Evaluation of the Preventive Effects of Neostigmine Plus Atropine on Post-Dural Puncture Headache.

Background: Post-dural puncture headache (PDPH) is one of the most common side effects of spinal anesthesia. Several strategies and drugs have been suggested for the treatment and/or prevention of this headache. The aim of this study is evaluating the effects of intravenous prescription of neostigmine plus atropine 15 minutes after dural puncture on incidence and severity of PDPH during 5 days of follow-up in the setting of lower limb orthopedic surgeries. Materials and Methods: In a randomized, controlled, double-blind clinical trial, 99 patients of lower limb orthopedic surgeries were randomized into study (49 patients) and control groups (50 patients). Fifteen minutes after dural puncture, participants in the two groups intravenously took neostigmine (40 µg/kg) plus atropine (20 µg/kg) and placebo (normal saline), respectively. Side effects of the studied drugs and incidence, severity, and duration of PDPH were evaluated 5 days after surgery. Results: A total of 20 patients in the study group and 31 in the control group showed a headache-with-PDPH profile during 5 days of follow-up (P-value = 0.035). The mean duration of PDPH was 1.15 ± 0.48 and 1.32 ± 0.54 days in the study and control groups, respectively (P-value = 0.254). Conclusion: Preventive administration of 40 µg/kg neostigmine plus 20 µg/kg of atropine may be effective in reducing the incidence and severity of PDPH after spinal anesthesia in lower limb orthopedic surgeries.

Evaluation of the effectiveness of the modified nutrition risk in the critically ill (mNUTRIC) score in critically ill patients affected by COVID-19 admitted to the intensive care unit (ICU).

BACKGROUND: COVID-19 is a very harmful pandemic, and its recovery process is highly influenced by nutritional status; however, an appropriate nutritional scale has not yet been proposed for these patients. Therefore, the purpose of this study was to evaluate the effectiveness of the modified Nutrition Risk in the Critically ill (mNUTRIC) score in critically ill patients affected by COVID-19 admitted to the intensive care unit (ICU). MATERIAL AND METHODS: This was a cross-sectional study performed on 204 critically ill patients affected by COVID-19 admitted to the ICU wards. Evaluated indicators include the mNUTRIC Score as well as demographic, and biochemical indicators. RESULTS: A high percentage of COVID-19 patients (67.2%) had severe disease. Hospital and ICU stay (p > 0.001) and PH (p > 0.001) values were significantly lower in non-survivors than in survivors. mNUTRIC score (p > 0.001), PCO2 (p = 0.003), and CRP levels (p = 0.021) were significantly higher in non-survivors than survivors. mNUTRIC score had a direct correlation with age (p > 0.001), AST (p = 0.000), LDH (p = 0.026), and CRP (p = 0.014) and an inverse correlation with hospital duration (p = 0.031), albumin (p = 0.003) and PH (p < 0.001). Furthermore, there was a non-significant correlation between the mNUTRIC score and mortality chance (OR = 1.085, 95%CI [0.83, 1.42], p = 0.552). While, patients with more severe COVID-19 disease (OR = 8.057, 95%CI [1.33, 48.64], p = 0.023) and higher PCO2 (OR = 1.042, 95%CI [1.01, 1.08], p = 0.023) levels had higher odds of mortality. CONCLUSIONS: Our findings revealed that COVID-19 patients with higher CRP levels and lower PH had higher mortality and poor nutritional condition. Moreover, there was a non-significant association between the mNUTRIC score and mortality chance.

Comparative Evaluation of the Effects of Three Different Recruitment Maneuvers during Laparoscopic Bariatric Surgeries of Morbid Obese Patients on Cardiopulmonary Indices.

BACKGROUND: Laparoscopic bariatric surgeries in morbid obese patients may be associated with atelectasis, hypercapnia, and hypoxemia, intra and postoperatively. Several strategies are used for the prevention of these consequences. This study aimed to examine the effects of three different recruitment maneuvers comparatively during surgery and the influence of the maneuvers on some cardiopulmonary indices. MATERIALS AND METHODS: In a clinical trial, ninety participants of laparoscopic surgery with body mass index higher than 40 were randomly divided into three equal groups. The first group was subject to 10 cmH2O positive end-expiratory pressure (PEEP) during surgery, the second group, after venting the pneumoperitoneum, had 5 deep breaths with a positive pressure of 40 cmH2O, and the third group was subject to both. Some pulmonary and hemodynamic parameters were measured every 15 min and compared between three groups. RESULTS: The average of peak airway pressure, plateau airway pressure, and SpO2 static and dynamic compliance between the three groups had no meaningful differences (P > 0.05), but PaCO2in the second group was statistically higher than the other two groups (P < 0.05). CONCLUSION: Multiple deep breaths alone are not as effective as PEEP or PEEP plus MDB in preventing adverse pulmonary effects in laparoscopic bariatric surgeries of morbid obese patients.

Effect of ondansetron on prevention of post-induction hypotension in elderly patients undergoing general anesthesia: A randomized, double-blind placebo-controlled clinical trial.

BACKGROUND: Elderly patients are susceptible to post-induction hypotension. Volume loading and vasopressors for prevention of hypotension in elderly patients may increase perioperative cardiovascular risks. Ondansetron by blocking Bezold-Jarisch reflex (BJR) through inhibition of serotonin receptors has been effective in the prevention of post-spinal hypotension, and bradycardia. Bradycardia frequently accompanies post-induction hypotension in elderly patients, which signifies a possible preventing role for ondansetron. No previous study has evaluated the prophylactic effects of ondansetron for the prevention of post-induction hypotension. MATERIALS AND METHODS: In this randomized placebo-controlled clinical trial, ondansetron 4 mg was given intravenously to 65 elderly patients, 20 min before induction of general anesthesia, and the rate of post-induction hypotension defined as 25% or more reduction in mean arterial blood pressure, compared with a placebo groups. RESULTS: A total of 114 patients completed the study (58 in ondansetron and 56 in the placebo group). Proportions of post-induction hypotension were 9 (16%) and 25 (45%) in ondansetron and placebo groups, respectively, (P = 0.001). Forty-five patients (40%) developed bradycardia. Rates of bradycardia were not significantly different between two groups. CONCLUSIONS: The results of this study show the effectiveness of intravenous ondansetron for prevention of post-induction hypotension in elderly patients. The mechanism of this effect largely is unknown. Role of ondansetron for prevention of post-induction hypotension may not fully understandable by its interaction with BJR, as has been shown in post-spinal hypotension.

The predicting ability of serum potassium to assess the duration of mechanical ventilation in critically ill patients.

BACKGROUND: No previous study has been done to evaluate the admission serum potassium level as a predictor of morbidity or need for mechanical ventilation. The aim of this study is to determine the predictive ability of serum potassium on admission, in critically ill trauma patients, and to evaluate the relation of the potassium level to organ failure, length of stay, ventilator need, and duration of mechanical ventilation. MATERIALS AND METHODS: A prospective, observational study was done on 100 patients >16 years old, admitted to the Medical-Surgical Intensive Care Units (ICU), for over one year. Patients were classified into Group A: Patients who required equal or less than five days of mechanical ventilation and Group B: Patients who required more than five days of mechanical ventilation. The total serum potassium concentrations were measured and the Sequential Organ Failure Assessment (SOFA) score was recorded at the time of admission to the ICU, when connected to the ventilator, and then at the time of weaning from the ventilator. RESULTS: There was no significant difference between the Serum K concentrations between the two groups, on admission. However, there were significant difference between the Serum K concentrations at times of receiving and weaning from mechanical ventilation (MV) between the two groups. We found the best cut-off point of 3.45 for serum potassium concentration, to predict the need for longer duration of MV. CONCLUSION: Development of hypokalemia during an ICU stay is associated with the need for mechanical ventilation. Monitoring of the serum potassium levels may be a good prognostic factor for the requirement of mechanical ventilation.

The effect of early ambulation on the incidence of neurological complication after spinal anesthesia with lidocaine.

BACKGROUND: Transient neurological symptoms (TNS), was described in patients recovering from spinal anesthesia with lidocaine but its etiology remains unknown this study was evaluated the influence of ambulation time on the occurrence of TNSs after spinal anesthesia with lidocaine 5%. MATERIALS AND METHODS: This randomized clinical trial was conducted on 60 patients with American Society of Anesthesiologists Grades I and II, who were candidates for lower abdominal surgery in supine or lithotomy positions. Patients were randomly divided into early ambulation group (Group A) who were asked to start walking as soon as the anesthesia was diminished or to the late ambulation group (Group B) who walked after at least 12 h bedridden. Participants were contacted 2 days after spinal anesthesia to assess any type of pain at surgical or anesthesia injection site, muscle weakness, fatigue, vertigo, nausea, vomiting, headache, and difficult urination or defecation. RESULTS: Four subjects (13.3%) in Group A and two patients (6.7%) in Group B had pain at anesthesia injection site (P = 0.019). Fourteen patients in Group A (46.7%) and six patients in Group B (20%) had post-dural puncture headache (P = 0.014). Participants in Group B reported difficult urination more than Group A (P = 0.002). there were not statistically significant differences between two groups regarding frequency of fatigue, muscle weakness, vertigo, nausea, vomiting, difficult defecation, paresthesia, and the mean of visual analogue scale at the surgical site. CONCLUSION: Early ambulation after spinal anesthesia with lidocaine did not increase the risk of neurologic complication.

Evaluation of in vivo effects of Oxytocin on coagulation of parturient during cesarean delivery by thromboelastography.

OBJECTIVE: Oxytocin routinely used as an uterotonic drug in cesarean delivery. Clothing problems, adverse effects on fibrinogen and bleeding were presented as side effects of oxytocin. In in vivo investigation, modest hypercoagulable state was suggested as a side effect for infusion of oxytocin in parturients. In this study, effects of two different infusion rates of oxytocin on coagulation of parturient were evaluated during cesarean delivery. METHODS: In a randomized double-blinded clinical trial, 84 healthy parturient in two equal groups took oxytocin infusion with the rate of 15 IU/h (Group A) or 30 IU/h (Group B), after the umbilical cord clamping. Coagulation status measured 30 min after beginning of infusion by thromboelastography. Data were analyzed by χ(2), paired sample test and ANOVA considering as significant at P < 0.05. FINDINGS: The mean (standard deviation) of variables in Groups A and B were 2.4024 (0.86) and 2.0429 (0.68) for K (kinetics of clot development), 55.4429 (11.30) and 60.7595 (10.41) for α (speed of clot strengthening) and 59.779 (19.15) and 70.61 (11.30) for maximum amplitude (maximum clot strength), respectively. The P values for these variables were 0.036, 0.028 and <0.001, respectively; these changes are consistent with increasing coagulability. Other measures did not have significant differences. CONCLUSION: This in vivo investigation clarified that increasing infusion rate of oxytocin to 30 IU/h can augment coagulability in term parturients.

Effects of intra-operative end-tidal carbon dioxide levels on the rates of post-operative complications in adults undergoing general anesthesia for percutaneous nephrolithotomy: A clinical trial.

BACKGROUND: A retrospective study has shown lesser days of hospital stay in patients with increased levels of intra-operative end-tidal carbon dioxide (ETCO2). It is probable that hypercapnia may exert its beneficial effects on patients' outcome through optimization of global hemodynamic and tissue oxygenation, leading to a lower rate of post-operative complications. This study was designed to test the hypothesis that higher values of intra-operative ETCO2 decrease the rate of post-operative complications. MATERIALS AND METHODS: In this randomized, double-blind clinical trial, 78 adult patients scheduled for percutaneous nephrolithotomy (PCNL) were prospectively enrolled and randomly divided into three groups. ETCO2 was set and maintained throughout the procedure at 31-33, 37-39 and 43-45 mmHg in the hypocapnia, normocapnia and hypercapnia groups, respectively. The rates of post-operative complications were compared among the three groups. RESULTS: Seventy-five patients completed the study (52 male and 23 female). Ten (38.5%), four (16%) and two (8.3%) patients developed post-operative vomiting in the hypocapnia, normocapnia and hypercapnia groups, respectively (P = 0.025). The nausea score was significantly lower in the hypercapnic group compared with the other groups (3.9 ± 1.8, 3.2 ± 2.1 and 1.3 ± 1.8 in the hypocapnia, normocapnia and hypercapnia groups, respectively; P = 0.000). Time to return of spontaneous respiration and awakening were significantly decreased in the hypercapnia group compared with the other groups (P < 0.01). CONCLUSION: Mild intra-operative hypercapnia has a protecting effect against the development of post-operative nausea and vomiting and decreases the duration of emergence and recovery from general anesthesia.

Comparative evaluation of hemodynamic and respiratory parameters during mechanical ventilation with two tidal volumes calculated by demi-span based height and measured height in normal lungs.

BACKGROUND: Appropriate determination of tidal volume (VT) is important for preventing ventilation induced lung injury. We compared hemodynamic and respiratory parameters in two conditions of receiving VTs calculated by using body weight (BW), which was estimated by measured height (HBW) or demi-span based body weight (DBW). MATERIALS AND METHODS: This controlled-trial was conducted in St. Alzahra Hospital in 2009 on American Society of Anesthesiologists (ASA) I and II, 18-65-years-old patients. Standing height and weight were measured and then height was calculated using demi-span method. BW and VT were calculated with acute respiratory distress syndrome-net formula. Patients were randomized and then crossed to receive ventilation with both calculated VTs for 20 min. Hemodynamic and respiratory parameters were analyzed with SPSS version 20.0 using univariate and multivariate analyses. RESULTS: Forty nine patients were studied. Demi-span based body weight and thus VT (DTV) were lower than Height based body weight and VT (HTV) (P = 0.028), in male patients (P = 0.005). Difference was observed in peak airway pressure (PAP) and airway resistance (AR) changes with higher PAP and AR at 20 min after receiving HTV compared with DTV. CONCLUSIONS: Estimated VT based on measured height is higher than that based on demi-span and this difference exists only in females, and this higher VT results higher airway pressures during mechanical ventilation.

Comparative evaluation of the effects of hydroxyethyl starch on coagulation state of patients during brain tumor surgeries in comparison to crystalloids by thromboelastography.

BACKGROUND: Hypercoagulability has been reported in primary brain tumors which can lead to thrombotic complications. Hydroxyethyl starch (hetastarch) is a synthetic colloid solution with adverse effects on blood coagulation. The aim of this study was to evaluate the protective effect of hetastarch in reducing thromboembolic events in these patients. MATERIALS AND METHODS: In a double-blinded clinical trial, 60 brain tumor surgery patients were randomly divided into two groups and given 10 mL/kg hetastarch or normal saline during surgery. Blood coagulation was compared before and after infusion of these fluids within and between groups by thromboelastography (TEG). RESULTS: There were no significant differences in bleeding (P = 0.126), duration of surgery (P = 0.504), and fluid intake (0.09L) between the two groups. Percentage of changes in R (R: Time to initiate fibrin formation), K (K: Measure of the speed taken to reach a specific level of clot strength), and Ly30 (Ly30: Percent of fibrin distraction after 30 minutes of clot formation) in the crystalloid group were -20.61 ± 26.46, -30.02 ± 49.10, and 1.27 ± 22.63, and that in the colloid group were 22.10 ± 26.11, 41.79 ± 37.15, and 59.09 ± 37.12, respectively. Deterioration in hemostasis during and after surgery was not observed. CONCLUSION: There was a reduction in the speed of clot formation and increase in clot lysis in the hetastarch group. Coagulability was decreased in the colloid group. Infusion of 10 mL/kg hetastarch in brain tumor resection surgeries can probably decrease susceptibility of these patients to deep vein thrombosis (DVT) and thromboembolic events.

Evaluation of intravenous neostigmine infusion on tolerance of enteral nutrition in Intensive Care Unit patients.

BACKGROUND: Based on the dramatic response of acute colonic pseudo-obstruction to neostigmine, we designed this study to evaluate the effect of neostigmine on the tolerance of enteral feeding in Intensive Care Unit (ICU) patients. MATERIALS AND METHODS: A total of 60 patients hospitalized in the ICU of Alzahra Hospital, Isfahan, Iran entered the study. They were randomly assigned to one of the two groups of case (who received intravenous neostigmine infusion) and control (normal saline). They were compared with respect to incidence of constipation, diarrhea, and vomiting. Arrhythmia, bronchospasm, mean arterial blood pressure (MAP), and heart rate (HR) were also evaluated at 0, 4, 8, 12, 16, 20, and 24 h. RESULTS: The frequency distribution of constipation, diarrhea, vomiting, and increase in gastric lavage volume in the intervention group was 20%, 33.3%, 46.7% and 43.3%, while these indices in the control group were 40%, 30%, 43.3%, and 63.3%, respectively (P > 0.05). Arrhythmia was observed in 3% and 6% in the case and control groups, respectively. Bronchospasm was not detected in any of patients. CONCLUSION: There was no significance difference between neostigmine and normal saline with respect to tolerance of enteral nutrition in ICU patients.

Hypercapnic hyperventilation shortens emergence time from Propofol and Isoflurane anesthesia.

OBJECTIVE: The aim of this study is to compare the effects of hypercapnic hyperventilation and normocapnic normoventilation on emergence time from propofol and isoflurane anesthesia. METHODS: In this clinical trial, the differences in emergence time were evaluated in 80 patients undergoing elective abdominal surgery in Alzahra University hospital, Isfahan, Iran, in 2011-2012. Patients were randomly divided into four groups (groups 1-4) receiving isoflurane hypercapnic hyperventilation, isoflurane normocapnic normoventilation, propofol hypercapnic hyperventilation, and propofol normocapnic normoventilation, respectively. Hypercapnia was maintained by adding CO2 to the patient's inspired gas during hyperventilation. The emergence time and the duration of stay in recovery room in the four groups were measured and compared by one-way analysis of variance (ANOVA) and least significant difference tests. FINDINGS: The average emergence time in groups 1, 2, 3, and 4 were (11.3 ± 3.2), (15.2 ± 3.8), (9 ± 4.2) and (11.8 ± 5.3) min, respectively. These differences were significant (P = 0.001). In patients receiving propofol hypercapnic hyperventilation, the emergence time was faster than in other groups. There was also a significant difference in duration of stay in recovery room between the groups (P = 0.004). Patients who received isoflurane hypercapnic hyperventilation had a shortest length of stay in the recovery room. CONCLUSION: The emergence time after intravenous anesthesia with propofol can be shortened significantly by using hyperventilation and hypercapnia, without any side effects.

Predicting efficiency of post-induction mask ventilation based on demographic and anatomical factors.

BACKGROUND: Failure to ventilate patients by mask leads to serious complications especially if associated with difficult intubation. Previous studies have used subjective and indirect measures to evaluate difficulty in mask ventilation, which are associated with high inter-observer discrepancies. In this study, we have defined and used efficiency of mask ventilation (EMV) as an objective and direct surrogate for ease of mask ventilation in patients undergoing GA and mask ventilation using neuromuscular relaxation. MATERIALS AND METHODS: 1050 adult patients prospectively were evaluated with respect to different patients demographic and physical factors and EMV. EMV was defined as the ratio of minute ventilation via anesthesia mask to that via tracheal tube expressed as percentage. Edentolous patients were ventilated using lip-over-mask techniques. Separate analyses were done for edentolous and non-edentolous patients. RESULTS: EMV in edentolous patients (n=269) using the lip-over-mask method was relatively high (90.9 ± 14.3%, 60.14-128.57 range). The result of multiple regression analysis in patients with normal denture determined receded chin, presence of beard, male gender, high Mallampati classes, high neck circumference, low inter-incisors gap, and old age as independent factors for estimating EMV. A regression formula for predicting EMV was developed which had an acceptable R-square value with a good model fit. CONCLUSIONS: Using EMV is an easy and reliable tool for measuring efficiency of mask ventilation. Based on the result of this study, EMV can be estimated from patient's demographic and physical factors. In edentolous patients, using the lip-over-mask method results in adequate ventilation of lungs.

Comparative evaluation of different values of bispectral index in determination of the appropriate level of anesthesia for tracheal intubation during inhalational induction of anesthesia in pediatrics.

BACKGROUND: Induction of anesthesia is the most crucial period of general anesthesia. Inhalational induction is the most commonly used technique in pediatric anesthesia. Tracheal intubation can be done after reaching the deep levels of anesthesia. The depth of anesthesia is often difficult to be judged. Bispectral index is a measure of the effects of anesthesia on brain. This study was designed to evaluate the efficacy of bispectral index (BIS) in clarifying suitable depth of anesthesia for tracheal intubation during inhalational induction of anesthesia. METHODS: In a clinical trial, ninety patients, ASA I & II, 1 to 6 years old, scheduled for elective surgery were enrolled into the study. After starting BIS monitoring, patients randomly were divided into three groups. Then, anesthesia was induced by gradual increase of halothane in 50% mixture of oxygen (O(2)) and N(2)O and continued until target BIS (60 ± 2, 50 ± 2 and 40 ± 2) achieved. After tracheal intubation, the duration of laryngoscopy and the presence of laryngospasm, bronchospasm, laryngoscopy failure, the movement of extremities and the changes in SpO2 and BIS were recorded. The data were analyzed by chi-square and ANOVA at 0.05 level of significance. RESULTS: BIS could not determine the appropriate level of anesthesia for tracheal intubation in this setting. There were no differences in laryngoscopy duration and the occurrence of laryngospasm, bronchospasm, laryngoscopy failure, extremity movement and awakening time among three groups. CONCLUSIONS: These results confirmed that there was no significant difference in the incidence of complications related to intubation at different BIS values (from 60 to 40) during inhalation induction, and probably to achieve an adequate or more reliable depth of anesthesia, the lower values of BIS is required.

Paradoxical reaction following intravenous midazolam premedication in pediatric patients - a randomized placebo controlled trial of ketamine for rapid tranquilization.

BACKGROUND: Paradoxical reactions to benzodiazepines include restlessness, violent behavior, physical assault, act of self-injury and need for restraints. These may occur at variable times after administration. This study was designed to determine the incidence of paradoxical reactions following intravenous midazolam premedication in pediatric patients and to compare the efficacy of extra doses of midazolam with low-dose intravenous ketamine to rapidly tranquillize them. METHODS: A total of 706 ASA I, II children scheduled for elective surgery were given intravenous midazolam premedication. Children who developed a paradoxical reaction were randomly divided into three equal groups to receive: (i) extra midazolam, (ii) ketamine, or (iii) placebo as the test drug for treatment of paradoxical reaction. Ease of rapid tranquillization and need for a rescue tranquillizer (i.e. ketamine; irrespective of patient group) were compared among the three groups. RESULTS: Twenty-four (3.4%) children developed paradoxical reaction after midazolam premedication. Those who received ketamine as the test drug responded rapidly to ketamine. But the responses of the other two groups to their test drug were poor and the majority of them required ketamine as rescue tranquillizer (six in midazolam, seven in placebo, but no patient in the ketamine group; P < 0.05). CONCLUSIONS: The results of this study demonstrate that ketamine is an effective drug for the treatment of paradoxical reaction following intravenous midazolam premedication. The exact mechanisms of these reactions and how it is aborted by ketamine are not clear.

Evaluating the relationship between arterial blood pressure changes and indices of pulse oximetric plethysmography.

UNLABELLED: The finger plethysmographic waveform of pulse oximeters is a qualitative indicator of fingertip perfusion. This waveform has been used to assess the depth of anesthesia. Its cyclical changes associated with mechanical ventilation have also been used to detect changes in blood volume under normotensive conditions and has revealed that minimal normotensive hypovolemia can cause a significant increase in the delta-down component of this waveform. Hypovolemia may be associated with hypotension; the latter may be due to causes other than hypovolemia. Because the effects of the hypotension on plethysmographic waveform have not been evaluated, it may be difficult to detect hypovolemia in these conditions by inspecting a plethysmogram. Therefore, we performed this study to evaluate the effect of normovolemic hypotension on characteristics of plethysmographic waveform in 33 adult patients undergoing general anesthesia with controlled hypotension. The delta-down and ventilatory systolic variation components were increased significantly with decreases in systolic blood pressure. The result of this study shows that the effect of pharmacologic hypotension on the plethysmographic waveform of pulse oximeter is similar to that of minimal hypovolemia. Therefore, blood volume may be inaccurately assessed by the inspection of ventilatory-induced cyclical changes of pulse oximetric waveform in the presence of hypotension. IMPLICATIONS: The cyclical respiratory-induced changes in the amplitude of the pulse oximeter waveform can be used to detect normotensive hypovolemia. This study shows that hypotension produces the same effect. Therefore, in hypotensive conditions, we cannot determine the presence of hypovolemia.