Background: Awareness during general anesthesia in different types of surgery is an important described adverse event. Bispectral (BIS) monitoring is one of the recent techniques proposed to monitor the depth of anesthesia.Objectives: The present study tested the hypothesis that the awareness rate and changes in hemodynamic parameters within anesthesia would be lower in patients allocated to BIS-guided management than those allocated to routine monitoring.Materials and Methods: In total, 333 adult patients with the American Society of Anesthesiologists (ASA) physical status I-III, aged between 18 and 65 years scheduled for elective abdominal surgery under general anesthesia were included in this randomized double-blind placebo controlled trial. Patients were randomly allocated to BIS monitoring (n=163) or routine monitoring (n=170). BIS values and hemodynamic parameters including systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), and SPO2 were marked before induction (control value), after intubation and laryngoscopy, at intubation, after incision, and also during the operation every 15 minutes until extubation.Results: The overall incidence of awareness in the BIS and routine monitoring groups were 5.5% and 4.1%, which was not significantly different. There were no significant differences in hemodynamic indices including SBP, DBP, HR, and SPO2 before induction of anesthesia between the two groups. These between-group differences in the studied indices remained insignificant at different time points after anesthesia induction as well as post ICU hospitalization. Furthermore, the trend of changes in hemodynamic parameters was comparable in the two groups.Conclusions: BIS-guided management may not be superior to routine monitoring protocols to prevent awareness as well as hemodynamic changes during general anesthesia in patients undergoing abdominal surgeries.

BACKGROUND: Because the effects of cricoid pressure (CP) on BIS values have not been evaluated, this prospective study was designed to assess the BIS values after application of CP in adult patients during the routine induction of general anesthesia.METHODS: We randomly allocated 70 patients (ASA-I) aged 18-64 years, listed for elective surgery into two groups of cricoid (CP) and non-cricoid (nCP). In the cricoid group, bimanual cricoid pressure was performed after the induction of anesthesia and in the nCP group, simple placement of hands without exerting pressure was performed. Arterial blood pressure, heart rate and BIS were measured and recorded immediately before and after application of cricoid pressure, before laryngoscopy and intubation and then every one minute after intubation until 4 minutes. The data were compared between and within groups using the mixed-design analysis of variance.RESULTS: One minute after application of cricoid pressure and before laryngoscopy, BIS showed significantly higher value compared with the nCP group. Furthermore, one min after intubation, BIS values and arterial blood pressure increased significantly in both groups compared with the baseline values, but the increase in BIS value was more significant in CP group than nCP group. Moreover, BIS values increased significantly 2 minutes after intubation in CP group compared with nCP group.CONCLUSIONS: It was concluded that the application of CP in combination with laryngoscopy and intubation increases the BIS values, which show the inadequacy of anesthesia and hypnosis during the routine induction of anesthesia.

Introduction: Vertical root fracture (VRF) is a complication which is chiefly diagnosed radiographically. Recently, film-based radiography has been substituted with digital radiography. At the moment, there is a wide range of MONITORS available in the market for viewing digital images. The present study aims to compare the diagnostic accuracy, sensitivity and specificity of medical and conventional MONITORS in detection of vertical root fractures. Material and Methods: In this in vitro study 228 extracted single-rooted human teeth were endodontically treated. Vertical root fractures were induced in 114 samples. The teeth were imaged by a digital charge-coupled device radiography using parallel technique. The images were evaluated by a radiologist and an endodontist on two medical and conventional liquid-crystal display (LCD) MONITORS twice. Z-test was used to analyze the sensitivity, accuracy and specificity of each monitor. Significance level was set at 0.05. Inter and intra observer agreements were calculated by Cohen’s kappa.Results: Accuracy, specificity and sensitivity for conventional monitor were calculated as 67.5%, 72%, 62.5% respectively; and data for medical grade monitor were 67.5%, 66.5% and 68% respectively. Statistical analysis showed no significant differences in detecting VRF between the two techniques. Inter-observer agreement for conventional and medical monitor was 0.47 and 0.55 respectively (moderate). Intra-observer agreement was 0.78 for medical monitor and 0.87 for conventional one (substantial). Conclusion: The type of monitor does not influence diagnosis of vertical root fractures.

BACKGROUND: Our objective was to examine the clinical properties of two anesthetic regimens, propofol targetcontrolled infusion (TCI), or desflurane using remifentanil TCI under bispectral index (BIS) guidance during ear, nose, and throat (ENT) procedures.METHODS: Forty consenting patients who scheduled for ENT procedures were prospectively studied and were included in one of the two groups: TCI group or desflurane (DES) group. General anesthesia was induced with 3 ng mL-1 and 4μg mL-1 effect site concentrations (Ce) of remifentanil and propofol, respectively, with TCI system. After intubation, while propofol infusion was continued in the TCI group, it was ceased in the DES group and desflurane with an initial delivered fraction of 6% was administered. The Ce of propofol infusion and inspired fraction of desflurane was adjusted in order to keep BIS as 50±10.RESULTS: General mean values of mean arterial pressure (MAP) and heart rate (HR) for the TCI group was significantly higher than DES group (89.3 mmHg and 72.4 bpm vs.77.1 mmHg and 69.5 bpm). Early emergence from anesthesia did not significantly differ between the groups. The rate of patients’ Aldrete score (ARS) to reach 10 was found to be 100% at the 15th min in both groups.CONCLUSIONS: Bispectral index guided combinations of remifentanil TCI either with propofol TCI or desflurane anesthetic regimens are both suitable for patients undergoing ENT surgery. The lower blood pressure in the remifentanil TCI with desflurane anesthetic regimens may be a significant advantage.

Introduction: Renal transplantation is the best method of treatment for renal failure and anesthetic management during this procedure is of great importance. Proper dosage of the anesthetic drug for maintaining the respective depth is crucial as well. Arterial unclamping following anastomosis between the donor and recipient’s kidney vessels, during which the functional kidney is inserted in the recipient’s circulation, is a critical step in transplantation.Objective: To investigate the changes in Bispectral number and pupil dilatation as confirmed and probable markers of anesthesia depth have been investigated.Materials and Methods: This descriptive-analytic study was conducted on 25 patients undergoing renal transplantation in Razi hospital. Alteration in the depth of anesthesia was analyzed using BIS (Bispectral) index (at unclamping moment and its highest value within five minutes following unclamping) as well as pupil dilatation (5 minutes after unclamping). All the patients underwent identical method of general anesthesia. Data were analyzed using SPSS version16, paired t-test and Mann-Whitney U test.Results: Mean and SD value of the maximum BIS number within 5 minutes after arterial unclamping (68/32±9/13) and its value at unclamping moment (59/48±10/65) were significantly different (P<0.0001).The pupil became wider in 84% of the patients immediately after unclamping. No significant relationship was found between the pupil size and BIS change.Conclusion: Considering the present findings, it seems that the depth of anesthesia declines after arterial unclamping following vascular anastomosis of the transplanted kidney. We also found a new sign in kidney transplantation anesthesia, introduced as “PUPIL SIGN”, that happens prior to urination from the transplanted kidney, which could have clinical implications for early prognosis of transplantation success.

Background: Bispectral Index (BIS) may be used in traumatic brain injured patients with different anatomical sites of injury to evaluate the level of CONSCIOUSNESS. The objective of this study is to evaluate the relation between type of brain injury and the presence or absence of frontal lobe damage based on brain CT-scan with BIS monitoring in intubated acute head trauma patients admitted to the intensive care unit (ICU).Methods: Participants of this cross-sectional study consisted of 30 intubated head trauma patients over the age of 15 years old, without any known history of visual or hearing impairments, neurologic disorders, mental retardation, or frontal skin laceration, who were admitted to the ICU in Rasool Akram University Hospital, Tehran. Patients who needed muscle relaxant administration, or those who showed instability of vital signs, hypoxemia, disorders of the blood biochemistry, or blood gases, liver or kidney failure, convulsion or hypoxic encephalopathy during the study were excluded.In the first three days of admission, each patient underwent monitoring of BIS every sixty minutes for just six hours a day. All the hypnotic drugs were discontinued six hours prior to the start of monitoring and fentanyl was the only opioid, which was administered if an analgesic was required. Statistical analysis were used to evaluate the data and p-value less than 0.05 was considered statistically significant.Results: Mean age of all patients was 43.6 years with a Standard Deviation (SD) of 18.96. Presence or absence of frontal lobe injury, had no statistically significant correlations with mean BIS in each three days of study and the mean BIS total. However, mean BIS in the second and third days had statistically significant differences in different types of cranial lesions (contusion, subdural hemorrhage, subarachnoid hemorrhage, etc) which usually have different prognoses.Conclusion: Different kinds of acute traumatic cranial lesions with different prognosis may have different values in BIS monitoring. Presence or absence of frontal lobe injury, had no statistically significant correlations with BIS values.

In many applications it is necessary to have a reference beam of the laser light and for this purpose a beam splitter is usually used. The goal of this paper is to show the potentials of photon drag MONITORS to be used in place of the conventional beam splitters. Characteristics, advantages and disadvantages of the longitudinal and transverse devices are reported in this article. Recorded signal for typical silicon monitored by using a laser beam at wavelength 496 µm (CH__3F laser) is presented here. Variation of the noise equivalent power as a function of the radiation wavelength is also given for different monitor resistivity. The reported photon drag monitor can be used as an "on-line" device for monitoring reference pulses in variety of signal processing and pulse shaping in laser applications.

Background: Morbid obesity is associated with a some of significant comorbidities. Early and uneventful postoperative recovery of obese patients remains a challenge for anesthesiologists. It seems Bispecteral Index (BIS) monitoring may reduce drug usage and hasten recovery time in inhalation anesthesia. The aim of this study was to investigate the effect of BIS monitoring on intraoperative isoflurane utilization and the early recovery profile.Methods: Fifty morbidly obese adult patients (Body Mass Index (BMI) of 35 kg/m2 or grater) undergoing elective laparoscopic cholecystectomy in Urmia Imam Khomeini Hospital were enrolled in this prospective, Cohort and single blind study. Duration of this study was six months between April to September 2012. Patients were randomly divided two groups (25 patients per group). In the first phase of the study, patients were anesthetized without the use of BIS monitoring and isoflurane being administered according to standard clinical practice (this group formed the control group). In a second phase, with use of BIS monitoring isoflurane was titrated to maintain a BIS value between 40 and 60 during surgery, and then 60-70 during 15 min before the end of surgery (this group formed the BIS group). Isoflurane consumption and recovery time were compared between two groups.Results: All patients completed the study. No differences were noted between demographic data. The isoflurane consumption in the BIS group was 30-35% lower than in the control group (P<0.001). The time to awakening and duration of extubation in the BIS group were significantly less than the control group (P<0.001). Furthermore, analgesic consumption in the recovery room and sedation score during postoperative phase were similar between the groups. Significant differences were noted in recovery time between two groups (P<0.001).Conclusion: The addition of Bispectral index monitoring to standard monitoring reduced isoflurane usage. We found use of BIS hastened recovery time after isoflurane anesthesia.