Evaluation of the endotracheal tube cuff pressure changes during cardiac operations under cardiopulmonary bypass.

Introduction: Tracheal intubation is used for most operations under general anesthesia. Prolonged hyperinflation of the tube cuff can compromise tracheal mucosal perfusion, and low pressure of the cuff may cause some other complications. The aim of this study was the evaluation of changes in intra-cuff pressure in patients undergoing cardiac surgeries under cardiopulmonary bypass. Methods: In an observational study 120 patient's candidate to cardiac operations under cardiopulmonary bypass were enrolled. After induction of anesthesia and tracheal intubation by same tracheal tubes, tracheal tube cuff pressure was adjusted to 20-25 mm Hg (T0). Then the cuff pressure was measured at beginning of CPB (Cardio Pulmonary Bypass) (T1), at 30º hypothermia (T2) and after separation from CPB (T3). Results: The mean cuff pressure was 33.5±7.3, 28.9±5.4, 25.6±5.2 and 28.1±3.7 at T0, T1, T2 and T3 respectively. Intra- cuff pressure changed significantly during cardiopulmonary bypass. Conclusion: The mean intra-cuff pressure was decreased during hypothermic cardiopulmonary bypass. The decrease in cuff pressure may protect the tracheal mucosa against hypotensive ischemic injury in these patients.

Investigating the effect of pregabalin on postoperative pain in non-emergency craniotomy.

BACKGROUND: Surgical procedures performed in the suboccipital and subtemporal regions are associated with severe pain. The present study was designed to determine pregabalin's effect on postoperative pain in elective craniotomy. METHOD: This double-blind prospective randomized clinical trial was conducted on 50 patients aged 20-60 with ASA classifications I and II. The patients who qualified for elective craniotomies were split into intervention (two capsules =300 mg pregabalin) and control groups (two capsule starch). Patients were also assessed at recovery, 2, 6, 12, and 24 h after surgery for their pain and level of sedation. Data were analyzed by SPSS software version 23, and a P-value ≤ 0.05 was considered significant. RESULTS: The mean pain score in the intervention group was lower than the control group at recovery (p = 0.224), 2 h (p = 0.001), 6 h (p = 0.011), and 12 h (p = 0.032) after surgery. The methadone consumption in the control group was significantly higher than the intervention group (p < 0.05). There was no significant difference between the two groups regarding the level of sedation (p > 0.05). The mean heart rate at induction (p = 0.01), 15 min (p = 0.01), 30 min (p = 0.025), recovery (p = 0.031), and 2 h (p = 0.021) after surgery and the MAP at recovery, 2 h, and 6 h after surgery was significantly lower than the control group (p = 0.029), (p = 0.013), and (p = 0.038), respectively. CONCLUSION: Our investigation demonstrated the effectiveness of pregabalin two hours before surgery on decreasing postoperative pain and analgesic consumption without disturbance in neurological examinations and any specific adverse effects.

The Effect of Chronic Consumption of Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Antagonists on Blood Pressure and Inotrope Consumption After Separation from Cardiopulmonary Bypass.

BACKGROUND: Chronic use of renin-angiotensin system (RAS) antagonists (angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor antagonists (ARAS)) can cause hypotension during anesthesia. In some studies hemodynamic instability, including hypotension and its effects on the clinical outcome in patients treated with these drugs during coronary artery bypass graft (CABG) and need to excessive vasoactive drugs in these patient population, has been described. The aim of this study was to evaluate the effect of chronic consumption of ACEIs and ARAS on blood pressure and inotrope consumption during coronary artery bypass graft under cardiopulmonary bypass. METHODS: A total of 200 patients undergoing coronary artery bypass graft surgery, who were treated with either ARAS or ACEIs (n = 100) over at least 2 months, or who were not treated with any RAS antagonists (control group, n = 100) were enrolled. The mean arterial blood pressure, central venous pressure, and need for vasoactive drugs, were measured after induction of anesthesia (T1) before cardiopulmonary bypass (T2) and after separation from (CPB), (T3). RESULTS: There were no significant differences regarding the mean arterial pressure (case group: T1: 84 ± 7 mmHg, T2: 77 ± 6 mmHg, T3: 83 ± 8 mmHg), (control group: T1: 85 ± 7 mmHg, T2: 81 ± 7 mmHg, T3:84 ± 6 mmHg) between two groups (P > 0.05). Also there were no significant differences regarding mean central venous pressure, mean heart rate, and vasoactive drug consumption between the two groups during the time of intervals. CONCLUSIONS: We found that preoperative (RAS) antagonist's continuation have not profound hemodynamic changes during coronary artery bypass graft under cardiopulmonary bypass and so we conclude that omitting these drugs before surgery did not have a sufficient advantage to be recommended routinely.

The Relationship between Arterial and Central Venous Blood Gases Values in Patients Undergoing Mechanical Ventilation after Cardiac Surgery.

BACKGROUND: The most straightforward method of ascertaining arterial PO2, PCO2, and other components of blood gas is to measure them directly from a blood sample. In situations in which arterial puncture cannot be achieved or may be technically difficult, the venous blood sample can be used. METHODS: In a prospective analytical study, 80 patients undergoing mechanical ventilation after open-heart surgery in the intensive care unit were evaluated. Simultaneous, matched arterial and central venous blood gas samples were taken from radial artery line and central vein, respectively, when the ABG (arterial blood gases) assessment was needed. Arterial and central venous blood samples were analyzed and data were expressed as mean and ± SD. RESULTS: The Pearson correlation coefficient for pH, PCO2, HCO3, and SatO2 was 0.898, 0.940, 0.840, and 0.567, respectively. There was a significant correlation between arterial and central venous values of pH, PCO2, and HCO3 (P < 0.0001). The mean difference between arterial and central venous PCO2 was -2.44 ± 2.6 mmHg, and the mean venous pH value was only 0.021 ± 0.037 units lower than the mean arterial value. In addition, the calculated mean bicarbonate concentration in venous blood was only about 0.06 ± 1.5 mEq.L higher than the mean arterial value. CONCLUSIONS: The central venous PCO2, pH, and HCO3 measured during mechanical ventilation in the intensive care unit approximate arterial values closely enough to permit the estimation of the adequacy of ventilation and acid-base status. The central venous Sat O2 does not reliably parallel the arterial Sat O2. In conclusion, venous blood sampling can potentially reduce the requirement for ABG sampling in special situations.

Comparing the effect of intravenous dexamethasone, intravenous ondansetron, and their combination on nausea and vomiting in cesarean section with spinal anesthesia.

BACKGROUND: Nausea and vomiting are frequently seen in patients undergoing cesarean section (CS) under regional anesthesia. We aimed to compare the antiemetic efficacy of ondansetron and dexamethasone combination with that of the use of each agent alone to decrease the incidence of postdelivery intra- and post-operative nausea and vomiting during CS under spinal anesthesia. MATERIALS AND METHODS: A randomized, prospective, double-blind study was performed on 90 patients undergoing planned CS under spinal anesthesia. The patients received 4 mg ondansetron in Group O, 8 mg dexamethasone in Group D, and 4 mg ondansetron +8 mg dexamethasone in Group OD intravenously within 1-2 min after the umbilical cord was clamped. Frequency of postdelivery intra- and post-operative nausea and vomiting episodes was recorded. RESULTS: A total of 90 eligible patients were included in the study. There were 30 patients in Group O, 30 patients in Group D, and 30 patients in Group OD. Intraoperative nausea in Group D was more than the other two groups. Postoperative nausea in group OD was lesser than the other two groups. Intraoperative vomiting in Group OD was lesser than the other two groups. There was no statistically significant difference among the groups in postoperative vomiting (P > 0.05). CONCLUSION: Combined use of dexamethasone and ondansetron for the same indication seems to increase the antiemetic efficacy.

Evaluating the quality of intravenous regional anesthesia following adding dexamethasone to lidocaine.

OBJECTIVES: The quality of anesthesia in intravenous regional anesthesia (IVRA) has been evaluated in many studies so far. This study was designed to evaluate the effects of adding the dexamethasone to lidocaine on the quality of IVRA. MATERIALS AND METHODS: A double-blind clinical trial was set up involving 50 hand surgery candidates, 20 to 55 years old, and with American Society of Anesthesiologists class of I and II. Patients were randomly allocated into two groups of 25 cases and received either 3 mg/kg of lidocaine (control group) or 3 mg/kg of lidocaine plus 8 mg of dexamethasone (study group). The onset and recovery times from sensory and motor blocks, the starting time of tourniquet pain, the amount of narcotics needed during patients' recovery, and probable side-effects were all compared between the two groups. RESULTS: No significant differences were detected concerning age, gender, length of surgery and the mean time of starting of tourniquet pain between the two groups. The mean times of both sensory (P = 0.002) and motor (P = 0.004) blocks onset were significantly shorter in the study group. The mean time of recovery from sensory block was significantly longer in the study group (P = 0.01). The average amount of narcotics needed during the recovery was significantly lower in the study group (P = 0.01). No side-effect was detected. CONCLUSION: We conclude that adding the dexamethasone to lidocaine can improve the quality of anesthesia in IVRA.

Comparison the effects of paracetamol with sufentanil infusion on postoperative pain control after craniotomy in patients with brain tumor.

BACKGROUND: Patients experience severe pain after craniotomy surgery that leads to discomfort. Our target in this study that performed in interventional method is an evaluation of sufentanil and paracetamol effect on postoperative pain control in patients undergone craniotomy surgery at Urmia Imam Khomeini Hospital. MATERIALS AND METHODS: Totally, 45 patients between the ages 18 and 65 were studied. The effect of sufentanil and paracetamol medicines in pain management, hemodynamic stability, and side effects compared with control group that were receiving morphine (subcutaneous [SC]) in 3 groups of 15 people at time 0, 2, 4, 12 and 24-h were evaluated. Collected data were included and monitoring blood pressure, O2 Sat, heart rate (HR) and pain, nausea, vomiting and use of morphine. RESULTS: According to the analysis of results, there was a significant difference between 3 groups on postoperative pain (P < 0.05). In patients that used sufentanil, pain score of visual analog scale (VAS) is lowest and in the paracetamol group the highest VAS score was seen. There was a significant difference in HR between 3 groups (P < 0.05). Maximum average of HR was observed in the paracetamol group. There was a significant difference in mean arterial pressure between 3 groups (P < 0.05). In paracetamol group, there was the highest value (99.3). There was no significant difference in Glasgow Coma scale and SPO2 between 3 groups (P > 0.05). CONCLUSION: Sufentanil compared to morphine (which is routinely used for patients pain control after craniotomy surgery) has better pain control, less nausea and vomiting, and better hemodynamic stability. Although paracetamol has the least nausea and vomiting, it has the lowest quality of pain relief.

Comparison of ondansetron and meperidine for treatment of postoperative shivering: a randomized controlled clinical trial.

BACKGROUND: The involved neurotransmitter pathways in the postoperative shivering (POS) are poorly understood. Recently, 5-hydroxytryptamine 3 (5-HT3) receptor antagonists have been reported to prevent POS. We investigated the effect of ondansetron, a 5-HT3 antagonist that is used to treat postoperative nausea and vomiting, on shivering. OBJECTIVES: This study aimed to compare the efficacy of ondansetron and meperidine in the treatment of shivering after general anesthesia. PATIENTS AND METHODS: In this double-blinded randomized clinical trial, 83 patients (age range, 18-60 years) who had shivering after general anesthesia were randomly allocated to any of these three groups: Group A, (number = 27) received 4 mg of intravenous ondansetron, Group B, (number = 27) received 8 mg of intravenous ondansetron, and Group C, (number = 29) received 0.4 mg/kg of intravenous meperidine at recovery room. The surface temperatures and the incidence as well as intensity of shivering were recorded. RESULTS: Shivering was controlled in 16 patients (59%) in Group A, 22 (81%) in Group B, and 25 (86%) in Group C (P = 0.01). Within each group, there were no significant differences among the surface temperature in recovery room. Patients in groups A and B had significantly lower incidence of nausea and vomiting than group C (P = 0.01). CONCLUSIONS: Ondansetron and meperidine have similar effects on shivering. We concluded that 8 mg of intravenous ondansetron can control shivering and this is the dose of choice, especially in patients with POS with nausea and vomiting.

The effect of low-dose remifentanil on the hemodynamic responses of endotracheal extubation.

Emergence from general anesthesia can be associated with coughing, agitation, and hemodynamic disturbances. Remifentanil may attenuate these responses. We have examined the effect of remifentanil on the hemodynamic response to the emergence from anesthesia and tracheal extubation. In a double-blind, randomized trial, we enrolled 50 adult patients undergoing abdominal surgery. All patients received a standard general anesthetic comprising propofol, atracurium and 1% isoflurane with 50% nitrous oxide in oxygen. At the end of surgery, a bolus dose of remifentanil 0.2 microgram/kg (n = 25) or saline placebo (n = 25) was given and tracheal extubation was performed when standard criteria were achieved. Arterial pressure and heart rate were measured non-invasively, immediately after tracheal extubation and then at 1-min intervals. Remifentanil attenuated the increase in both systolic and diastolic arterial pressure and heart rate after extubation compared to the control group. No differences in SpO2, cough and laryngospasm were observed between two groups. Use of a low-dose remifentanil has clinically acceptable effect in blunting the cardiovascular changes induced by tracheal extubation.

Comparing the effect of pregabalin, gabapentin, and acetaminophen on post-dural puncture headache.

INTRODUCTION: Post-dural puncture headache (PDPH) is a common complication of lumbar puncture for any purpose. To avoid the need for invasive methods of treating PDPH such as blood patch, the search for novel pharmacological agents to manage PDPH continues. The aim of this study was to compare the effects of acetaminophen, gabapentin and pregabalin in controlling PDPH in patients who underwent surgery under spinal anesthesia. MATERIALS AND METHODS: A total of 90 patients who underwent elective orthopedic surgery under spinal anesthesia and suffered from PDPH consequently were enrolled in this randomized trial. Patients were categorized randomly into three groups. Group A, B and C have received Acetaminophen, Gabapentin and Pregabalin (3 times a day for 3 days), respectively. The effect of medications on the severity of PDPH was evaluated and compared using visual analog scale (VAS). RESULTS: The mean VAS score was significantly lower in pregabalin group compared with others 24, 48 and 72 h after the onset of headache (P = 0.001 for all of them) and lower in Gabapentin group compared with Acetaminophen group 24, 48 and 72 h after the onset of headache (P = 0.001 for all analyses). No adverse outcome was reported in groups. CONCLUSION: Pregabalin and gabapentin are both useful and safe in management of PDPH, but pregabalin is more effective in this regard.

Correlation between arterial blood gas analysis and outcome in patients with severe head trauma.

BACKGROUND: Traumatic brain injury is one of the major concerns of global public health, because it is the main cause of morbidity and mortality between young people. This study aimed to investigate the possible association between the parameters of arterial blood gas (ABG) and outcome of patients with severe head trauma. METHODS: In this prospective study, 70 patients with severe head trauma were studied in Urmia Imam Khomeini hospital during 18-month period of time. The parameters of ABG were documented within the 1st hour of admission, and their correlation was evaluated with Glasgow coma scale (GCS) and Glasgow outcome score (GOS). These parameters also were compared between expired and discharged patients. RESULTS: Seventy patients with severe head trauma including 60 males (85.7%) and 10 females (14.3%) with a mean age of 34.34±14.82 (range: 18-76) years were studied. The mortality rate during hospitalization was 38.6% (n=27). There was no significant correlation between the parameters of ABG and GCS score and GOS scores. Furthermore, there was no significant difference between the survivors and non-survivors in terms of the mean value of ABG parameters (p>0.05). CONCLUSION: ABG at the time of admission is not a significant predictor of outcome in patients with severe head trauma.

The effect of pre-operative administration of gabapentin on post-operative pain relief after herniorrhaphy.

BACKGROUND: Gabapentin, an anticonvulsant, recently has been suggested as an effective post-operative "analgesic" agent. The objective of the present study was to examine the analgesic effectiveness and opioid-sparing effects associated with the use of a single dose of gabapentin as a prophylactic analgesic. MATERIALS AND METHODS: In a randomized double-blinded clinical trial, 50 American Society of Anesthesiologists I and II patients with an age range of 40-60 years who were the candidate for inguinal herniorrhaphy under spinal anesthesia were randomly assigned to receive 400 mg gabapentin or placebo 2 h prior to surgery. Post-operatively, the pain was assessed on a visual analog scale (VAS) at 2, 4, 12 and 24 h at rest. Morphine 0.05 mg/kg intravenously was used to treat post-operative pain on patient's demand. Total morphine consumption in the first 24 h after surgery was also recorded. RESULTS: Patients in the gabapentin group had significantly lower VAS scores at the all-time intervals of study than those in the placebo group (P < 0.05). The total morphine consumption in the first 24 h after surgery was also significantly lower in gabapentin group than in the placebo group (0.9 ± 1.23 vs. 1.8 ± 1.5; P = 0.003). There was no significant difference between the first time of analgesic request among the two groups. CONCLUSION: In conclusion, prophylactic administration of gabapentin decreases pain scores and analgesic consumption in the first 24 h after repair of inguinal hernia.

Percutaneous dilatational tracheostomy and surgically created thracheostomy in ICU patients.

INTRODUCTION: Following advances of Intensive Care medicine and widespread administration of mechanical ventilation, tracheostomy has become one of the indispensable surgical procedures. During this research we tried to assess and compare two main strategies for doing tracheostomy: Surgically Created Tracheostomy (SCT) and Percutaneous Dilatational Tracheostomy (PDT). METHODS: In a randomized clinical trial, 60 cases of patients who were admitted in Intensive Care Unit (ICU) and needed tracheostomy during their stay were enrolled. Patients were randomly divided into two groups. SCT technique was considered for the first group and PDT for the second one. Demographic characteristics, associated and underlying diseases, type and duration of procedure, duration of receiving mechanical ventilation and ICU stay, expenses and complications of tracheostomy including bleeding, subcutaneous emphysema, pneumothorax, stomal infection and airway loss were all recorded during study and compared between both groups. RESULTS: There were significant differences between two groups of patients in terms of duration of receiving mechanical ventilation (P=0.04), duration of tracheostomy procedure (P=0.001) and procedure expenses (P=0.04). There was no significant difference between two groups in terms of age and gender of patients, duration of ICU stay and complications of tracheostomy including copious bleeding, stomal infection, subcutaneous emphysema and airway. CONCLUSION: According to the results of our study and similar researches, it can be concluded that PDT can be considered as the preferred procedure in cautiously selected patients during their ICU stay.

The effect of acupressure on nausea and vomiting after cesarean section under spinal anesthesia.

Postoperative nausea and vomiting (PONV) is one of the most common postoperative complications. Aside from pharmacological interventions, other complementary healing modalities have been introduced to assist patients in decreasing PONV and improving postoperative outcomes. This study examined acupressure as a safe complement to the more traditional approach of using drugs to prevent and/or relieve nausea and vomiting in the Cesarean section (C/S) under spinal anesthesia. In a prospective randomized clinical trial, 152 patients who were candidate for elective C/S under spinal anesthesia were evaluated in two groups (acupressure vs control groups). Subjects in the acupressure group received constant pressure by a specific wrist elastic band (without puncture of the skin) on the Nei-Guan acupuncture point, 30 min prior to spinal anesthesia. The incidence of PONV was assessed during the surgery, at recovery room and at 1st, 2nd and 3rd two hours after the surgery. Significant differences in the incidence of the post-operative nausea and vomiting were found between the acupressure and control groups, with a reduction in the incidence rate of nausea from 35.5% to 13.2%. The amount of vomitus and the degree of discomfort were, respectively, less and lower in the study group. In view of the total absence of side-effects in acupressure, its application is worthy. Our study confirmed the effectiveness of acupressure in preventing post-operative nausea and vomiting, when applied 30 minutes prior to surgery.

Theophylline versus acetaminophen in the treatment of post-dural puncture headache (PDPH).

BACKGROUND: Post-dural puncture headache (PDPH) is the most frequent complication of procedures associated with dural puncture for spinal anesthesia or following accidental dural puncture during epidural anesthesia. Since invasive treatments have known complications, pharmacologic management may be preferable. The aim of this study was to evaluate and compare the efficacy of theophylline and Acetaminophen in treatment of PDPH. METHODS: In this single-blind randomized clinical trial, 60 patients with Class I physical status according to ASA classification system, who suffered from PDPH were enrolled. Patients in Theophylline group were received theophylline tablet 250 mg three times per day, and in the other group acetaminophen 500 mg three times per day was administered. Pain intensity was assessed 2, 6, and 12 hour after drug administration using 0-10 cm Visual Analog Scale. RESULTS: The main VAS values is significantly lower in theophylline group in comparison with the acetaminophen group at 2 (5 +/- 1.57 vs. 5.97 +/- 1.27), 6 (3.43 +/- 1.73 vs. 4.33 +/- 1.49), and 12 (2.67 +/- 2.35 vs. 4.24 +/- 1.97) hours after drug administration (p < 0.05). No adverse effects were reported. DISCUSSION: Theophylline is a safe and effective treatment for PDPH. It may be tried in PDPH patients before using any invasive technique. Further investigations studying other Methylxanthines are recommended as well.

Intraoperative minimal acute normovolemic hemodilution in patients undergoing coronary artery bypass surgery.

BACKGROUND & OBJECTIVE: Efficacy of minimal acute normovolemic hemodilution (ANH) in avoiding homologous blood transfusion during cardiovascular surgery remains controversial. Postoperative bleeding and transfusion remain a source of morbidity and cost after open heart operations. Our objective was to evaluate the impact of minimal ANH on blood transfusion requirements during open cardiovascular surgery using cardiopulmonary bypass (CPB). METHODS: This study was a randomized controlled trial. One hundred one patients scheduled for elective coronary artery bypass graft (CABG) under cardiopulmonary bypass in October 2007 through March 2008 in Imam Khomeini hospital were randomly assigned to a control group (standard care, no = 47) or an ANH or study group (no = 54). We used minimal ANH (representing 10% of patients' blood volume). Mean 490 +/- 50 mL of fresh autologous blood was removed after induction of anesthesia and reinfused at the end of CPB. The blood transfusion guidelines were uniformly applied to all patients. RESULTS: Significant decrease in the number of red blood cell units transfused per patient per group (1.39 +/- 1.0 and 2.551.9 +/- units; p < 0.0001) in the ANH group versus the control group was observed. Conversely, chest tube output, postoperative hematocrits, and platelet count did not differ between two groups. Percentage of patients in whom allogeneic red blood cells were transfused was 44% in study group versus 76% in control group; (p < 0.01). No patient was transfused with platelet concentrates or fresh frozen plasma. CONCLUSIONS: Minimal ANH is safe and cost effective and its routine use in eligible patients is therefore justified. Intraoperative autologous blood donation in CABG surgery decreased perioperative allogeneic blood requirement. However, the removal and reinfusion of about one unit autologous blood had no effect on postoperative bleeding or platelet count.

Use of ketamine in severe status asthmaticus in intensive care unit.

Bronchial asthma represents an increased airways responsiveness to various stimulants, leading to reversible obstruction of expiratory flow and chronic inflammatory changes in airways wall. Ketamine has been demonstrated to lower airway resistance and to increase lung compliance in the asthmatic patients. In several studies and case reports it has been used successfully in the management of status asthmaticus, resistant to conventional therapy, but so far no clinical trial has been carried out to support this empirical use of ketamine. For this reason, we designed a prospective observational study.Eleven, 15-40 years old patients, with status asthmaticus whose respiratory failure did not respond to conventional therapy and mechanical ventilation (after 24h), were entered in this study (provided that there were not any contraindications to ketamine use). These patients received ketamine at a loading dose of 1 mg/kg (IV), followed by a continuous infusion of 1 mg/kg/hr for 2h. Peak airway pressure, PaCO2 and PaO2 were measured prior to ketamine administration, 15min after administration and 2h after infusion of ketamine. Mean peak airway pressure and PaCO2 significantly decreased 15min and 2h after administration and infusion of ketamine (p<0.005) and PaO2 significantly increased in these time intervals (p<0.005).Ketamine is a useful and safe drug in the intensive treatment of status asthmaticus. However, ketamine should only be used for asthmatics whose respiratory failure does not respond to standard therapy.