Yu-Chang Yeh

Effect of combining dexmedetomidine and morphine for intravenous patient-controlled analgesia

BACKGROUND Perioperative use of dexmedetomidine is associated with reduction in postoperative analgesic requirements. This study examined whether dexmedetomidine added to i.v. patient-controlled analgesia (PCA) morphine could improve analgesia while reducing opioid-related side-effects. METHODS In this double-blinded, randomized, controlled study, 100 women undergoing abdominal total hysterectomy were allocated to receive either morphine 1 mg ml(-1) alone (Group M) or morphine 1 mg ml(-1) plus dexmedetomidine 5 microg ml(-1) (Group D) for postoperative i.v. PCA, which was programmed to deliver 1 ml per demand with a 5 min lockout interval and no background infusion. Cumulative PCA requirements, pain intensities, cardiovascular and respiratory variables, and PCA-related adverse events were recorded for 24 h after operation. RESULTS Compared with Group M, patients in Group D required 29% less morphine during the 0-24 h postoperative period and reported significantly lower pain levels from the second postoperative hour onwards and throughout the study. Whereas levels of sedation were similar between the groups at each observational time point, decreases in heart rate and mean blood pressure from presurgery baseline at 1, 2, and 4 h after operation were significantly greater in Group D (by a range of 5-7 beats min(-1) and 10-13%, respectively). The 4-24 h incidence of nausea was significantly lower in Group D (34% vs 56.3%, P<0.05). There was no bradycardia, hypotension, oversedation, or respiratory depression. CONCLUSIONS The addition of dexmedetomidine to i.v. PCA morphine resulted in superior analgesia, significant morphine sparing, less morphine-induced nausea, and was devoid of additional sedation and untoward haemodynamic changes.

Preoperative Proteinuria Predicts Adverse Renal Outcomes after Coronary Artery Bypass Grafting

Whether preoperative proteinuria associates with adverse renal outcomes after cardiac surgery is unknown. Here, we performed a secondary analysis of a prospectively enrolled cohort of adult patients undergoing coronary artery bypass grafting (CABG) at a medical center and its two affiliate hospitals between 2003 and 2007. We excluded patients with stage 5 CKD or those who received dialysis previously. We defined proteinuria, measured with a dipstick, as mild (trace to 1+) or heavy (2+ to 4+). Among a total of 1052 patients, cardiac surgery-associated acute kidney injury (CSA-AKI) developed in 183 (17.4%) patients and required renal replacement therapy (RRT) in 50 (4.8%) patients. In a multiple logistic regression model, mild and heavy proteinuria each associated with an increased odds of CSA-AKI, independent of CKD stage and the presence of diabetes mellitus (mild: OR 1.66, 95% CI 1.09 to 2.52; heavy: OR 2.30, 95% CI 1.35 to 3.90). Heavy proteinuria also associated with increased odds of postoperative RRT (OR 7.29, 95% CI 3.00 to 17.73). In summary, these data suggest that preoperative proteinuria is a predictor of CSA-AKI among patients undergoing CABG.

Combination of opioid agonist and agonist–antagonist: patient-controlled analgesia requirement and adverse events among different-ratio morphine and nalbuphine admixtures for postoperative pain

BACKGROUND Nalbuphine, a mixed agonist-antagonist opioid, has a potential to attenuate the mu-opioid effects and to enhance the kappa-opioid effects. However, when morphine and nalbuphine are mixed together, the clinical interactions in different combining ratios on analgesic effect and adverse events are unknown. METHODS This randomized, double-blind controlled study investigated five different combining ratios of morphine and nalbuphine in 311 patients undergoing gynaecologic operations. The concentrations [morphine (mg ml(-1))]/[nalbuphine (mg ml(-1))] were 1/0 in Group 1, 0.75/0.25 (ratio 1:3) in Group 2, 0.5/0.5 (ratio 1:1) in Group 3, 0.25/0.75 (ratio 3:1) in Group 4, and 0/1 in Group 5. Patient-controlled analgesia (PCA) requirement, postoperative pain, and adverse events were evaluated throughout the postoperative 24 h period. RESULTS Twenty-four hour PCA requirements were similar among the five groups. Verbal rating scores for pain were statistically higher in Groups 2 and 4 than in Group 3. The incidences of pruritus were higher in Group 1 (15.6%) than in Group 2 (6.2%), Group 3 (3.4%), Group 4 (1.6%), and Group 5 (0%). The incidences and severity of dizziness, nausea, and vomiting were not significantly different. CONCLUSIONS The interaction between morphine and nalbuphine in PCA admixture on analgesia is additive. Combinations of morphine and nalbuphine in PCA can decrease the incidence of pruritus, and the antipruritus effect is ratio-dependent. This may provide a novel combination strategy of opioid agonist and agonist-antagonist for postoperative pain management after gynaecologic surgery.

Phaeochromocytoma crisis – a rare indication for extracorporeal membrane oxygenation

We report on a case of phaeochromocytoma whose initial presentation mimicked an acute myocardial infarction. Veno‐arterial extracorporeal membrane oxygenation was used for the management of refractory cardiogenic shock and massive lung oedema. Suspicion and diagnosis of a phaeochromocytoma were made due to its unique clinical presentation during extracorporeal membrane oxygenation. Stabilisation of the crisis and recovery of cardiopulmonary function were achieved using the support of extracorporeal membrane oxygenation. This case highlights the difficulty in the differential diagnosis of cardiogenic shock secondary to phaeochromocytoma and the important role of extracorporeal membrane oxygenation can have in the successful resuscitation and management of these patients.

Combination of Low-dose Nalbuphine and Morphine in Patient-controlled Analgesia Decreases Incidence of Opioid-related Side Effects

BACKGROUND/PURPOSE The addition of ultra-low-dose naloxone to patient-controlled analgesia (PCA) with morphine reduces opioid-related side effects. Nalbuphine, a mixed opioid agonist-antagonist, may be able to attenuate opioid-related side effects. The goal of the present study was to investigate the effect of combined low-dose nalbuphine and morphine in PCA for postoperative pain control after gynecological surgery. METHODS This randomized, double-blind, controlled study enrolled 174 female patients who were undergoing total abdominal hysterectomy, myomectomy, or ovarian tumor excision. In the control group, the PCA formula was 1 mg/mL pure morphine. In the study group, the PCA formula was 1 mg/mL morphine and 10 microg/mL nalbuphine (1:100). Numerical rating score, PCA requirement, nausea, vomiting, use of antiemetics, pruritus, use of antipruritics, and opioid-related adverse events were investigated at 1, 2, 4, and 24 hours postoperatively. RESULTS One hundred and sixty-nine patients completed the study: 86 in the control group and 83 in the study group. The incidence of nausea was lower in the study group (41%) than in the control group (65%). The incidence of vomiting, use of antiemetics, pruritus, and use of antipruritics did not differ between the two groups. The numerical rating pain score and PCA requirements were not significantly different between the two groups. CONCLUSION Combination of low-dose nalbuphine and morphine in PCA decreases the incidence of opioid-related nausea, without affecting the analgesia and PCA requirement. This novel combination can improve the quality of PCA used for postoperative pain control after gynecological surgery.

Dexmedetomidine prevents alterations of intestinal microcirculation that are induced by surgical stress and pain in a novel rat model.

BACKGROUND: Anesthesia can become inadequate inadvertently or by misjudgment during surgery or emergence, and the surgical stress and pain stimulation will increase without adequate treatment. Overt stimulation may activate the sympathetic nervous system, increase the blood level of catecholamines, and lead to splanchnic arterial vasoconstriction. METHODS: We divided 30 male Wistar rats into the following 3 groups: control, surgical stress and pain (SSP), and surgical stress and pain + dexmedetomidine (SSP + Dex). The rats received midline laparotomy to exteriorize a segment of terminal ileum for microcirculation examination by a full-field laser perfusion imager and sidestream dark-field video microscope on mucosa, muscle, and Peyer patch. The inspired concentration of isoflurane was decreased from 1.2% to 0.7% in SSP and SSP + Dex groups. In the SSP + Dex group, the rats received an initial loading dose of dexmedetomidine (0.5 &mgr;g/kg) and a maintenance infusion (0.5 &mgr;g · kg−1 · h−1). RESULTS: Dexmedetomidine prevented surgical stress and pain-related tachycardia and hypertension, and it attenuated the reduction of the microcirculatory blood flow intensity in intestinal mucosa (1100 ± 185 perfusion units [PU] vs 800 ± 105 PU, P = 0.001) and muscle (993 ± 208 PU vs 713 ± 92 PU, P < 0.001). Dexmedetomidine restored perfused small vessel density in intestinal mucosa and muscle. CONCLUSIONS: We established a promising rat model to investigate the effect of surgical stress and pain stimulation on the intestinal microcirculation during light anesthesia. Using this rat model, we found that dexmedetomidine can normalize global hemodynamics and prevent the alteration of intestinal microcirculation.

Prolonged retraction on the normal common carotid artery induced lethal stroke after cervical spine surgery.

Study Design. Case report. Objective. To report a previously undescribed complication of prolonged retraction on the normal common carotid artery after anterior cervical spine surgery. Summary of Background Data. Previous study showed that prolonged retraction could decrease the blood flow of the common carotid artery during anterior cervical spine surgery. A case report revealed that prolonged retraction could induce the formation of thrombosis in the atherosclerotic common carotid artery. Methods. Notes review. Computed tomography of the brain was performed on the first and the fourth postoperative day. Carotid Doppler ultrasound and transcranial Doppler ultrasound were performed to evaluate the left common carotid artery and the left intracranial cerebral arteries. Results. After lengthy anterior cervical spinal surgery, the patient did not regain his consciousness during the stay in the postoperative care unit. Large infarction of left cerebral hemisphere was revealed by computed tomography. The patient died on the seventh postoperative day of perioperative lethal stroke. Conclusion. We suggest that prolonged retraction, even on the normal common carotid artery, could induce lethal stroke after anterior cervical spine surgery. We recommend that retractor should be placed carefully and cerebral perfusion should be maintained adequately.

Effects of different types of fluid resuscitation for hemorrhagic shock on splanchnic organ microcirculation and renal reactive oxygen species formation

IntroductionFluid resuscitation is an indispensable procedure in the acute management of hemorrhagic shock for restoring tissue perfusion, particularly microcirculation in splanchnic organs. Resuscitation fluids include crystalloids, hypertonic saline (HTS), and synthetic colloids, and their selection affects the recovery of microcirculatory blood flow and reactive oxygen species (ROS) formation, which is often evident in the kidney, following reperfusion. In this study, the effects of acute resuscitation with 0.9 % saline (NS), 3 % HTS, 4 % succinylated gelatin (GEL), and 6 % hydroxyethyl starch (HES) 130/0.4 were compared in a hemorrhagic shock rat model to analyze restoration of microcirculation among various splanchnic organs and the gracilis muscle and reperfusion-induced renal ROS formation.MethodsA total of 96 male Wistar rats were subjected to sham operation (sham group), hemorrhagic shock (control group), and resuscitation with NS, HTS, GEL and HES. Two hours after resuscitation, changes in the mean arterial pressure (MAP), serum lactate level and the microcirculatory blood flow among various splanchnic organs, namely the liver, kidney, and intestine (mucosa, serosal muscular layer, and Peyer’s patch), and the gracilis muscle, were compared using laser speckle contrast imaging. Renal ROS formation after reperfusion was investigated using an enhanced in vivo chemiluminescence (CL) method.ResultsMicrocirculatory blood flow was less severely affected by hemorrhaging in the liver and gracilis muscle. Impairment of microcirculation in the kidney was restored in all resuscitation groups. Resuscitation in the NS group failed to restore intestinal microcirculation. Resuscitation in the HTS, GEL, and HES groups restored intestinal microcirculatory blood flow. By comparison, fluid resuscitation restored hemorrhagic shock-induced hypotension and decreased lactatemia in all resuscitation groups. Reperfusion-induced in vivo renal ROS formation was significantly higher in the GEL and HES groups than in the other groups.ConclusionAlthough fluid resuscitation with NS restored the MAP and decreased lactatemia following hemorrhagic shock, intestinal microcirculation was restored only by other volume expanders, namely 3 % HTS, GEL, and HES. However, reperfusion-induced renal ROS formation was significantly higher when synthetic colloids were used.

The mutagenicity of soy bean sauce

Abstract Soy bean sauce is commonly used as a food material in Taiwan where the incidence of hepatoma and gastric cancer is high. We have therefore investigated the mutagenicity of soy bean sauce in vitro . When treated with nitrite at the 2000 ppm level soy bean sauce produced a mutagenic substance as demonstrated using the Salmonella /mammalian microsome mutagenicity test. All 21 different brands of soy bean sauce showed similar results. Most mutagenic material was formed when the nitrite level was 2000 ppm and the pH was 3; ascorbic acid prevented the formation of mutagenic products in nitrite-treated soy bean sauce.

Effect of Diuretic Use on 30-Day Postdialysis Mortality in Critically Ill Patients Receiving Acute Dialysis

Background The impact of diuretic usage and dosage on the mortality of critically ill patients with acute kidney injury is still unclear. Methods and Results In this prospective, multicenter, observational study, 572 patients with postsurgical acute kidney injury receiving hemodialysis were recruited and followed daily. Thirty-day postdialysis mortality was analyzed using Coxs proportional hazards model with time-dependent covariates. The mean age of the 572 patients was 60.8±16.6 years. Patients with lower serum creatinine (p = 0.031) and blood lactate (p = 0.033) at ICU admission, lower predialysis urine output (p = 0.001) and PaO2/FiO2 (p = 0.039), as well as diabetes (p = 0.037) and heart failure (p = 0.049) were more likely to receive diuretics. A total of 280 (49.0%) patients died within 30 days after acute dialysis initiation. The analysis of 30-day postdialysis mortality by fitting propensity score-adjusted Coxs proportional hazards models with time-dependent covariates showed that higher 3-day accumulated diuretic doses after dialysis initiation (HR = 1.449, p = 0.021) could increase the hazard rate of death. Moreover, higher time-varying 3-day accumulative diuretic doses were associated with hypotension (p<0.001) and less intense hemodialysis (p<0.001) during the acute dialysis period. Background and Significance Higher time-varying 3-day accumulative diuretic dose predicts mortality in postsurgical critically ill patients requiring acute dialysis. Higher diuretic doses are associated with hypotension and a lower intensity of dialysis. Caution should be employed before loop diuretics are administered to postsurgical patients during the acute dialysis period.