Biomedical subjects

W Steve Eubanks

Publications and source records attributed to W Steve Eubanks.

11 recordsLinked to original sources

PubMed2005

General anesthesia improves fetal cerebral oxygenation without evidence of subsequent neuronal injury.

Anesthetic exposure during pregnancy is viewed as a relatively routine medical practice. However, recent rodent studies have suggested that common anesthetic agents can damage the developing brain. Here we assessed this claim in a higher order species by exposing previously instrumented near-term pregnant sheep at gestational day 122 (+/-1) to a combination of midazolam, sodium thiopental, and isoflurane at clinically relevant doses and means of anesthetic delivery (i.e., active ventilation). Four hours of maternal general anesthesia produced an initial increase in fetal systemic oxygenation and a sustained increase in fetal cerebral oxygenation, as determined by in utero near-infrared spectroscopy. Postexposure monitoring failed to identify changes in physiologic status that could be injurious to the fetal brain. Finally, through the histologic assessment of noninstrumented sheep at the same gestational time point, we found no evidence for a direct fetal neuro-toxic effect of our triple-drug regimen. Collectively, these results appear to corroborate the presumed safety of inhalational anesthetic use during pregnancy.

Anesthesia, General↗

PubMed2005

A method to attenuate pneumoperitoneum-induced reductions in splanchnic blood flow.

OBJECTIVE: To determine if increasing nitric oxide bioactivity by inclusion of ethyl nitrite (ENO) in the insufflation admixture would attenuate pneumoperitoneum-induced decreases in splanchnic perfusion. SUMMARY BACKGROUND DATA: Organ blood flow is reduced during pneumoperitoneum and can contribute to laparoscopy-associated morbidity and mortality. Previous attempts to control such decreases in flow have been ineffective. METHODS: Laser-Doppler flow probes were placed on the liver and right kidney of anesthetized pigs. After a baseline recording period, animals were insufflated to a final intraperitoneal pressure of 15 mm Hg. Group one received CO2 (standard practice), whereas group 2 received CO2 plus 100 ppm ENO. Insufflation was maintained for 60 minutes and then the abdomen was manually deflated; monitoring was continued for another 60 minutes. RESULTS: CO2 insufflation (n = 5) cut liver blood flow in half; liver flow remained at this level throughout the postinsufflation period. Inclusion of 100 ppm ENO (n = 6) attenuated both the acute and prolonged blood flow decreases. Statistical modeling of the data showed that, on average, liver blood flow was 14.3 U/min higher in the ENO pigs compared with the CO2 group (P = 0.0454). In contrast, neither treatment significantly altered kidney blood flow (P = 0.6215). CONCLUSION: The data indicate that ENO can effectively attenuate pneumoperitoneum-induced blood flow decreases within the peritoneal cavity. The result suggests a novel therapeutic method of regulating hemodynamic changes during laparoscopic procedures.

Animals↗

PubMed2004

Laparoscopic Nissen fundoplication for treating reflux in lung transplant recipients.

Gastroesophageal reflux disease may contribute to pulmonary injury and the development of bronchiolitis obliterans syndrome in lung transplant patients. As a result, such individuals are increasingly likely to undergo corrective gastrointestinal surgery. The present study collected outcome data for 28 lung transplant patients with documented reflux who underwent an uncomplicated laparoscopic Nissen fundoplication at our institution. The results were compared to data from 63 nontransplant reflux patients who had undergone the procedure over the same time period. All Nissen fundoplications were conducted by the same surgeon. There were no intraoperative or perioperative deaths in either patient group. Operative parameters did not differ but the postoperative hospital stay was significantly greater for the lung transplant patients (P<0.05). Seven transplant patients (25%) were readmitted within 30 days compared to two readmissions (3.2%) in the reflux group. Five transplant patients (17.9%) have died, all from pulmonary complications; on average, death occurred 15.5 months after the Nissen surgery. There have been no deaths in the reflux group. These data indicate that laparoscopic Nissen fundoplication can be performed on lung transplant recipients to treat reflux. The average hospital stay is longer and there are more frequent readmissions in this population, but this does not appear to be due to any Nissen-related morbidity.

Adult↗

PubMed2004

Maternal insufflation during the second trimester equivalent produces hypercapnia, acidosis, and prolonged hypoxia in fetal sheep.

BACKGROUND: Anecdotal reports suggest that the second trimester is the safest time to conduct a laparoscopic procedure on a pregnant patient, but this supposition has not been tested empirically. METHODS: Previously instrumented preterm sheep (total n = 8) at gestational day 90 (term, 145 days) were anesthetized and then insufflated with carbon dioxide for 60 min at a pressure of 15 mmHg. Cardiovascular parameters were continuously recorded while blood gas status was determined before and at 15-min intervals during and up to 2 h after insufflation. RESULTS: Insufflation produced minimal maternal blood gas or cardiovascular changes except for a significant reduction in uterine blood flow. The decrease in perfusion increased fetal arterial blood partial pressure of carbon dioxide and decreased fetal pH, oxygen saturation, and oxygen content; there was also progressive fetal hypotension and bradycardia. After manually deflating the ewe, uterine blood flow returned to normal, and the fetal partial pressure of carbon dioxide and pH changes resolved within 1 h. However, fetal oxygen saturation and content remained depressed, and fetal cardiovascular status continued to decline during the 2-h postinsufflation monitoring period. CONCLUSION: Previous studies with near-term sheep determined that carbon dioxide pneumoperitoneum produces respiratory acidosis but does not decrease fetal oxygenation. In contrast, the current findings indicate that in the preterm fetus, insufflation-induced hypercapnia and acidosis are accompanied by prolonged fetal hypoxia and cardiovascular depression. This result suggests that additional work should be conducted to confirm the presumed safety of conducting minimally invasive procedures during the second trimester.

Acidosis↗

PubMed2003

Endoscopic components separation for abdominal compartment syndrome.

BACKGROUND: Sustained intraabdominal pressures of 14 to 20 mm Hg have significant pathophysiological consequences, but there is currently no satisfactory low-morbidity procedure appropriate for intervention early in the disease process of abdominal compartment syndrome (ACS). The anatomical principles of abdominal wall components separation were used to develop a percutaneous procedure that increased abdominal capacity and decreased abdominal pressure. METHODS: Using a porcine model, we determined abdominal capacity changes by helium insufflation. Corn oil was then used to create an episode of sustained intraabdominal hypertension and changes in intraabdominal pressure and intestinal mucosal oxygenation were determined. RESULTS: Endoscopic abdominal wall components separation (EACS) increased abdominal capacity by 1 L (from 0.89 +/- 0.39 L to 1.95 +/- 0.48 L; P <0.001). During intraabdominal hypertension, EACS decreased abdominal pressure by 31.6% (from 15.9 +/- 2.1 to 11.0 +/- 1.5 mm Hg; P <0.001). Intestinal PO(2) was increased by 61% (18.8 +/- 11.4 to 30.3 +/- 11.7; P = 0.012) CONCLUSIONS: A minimally invasive procedure (EACS) is feasible and has demonstrated effectiveness in a porcine model of ACS.

Abdominal Wall↗

PubMed2002

Celecoxib (celebrex) increases canine lower esophageal sphincter pressure.

BACKGROUND: Prostaglandins inhibit the contraction of gastrointestinal smooth muscle and may decrease lower esophageal sphincter tone. The purpose of this study was to determine whether the cyclooxygenase-2 inhibitor celecoxib (Celebrex) could increase lower esophageal pressure (without affecting gastric emptying) compared to placebo and cisapride (Prepulsid), a compound previously used to treat reflux disease. MATERIALS AND METHODS: Six mongrel dogs were assigned to receive celecoxib, cisapride, and placebo using a randomized cross-over design with a 1-week washout period between treatments. Prior to dosing, each dog underwent an esophagopexy to provide access to the esophagus and stomach. On the fourth day of dosing, sphincter tone was measured in awake unsedated dogs using radial manometry. In a different set of six dogs, liquid and solid gastric emptying rates were scintigraphically determined. RESULTS: Celecoxib significantly increased mean and average maximum lower esophageal pressures compared to placebo without affecting the gastric emptying rate. The magnitudes of these increases were similar to that produced by cisapride. CONCLUSIONS: Celecoxib had a positive effect on canine lower esophageal sphincter tone. This finding, combined with the drug's low incidence of gastrointestinal toxicity, suggests that celecoxib may warrant consideration and investigation as a pharmacotherapy for human reflux disease.

Animals↗

PubMed2002

Laparoscopic repair of a Morgagni hernia presenting with syncope in an 85-year-old woman: case report and update of the literature.

An 85-year-old woman was transferred from her local hospital for cardiac evaluation after presenting with repeated episodes of syncope during bowel movements. A thorough evaluation revealed no cardiac abnormalities but did reveal a Morgagni hernia with transverse colon in the mediastinum. She underwent laparoscopic reduction of the colon and repair of the hernia with mesh and had a rapid and uneventful recovery.

Aged↗

PubMedDate not supplied

A review of laparoscopy for non-obstetric-related surgery during pregnancy.

PURPOSE: Similar to the general population, parturients (and their fetuses) could benefit from the reduced manipulation associated with laparoscopy. The purpose of this article is to review the current state of knowledge (both clinical and experimental) with respect to the fetal effects of maternal laparoscopy for non-obstetric-related surgery during pregnancy. METHODS: Human and experimental animal results are examined, and we present preliminary data from our own laboratory. CONCLUSIONS: Future experiments are proposed to further develop and refine standards of care for general surgeons and obstetricians who are presented with gravid females in abdominal distress.

Animals↗

PubMedDate not supplied

Surgical management of pancreaticocutaneous fistula.

Although enteric drainage of the fistula tract is a widely accepted treatment for pancreaticocutaneous fistula, few data have been published on the outcome of this procedure. We conducted a retrospective chart review of 30 patients with pancreaticocutaneous fistula who underwent surgical management at a single institution over a 13-year period. The operative morbidity rate was 30%. Overall the incidence of recurrent ductal leaks requiring further intervention was 23%. Six of seven patients who had a recurrence had an ongoing inflammatory pathology, and three of seven had pancreas divisum. Recurrence was most likely when cystenterostomy was used. Enteric drainage of pancreaticocutaneous fistulas is not always curative. Fistulojejunostomy gives a better outcome than cystenterostomy. Recurrence may be expected in patients with continuing inflammatory ductal pathology.

Adolescent↗

PubMedDate not supplied

Paravertebral somatic nerve block compared with peripheral nerve blocks for outpatient inguinal herniorrhaphy.

BACKGROUND: Inguinal herniorrhaphy (IH) is a common outpatient procedure, yet postoperative pain and anesthetic side effects remain a problem. Paravertebral somatic nerve blocks (PVB) have the potential to offer unilateral abdominal wall anesthesia and long-lasting pain relief with minimal side effects. We compared PVB with peripheral neural blocks for outpatient IH. METHODS: Forty-six patients scheduled for IH were entered into this prospective, single-blind study. All patients underwent a standardized general anesthetic. Patients were randomly assigned to receive a PVB (levels T10-L2) preoperatively (n = 24) or an intraoperative peripheral block (PB) by the surgeon (n = 22), using 0.5% ropivacaine (40 mL). Opioid use, verbal analog pain scores, and side effects were documented for 72 hours. RESULTS: The use of opioids during surgery was less for the PVB group 162 +/- 70 mg than the PB group, 210 +/- 60 (P =.02). Need for opioids in PACU was less for the PVB group (39%) than the PB group (61%) (P =.002). Time until first pain after discharge was not different between groups, 312 +/- 446 minutes (PB) and 425 +/- 384 minutes (PVB) (P =.12). Of the PVB patients, 29% used no opioids at all compared with 18% of PB patients (P =.12). Mean time until first oxycodone use was similar between groups, 303 +/- 469 minutes (PB) and 295 +/- 225 minutes (PVB) (P =.18). Oxycodone use was also similar; 35 +/- 34 mg (PVB) versus 49 +/- 42 mg (PB) (P =.30). More patients in the PB group (50%) required antiemetic treatment in the postanesthesia care unit than the PVB group (21%) (P <.001). Side effects were similar at all other measurements. CONCLUSIONS: This study shows that PVB provides analgesia equivalent to extensive peripheral nerve block for inguinal herniorrhaphy, offering an alternative method of postoperative pain management and perhaps fewer side effects.

Abdominal Wall↗

PubMedDate not supplied

Robotically assisted laparoscopic Roux-en-Y hepaticojejunostomy.

INTRODUCTION: This study evaluates the feasibility and safety of using robotically assisted laparoscopy to perform a Roux-en-Y hepaticojejunostomy. This new method was compared with the open and standard laparoscopic approaches. METHODS: Eighteen pigs underwent a needlescopic common bile duct ligation to create a jaundice model. Three to 5 days later, transabdominal ultrasound was performed, and the common bile duct diameter was documented. For the Roux-en-Y hepaticojejunostomy, the pigs were randomly assigned to the open group (n=6), standard laparoscopy group (n=6), or robotically assisted laparoscopy group (Zeus) (n=6). One surgeon performed all 3 approaches with 1 assistant. Operative times, techniques, and complication rates were documented. RESULTS: The open approach was faster in all instances. At the hepaticojejunostomy, no difference was noted between the groups with the total number of stitches used. The robot required fewer stitches and less time in the posterior wall of the hepaticojejunostomy (P=-0.0083 and P=0.02049, respectively). The hepaticojejunostomy time was similar for the laparoscopy and robotically assisted groups. CONCLUSION: Robotically assisted laparoscopic Roux-en-Y hepaticojejunostomy is a feasible procedure. When compared with standard laparoscopy, operating time is similar.

Anastomosis, Roux-en-Y↗