabetic and type 2 diabetic patients undergoing abdominal surgery. Poorly controlled diabetes and severe obesity can influence the development of hyperglycaemia

Combined use of Bispectral Index (TM) and A-Line (TM) Autoregressive Index (TM) to assess anti-nociceptive component of balanced anaesthesia during lumbar arthrodesis

BACKGROUND: This study evaluated the A-Line Autoregressive Index (AAI) response to surgical stimulation during lumbar arthrodesis, as an estimate of the anti-nociceptive component of a Bispectral Index (BIS) guided anaesthesia combined with epidural analgesia. METHODS: An epidural catheter was inserted in 23 patients allocated randomly to receive ropivacaine plus clonidine (Group R) or normal saline (Group S) epidurally. General anaesthesia was induced with propofol, cis-atracurium and a remifentanil infusion that was stopped 3 min after tracheal intubation, and maintained using sevoflurane to keep BIS at 50 (range 40-60). Mean arterial pressure, heart rate, end-tidal sevoflurane, BIS and AAI were analysed from 2 min before to 17 min after surgical incision. RESULTS: While BIS was maintained at 50, AAI significantly increased from a 2 min averaged value of 12 (4) to 21 (7) in Group S within the first 5 min after surgical incision, but did not change in Group R. Maximum AAI values reached during the study period were significantly higher in Group S than in Group R [38 (12) and 27 (10), respectively]. Binary logistic regression analysis allowed the calculation of AAI threshold values above which the probability of predominant nociception over anti-nociception was higher than 95%. At 1 MAC sevoflurane concentration, a 2 min averaged AAI of 35 or an AAI peak value of 62 were associated with such a probability. CONCLUSIONS: During a BIS-guided constant level of hypnosis, AAI response to the onset of surgical stimulation significantly differs according to the analgesic regimen. Further studies are needed to refine the estimation of sensitivity and specificity of this variable in assessing the balance between nociception and anti-nociception during general anaesthesia

Deep Neural Networks for Automatic Classification of Anesthetic-Induced Unconsciousness

Despite the common use of anesthetics to modulate consciousness in the clinic, brain-based monitoring of consciousness is uncommon. We combined electroencephalographic measurement of brain activity with deep neural networks to automatically discriminate anesthetic states induced by propofol. Our results with leave-one-participant-out-cross-validation show that convolutional neural networks significantly outperform multilayer perceptrons in discrimination accuracy when working with raw time series. Perceptrons achieved comparable accuracy when provided with power spectral densities. These findings highlight the potential of deep convolutional networks for completely automatic extraction of useful spatio-temporo-spectral features from human EEG

Comparison of the Surgical Pleth Index (TM) with haemodynamic variables to assess nociception-anti-nociception balance during general anaesthesia

BACKGROUND: The Surgical Pleth Index (SPI) is proposed as a means to assess the balance between noxious stimulation and the anti-nociceptive effects of anaesthesia. In this study, we compared SPI, mean arterial pressure (MAP), and heart rate (HR) as a means of assessing this balance. METHODS: We studied a standard stimulus [head-holder insertion (HHI)] and varying remifentanil concentrations (CeREMI) in a group of patients undergoing neurosurgery. Patients receiving target-controlled infusions were randomly assigned to one of the three CeREMI (2, 4, or 6 ng m(1)), whereas propofol target was fixed at 3 microg ml(1). Steady state for both targets was achieved before HHI. Intravascular volume status (IVS) was evaluated using respiratory variations in arterial pressure. Prediction probability (Pk) and ordinal regression were used to assess SPI, MAP, and HR performance at indicating CeREMI, and the influence of IVS and chronic treatment for high arterial pressure, as possible confounding factors. RESULTS: The maximum SPI, MAP, or HR observed after HHI correctly indicated CeREMI in one of the two patients [accurate prediction rate (APR)=0.5]. When IVS and chronic treatment for high arterial pressure were taken into account, the APR was 0.6 for each individual variable and 0.8 when all of them predicted the same CeREMI. That increase in APR paralleled an increase in Pk from 0.63 to 0.89. CONCLUSIONS: SPI, HR, and MAP are of comparable value at gauging noxious stimulation-CeREMI balance. Their interpretation is improved by taking account of IVS, treatment for chronic high arterial pressure, and concordance between their predictions

Does it remain any contraindication to regional anaesthesia in obstetrics?

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