Michal Barak

Diabetes blockade of sevoflurane postconditioning is not restored by insulin in the rat heart: phosphorylated signal transducer and activator of transcription 3- and phosphatidylinositol 3-kinase-mediated inhibition.

Background:The possibility of restoring sevoflurane postconditioning (sevo-postC) cardioprotection in diabetic animals is uncertain. We hypothesized that attenuation of myocardial injury by sevo-postC might be hindered by inhibition of signal transducer and activator of transcription (STAT) 3–regulated activity of phosphatidylinositol 3-kinase (PI3K) in diabetic animals. To determine whether postC cardioprotection can be restored by normoglycemia, we treated rats with insulin. Methods:Diabetic or nondiabetic rats were randomly subjected to 30-min ischemia/reperfusion, with ischemic postC or sevo-postC, with and without mitochondrial adenosine triphosphate–dependent potassium channel blocker 5-hydroxy decanoate sodium and PI3K antagonist wortmannin. The infarct area, phosphorylated STAT3, and apoptosis were examined. Studies were repeated after insulin treatment. Results:Ischemic postC and sevo-postC significantly reduced infarct size by 50% in the nondiabetic rats (P < 0.002), a phenomenon completely reversed by 5-hydroxy decanoate sodium and wortmannin. Diabetes mellitus blocked the protective effect of postC, and insulin treatment to achieve normoglycemia did not restore cardioprotection. Phosphorylated STAT3 nuclear retention was significantly increased after ischemia-reperfusion and was further enhanced in response to ischemic postC (P < 0.05) but was significantly reduced in diabetic rats (by 43%; P < 0.01). Conclusions:The effective reduction in infarct size and apoptosis in the nondiabetic rat heart by postC was completely abrogated in diabetic rats. This inhibition is not relieved by insulin-induced normoglycemia. The PI3K pathway and mitochondrial adenosine triphosphate–dependent potassium channel activation are involved in the mechanism of postC. In diabetic rats, STAT3 activation was strongly reduced, as was postC cardioprotection, suggesting that the inability of insulin to restore postC may be attributed to diabetes-induced STAT3-mediated inhibition of PI3K signaling.

HEMODYNAMIC AND CATECHOLAMINE RESPONSE TO TRACHEAL INTUBATION: DIRECT LARYNGOSCOPY COMPARED WITH FIBEROPTIC INTUBATION

STUDY OBJECTIVEnTo compare the stress response following tracheal intubation using direct laryngoscopy to that using fiberoptic bronchoscopy technique.nnnDESIGNnRandomized, prospective study.nnnSETTINGnOperating rooms in a teaching hospital.nnnPATIENTSn51 ASA physical status I and II patients who were scheduled for an elective surgery with general anesthesia.nnnINTERVENTIONSnPatients were randomly assigned to receive either direct laryngoscopy or fiberoptic orotracheal intubation, as part of general anesthesia. A uniform protocol of anesthetic medications was used.nnnMEASUREMENTSnBlood pressure and heart rate were measured before induction, before endotracheal intubation, and 1, 2, 3, and 5 minutes afterwards. Catecholamine (epinephrine and norepinephrine) blood samples were drawn before the induction, and 1 and 5 minutes after intubation.nnnMAIN RESULTSnDuration of intubation was shorter in the direct laryngoscopy group (16.9 (16.9 +/- 7.0 sec, range 8 to 40) compared with the fiberoptic intubation group (55.0 +/- 22.5 sec, range 29 to 120), p < 0.0,001. In both groups, blood pressure and heart rate were significantly increased at 1, 2, and 3 minutes after intubation, but there was no significant difference between the two study groups. Catecholamine levels did not increase after intubation and did not correlate with the hemodynamic changes.nnnCONCLUSIONSnThe use of either direct laryngoscopy or fiberoptic bronchoscopy produces a comparable stress response to tracheal intubation. Catecholamine levels do not correlate with the hemodynamic changes.

Posterior reversible encephalopathy syndrome after combined general and spinal anesthesia with intrathecal morphine.

We describe a patient who was in a stupor for several days after combined general-spinal anesthesia. Both clinical manifestations and magnetic resonance imaging findings were consistent with posterior reversible encephalopathy syndrome and resolved after the patient recovered spontaneously.

Cerebral microemboli during hip fracture fixation: a prospective study.

BACKGROUND: Recent studies have shown that cerebral fat microembolism takes place during surgery for hip or knee replacement. In this study, we examined the occurrence of cerebral microembolism, solid or gas, during a standard procedure of hip fracture fixation. METHODS: This was a prospective study of patients who underwent urgent surgery with a dynamic hip screw for hip fracture fixation. During surgery, patients were monitored with transcranial Doppler for detection of microemboli from right and left middle cerebral arteries. RESULTS: Twenty-two patients were included in the study; their median age was 82 yr (range, 51–97 yr). In nine (41%) patients, high intensity transient signals were recorded, indicating microemboli passage in the middle cerebral arteries. All nine patients had signals of both solid and gas emboli. One of these nine patients had a postoperative cerebrovascular accident. CONCLUSIONS: The incidence of cerebral microemboli during urgent surgery for hip fracture fixation is considerable. This phenomenon is not confined to hip or knee replacement surgery. The clinical implications of this finding require further investigation.

Perioperative morbidity and mortality in 80 years and older undergoing elective urology surgery – A prospective study

Background and purpose. The number of octogenarians requiring surgery increases constantly. Data regarding perioperative morbidity and mortality in octogenarians is limited. Our aim was to assess surgery-related complications in octogenarians, undergoing urological surgery. Patients and methods. We prospectively collected data from octogenarians and a control group of younger patients undergoing an elective urological surgery in our institution. Recorded data included: age, gender, American Society of Anesthesiologists (ASA) score, co-morbidities, number of medications, operation extent, anaesthesia type, surgery duration and perioperative morbidity and mortality. Results. Forty-seven octogenarians and 80 patients with a median age of 59 years (range 19–75) enrolled prospectively. Gender ratio, surgeries extent and median operative time were similar among groups. General anaesthesia was more prevalent in the control group. ASA classification and duration of hospitalization were significantly higher in octogenarians. The rate of intra-operative complications was significantly higher in the octogenarians group 6.38% versus 3.75% (p = 0.007), there was no significant difference in immediate post-operative and post-discharge complications among groups. One octogenarian patient died 2 days post-surgery, no death occurred in the control group. Conclusions. Octogenarians have higher rate of intra-operative morbidity, leading to longer hospital stay. More experienced surgeons and anaesthetists should be involved in the operation; and careful surgical technique, tapered anaesthesia and higher level of post-operative monitoring should be applied for patients in this age.

Rapid atrial fibrillation following tube thoracostomy insertion.

We report a case of trauma patient, whose heart rhythm and rate changed from sinus tachycardia to rapid atrial fibrillation. The change occurred immediately after the insertion of left thoracostomy tube. The patient did not respond to pharmacological treatment. Only when the tube was pulled out, the rhythm returned to sinus. Chest radiogram shows the position of the tube, in close proximity to the cardiac silhouette.

Pulmonary Complications following Percutaneous Nephrolithotomy: A Prospective Study

Introduction: Pulmonary complications may occur in the post-operative period and are a significant cause of morbidity and mortality in patients undergoing anesthesia and surgery. Complication rates vary according to different procedures and different types of anesthesia and may be affected by the patient condition. The purpose of this study was to examine pulmonary complications following percutaneous nephrolithotomy (PCNL) and to search for associations between the pre- and intra- operative factors and the risk of post-operative pulmonary complications (PPC). Patients and Methods: This was a prospective observational study of 100 consecutive adult patients who underwent PCNL surgery. We collected data of the patient, surgery and anesthesia and analyzed it to find correlations with PPC. Results: Eight (8%) patients had PPC following PCNL, 7 patients had pneumothorax and 1 had atelectasis and pleural effusion. The latter patient died at post-operative day 24 due to respiratory failure. It was found that patients who had PCNL on the right kidney were at lower risk for PPC. In addition it was found that younger patients had a higher incidence of PPC. Conclusions: Based on this study the most common type of post-operative complication following PCNL is pulmonary, with pneumothorax being the main complication. PPC may result in patient mortality. The side of the operation and the patients age might affect the risk of PPC.

The utility of routine postoperative chest radiography in the postanesthesia care unit

STUDY OBJECTIVEnTo evaluate the clinical significance and cost effectiveness of routine chest radiographs in the postanesthesia care unit (PACU).nnnDESIGNnProspective study.nnnSETTINGnUniversity hospital.nnnPATIENTSn100 patients who were admitted to the PACU following various surgical procedures, and in whom a postoperative chest radiograph was routinely performed.nnnINTERVENTIONSnChest radiograph was taken in each study patient soon after admission to the PACU. The indications for postoperative chest radiograph were: thoracotomy (30 patients), thoracoscopy (7), central vein catheterization (CVC) (75), pulmonary artery catheterization (3), and mechanical ventilation (36). A staff anesthesiologist examined each patient, evaluated each chest radiograph, and decided if a treatment action was to be taken. A chest radiologist later evaluated each chest radiograph, and her interpretation was compared with the anesthesiologists interpretation to assess if this may affect patient management.nnnMEASUREMENTS AND MAIN RESULTSnThe anesthesiologist found eight abnormal chest radiographs (8%): three with pulmonary congestion, four in whom the CVC was in the right atrium, and one with malpositioned CVC. In four patients (4%), the chest radiographic findings directly affected patient management. The radiologist confirmed the anesthesiologists interpretation and found four additional abnormalities: one pulmonary congestion, one malpositioned CVC, and two chest radiographs, each with a small pneumothorax.nnnCONCLUSIONSnAbnormal chest radiographic findings resulted in a change in the management of only 4% of the patients. Therefore, the yield of a routine postoperative chest radiograph in the PACU is low. Performing a chest radiograph for a specific indication rather than on a routine basis, may decrease work load and save expenses. Postoperative chest radiography can be safely evaluated by a staff anesthesiologist.

Delayed awakening following inadvertent high-dose remifentanil infusion in a 13 year old patient

We report the case of a 13 year old patient who received 3.0 mg of remifentanil during a 50-minute surgical procedure as a result of a dosage miscalculation. The patient failed to awaken at the conclusion of the procedure and showed signs of opioid overdose. She recovered spontaneously two hours later.

Prolonged international normalized ratio correlates with a large intravascular fluid balance after major abdominal surgery.

We performed a prospective randomized study of 32 patients who had undergone pancreaticoduodenectomy and did not receive blood during and after surgery. The patients were prospectively assigned to two groups related to fluid balance in the immediate postoperative period. Group 1 (14 patients) were maintained at a positive intravascular fluid balance of 0–1000 mL; Group 2 (18 patients) were maintained at a positive balance of 1000–2000 mL. Complete blood counts and coagulation tests (International Normalized Ratio) and activated partial thromboplastin time (aPTT) were performed at three time points: the day before surgery, on arrival at the postanesthesia care unit, and on leaving the postanesthesia care unit (16 h later). There were significant differences in International Normalized Ratio values between the groups with deterioration during the time they were in the postanesthesia care unit but not in aPTT values. Positive correlation was found between the amount of positive fluid balance and International Normalized Ratio prolongation, but not with aPTT, suggesting that restricted intravascular fluid balance is beneficial for preservation of coagulation after major abdominal surgery.