Prediction of post-induction hypotension by point-of-care echocardiography: A prospective observational study.

BACKGROUND: Post-induction hypotension (PIH) is a common side effect of general anaesthesia and is associated with poor perioperative outcomes. We assessed the ability of two point-of-care echocardiographic variables to predict the occurrence of PIH: the passive leg raising-induced changes in the velocity-time integral of the left ventricular outflow tract (ΔVTI-PLR) and the inferior vena cava collapsibility index (IVC-CI). METHODS: We studied 64 patients > 50 years scheduled for elective abdominal surgery. ΔVTI-PLR and IVC-CI were prospectively obtained before general anaesthesia induction. PIH was defined by a systolic arterial pressure < 90 mmHg or a mean arterial pressure < 65 mmHg or by a decrease in systolic or mean arterial pressure > 30% from pre-induction level. Intraclass correlation coefficients (ICCs) were calculated to assess the reproducibility of echocardiographic measurements. Receiver operating characteristic (ROC) curves with 95% confidence intervals (CIs) were generated to test the ability of ΔVTI-PLR and IVC-CI to predict the occurrence of PIH. RESULTS: PIH occurred in 33 (51%) patients. The ICCs for VTI and IVC measurements showed excellent reproducibility. The occurrence of PIH was accurately predicted by ΔVTI-PLR with an area under the ROC curve (AUROC) of 0.89 (95% CI: 0.80-0.97), a threshold value of 18% with a sensitivity of 88% (95% CI: 71-97%) and a specificity of 84% (95% CI: 66-94%). The occurrence of PIH was poorly predicted by IVC-CI with an AUROC of 0.68 (95% CI: 0.54-0.80) and a threshold value of 42%. CONCLUSIONS: ΔVTI-PLR, unlike IVC-CI, could reliably predict the occurrence of PIH. The use of ΔVTI-PLR could help individualise anaesthesia management to prevent PIH.

[Spontaneous pneumomediastinum in an asthmatic patient]. / Pneumomediastin spontané chez un asthmatique.

Spontaneous pneumomediastinum is a rare disease. It especially affects young adults. The onset is usually sudden, involving chest pain, subcutaneous emphysema and dyspnea. We report the case of a 24-year old asthmatic patient with pneumomediastinum after coughing effort. The patient presented with acute respiratory failure associated with retrosternal chest pain. Chest X-ray confirmed the diagnosis of pneumomediastinum. The patient evolved favorably within 4 days after exsufflation, oxygen therapy and conventional medical treatment.

Fatal intoxication caused by the application of the multiple transdermals patchs of fentanyl.

Fentanyl (N-phenyl-N-(1-2-phenylethyl-4-piperidyl)propanamide) is a potent synthetic narcotic analgesic. He has an analgesic effect 100 times greater than that of morphine. The use of transdermal fentanyl delivrery systems has increased over recent years especially in patients with chronic pain who are already treated with high doses of morphine or it is derivate. However, many cases of fentanyl intoxication through a variety of transderrmal systems have been reported. This paper reports a fatality due to excessive administered Fentanyl Sandoz® Matrix 50 µg/h transdermal therapeutic systems.

The parasacral sciatic nerve block does not induce anesthesia of the obturator nerve.

PURPOSE: The ability of the parasacral sciatic nerve block (PSNB) to induce anesthesia of the obturator nerve remains controversial. Our objective was to evaluate the anesthesia of the obturator nerve after a PSNB. METHODS: Forty patients scheduled to undergo knee surgery (anterior cruciate ligament reconstruction) were included in this prospective, randomized, controlled study. Patients were randomized to receive PSNB alone (control group, n = 20) or PSNB in combination with an obturator nerve block (obturator group, n = 20). After evaluation for 30 min, the two groups received a femoral nerve block, and patients were taken to surgery. The obturator nerve blockade was assessed by measurement of adductor strength at baseline (T0) and every 10 min during the 30-min evaluation (T10, T20, and T30). Pain scores after tourniquet inflation and during surgery were compared between the two groups. The requirement for additional intravenous analgesia and/or sedation was also recorded. RESULTS: The two groups had comparable demographic and surgical characteristics. Four patients were excluded from the study because of PSNB or femoral nerve block failure. The adductor strength values were similar between groups at T0 but were significantly lower in the obturator group at T10, T20, and T30 (p < 0.0001). Patients in the obturator group reported less pain than those in the control group (p < 0.05). They also required less additional intravenous sedation and/or analgesia (p < 0.05). CONCLUSION: This clinical study demonstrated that the PSNB is an unreliable means of inducing anesthesia of the obturator nerve and emphasizes the need to block this nerve separately to induce adequate analgesia during knee surgery.

Magnesium sulphate: an adjuvant to tracheal intubation without muscle relaxation--a randomised study.

CONTEXT: Tracheal intubation without administration of a neuromuscular blocking drug is used frequently in anaesthesia. Several techniques and adjuvants have been tried to improve intubating conditions. Magnesium sulphate is an agent with analgesic, anaesthetic and muscle relaxant effects. OBJECTIVE: To assess the effect of magnesium sulphate on intubating conditions after induction of anaesthesia without a neuromuscular blocking drug. DESIGN: Double-blinded randomised study. PATIENTS: Sixty patients with American Society of Anesthesiologists physical status 1/2 scheduled for elective surgery under general anaesthesia were included. SETTING: Avicenna Military Hospital between June 2010 and March 2011. INTERVENTIONS: Before induction of general anaesthesia, patients were assigned to receive either a 10-min infusion of magnesium sulphate 45 mg kg(-1) in 100 ml of isotonic saline (magnesium group, n = 30) or the same volume of saline (control group, n = 30). Anaesthesia was induced with fentanyl 3 µg kg(-1) followed 3 min later by propofol 2.5 mg kg(-1). MAIN OUTCOME MEASURES: Intubating conditions were evaluated by a blinded anaesthesiologist using the criteria of the Copenhagen consensus conference: ease of laryngoscopy, vocal cord position and/or movement and response to intubation or cuff inflation (cough or diaphragmatic movement). Intubating conditions were considered as acceptable (excellent or good) or unacceptable (poor). Mean arterial pressure and heart rate were also recorded during the study period. RESULTS: The two groups were comparable in their demographic profiles. Clinically acceptable intubating conditions were observed more frequently in the magnesium group than in the control group: 25 (83%) vs. 18 patients (60%) (P = 0.042). There was no failed intubation. There were no differences between the groups with regard to haemodynamic variables. CONCLUSION: Addition of magnesium sulphate to propofol and fentanyl at induction of anaesthesia significantly improved intubating conditions without administration of a neuromuscular blocking drug.