A randomized trial of bupivicaine pain pumps to eliminate the need for patient controlled analgesia pumps in primary laparoscopic Roux-en-Y gastric bypass.

BACKGROUND: The use of a bupivicaine pain pump has previously been reported to lower costs to hospitals, while providing similar pain relief to opioid-based patient controlled analgesia (PCA) pumps. However, these benefits have not been investigated in laparoscopic bariatric surgery. METHODS: We prospectively randomized 40 laparoscopic Roux-en-Y gastric bypass (LRYGBP) patients into two groups. The first group received the ON-Q bupivicaine pain pump placed subxiphoid and radiating in both directions caudally beneath the lowest rib. The second group was treated with a meperidine PCA, which was initiated in the PACU and discontinued at 06:00 hrs the following morning. Both groups had identical surgery, anesthesiologists, anesthesia protocol and postoperative nausea prophylaxis. RESULTS: There were no significant differences between the groups with regard to age, sex, pain scores, nausea scores, gas pain scores, antiemetic use throughout their stay, or opioid use in the PACU. However, there was a dramatic decrease in opioid use between the two groups over the time interval from leaving the PACU to 06:00 hrs (meperidine by PCA mean 217 mg vs ON-Q 129 mg meperidine equivalents, P=0.008). CONCLUSIONS: The use of a bupivicaine pain pump offers the opportunity to dramatically reduce the use of opioids postoperatively in all bariatric patients by eliminating PCA. This change could potentially reduce the incidence of respiratory failure from oversedation, while offering the same levels of pain control.

A case-controlled matched-pair cohort study of laparoscopic Roux-en-Y gastric bypass and Lap-Band patients in a single US center with three-year follow-up.

BACKGROUND: Open or laparoscopic Roux-en-Y gastric bypass (RYGBP) is the most common operation for treatment of morbid obesity in USA. The laparoscopic adjustable gastric band (LAGB) has been the most common bariatric operation performed worldwide. The LapBand was approved for use in USA in July 2001. Since then, several US surgeons have adopted one procedure preferentially over the other, and several have reported patient outcomes. We added the option of the LAGB to the RYGBP in our practice in July 2001. We hypothesized that both procedures will provide similar weight loss and co-morbidity reduction if followed for a sufficient length of time. To enhance weight loss, we adopted a patient behavioral program that is easy to remember, in an attempt to ensure a reduction in caloric intake and reduce hunger regardless of the operation performed. METHODS: A case-controlled matched-pair cohort study was conducted. All patients who presented to the Surgical Weight Control Center of Las Vegas between Aug 2001 and Aug 2004 for LAGB were placed into one group, and a matched-pair RYGBP cohort group was created. Patients in the RYGBP cohort were matched for age, sex, date of surgery, and BMI. All patients were evaluated on an intention to treat basis. Data were collected prospectively and analyzed retrospectively. All patients were subjected to the same preoperative education regarding calorie reduction behaviors and diet change, and received the same postoperative counseling regarding long-term eating behavior and food choices. RESULTS: During this period, 208 patients underwent LAGB and 600 underwent RYGBP. Of the 208 LAGB patients, 181 had suitable open or laparoscopic RYGBP matches. The two groups were similar in terms of age, sex, BMI, and co-morbidities. There were no deaths in either group. Resolution of co-morbidities statistically favored RYGBP as did the weight loss, over the study period. CONCLUSION: When patients are matched with 3-year follow-up according to time of surgery, age, sex and BMI, LRYGBP provides superior weight and co-morbidity reduction and can be done without severe complications. However, the LAGB is an effective weight loss tool and not every patient wishes to have the LRYGBP.

In Vivo Evaluation of a Pneumatic Extracorporeal Ventricular Assist Device for up to 90 Day Support.

In a previous study, we showed that the Vitalmex Extracorporeal Ventricular Assist Device-Pneumatic (EVAD-P)-a low-cost, pneumatically actuated, pulsatile blood pump-is easy to implant and safe for short-term in vivo support (30 ± 5 days). In the current study, we included additional 30 day experiments and assessed the safety and durability of the EVAD-P for up to 90 days of support. Using the same surgical procedure as in the previous study, we implanted the device into 14 healthy sheep. Group I subjects (n = 7) were evaluated for up to 30 days, and group II (n = 2) and group III (n = 5) subjects were evaluated for up to 49 and 93 days, respectively. After a system redesign, two of the five sheep in group III reached the scheduled end-point without device-related problems at a fixed beat rate of 56 bpm, a stroke volume (SV) of 58.0 ± 2.3 ml, and a flow of 3.5 ± 0.2 L/min. This study shows that the EVAD-P can provide safe pulsatile mechanical circulatory support (MCS) for up to 93 days. To further confirm that the system can consistently provide MCS for this duration, additional studies are recommended.

Comparative Efficacy of Nebivolol and Metoprolol to Prevent Tachycardia-Induced Cardiomyopathy in a Porcine Model.

Chronic tachycardia is a well-known cause of nonischemic cardiomyopathy. We hypothesized that nebivolol, a ß-blocker with nitric oxide activity, would be superior to a pure ß-blocker in preventing tachycardia-induced cardiomyopathy in a porcine model. Fifteen healthy Yucatan pigs were randomly assigned to receive nebivolol, metoprolol, or placebo once a day. All pigs underwent dual-chamber pacemaker implantation. The medication was started the day after the pacemaker implantation. On day 7 after implantation, each pacemaker was set at atrioventricular pace (rate, 170 beats/min), and the pigs were observed for another 7 weeks. Transthoracic echocardiograms, serum catecholamine levels, and blood chemistry data were obtained at baseline and at the end of the study. At the end of week 8, the pigs were euthanized, and complete histopathologic studies were performed. All the pigs developed left ventricular cardiomyopathy but remained hemodynamically stable and survived to the end of the study. The mean left ventricular ejection fraction decreased from baseline by 34%, 20%, and 20% in the nebivolol, metoprolol, and placebo groups, respectively. These changes did not differ significantly among the 3 groups (P =0.51). Histopathologic analysis revealed mild left ventricular perivascular fibrosis with cardiomyocyte hypertrophy in 14 of the 15 pigs. Both nebivolol and metoprolol failed to prevent cardiomyopathy in our animal model of persistent tachycardia and a high catecholamine state.

Tumor growth factor expression in obesity and changes in expression with weight loss: another cause of increased virulence and incidence of cancer in obesity.

BACKGROUND: Obesity is associated with increased tumorigenesis. Previously, we demonstrated that inflammation in obesity caused cancer fighting cells to display greater surface receptor levels, predisposing them to early cell death. We measured the inflammatory tumor growth factor levels to determine whether inflammation in obesity increases expression of these factors, potentially predisposing these patients to greater rates of neoplasia. METHODS: A total of 24 patients undergoing weight loss surgery had samples collected preoperatively and at 6 and 12 months after surgery. The growth factors analyzed included tumor necrosis factor (TNF)-α, granulocyte-macrophage colony-stimulating factor, interferon-γ, interleukin (IL)-1b, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, vascular endothelial growth factor, hepatocyte growth factor, TNF-receptor I (TNF-RI), TNF-RII, death receptor 5, leptin, and adiponectin. Control samples were obtained from 10 healthy, normal weight volunteers. RESULTS: The tumor growth factors TNF-α, TNF-RI, TNF-RII, vascular endothelial growth factor, hepatocyte growth factor, interferon-γ, IL-2, IL-5, and IL-6 all decreased significantly (P <.05) compared with the preoperative values. The IL-4, IL-8, leptin, death receptor 5, adiponectin, and granulocyte-macrophage colony-stimulating factor levels did not change significantly over time. The IL-1b and IL-10 levels were less than the detection limit at all points. When obese patient serum was compared with healthy volunteer pooled serum, we found that the leptin, death receptor 5, hepatocyte growth factor, vascular endothelial growth factor, TNF-RI, TNF-RII, TNF-α, IFN-γ, granulocyte-macrophage colony-stimulating factor, IL-4, IL-5, IL-6, and IL-8 levels were all 2-37 times greater than the levels in the controls at baseline. The concentrations of these same growth factors had decreased levels only 1-3.5 times greater than those of the controls at 12 months postoperatively. CONCLUSION: Many inflammatory tumor growth factors are present in greater concentrations in obese individuals. This could explain the greater prevalence of neoplasia in the morbidly obese population.

Does lidocaine more effectively prevent pain upon induction with propofol or etomidate when given preemptively than when mixed with the drug?

STUDY OBJECTIVE: To compare the efficacy of 2% lidocaine "timing" on alleviation of pain upon induction using propofol or etomidate. DESIGN: Prospective, randomized, double-blinded study. SETTING: Academic teaching hospital. PATIENTS: 80 adult, ASA physical status I, II, and III patients scheduled for elective outpatient or inpatient surgery with an intravenous induction agent. INTERVENTIONS: Patients were randomly assigned to two groups. Group A received preemptive saline 4 mL and lidocaine 4 mL mixed with either propofol 20 mL (n = 20) or etomidate 20 mL (n = 20). Group B received preemptive lidocaine 4 mL and saline 4 mL mixed with either propofol 20 mL (n = 20) or etomidate 20 mL (n = 20). The 4 mL dose of preemptive drug dwelled for three minutes. MEASUREMENTS: The induction drug mixture was injected over 60 seconds while the patient was assessed for pain using a 4-point scale (0 = no pain,1 = mild, 2 = moderate, and 3 = severe). MAIN RESULTS: Mean induction pain scores were 1.0 (SD = 0.89) for propofol and 0.9 (SD = 0.90) for etomidate, representing mild induction pain. Mean induction pain scores were 0.93 (SD = 0.92) for the simultaneous treatment groups and 0.98 (SD = 0.87) for the preemptive treatment groups. The observed differences in pain scores between the techniques were not statistically (P > 0.62) or clinically meaningful. CONCLUSIONS: Alleviation and intensity of post-injection pain were not significantly influenced by the "timing" of administration of lidocaine 80 mg or by the specific induction drug. Pre-lidocaine and "simultaneous" lidocaine with either propofol or etomidate prevented severe pain in 95% of patients.