Postoperative infusion of a low dose of dexmedetomidine reduces intravenous consumption of sufentanil in patient-controlled analgesia.

BACKGROUND: Combining adjunctive medications with patient-controlled analgesia (PCA) has been used to minimize opioid related side-effects. The aim of this study was to evaluate whether postoperative infusion of a sub-sedative dose of dexmedetomidine can reduce opioid consumption and opioid related side-effects. METHODS: We selected 60 patients from 18 to 60 years old with an American Society of Anesthesiologists physical status of 1-2 who were scheduled for elective surgery. The types of surgery were limited to thoracoscopic wedge resection of the lung and pulmonary wedge resection under a mini-thoracotomy. Patients received PCA with sufentanil upon arrival in the recovery room, along with a separate continuous infusion of dexmedetomidine that was not mixed in the PCA but started at the same time. Patients were randomly allocated to two groups: dexmedetomidine 0.15 µg/kg/h was administered to patients in group D and normal saline was administered to patients in group C. The visual analogue scale (VAS) pain score, blood pressure, pulse rate, and respiratory rate were measured at each assessment. PCA related side-effects were evaluated. RESULTS: The VAS pain score was significantly lower in the dexmedetomidine group. Patients in the dexmedetomidine group required significantly less PCA at postoperative 1-4, 4-8, and 8-24 h time intervals. The incidence of nausea was significantly less in the dexmedetomidine group, and levels of sedation and hemodynamic variables except for blood pressure at postoperative 8 h were similar between the groups. CONCLUSIONS: In conclusion, a postoperatively administered sub-sedative dose of dexmedetomidine reduces PCA sufentanil consumption and decreases nausea.

Cyanide toxicity during cardiopulmonary bypass with small dose of nitroprusside: a case report.

Sodium nitroprusside (SNP) is an anti-hypertensive drug, commonly used to decrease the systemic vascular resistance and lower the blood pressure. When the amount of cyanide generated by the SNP exceeds the metabolic capacity for detoxification, cyanide toxicity occurs. Under general anesthesia and cardiopulmonary bypass (CPB), it may be difficult to detect the development of cyanide toxicity. In cardiac surgical patients, hemolysis, hypothermia and decreased organ perfusion, which emphasize the risk of cyanide toxicity, may develop as a consequence of CPB. In particular, hemolysis during CPB may cause an unexpected overproduction of cyanide due to free hemoglobin release. We experienced a patient who demonstrated SNP tachyphylaxis and cyanide toxicity during CPB, even though the total amount of SNP administered was much lower than the recommended dose. We therefore report this case with a review of the relevant literature.

Effect of a Single Bolus of Erythropoietin on Renoprotection in Patients Undergoing Thoracic Aortic Surgery With Moderate Hypothermic Circulatory Arrest.

BACKGROUND: Acute kidney injury (AKI) is associated with high morbidity and mortality. Recombinant human erythropoietin has been shown to exert cytoprotection against ischemia. This study examined the effect of erythropoietin in preventing AKI during thoracic aortic surgery with moderate hypothermic circulatory arrest. METHODS: In this double-blind, randomized study, 66 patients undergoing thoracic aortic surgery with moderate hypothermic circulatory arrest (target temperature, 28°C) randomly received either erythropoietin 500 IU·kg(-1) or the same amount of normal saline intravenously after anesthesia induction. The primary endpoint was incidence of AKI defined according to the RIFLE criteria during the first 7 postoperative days. RESULTS: AKI occurred in 60% of all patients. The two groups did not show any differences in the incidence and severity of AKI. Also, there was no difference in the level of serum neutrophil gelatinase-associated lipocalin between the groups. The cardiac index was higher in the erythropoietin group, however, immediately after weaning from cardiopulmonary bypass (p = 0.02). Furthermore, postoperative cardiac complications and prolonged vasopressor dependence were reduced in the erythropoietin group (p = 0.04 and p = 0.049, respectively). CONCLUSIONS: A single bolus administration of erythropoietin 500 IU·kg(-1) at anesthesia induction failed to provide renoprotection in patients who underwent thoracic aortic surgery with moderate hypothermic circulatory arrest. However, erythropoietin significantly reduced cardiac complications, and lowered the incidence of prolonged vasopressor dependence.

Comparison of clinical effects according to the dosage of sufentanil added to 0.5% hyperbaric bupivacaine for spinal anesthesia in patients undergoing cesarean section.

BACKGROUND: Subarachnoid block is a widely used technique for cesarean section. To improve the quality of analgesia and prolong the duration of analgesia, addition of intrathecal opioids to local anesthetics has been encouraged. We compared the effects of sufentanil 2.5 µg and 5 µg, which were added to intrathecal hyperbaric bupivacaine. METHODS: We enrolled 105 full term parturients were randomly divided into 3 groups: Group 1 (control), Group 2 (sufentanil 2.5 µg), and Group 3 (sufentanil 5 µg). In every group, 0.5% heavy bupivacaine was added according to the adjusted dose regimen. We determined the maximum level of sensory block and motor block, the quality of intraoperative analgesia, the duration of effective analgesia and side effects. RESULTS: There were no significant differences among the 3 groups in the maximum level of the sensory block and motor block. Recovery rate of the sensory block, however, was significantly slower in Group 3 than Group 1. Quality of intraopertive analgesia, muscle relaxation, and duration of effective analgesia were enhanced by increasing the dosage of intrathecal sufentanil. Frequencies of hypotension, maximum sedation level, and pruritus were directly related to the dosage of intrathecal sufentanil, whereas nausea and vomiting occurred only in the groups using sufentanil. CONCLUSIONS: The addition of sufentanil 2.5 µg for spinal anesthesia provides adequate intraoperative analgesia and good postoperative analgesia with minimal adverse effects on the mother.

Unexpected difficulty in ventilating the lungs after tracheal intubation -A case report-.

We experienced difficulty in ventilating the lungs of a patient after tracheal intubation. After intubation, an insufficient amount of tidal volume (V(T)) was delivered to the patient and the fiberoptic bronchoscopic examination identified partial abutment of the endotracheal tube (ETT) orifice against the tracheal wall. After various attempts to correctly place the ETT, a double-lumen endotracheal tube was placed to achieve a sufficient V(T). It is important to notice that even an appropriately placed ETT may get obstructed due to the left sided bevel at its tip.

The relationship between symphysis-fundal height and intravenous ephedrine dose in spinal anesthesia for elective cesarean section.

BACKGROUND: A decreased lumbosacral subarachnoidal space volume is a major factor in the cephalad intrathecal spread of local anesthetics in term parturients and their subarachnoidal space is decreased due to the compressive effect of huge uteri. Therefore, they show a higher level of sensory block and hypotensive episodes. The purpose of this study is to investigate whether the symphysis-fundal height (SFH) correlates with the highest sensory level and the amount of ephedrine administered under spinal anesthesia. METHODS: Fifty-two uncomplicated parturients who consented to spinal anesthesia for elective cesarean section were studied. The SFH of all parturients had been measured just before the spinal anesthesia administered by one person. Hyperbaric bupivacaine with fentanyl 20 µg, was administered for spinal anesthesia. The amount of 0.5% bupivacaine was adjusted according to the patient's height and weight. The level of sensory block and the amounts of ephedrine to treat hypotension, nausea and vomiting were assessed. Linear regression and correlation analysis were applied to analyze the data. RESULTS: According to the results of correlation analysis, there was no significant correlation between the level of sensory block and SFH. There were statistically significant positive correlations between the amount of ephedrine administered due to hypotension and SFH. CONCLUSIONS: In term parturients choosing elective cesarean section, the SFH is not correlated with the sensory level of spinal anesthesia, but is correlated with the amount of ephedrine administered during spinal anesthesia.

Intrathecal meperidine reduces intraoperative shivering during transurethral prostatectomy in elderly patients.

BACKGROUND: Shivering is a frequent event during the perioperative period. We performed a prospective, randomized, double-blind study to determine whether intrathecal meperidine (0.2 mg/kg) decreases the incidence and intensity of shivering after spinal anesthesia for transurethral operations. METHODS: Fifty patients scheduled for elective transurethral resection operations under spinal anesthesia were randomly allocated to two groups. Spinal anesthesia consisted of 0.5% hyperbaric bupivacaine 8 mg and, mperidine (0.2 mg/kg) (meperidine group) or, normal saline (saline group). Data collection, including sensory block level (by pinprick), blood pressure, heart rate, sublingual temperature, incidence and intensity of shivering, pruritus, nausea, and vomiting was performed at 10 minute intervals. RESULTS: The incidence and intensity of shivering was significantly less in the meperidine group than saline group (P = 0.012 and P = 0.008, for incidence and intensity, respectively). However, pruritus was more common in the meperidine group compared with the saline group (16% vs. 0%, P < 0.05). CONCLUSIONS: The addition of meperidine 0.2 mg/kg to intrathecal bupivacaine lowers the incidence and severity of shivering during transurethral prostatectomy in elderly patients.