Effect of intravenous magnesium on postoperative pain control for major abdominal surgery: a randomized double-blinded study

Background

This study aimed to evaluate the postoperative analgesic effect of magnesium sulfate during abdominal surgery.

Methods

This randomized double-blinded study involved 84 patients candidates for abdominal surgery into two same groups. In the magnesium group, at first 25 mg/kg/1 h magnesium sulfate; and then, 100 mg/kg/24 h was infused in the intensive care unit. The pain intensity (the primary outcome), was assessed using the numeric rating scale (NRS) every 3 h. If the NRS was > 3, morphine (as a secondary outcome) was used and evaluated. The results were analyzed using SPSS ver. 19 software, and statistical significance was set at P < 0.05

Results

Demographic parameters were similar between the groups. The pain intensity were similar at first and then at the third hour in both groups (P = 0.393 and P = 0.172, respectively), but thereafter between 6 and 24 h, the pain severity was significantly lower in the magnesium group (4.4 ± 1.3 in the control and 3.34 ± 1 in the magnesium group at 6th hour and P = 0.001). In addition, morphine intake in the first 24 h in the two groups had a significant difference, with 13.2 ± 5.7 mg in control group and 8 ± 3.5 mg in magnesium group (P = 0.001).

Conclusions

In this study, intravenous magnesium sulfate after abdominal surgeries for 24 h resolved the pain intensity after six hours and reduced morphine dosage.

Comparison of the effects of 2 ventilatory strategies using tidal volumes of 6 and 8 ml/kg on pulmonary shunt and alveolar dead space volume in upper abdominal cancers surgery

Background: High tidal volume leads to inflammation, and low tidal volume leads to atelectasia and hypoxemia. This study was conducted to compare the effect of 6 mL/kg with positive end-expiratory pressure (PEEP) and 8 mL/kg without PEEP on pulmonary shunt and dead space volume.

Methods: This clinical trial was done on 36 patients aged 20 to 65 years old with ASA I-II. They were candidates for upper abdominal surgery and divided randomly into 2 groups. One group were ventilated with the tidal volume = 8 mL/kg without PEEP (TV8). The other group received the tidal volume = 6 mL/kg with low PEEP = 5 cm H2O (TV6). Arterial and central venous blood gases were taken after intubation and 2 hours later. Additionally, the vital signs of the patients were checked every 30 minutes. Data analysis was performed using t test, chi-square test, and repeated measures analysis of variance with SPSS software, version 16 (SPSS Inc). P value less than.05 were meaningful.

Results: There was no significant difference on the preanesthesia parameters. The pulmonary shunt was 13.5±0.1% and 18.6±0.2% in the groups TV6 and TV8, respectively (p=0.132), which slightly decreased after 2 hours in both groups without any significant difference (p=0.284). Prior to the ventilation, the ratios of dead space to tidal volume were 0.25±0.2 and 0.14±0.1 in the TV6 and TV8 groups, respectively (p=0.163), and after 2 hours, they were 0.23±0.11 and 0.16±0.1 in the TV6 and TV8 groups, respectively (p=0.271). There was no significant difference between the groups for blood pressure and peripheral and arterial oxygenation changes.

Conclusion: The tidal volume of 6 mL/kg with the PEEP of 5 mmHg was similar to the tidal volume of 8 mL/kg without PEEP for hemodynamic and pulmonary changes (oxygenation, shunt, and dead space).

Foot drop after spinal anesthesia for cesarean section: a case report

Objective

Spinal anesthesia is the preferred anesthetic technique for cesarean section. Neurological complications are very rare and often transient after spinal anesthesia.

Case report

In the present case, a 37-year-old woman was considered eligible for cesarean section due to fetal distress. She underwent spinal anesthesia with a 25-gauge pencil-point spinal needle. In the sitting position, 3 mL of 0.5% bupivacaine was injected following free flow of cerebrospinal fluid. The cesarean delivery was uneventful without severe and significant hemodynamic changes. After recovery, the patient complained of tingling and stiffness in the left leg, accompanied with movement disorders and foot drop. Lumbar magnetic resonance imaging was normal. After receiving 500 mg intravenous methylprednisolone daily for 72 hours, she was discharged from the hospital with no particular problems.

Conclusion

Foot drop is a neurological disorder, which occurs following natural childbirth and spinal anesthesia due to direct needle trauma or local anesthetic toxicity. This complication is transient and usually resolves within a few days. In our patient, the neurological complication appeared after labor and anesthesia recovery, which was treated by corticosteroids and anti-inflammatory drugs, with no particular side effects.

Central Venous Cannulation of the Internal Jugular Vein Using Ultrasound-Guided and Anatomical Landmark Techniques

Background

Central venous cannulation is a current and important procedure used in the operating room and intensive care unit. Some studies have shown that the application of ultrasound-guided cannulation can improve the success rate of surgery, save time, reduce the number of required needlesticks, and mitigate many complications compared to anatomical landmark-guided cannulation.

Objectives

The aim of the present study was to draw a comparison between central venous cannulation of the internal jugular vein using ultrasound-guided and anatomical landmark-guided techniques.

Patients and Methods

A total of 321 patients scheduled for cardiac surgery in the surgical ward of a general hospital were randomly treated with central venous cannulation using either anatomical landmarks (150 patients) or ultrasound guidance (170 patients). The demographic data of patients, the success rate of cannulation, the execution time, and the number of attempts for successful cannulation as well as the complications were recorded and subjected to statistical analysis.

Results

The success rate of cannulation was 98.7% in the anatomical landmark-guided group and 99.4% in the ultrasound-guided group. The average operation times were 46.05 and 45.46 seconds in the anatomical landmark and ultrasound-guided groups, respectively. The two groups were not significantly different in terms of the success rates of treatment, the number of attempts, the time required for successful cannulation, or the prevalence of complications (P > 0.05) other than carotid artery puncture (P = 0.04)

Conclusions

In our conditions, the use of an anatomical landmark-guided procedure was the preferred treatment method due to limited resources and a lack of adequate training.

Lipid composition and lidocaine effect on immediate and delayed injection pain following propofol administration

Background:

Propofol has been used for the induction and maintenance of anesthesia. However, patients experience vascular pain during its injection.

Aims:

The objective of this study was to compare the effect of the lipid type used in propofol preparations and that of lidocaine on the immediate and delayed vascular pain induced by propofol administration.

Materials and Methods:

In this double-blinded clinical study, 150 patients at American Society of Anesthesiologists level I-II were randomly divided into three equally sized groups. A propofol with medium and long-chain triglycerides (propofol-MCT/LCT) was administered to the first group. The second group received propofol containing propofol-LCT, and the third group received propofol-LCT and pretreatment lidocaine 20 mg. The incidence and the intensity of immediate (during injection) and delayed injection pain (after 20 s) were evaluated on a verbal analog scale (1–10) until patients’ unconsciousness.

Statistical Analysis:

Sample size was calculated with SigmaPlot version 12.5 software. Data were analyzed with Statistical Package for the Social Sciences (SPSS) version 16, one-way analysis of variance, and post-hoc Tukey. P < 0.05 was considered statistically significant.

Results:

The demographic parameters of the three groups were similar. The lidocaine group experienced the least immediate vascular pain. The intensity of pain was highest in the propofol-LCT group (P = 0.04). Additionally, the intensity of delayed pain was lowest in the propofol-MCT/LCT group (P = 0.01). The incidence of pain associated with the propofol administration was 26.5, 44, and 18%, respectively, in propofol-MCT/LCT, propofol-LCT, and lidocaine and propofol-LCT groups.

Conclusion:

The results indicate an effect of the lipid type on delayed pain reduction, especially propofol-MCT/LCT. On the other hand, the lidocaine decreases immediate propofol-LCT vascular pain.

A Survey of Blood Request Versus Blood Utilization at a University Hospital in Iran

BACKGROUND

Reservation of blood leads to blood wastage if the blood is not transfused. Therefore, in some centers only blood type and screen are evaluated. In this study, the efficacy of a blood crossmatch-to-transfusion ratio was measured and then compared with the standard levels.

METHODS

This prospective study was conducted during one year in a university hospital. During this period, 398 patients for whom blood had been requested were studied. In these patients, at the first surgical type, the laboratory tests (hematocrit, hemoglobin, platelet count, and prothrombin time) and the number of preoperative crossmatched and intraoperative transfused blood units were recorded. Then the crossmatch-to-transfusion ratio, transfusion probability, transfusion index, and correlation between related factors, and the transfusion ratio were evaluated.

RESULTS

In this cross-sectional study, blood was requested for 398 patients. According to available blood unit deficiency, from 961 blood unit requisitions, only 456 units were crossmatched and 123 units were transfused. The crossmatch-to-transfusion ratio, transfusion probability, and transfusion index were 3.71 (7.81 if all requisitions were crossmatched), 16.83%, and 0.31, respectively. The most unfavorable indexes were observed in patients who had ear, nose, and throat surgeries (0 transfused from 19 crossmatched blood units) and obstetric and gynecologic surgery (crossmatch-to-transfusion ratio was 18.6). The best indexes were related to thoracic surgery and neurosurgery (crossmatch-to-transfusion ratio was 1.53 and 1.54, respectively). There were no significant correlations between hemoglobin, hematocrit, platelet count, and prothrombin time with the number of transfused blood units (P = 0.2, 0.14, 0.26, and 0.06, respectively).

CONCLUSION

The data for the crossmatch-to-transfusion ratio, transfusion probability, and transfusion index were suboptimal at this center, especially for ear, nose, and throat and obstetric and gynecologic surgeries. Further multidimensional studies and determination of a new model for blood requests and to decrease blood wastage are needed.

Reducing sore throat following laryngeal mask airway insertion: comparing lidocaine gel, saline, and washing mouth with the control group

BACKGROUND

Laryngeal mask airway is still accompanied by complications such as sore throat. In this study, effects of three methods of reducing postoperative sore throat were compared with the control group.

METHODS

240 patients with ASA I, II candidates for cataract surgery were randomly divided into four same groups. No supplementary method was used in the control group. In the second, third and fourth groups, lidocaine gel, washing cuff before insertion, and washing mouth before removing laryngeal mask airway were applied, respectively. Anesthesia induction was done with fentanyl, atracurium, and propofol and maintained with propofol infusion. The incidence of sore throat was evaluated during the recovery, 3-4h later and after 24h using verbal analog scale. The data were analyzed by t-test, analysis of variance and chi-square using SPSS V11.5.

RESULTS

Age, gender, duration of surgery and cuff pressure were the same in all the four groups. Incidence of sore throat at recovery room was highest in the control group (43.3%) and lowest in the washing mouth group (25%). However, no significant statistical difference was observed between these four groups (recovery, p=0.30; discharge, p=0.31; examination, p=0.52). In this study, increased duration of operation had a significant relationship with the incidence of sore throat (p=0.041).

CONCLUSION

Sore throat is a common postoperative problem, but no special method has been found completely efficient yet. In this study, cuff washing, lidocaine gel, and mouth washing before removing laryngeal mask airway were not helpful for sore throat.

Pharyngeal Packing during Rhinoplasty: Advantages and Disadvantages

INTRODUCTION

Controversy remains as to the advantages and disadvantages of pharyngeal packing during septorhinoplasty. Our study investigated the effect of pharyngeal packing on postoperative nausea and vomiting and sore throat following this type of surgery or septorhinoplasty.

MATERIALS AND METHODS

This clinical trial was performed on 90 American Society of Anesthesiologists (ASA) I or II patients who were candidates for septorhinoplasty. They were randomly divided into two groups. Patients in the study group had received pharyngeal packing while those in the control group had not. The incidence of nausea and vomiting and sore throat based on the visual analog scale (VAS) was evaluated postoperatively in the recovery room as well as at 2, 6 and 24 hours.

RESULTS

The incidence of postoperative nausea and vomiting (PONV) was 12.3%, with no significant difference between the study and control groups. Sore throat was reported in 50.5% of cases overall (56.8% on pack group and 44.4% on control). Although the severity of pain was higher in the study group at all times, the incidence in the two groups did not differ significantly.

CONCLUSION

The use of pharyngeal packing has no effect in reducing the incidence of nausea and vomiting and sore throat after surgery. Given that induced hypotension is used as the routine method of anesthesia in septorhinoplasty surgery, with a low incidence of hemorrhage and a high risk of unintended retention of pharyngeal packing, its routine use is not recommended for this procedure.

The Assessment of Addition of Either Intravenous Paracetamol or Diclofenac Suppositories to Patient-Controlled Morphine Analgesia for Postgastrectomy Pain Control

Background:

Major surgical procedures, such as gastrectomy, result in extensive postoperative pain, which can lead to increased morbidity, discomfort and dissatisfaction among the patients.

Objectives:

The aim of this study was to evaluate the effect of adding diclofenac suppositories or intravenous paracetamol, on morphine consumption and on the quality of postgastrectomy pain control.

Patients and Methods:

This randomized double blinded clinical trial was carried out in 90 patients with gastric cancer, who were candidates for gastrectomy, which were divided into three similar groups. The patients were transferred to an intensive care unit after the operation and received patient-controlled analgesia (PCA) with morphine, morphine PCA plus intravenous paracetamol 1 g, every 6 hours, and morphine PCA plus diclofenac suppositories, 100 mg every 8 hours. The patients were evaluated for up to 24 hours after the operation for the severity of pain, alertness, and opioid complications.

Results:

There was no significant difference in pain scores among the three groups (P values, after extubation, at 2, 4, 6, 12, 18 and 24 hours were 0.72, 0.19, 0.21, 0.66, 0.54, 0.56, and 0.25, respectively), although morphine consumption was greater in the morphine group, compared with the other two groups (21.4 ± 7.7 mg in morphine group vs. 14.3 ± 5.8 mg in morphine-paracetamol group and 14.3 ± 3.9 in morphine-diclofenac group; P = 0.001). In morphine group, during the first 24 hours, the patients had lower levels of consciousness (P values, after extubation, at 2, 4, 6, 12, 18 and 24 hour were 0.6, 0.95, 0.28, 0.005, 0.027, 0.022 and 0.004 respectively), even though the incidence of complications was similar among the three groups.

Conclusions:

In this study, intravenous paracetamol or diclofenac suppositories, administered for postgastrectomy pain control, decreased morphine consumption by almost 32% and also improved alertness. Nevertheless, the amount of opioids did not affect the incidence of complications.

Association of Obstructive Sleep Apnea Syndrome and Buerger's Disease: a Pilot Study

In this study we evaluated the incidence and severity of obstructive sleep apnea and Obstructive sleep apnea syndrome in patients with thromboangiitis obliterans for reduction of crisis. In 40 patients with Buerger's disease daily sleepiness and risk of Obstructive sleep apnea were evaluated using the Epworth sleeping scale (ESS) and the Stop-Bang score. An Apnea-link device was used for evaluation of chest motion, peripheral oxygenation, and nasal airflow during night-time sleep. The apnea/hypopnea index (AHI) and respiratory disurbance index were used for Obstructive sleep apnea syndrome diagnosis. All subjects were cigarette smokers and 80% were opium addicted. The prevalence of Obstructive sleep apnea (AHI>5) was 80%, but incidence of Obstructive sleep apnea syndrome (AHI>5 + ESS≥10) was 5% (2/40). There was no association between duration or frequency of hospitalization and Obstructive sleep apnea syndrome (P=0.74 and 0.86, respectively). In addition, no correlation between ESS and Stop-Bang scores and AHI was observed (P=0.58 and 0.41, respectively). There was an inverse correlation between smoking rate and AHI (P=0.032, r = -0.48). We did not find an association between Buerger's disease and Obstructive sleep apnea syndrome. Although the AHI was high (80%) and daily sleepiness was low. The negative correlation of smoking with AHI and on the other hand daily napping in addiction may be caused by the absence of a clear relationship between Obstructive sleep apnea syndrome and Buerger's disease.

Efficacy of ephedrine in the prevention of vascular pain associated with different infusion rates of propofol

Context:

Vascular pain is a frequent and hypotension is most important complications of propofol administration.

Aims:

The goal of this study is to evaluate frequency of vascular pain during rapid and slow injection of propofol and also effect of ephedrine for decreasing of vascular pain.

Materials and Methods:

After approval of local ethical committee, 120 patients with American Society of Anesthesiologists status I (ASA I), who were candidates for cataract surgery, were divided randomly into three groups. The first group received 20 mg of lidocaine, and propofol 1% at 1 ml per 5 seconds (slow injection). The second and third groups received propofol at 10 ml per 5 seconds without lidocaine (rapid injection) and also in the third group, 10 mg of ephedrine were injected at first and vascular pain were evaluated with 5-point scale.

Statistical analysis:

Data were analyzed with Statistical Package for the Social Sciences (SPSS) v16, Chi-square test, one-way analysis of variance (ANOVA), Kruskel-Wallis. P <0.05 was considered statistically significant.

Results:

Demographic characteristics of the three groups were similar. The vascular pain was 52.5%, 40%, and 27.5% in first, second, and third group, respectively. The injection pain was more severe in the slow injection (P = 0.025), but was the same between two rapid groups (P = 0.76). Heart rate and blood pressure changes were similar between all groups (P = 0.45 and P = 0.58, respectively).

Conclusion:

Rapid propofol injection induced less vascular pain compared with slow injection, but 10 mg ephedrine was not more effective.

Accidental intrathecal injection of magnesium sulfate for cesarean section

Magnesium sulfate is used frequently in the operation room and risks of wrong injection should be considered. A woman with history of pseudocholinesterase enzyme deficiency in the previous surgery was referred for cesarean operation. Magnesium sulfate of 700 mg (3.5 ml of 20% solution) was accidentally administered in the subarachnoid space. First, the patient had warm sensation and cutaneous anesthesia, but due to deep tissue pain, general anesthesia was induced by thiopental and atracurium. After the surgery, muscle relaxation and lethargy remained. At 8-10 h later, muscle strength improved and train of four (TOF) reached over 0.85, and then the endotracheal tube was removed. The patient was evaluated during the hospital stay and on the anesthesia clinic. No neurological symptoms, headache or backache were reported. Due to availability of magnesium sulfate, we should be careful for inadvertent intravenous, spinal and epidural injection; therefore before injection must be double checked.

Use of two Endotracheal Tubes to Perform Lung Isolation and One-Lung Ventilation in a Patient With Tracheostomy Stenosis: A Case Report

Introduction:

Lung isolation is a common technique used in thoracic surgery to prevent spillage to unaffected lung and to provide a better view for the surgeon.

Case Presentation:

A 41-year-old woman with a history of pharyngo-laryngo-oesophagectomy (PLO) and tracheostomy was a candidate for thoracic duct ligation because of chylothorax. Since the patient had tracheostmy stomal stenosis, two cuffed tracheal tubes (internal diameter = 4.5 mm) were used; one tube was placed in the right bronchus and the other tube in the left one by fiberoptic laryngoscopy in 10 minutes. Right lung was collapsed during the surgery for 3.5 hours with a slight decrease in oxygenation (SpO₂ = 91%–93%) and with no evident hemodynamic change. Potential trauma from a double-lumen tube and a bronchial blocker as well as inaccessibility to a univent tube prevented us to use these standard methods in this case.

Conclusions:

This report presents a new method for lung isolation in specific cases and in the absence of certain equipment.