PubMed Health⌕ Search

Biomedical subjects

Theodore N Pappas

Publications and source records attributed to Theodore N Pappas.

At least 55 records · Page 3Linked to original sources
PubMed2004

A randomized comparison of a multimodal management strategy versus combination antiemetics for the prevention of postoperative nausea and vomiting.

A multimodal management strategy for the prevention of postoperative nausea and vomiting (PONV) appears to be superior to single-drug prophylaxis. We tested the hypothesis that a multimodal PONV prophylaxis regimen incorporating total IV anesthesia (TIVA) with propofol and a combination of ondansetron and droperidol is more effective than a combination of these antiemetics in the presence of an inhaled anesthetic. Ninety patients undergoing laparoscopic cholecystectomy were randomized to one of three groups. Group 1 (multimodal group) received TIVA with propofol, droperidol, and ondansetron. Group 2 (combination group) received droperidol and ondansetron with isoflurane and nitrous oxide for the maintenance of anesthesia. Group 3 (TIVA group) received propofol for the induction and maintenance of anesthesia. The complete response rate (no PONV and no rescue antiemetic) at 2 h after surgery was 90%, 63%, and 66% in Groups 1, 2, and 3, respectively (P < 0.05, Group 1 versus Group 2). At 24 h, the complete response rate was 80%, 63%, and 43% in Groups 1, 2, and 3, respectively (P < 0.05, Group 1 versus Group 3). Patient satisfaction was also greater in the multimodal group than in the other two groups in the postanesthesia care unit (P < 0.05). In conclusion, the multimodal management strategy for PONV was associated with a higher complete response rate and greater patient satisfaction when compared with similar antiemetic prophylaxis with inhaled anesthesia or TIVA with propofol.

Adult↗
PubMed2003

Elective stoma construction improves outcomes in medically intractable pressure ulcers.

PURPOSE: Perineal pressure ulcers are a common and devastating complication for paralyzed or chronically bedridden patients. Controversy exists on the benefit of fecal diversion for the treatment and prevention of these ulcers. This study compared outcomes in bed-bound patients with pressure ulcers who electively underwent fecal diversion with those who did not. METHODS: A retrospective review was performed on all disabled patients who underwent surgery for medically intractable pressure ulcer from 1993 to 2001. Charts were divided into the colostomy group or noncolostomy group. Recurrence rates, healing times, morbidity and mortality, and number of reoperations were calculated for each group. Additionally, stoma patients were interviewed for quality of life assessment. RESULTS: Sixty-seven patients were treated during the study period (colostomy, n = 41; noncolostomy, n = 26). The majority of colostomies were performed laparoscopically, with a 9.7 percent incidence of postoperative complications. The ulcer recurrence rate was lower in the treated colostomy group (43 percent) compared with the noncolostomy group (69 percent; P < 0.05). In addition, noncolostomy patients had longer healing times (7 vs. 3 months; P < 0.05), and this group required more ulcer operations than the stoma patients did. Quality of life and bowel care were much improved by the colostomy. CONCLUSIONS: Stoma construction is a safe procedure with low morbidity and mortality that helps heal pressure ulcers and decreases the incidence of recurrence. Additionally, laparoscopic stoma construction represents a technical advance that may reduce operative complications that have been previously reported with open fecal diversion.

Adolescent↗
PubMed2003

Outcomes after esophagectomy: a ten-year prospective cohort.

BACKGROUND: The Department of Veterans Affairs National Surgical Quality Improvement Program is a unique resource to prospectively analyze surgical outcomes from a cross-section of surgical services nationally. We used this database to assess risk factors for morbidity and mortality after esophagectomy in Veterans Affairs Medical Centers from 1991 to 2001. METHODS: A total of 1,777 patients underwent an esophagectomy at 109 Veterans Affairs hospitals with complete in-hospital and 30-day outcomes recorded. Bivariate and multivariable analyses were completed. RESULTS: Thirty-day mortality was 9.8% (174/1,777) and the incidence of one or more of 20 predefined complications was 49.5% (880/1,777). The most frequent postoperative complications were pneumonia in 21% (380/1,777), respiratory failure in 16% (288/1,777), and ventilator support more than 48 hours in 22% (387/1,777). Preoperative predictors of mortality based on multivariable analysis included neoadjuvant therapy, blood urea nitrogen level of more than 40 mg/dL, alkaline phosphatase level of more than 125 U/L, diabetes mellitus, alcohol abuse, decreased functional status, ascites, and increasing age. Preoperative factors impacting morbidity were increasing age, dyspnea, diabetes mellitus, chronic obstructive pulmonary disease, alkaline phosphatase level of more than 125 U/L, lower serum albumin concentration, increased complexity score, and decreased functional status. Intraoperative risk factors for mortality included the need for transfusion; intraoperative risk factors for morbidity included the need for transfusion and longer operative time. CONCLUSIONS: These data constitute the largest prospective outcomes cohort in the literature and document a near 50% morbidity rate and 10% mortality rate after esophagectomy. Data from this study can be used to better stratify patients before esophagectomy.

Age Factors↗
PubMed2003

Percutaneous cholecystostomy in patients with acute cholecystitis: experience of 45 patients at a US referral center.

BACKGROUND: Standard treatment for acute cholecystitis is cholecystectomy, but some patients are at high risk for immediate surgery. Percutaneous cholecystostomy might be the procedure of choice in this group. We reviewed the experience of percutaneous cholecystostomy in a large tertiary center population. STUDY DESIGN: We performed a retrospective analysis of patients who underwent percutaneous cholecystostomy, and recorded indications for cholecystostomy, duration of tube placement, clinical outcome, death within 30 days of procedure, complications, bacteriology of aspirated bile, gallbladder contents, and performance of interval cholecystectomy. RESULTS: Forty-five patients (mean age 63 years) had cholecystostomy tubes placed from July 1999 to March 2002. All had confirmed or presumed acute cholecystitis. Mean duration of tube insertion was 54.3 days. Thirty-six patients improved clinically within 5 days. Nine patients died within 30 days; only one death was directly related to gallbladder sepsis. Nine patients subsequently had laparoscopic cholecystectomy, eight had open cholecystectomy, and two had cholecystoenterostomy. Cholecystectomy was planned in another five patients. Cholecystostomy tubes leaked in two patients, blocked in four, and dislodged in one. One patient developed a hemoperitoneum. Bile aspirated at cholecystostomy was culture positive in 12 patients, negative in 16, and not sent or recorded in 17. Twenty-two patients had gallstones, 10 had sludge, 9 had both, and 4 had neither. CONCLUSIONS: In experienced hands, percutaneous cholecystostomy is easy to perform, with low complication and high success rates. It is the procedure of choice in patients with acute cholecystitis unfit for emergency surgery. Patients often improve clinically, so that cholecystectomy can be done electively.

Acute Disease↗
PubMed2003

Evaluation of porcine-derived small intestine submucosa as a biodegradable graft for gastrointestinal healing.

High-risk anastomoses in the gut may benefit from the application of a synthetic reinforcement to prevent an enteric leak. Recently a porcine-derived small intestine submucosa (SIS) was tested as a bioscaffold in a number of organ systems. The aim of this study was to evaluate the effectiveness of SIS in stimulating healing in the stomach. Twelve rats underwent surgical removal of a full-thickness gastric defect (1 cm) and subsequent repair with a double-layer patch of porcine-derived SIS. The graft was secured with interrupted sutures placed within 1 mm of the edge of the graft. After 21 days, the animals were killed and their stomachs harvested for histologic examination. Cross sections were processed for paraffin embedding and 4-micron sections were stained with hematoxylin and eosin. All animals survived, gained weight, and demonstrated no signs of peritonitis over the 3-week postoperative period. On postmortem examination, the defect was completely closed in all animals by granulation tissue and early fibrosis. Although most of the luminal surface of the grafted areas remained ulcerated, early regeneration of normal gastric mucosa was seen at the periphery of the defect. SIS may act as an effective scaffolding agent for intestinal mucosa and may offer protection in high-risk anastomoses.

Absorbable Implants↗
PubMed2003

Neural mechanism of acupuncture-induced gastric relaxations in rats.

Acupuncture has been used to treat gastrointestinal symptoms in China for more than 3000 years. However, the mechanism of the beneficial effects of acupuncture remains unknown. Strain gauge transducers were implanted on the serosal surface of the stomach to record circular muscle contractions in thiobutabarbital-anesthetized rats. Acupuncture on the right lower abdomen caused a transient relaxation of the stomach. Acupuncture-induced gastric relaxations were abolished by guanethidine, propranolol, splanchnic ganglionectomy, spinal cord transection, and spinomedullary transection. In contrast, N(G)-nitro-L-arginine, phentolamine, truncal vagotomy, and pontomedullary transection had no effect. Acupuncture increased the number of c-Fos immunopositive cells at the ventrolateral medulla (VLM). It is concluded that acupuncture-induced gastric relaxations are mediated via the somatosympathetic reflex. Its afferent limb is composed of abdominal cutaneous and muscle afferent nerves. Its efferent limb is the gastric sympathetic nerve and the reflex center is within the medulla. VLM neurons may play an important role in mediating this reflex.

Acupuncture↗
PubMed2003

Inguinal hernia: an old condition with new solutions.

OBJECTIVE: To review the recent surgical advances in the treatment of inguinal hernias. SUMMARY BACKGROUND DATA: Traditional tissue-based techniques (eg, Bassini, McVay, Shouldice) characterized the armamentarium of the inguinal hernia surgeon during the 1970s and early 1980s. With the need to reduce the rate of hernia recurrence, as well as postoperative pain and convalescence, the treatment of inguinal hernias underwent a dramatic evolution over the past 15 years. The major advances included the introduction of the concept of tension-free hernia surgery, the use of prosthetic materials, and the development of laparoscopic techniques. RESULTS: The recognition that excessive suture-line tension was primarily responsible for high recurrence rates and significant postoperative pain following tissue-based repairs led to the introduction of the concept of tension-free hernia surgery. The development of prosthetic materials ushered in the current era of hernia surgery, allowing a tension-free repair to be performed even for the largest defects and the most difficult procedures. Tension-free mesh-based repairs (eg, Lichtenstein, plug and patch) began to increase in number in the late 1980s. More recently, with the advent of laparoscopy for general surgery, various laparoscopic techniques have been developed for inguinal hernia repair, including the transabdominal preperitoneal repair, the intraperitoneal onlay mesh repair, and the totally extraperitoneal repair. CONCLUSIONS: Today, open and laparoscopic mesh-based techniques dominate the inguinal hernia repair marketplace. The Lichtenstein tension-free mesh onlay repair is the most frequently performed inguinal hernia operation, with a recurrence rate of less than 1%. Although the use of laparoscopic techniques for bilateral or recurrent hernias is now accepted, the application of laparoscopy to unilateral primary inguinal hernias remains controversial. Ongoing studies will address the questions of long-term recurrence and cost-effectiveness of laparoscopic hernia repair.

Hernia, Inguinal↗
PubMed2003

Short-chain fatty acids stimulate colonic transit via intraluminal 5-HT release in rats.

We studied whether physiological concentration of short-chain fatty acids (SCFAs) affects colonic transit and colonic motility in conscious rats. Intraluminal administration of SCFAs (100-200 mM) into the proximal colon significantly accelerated colonic transit. The stimulatory effect of SCFAs on colonic transit was abolished by perivagal capsaicin treatment, atropine, hexamethonium, and vagotomy, but not by guanethidine. The stimulatory effect of SCFAs on colonic transit was also abolished by intraluminal pretreatment with lidocaine and a 5-hydroxytryptamine (HT)(3) receptor antagonist. Intraluminal administration of SCFAs provoked contractions at the proximal colon, which migrated to the mid- and distal colon. SCFAs caused a significant increase in the luminal concentration of 5-HT of the vascularly isolated and luminally perfused rat colon ex vivo. It is suggested that the release of 5-HT from enterochromaffin cells in response to SCFAs stimulates 5-HT(3) receptors located on the vagal sensory fibers. The sensory information is transferred to the vagal efferent and stimulates the release of acetylcholine from the colonic myenteric plexus, resulting in muscle contraction.

Animals↗
PubMed2003

Dual effects of acupuncture on gastric motility in conscious rats.

The effects of manual acupuncture on gastric motility were investigated in 35 conscious rats implanted with a strain gauge transducer. Twenty (57.1%) rats showed no cyclic groupings of strong contractions (type A), whereas 15 (42.9%) rats showed the phase III-like contractions of the migrating motor complex (type B) in the fasting gastric motility. Acupuncture at the stomach (ST)-36 (Zusanli), but not on the back [Weishu, bladder (BL)-21], increased the peak amplitude of contractions to 172.4 +/- 25.6% of basal in the type A rats (n = 20, P < 0.05). On the other hand, the motility index for 60 min after the acupuncture was not affected by the acupuncture in this group. On the contrary, acupuncture decreased the peak amplitude and motility index to 72.9 +/- 14.0% and 73.6 +/- 16.2% in the type B rats (n = 15, P < 0.05), respectively. The stimulatory and inhibitory effects of acupuncture observed in each type were reproducible on the separate days. In 70% of type A rats, acupuncture induced strong phase III-like contractions lasting for over 3 h that were abolished by atropine, hexamethonium, atropine methyl bromide, and vagotomy. Naloxone significantly shortened the duration of the stimulatory effects from 3.52 +/- 0.21 to 1.02 +/- 0.15 h (n = 3, P < 0.05). These results suggest that acupuncture at ST-36 induces dual effects, either stimulatory or inhibitory, on gastric motility. The stimulatory effects are mediated in part via vagal efferent and opioid pathways.

Acupuncture↗
PubMed2002

Inhibitory effects of hyperglycemia on neural activity of the vagus in rats.

OBJECTIVES: Although it has been demonstrated that hyperglycemia inhibits gastrointestinal (GI) motility, its inhibitory mechanism remains unclear. DESIGN: Electrophysiological study. SETTINGS: As GI motility is under the influence of the vagus, we studied the effects of hyperglycemia on neural activity of the dorsal motor nucleus of vagi (DMV) in anesthetized rats. MEASUREMENTS AND RESULTS: A tungsten electrode was placed in the left side of the DMV area and extracellular electrical signals from the electrode were recorded. Single unit nerve activity was identified by the discriminator. D-glucose infusion elevated the peripheral blood glucose concentration from 3.4-5.9 mm to 12.0-21.8 mm and the neural firing of the DMV was significantly reduced by D-glucose infusion. After the 30 min D-glucose infusion, saline was re-infused for 90 min. Blood glucose level returned to 6.5-7.8 m m and the neural firing partially recovered 90 min after the saline re-infusion. There was a significant negative correlation observed between the counts of neural spikes and blood glucose concentrations ( r=0.84, p<0.01). CONCLUSION: It is suggested that hyperglycemia impairs GI motility by inhibiting vagal efferent activity. A recent study in intensive care unit (ICU) patients demonstrated that uncontrolled hyperglycemia is associated with poor outcomes. We propose that glycemia control is crucial in ICU patients to maintain the GI motility and vagus nerve activity.

Acute Disease↗
PubMed2002

Clinical utility of positron emission tomography in the diagnosis and management of periampullary neoplasms.

BACKGROUND: This study examined the effect that 18-fluorodeoxyglucose positron emission tomography ((18)FDG-PET) imaging had on the clinical management of patients with suspected periampullary malignancy. METHODS: Fifty-four patients with suspected pancreatic neoplasms underwent both whole-body (18)FDG-PET and abdominal computed tomography (CT). Malignant or benign disease was confirmed pathologically in 47 patients. RESULTS: Of the 41 patients with malignancy, (18)FDG-PET failed to identify the primary tumor in 5 patients. (18)FDG-PET demonstrated increased uptake suggesting primary malignancy in 37 patients. Malignant pathology was confirmed in 36 cases. (18)FDG-PET identified malignant locoregional lymph node metastases in six of ten patients. All nodes identified before surgery by (18)FDG-PET were also seen on preoperative CT. Six patients who were thought to have resectable disease by CT were found to have distant metastasis at laparotomy. (18)FDG-PET did not detect metastasis in any of these cases. Before surgery, (18)FDG-PET identified distant metastases that were not detected by CT in one patient. CONCLUSIONS: Despite high sensitivity and specificity in diagnosing periampullary malignancy, (18)FDG-PET did not change clinical management in the vast majority of patients previously evaluated by CT. In addition, (18)FDG-PET missed >10% of periampullary malignancies and did not provide the anatomical detail necessary to define unresectabilty.

Adenocarcinoma↗
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

Extensive investigation of patients with mild elevations of serum amylase and/or lipase is 'low yield'.

BACKGROUND: Serum amylase and lipase levels are widely used as markers of pancreatic inflammation. However, it would seem that mild elevations of amylase and lipase rarely predict significant pancreatic pathology. Pancreatic imaging tests are expensive. The gold standard, endoscopic retrograde cholangiopancreatography, carries risk of morbidity and mortality. OBJECTIVE: To determine whether extensive investigation of patients with mild, nonspecific abdominal symptoms and mild elevations of amylase and/or lipase results in a significant diagnostic yield. METHODS: Outpatient evaluations were retrospectively analyzed over 12 months. Inclusion criteria were nonspecific abdominal pain, and mild elevations (less than three times the upper limit of normal) of serum amylase or lipase, or both. Exclusion criteria included a history of chronic pancreatitis, elevation of liver tests and acute pain syndromes. RESULTS: Nineteen patients over the study period met the criteria. Of the nineteen patients, 58% had elevation of lipase alone, 21% amylase alone and 21% had elevations of both. In addition, 89.5% of the patients had nonspecific abdominal pain. After imaging with one or more of ultrasound, computed tomography, magnetic resonance cholangiopancreatography, endoscopic ultrasound and endoscopic retrograde cholangiopancreatography, small bowel follow through or hepatobiliary scanning, 78.9% patients were thought to have a normal pancreas. Of the remaining patients, 15.8% had mild or equivocal changes of chronic pancreatitis, and one patient was found to have a pancreatic tail pseudocyst. The average cost of investigation was US$2,255, taking only direct procedural costs into account. No patient was found to have malignancy. CONCLUSIONS: The majority of patients with nonspecific abdominal pain and isolated elevations of amylase and/or lipase (less than three times the upper limit of normal) had no identifiable pancreatic pathology. The diagnostic yield in patients with mild elevations of lipase alone was particularly poor. The cost effectiveness and risk-benefit ratio of extensive investigation of this group of patients warrants further study.

Abdominal Pain↗
PubMed2002

Simple pancreatic cysts: CT and endosonographic appearances.

OBJECTIVE. This report describes the CT and endoscopic sonographic appearance of simple pancreatic cysts in three adults. CONCLUSION. Simple pancreatic cysts are typically an incidental finding in adults who have no history of pancreatic disease. The imaging characteristics of simple pancreatic cysts on CT and endosonography are similar to those of benign cysts.

Adult↗
PubMedDate not supplied

Pancreas-preserving duodenectomy in the management of duodenal familial adenomatous polyposis.

Most patients with familial adenomatous polyposis (FAP) develop disease in the duodenum. The duodenal lesions mostly occur in the periampullary region, but some patients develop diffuse polyposis involving all parts of the duodenum. These neoplastic polyps have malignant potential, and thus warrant surveillance and timely intervention. We reviewed our experience with management of FAP over a 10-year period, focusing on patients who had diffuse polyposis of the duodenum and their subsequent management. Three patients with FAP had diffuse duodenal involvement, documented by upper gastrointestinal endoscopy. Neoplasia was confirmed by endoscopic biopsy, but no patients had histologic evidence of carcinoma. The patients underwent resection of the entire duodenum from the pylorus to the ligament of Treitz with preservation of the pancreas. Our surgical technique is described. One patient had a postoperative wound infection and one patient had a biliary leak that resolved with closed suction drainage for 5 days. Long-term follow-up in these patients revealed excellent functional status. One patient had polyp recurrence in the jejunum at 5-year follow-up, but no patients have developed adenocarcinoma. We conclude that patients with duodenal polyps associated with FAP may be safely and effectively treated by pancreas-preserving duodenectomy.

Adenomatous Polyposis Coli↗