Journal of Anesthesiology and Pain

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Aim and Background:

Awareness during anesthesia is recalling the events that occurred during general anesthesia and surgery. The experience of awareness is emotional trauma that causes a painful and exhausting emotional, and post-traumatic stress. The goal of this study is assesing the incidence of awareness during general anesthesia in patients undergoing surgery at a universitial hospital.

Methods and Materials:

This was a descriptive study performed in a university hospital affiliated to Tehran University of Medical Sciences. 700 patients more than 18 years old, in good physical condition and cooperative who were able to speak in Persian were enrolled. The participants were interviewed 24 hours after general anesthesia and surgery using a standardized questionnaire.

 Findings:

 A total of 18 patients (2.6%) recalled some events between sleeping and waking. 59 (8.5%) had seen dreams, 19 (2.7%) had felt pain and 23 patients (3.4%) had hearing experiences. The only significant correlation between hearing awareness and location of operation, dreams and weight were obtained.

 Conclusions:

The incidence of awareness during general anesthesia in this study is more than reports from other countries.

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Aim and Background:

Emergence from general anesthesia can be associated with coughing, agitation, and hemodynamic disturbances. Remifentanil may attenuate these response, so we examined the effects of maintaining a remifentanil infusion in the recovery room, on recovery profiles such as coughing and cardiovascular responses after general anesthesia.

Methods and Materials:

In a prospective, double-blinded, randomized trial, we enrolled 60 adult patients undergoing nasal surgery with remifentanil-based anesthesia. During the emergence phase, the infusion rate of remifentanil was reduced to 0.02 micro/kg/min in treatment group 1 and to 0.05 micro/kg/min in treatment group 2, whereas in the control group remifentail was discontinued and placebo was started instead.

Findings: 

During emergence, both of the treatment groups had a significantly lower incidence and severity of coughing and slower heart rate. The mean systolic blood pressure (MAP) in the treatment group 2 was significantly lower compared with the other groups, but the awakening or extubation time was prolonged in this group, whereas time interval to awakening and tracheal extubation was similar between the control group and treatment group 1.

Conclusions:

Maintaining a low-dose remifentanil infusion during emergence did not prolong awakening but reduced heart rate and the incidence and severity of coughing due to the endotracheal tube, whereas high-dose remifentanil infusion reduced the hemodynamic changes and coughing associated with tracheal extubation while significantly delaying the extubation time.

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Aims and Background: Although controversial, many studies have shown effectiveness of colloid loading as a substitute for crystalloids on reducing the incidence of hypotension in spinal anesthesia. This study was conducted to compare the effects of three intravenous fluid regimens on hemodynamic changes following spinal anesthesia in cesarean section. The regimens included 6% Hydroxy ethyl starch 130/0.4 (HES) as a colloid and two crystalloids (lactated ringer’s solution and sodium chloride 0.9%).

 Methods and Materials: In a double-blind clinical trial, 90 otherwise healthy parturients candidate for elective caesarean section, were randomly allocated to receive lactated ringer’s solution (1000 ml), sodium chloride 0.9% (1000 ml) or HES (7.5 mL/Kg) as preloading before spinal anesthesia. Hemodynamic parameters including blood pressure and heart rate, umbilical cord blood pH and the neonatal Apgar score were compared among the three groups.

 Findings: There was no difference in the basic hemodynamic measurements among the three groups. The incidence of hypotension and the required dose of ephedrine were lower in HES group (p=0.008). There was no significant difference in umbilical cord blood PH or Apgar scores among the intervention groups.

  Conclusion: Preloading with HES is more effective than crystalloids in preventing hypotension after spinal anesthesia without leading to a significant difference in Apgar score and umblical cord blood pH.

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 Aims and background: Intraoperative blood loss during craniotomy for brain tumor excision needs blood transfer in most of the cases. Tranexamic acid is an anti-fibrin lytic drug. The aim of this study was to evaluate the effect of Tranexamic acid on intraoperative blood loss in patients undergoing craniotomy for brain tumor excision. Materials and Methods: Fifty patients suffering from brain tumor underwent craniotomy. Thirty minutes before incision, patients were randomly allocated into two groups of intervention (Tranexamic acid) or control group (normal saline). Fifteen mg/kg Tranexamic acid in combination with 500 cc normal saline in a 30 minutes period was injected in the form of bolus in the intervention group. In control group, patients received normal saline in same amounts. Intraoperative blood loss was estimated by observing Suction bottles, weighting the used medical gauzes and the remained blood on the surgery field during the surgery. This was done by counting small cotton and converting the surgery field to used medical gauzes. Blood loss was measured every one hour. Findings: The mean blood loss during surgery in the intervention group was 858±314 and 1050±398 in the control group. Although this amount was less in intervention group, the trend was not significant (P= 0.076). Also the mean amount of estimated blood loss in intervention group was 798± 365 and 906±378 in the control group (P=0.31). conclusion: Tranexamic acid administration may decrease the blood loss but this study could not observe any significant trend. The number of blood pack cells and estimated blood loss were not significantly different in two groups of intervention and control.

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 Aims and background:    This    study    develops    a    computational    framework    for    the    classification    of    different    anesthesia    states,    including    awake,    moderate    anesthesia,    and    general    anesthesia,    using    electroencephalography    (EEG)    signals    and    peripheral    parameters. Materials and Methods: The    proposed    method    proposes    data    gathering;    preprocessing;    a    new    labeling    process    of    EEG    signal;    appropriate    selection    of    window    length    by    genetic    algorithm;    feature    extraction    by    Hjorth    parameters,    approximate    entropy,    Petrosian    fractal    dimension,    Hurst    exponent,    largest    Lyapunov    exponent,    Lempel-Ziv    complexity,    correlation    dimension,    and    Daubechies    wavelet    coefficients;    feature    normalization;    feature    selection    by    non-negative    sparse    principal    component    analysis;    and    classification    by    radial    basis    function    (RBF)    neural    network.    Correct    labeling    process    of    EEG    signals    is    performed    by    an    expert    opinion    and    also    qualitative    and    quantitative    analysis    of    the    extracted    parameters    from    peripheral    nerve    stimulator,    pulse    oximetry,    blood    pressure,    and    the    time    of    drug    injection.    Findings:    The    results    indicate    that    the    proposed    method    would    classify    different    anesthesia    states    including    awake,    moderate    anesthesia,    and    general    anesthesia,    with    the    accuracy    of    93.98%,    98.62,    and    97.3,    respectively.    Therefore,    the    proposed    method    can    classify    different    anesthesia    states    with    the    average    accuracy    of    97.3%. conclusion: Finally,    the    proposed    method    provided    a    good    representation    of    the    brain    behavior    in    different    anesthesia states.

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 Aims and background: Poincare plot and its length and width are known as a criterion for short-term variations of electroencephalogram signals )EEGs(. This study evaluates the effect of time delay on changes in the width of the Poincare plot in brain signal during different anesthesia states. Materials and Methods: Poincare plots are drawn with one to six delay in three sets, including awake state, light anesthesia, and general anesthesia, and also for each data, the width of the Poincare plot is calculated using the SD1 and SD2 characteristics. Findings: The results show that during  general anesthesia, the width of the Poincare plot increases with increasing latency. During anesthesia, the width of the Poincare plot is achieved by applying a unit delay of 8.1 ± 1.2 and a six-unit delay of 15.9 ± 0.8. Also, the Poincare plot is shifted to lower values during anesthesia. It is also shown that with increasing delay in general anesthesia, the SD1 value increase rate is higher than the previous ones, such as light anesthesia and awake state. Conclusion: Simplicity of calculating the width of the Poincare plot and its adaptation to the chaotic nature of vital signals can be useful in evaluating the brain signal in different states of anesthesia.

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Introduction: During the last few years, the trend of using non-opioid drugs for the management of pain after surgery has been highly welcomed, and on the other hand, considering the contradictory results of the preventive use of intravenous ibuprofen before surgery, the present study aimed at the effect of a single dose of intravenous ibuprofen before surgery. A systematic review and meta-analysis was conducted on post-anesthesia pain surgery.
Methods: This study was conducted as a systematic review and meta-analysis in the first six months of 1401 based on the PRISMA statement. For this purpose, the keywords of ibuprofen, intravenous, post-surgical pain, analgesia, opioid and analgesia under patient control in the databases PubMed, Scopus, MEDLINE, Embase, Cochrane Center for Controlled Trials and Web of Science, Mag Iran and SID databases.
Results: Examining pain intensity at 12 hours (MD=-1.64 (-2.56, -0.72), 95%CI P=0.001 and I=95%) and 24 hours (-0.58) MD = (-0.18, -0.99) 95% CI- P = 0.001 and I = 90%) after surgery indicated that prophylactic administration of ibuprofen significantly reduced pain intensity.
Conclusion: The administration of a single prophylactic dose of intravenous ibuprofen leads to a decrease in pain intensity during the first 24 hours after surgery, however, its effects decrease over time.