Characterization of alpha-adrenoceptor activity in the preterm piglet mesentery

To characterize neonatal mesenteric alpha-adrenoceptor populations, an extracorporeal perfusion circuit was established to control intestinal blood flow in prematurely delivered (by cesarean section at 90% of gestational age) piglets. Activation of alpha 1-adrenoceptors was documented by observing dose-dependent increases in mesenteric perfusion pressure after intramesenteric arterial injection of methoxamine; alpha 2-adrenoceptor activity was confirmed by finding similar increases in mesenteric perfusion pressure after intramesenteric arterial injections of BHT 933. Peripheral intravenous injections of WB 4101 (a competitive alpha 1A-adrenoceptor antagonist), but not clorethylclonidine (CEC, an alpha 1B-adrenoceptor antagonist), significantly blunted (P < .05, ANOVA) the mesenteric vasoconstrictor responses to methoxamine. The mesenteric vasoconstrictor response to BHT 933 (an alpha 2-adrenoceptor agonist) also was blunted by WB 4101, but not by CEC. These data suggest that alpha 1A- and alpha 2-adrenoceptors can be activated in the small intestinal mesentery of piglets well before they reach full-term maturation, although receptor specificity has not been fully established.

Characterization of alpha-adrenoceptor activity in term-newborn piglet mesentery

For further characterization of neonatal mesenteric alpha 1-adrenoceptor populations, an extracorporeal perfusion circuit was established to control intestinal blood flow in 0-2 day old piglets. Activation of alpha 1-adrenoceptors was first documented by observing dose-dependent increases in mesenteric perfusion pressure after intra-mesenteric arterial injection of methoxamine and noradrenaline. Peripheral intravenous injections of WB 4101 (a competitive alpha 1A-adrenoceptor antagonist), but not clorethylclonidine (CEC, an alpha 1B-adrenoceptor antagonist), significantly (P < 0.05, analysis of variance) blunted mesenteric vasoconstrictor responses to those agonists. That the mesenteric vasoconstrictor response to mesenteric plexus stimulation was unaltered by CEC, but was muted by both WB 4101 and SK&F 104856 (a post-junctional alpha 1- and alpha 2-adrenoceptor antagonist) suggests that pre- and post-junctional alpha 1A-adrenoceptors are present and functional at birth.

Small bowel necrosis in association with jejunostomy tube feedings

Nutritional support is thought to be an important adjunct for minimizing perioperative morbidity. For a variety of reasons, it is now felt that nutrition delivered by the enteral route is preferred over that given parenterally. Although delivery of nutrients into the small intestine, either via a nasoduodenal tube or a surgically placed jejunostomy, is effectively tolerated by most patients, morbid complications are being described with increased frequency. Herein, we describe two patients who underwent major intra-abdominal surgery, one for a malignancy, the other for trauma management. Immediate postoperative feedings were instituted through a surgically placed jejunostomy tube. Several days later, each patient underwent emergency reoperation for clinical findings of an intra-abdominal catastrophe. In both patients, small intestinal infarction in juxtaposition to the site of the tube feedings was found. This experience suggests that the enteral feedings were causally related to this morbid complication, which proved fatal in one patient.

Iatrogenic esophageal pseudodiverticulum: a case report

Iatrogenic injury of the esophagus is not an uncommon complication of diagnostic endoscopy and dilation. Herein is described what is felt to be the first reported case of a traumatic pseudodiverticulum after dilation of an esophageal stricture. The management of what was preoperatively felt to be an esophageal perforation is discussed.

Effects of anti-inflammatory agents on hydrochloric acid-induced pulmonary injury

To determine the effects of anti-inflammatory agents on hydrochloric acid lung injury, the heart and lungs were harvested from rats, placed in a lung chamber, constant flow perfused with whole blood, and ventilated. The following experiments were conducted: observation alone; intratracheal injection of normal saline; intratracheal hydrochloric acid; and intravenous meclofenamate or indomethacin before intratracheal hydrochloric acid. Wet-to-dry lung weights were measured. Peak airway pressures increased immediately (p < .001 vs. baseline; ANOVA) in all intratracheal groups, hydrochloric acid producing even greater (p < .05) increases than saline-effects unaltered by meclofenamate or indomethacin. The increased (p < .001 vs. baseline) 2-h pulmonary artery pressures in hydrochloric acid-treated groups were unaltered by meclofenamate or indomethacin. All hydrochloric acid-treated groups demonstrated increases (p < .05) in weight that were unchanged by meclofenamate or indomethacin. These data suggest that the beneficial effects of these medications described elsewhere, using a variety of in vivo lung injury experimental models, may be attributed to their experimental design, or to contributions from organs/systems outside the pulmonary circuit.

Effect of maturation on alpha-adrenoceptor activity in newborn piglet mesentery

To characterize the mesenteric alpha1- and alpha2-adrenoceptor populations in newborn piglets, an extracorporeal circuit was established to control intestinal blood flow in 0- to 2-day old and 10- to 14-day old animals. In both groups, alpha-adrenoceptor activation was first documented by observing dose-dependent increases in mesenteric perfusion pressure after intramesenteric arterial injection of alpha-adrenoceptor agonists. In the 10- to 14-day old piglets, mesenteric vasoconstrictor responses to alpha1-adrenoceptor agonists (methoxamine and norepinephrine) and an alpha2-adrenoceptor agonist (BHT-933) were each blunted (P < 0.05, analysis of variance) by peripheral intravenous injections of prazosin (an alpha1-adrenoceptor antagonist) and yohimbine (an alpha2-adrenoceptor antagonist), respectively. The mesenteric vasoconstrictor responses to those agonists were not significantly attenuated by prazosin or yohimbine in 0- to 2-day old animals, nor were they blunted by YM-12617 (alpha1-adrenoceptor antagonist) or idazoxan (alpha2-adrenoceptor antagonist)--compounds that are structurally unrelated to prazosin and yohimbine, respectively. In addition, mesenteric vasoconstrictor responses to other known vasoconstrictor agents--angiotensin II, neuropeptide Y, and a thromboxane A2 mimic (U-46619)--were not effected in either age group by prazosin or yohimbine, implying these agents act independently of alpha-adrenoceptor mechanisms. These data suggest that (1) there exists functional mesenteric alpha1- and alpha2-adrenoceptor-like activity in 10- to 14-day old piglets that, in 0- to 2-day old animals, is not specifically expressed; and (2) mesenteric alpha-adrenoceptor function becomes more selective as newborn piglets mature.

Burn edema reduction by methysergide is not due to control of regional vasodilation

To determine the extent to which edema modulation by methysergide is due to a blunting of the regional vasodilator response to scald and/or local reduction of transvascular fluid flux, a canine hind limb lymphatic was cannulated. Femoral blood flow (Qa; ml/min), lymph flow (QL; microliter/min/100 g), and lymph-to-plasma protein ratios (CL/CP) were monitored in groups of five dogs before and 4 hr after 5-sec, 100 degrees C foot paw scald; high (1.0 mg/kg) or low (.5 mg/kg) dose of methysergide 30 min before scald. The compression on a clamp placed around the femoral artery in other dogs was adjusted after scald to simulate the blunting effect on Qa observed in methysergide treated dogs. Hind leg venous pressure was elevated to approximately = 40 mm Hg before experimentation until steady state QL and (CL/CP)min were reached. Protein reflection coefficient (sigma d; 1-C1/ CP) and fluid filtration coefficient (Kf) were calculated. Compared to preburn values, all groups showed significant (P < 0.002, analysis of variance) increases in CL/CP and Kf. Contrasted with the burn only group, methysergide blunted increases in Qa, Kf and paw weight gain in a dose-dependent fashion, with no effect on the reflection coefficient. Compression clamp control of femoral Qa caused no effects on permeability. Methysergide limits burn edema in a dose-related fashion, though not due to a blunting of the regional vasodilator response. Local, not regional, mechanism(s) likely mediate this response.

Evaluation of a novel synthetic material for closure of large abdominal wall defects

BACKGROUND

This study was undertaken to compare the efficacy of a novel synthetic material (TMS-1) with polytetrafluoroethylene, polypropylene, and primary closure of experimentally fashioned clean and contaminated abdominal wounds.

METHODS

One square centimeter full-thickness abdominal wall defects were created in each of the four abdominal quadrants of anesthetized rats (n = 6). Patches of polytetrafluoroethylene, polypropylene, and a polyurethane-polypropylene composite material (TMS-1) were used to repair three of these defects; the fourth was primarily closed. A second group of rats (n = 9) underwent the same operative protocol; however, peritonitis was induced at the time of operation by using the fecal inoculation technique. Animals were killed 2 to 3 weeks later, and surface area and severity of formed adhesions were assessed.

RESULTS

By all methods of assessment, primary closure proved significantly superior to all other methods of closure in clean and contaminated conditions. The three synthetic materials were equally matched for surface area involved in adhesion formation. When compared with the other synthetic materials, TMS-1 was associated with significantly milder adhesions in uninfected (p < 0.002) and in infected (p < 0.002) conditions.

CONCLUSIONS

The clear superiority of TMS-1 over other nonabsorbable synthetic materials shown in this pilot study warrants further investigation relative to its use to close large abdominal wall defects.

Polypropylene mesh closure of the complicated abdominal wound

BACKGROUND

Closure of the abdominal wall in the face of fascial necrosis or massive intestinal edema remains a difficult problem with frequent complications. Prior studies have addressed both the utility and the pitfalls of placing polypropylene mesh in this setting.

METHODS

We performed a retrospective evaluation of our experience with polypropylene mesh in traumatic and nontraumatic difficult abdominal closures. Timing of mesh placement and removal relative to the initial operation were recorded, as were abdominal complications, number of operative procedures, and type of ultimate abdominal closure.

RESULTS

Between 1988 and 1993, polypropylene mesh was placed in 26 critically ill or injured patients requiring celiotomy, of whom 23 survived more than 3 weeks. Ultimate wound management was delayed mesh removal and primary closure (17%), myocutaneous flap coverage over mesh (4%), split-thickness skin grafting to the granulating wound (35%), or closure by secondary intention over mesh (43%). Split-thickness skin grafting and closure by secondary intention resulted in enterocutaneous fistulas in 50% and 40% of cases, respectively. Full-thickness closure with or without mesh removal resulted in no fistulas.

CONCLUSION

Mesh provided adequate fascial closure, even with gross wound contamination. Coverage of polypropylene mesh by secondary intention or split-thickness skin grafting resulted in unacceptably high rates of fistulous complications, and this procedure should be replaced by either mesh removal or full-thickness coverage.

Serotonin receptors regulate canine regional vasodilator responses to burn

OBJECTIVE

To determine which serotoninergic receptor subtype(s) mediates the regional vasodilator response to scald injury.

DESIGN

Prospective, randomized trial.

SETTING

Microcirculation research laboratory.

SUBJECTS

Anesthetized dogs.

INTERVENTIONS

Mechanically ventilated dogs underwent cannulation of a brachial artery and placement of an ultrasonic flow probe around one femoral artery. All animals received a 2% to 3% body surface area partial thickness scald injury by immersing the paw ipsilateral to the instrumented femoral artery into 100 degrees C water for 5 secs. In one group of dogs, BMY 7378 (a serotoninergic1A receptor antagonist) was given by the peripheral intravenous route before burn. These results were compared with those findings obtained from a group of animals that received a burn only, and groups of animals given a peripheral intravenous injection of methysergide (a serotoninergic receptor antagonist) or ritanserin (a serotoninergic2 receptor blocking agent) before burn. Experiments were conducted for two postburn hours.

MEASUREMENTS AND MAIN RESULTS

Burn injury caused a marked and persistent increase in regional (e.g., femoral artery) blood flow, an effect that was significantly blunted by preburn administration of the serotoninergic receptor antagonist, methysergide. Preburn administration of BMY 7378 increased baseline femoral blood flow by 13%, reflecting its known serotonin agonist properties. However, when compared with the mean postscald increases in femoral blood flow over baseline seen in scald only dogs and in animals given the serotoninergic2 receptor blocking agent, ritanserin (before scald), the BMY 7378-treated group demonstrated a significant (p < .001 by analysis of variance) 2-hr-postscald blunting of this femoral vasodilator response.

CONCLUSION

These data suggest that serotoninergic1A-like receptors play an integral, albeit not an exclusive, role in blood flow regulation to the site of burn injury.

Prospective assessment of the value of computed tomography for trauma

The use of computed tomography (CT) has helped revolutionize the process and accuracy of diagnosis of the trauma patient. We have noted a striking increase in the use of CT scanning early in the management of trauma patients at our trauma center and sought to assess our experience.

METHODS

All trauma patients admitted to our trauma center from February 1991 to February 1992 who received any CT scan within the first 12 hours after arrival were enrolled in the study. A positive (+) CT scan was defined as a scan that demonstrated a significant finding consistent with the injury and a negative (-) CT scan was one in which there were either no abnormalities or only incidental findings unrelated to the injury. Each patient was followed daily by one of the authors (A.G.R.). Patient records were reviewed and treating surgeons were interviewed to determine whether the CT scan improved the process of therapy. Morbidity incident to the performance of the CT scans was assessed.

RESULTS

1609 trauma patients underwent 2047 CT scans (1.3 CT scans per patient). Sixteen percent (n = 260) had scans of more than one part of the body. Thirty-eight percent (n = 770) of scans were positive but 29% (n = 225) of these were not helpful to the patient care process. Overall, 29% of scans, either because they were positive or negative, assisted in the clinical care of the patient. Six percent (n = 45) of CT scans were falsely positive. Sixty-five percent of scans were true negatives. Two patients died in the CT suite, 6 died shortly after completion of the scan, and 12 required emergency trips to the operating room from the CT suite.

CONCLUSIONS

A large number of CT scans are being performed in our trauma patient population. Less than 30% contributed to patient management. Because of morbidity and cost, strict surgeon and radiologist oversight of CT for trauma is essential.

Effects of methysergide administration on edema formation at the site of scald

Femoral blood flow (Qa), hind paw lymph flow (Qlym), and lymph-to-plasma protein concentration ratio (Clym/Cp) were monitored before and 4 h after 1) 5-s 100 degrees C paw scald, 2) methysergide (1 mg/kg iv) 20 min before scald, 3) methysergide 30 min after scald, and 4) methysergide only. Before experimentation, hind paw venous pressure was elevated and maintained until steady-state Qa, Qlym, and minimal Clym/Cp levels were reached. The reflection coefficient (sigma d) was determined as 1 - minimal Clym/Cp; the filtration coefficient (Kf) was calculated. Methysergide alone caused no changes. Increases in Qa, Qlym, Clym/Cp, and Kf were identified in all scald groups. Compared with scald only animals, pre- and postscald methysergide blunted the increases in Qa, Qlym, Kf, and paw weight gain without an effect on sigma d. These data demonstrate that methysergide reduces edema formation at the site of scald, perhaps by modulating the burn-induced vasodilator response and/or by limiting the burn-induced increase in microvascular surface area.

Laparoscopic cholecystectomy: what's so special?

One hundred seventy-one laparoscopic cholecystectomies were done by senior surgery residents who received only traditional "hands-on" training. Eight patients (5%) required conversion to open cholecystectomy, and two had complications requiring immediate celiotomy (one common bile duct injury, one "dropped" gallbladder). The average operative time was 91 minutes (range, 30 to 245 minutes). There were no deaths and only five postoperative complications related to the procedure (retained common bile duct stone in four cases, intra-abdominal hemorrhage in one). There were three complications unrelated to the procedure. Data acquired from recent resident training program graduates show that these practicing surgeons are doing laparoscopic cholecystectomy with a 95% success rate and have yet to encounter appreciable complications. We concluded that a large-volume general surgery resident training program provides adequate opportunity for training surgeons in the techniques of laparoscopic cholecystectomy; there is no need to attend an expensive and time-consuming classroom and animal laboratory course.

Preventive antibiotic usage in traumatic thoracic injuries requiring closed tube thoracostomy

OBJECTIVE

To evaluate the safety and effectiveness of antibiotics in reducing the infectious complications following closed tube thoracostomy for isolated chest trauma.

DESIGN

Double-blind, randomized clinical trial.

SETTING

Medical school affiliated large urban teaching hospital and trauma center.

PATIENTS

One hundred nineteen of 159 patients over 18 years old presenting to the emergency department requiring closed tube thoracostomy for isolated chest injuries (113 penetrating, 6 blunt).

INTERVENTION

Patients received either placebo or 1 g cefonicid daily intravenously started at chest tube insertion and stopped within 24 h of removal.

MEASUREMENTS AND RESULTS

The development of wound infections, pneumonia (CDC criteria), or empyema; the incidence of adverse events; length of hospitalization. One nonspecific infection was seen in the cefonicid group (1.6 percent) and six respiratory tract infections (10.7 percent) in the placebo group (three empyema, one empyema with pneumonia, two pneumonia) (p = 0.0505; p = 0.0094 [excluding nonspecific infection]). No significant differences with antibiotic use were seen in the duration of chest tube use (p = 0.766), peak WBC counts (p = 0.108), lower peak temperatures (p = 0.063), or length of hospitalization (p = 0.165). Patients who developed infectious complications averaged approximately 8 days longer hospitalization than those without (p < 0.0001).

CONCLUSION

This study showed that patients receiving antibiotics had a significantly reduced rate of infection than did patients administered placebo. No significant adverse events were seen in either group.

Effects of graded thermal injury on microvascular permeability at the site of injury

To define whether capillary permeability traits at the site of a burn differ according to injury severity, a canine hind leg lymphatic was cannulated to measure macromolecular permeability in response to three different scalding solutions. Leg venous pressure was raised to approximately 40 mm Hg and maintained until a minimal lymph-to-plasma total protein ratio (CL/CP)min and steady-state lymph flow (QL; microliter/min/100 g) was attained. The protein reflection coefficient (1-CL/CP), fluid filtration coefficient (Kf; microliter/min/mm Hg/100 g), and QL were determined before and for 6 hr after a 5-sec hind paw immersion in either 100 degrees C (n = 7), 80 degrees C (n = 7), or 70 degrees C (n = 7) water. A group of five animals served as controls. In the absence of any systemic hemodynamic alterations, the 100 and 80 degrees C scald groups experienced significant (P < 0.05, ANOVA) increases in QL, CL/CP, and Kf as compared to respective preburn values and time-matched unburned control values. Most monitored parameters were significantly higher following 100 degrees C injury vs 80 degrees C injury. Parameters in the 70 degrees C group did change after scald, but were not significantly different from preburn values or from the control group. Alterations in capillary permeability to protein and fluid flux measured at the burn site are graded, not all or none phenomena, being dependent upon the severity of injury.

Utility of the biofragmentable anastomotic ring in traumatic small bowel injury

OBJECTIVE

To evaluate the use of the 25 mm Biofragmentable Anastomotic Ring (BAR) in traumatic small bowel injury.

METHODS

In a one year prospective, nonrandomized study, 18 patients (x age = 25 yrs) with penetrating small bowel injury had 25 BAR devices placed to restore intestinal continuity. Using one-way analysis of variance, this group was compared to 63 historical controls (x age = 27 yrs) with small bowel trauma who had either sutured or stapled anastomoses (SSA), with regard to Penetrating Abdominal Trauma Index (PATI) score, time until return of bowel function, and postoperative morbidity.

RESULTS

PATI scores for the two groups were not significantly different (P = 0.099). No deaths in the SSA group (n = 8) or in the BAR group (n = 1) were related to the anastomotic technique. There was no significant difference (P = 0.991) in the rate of post-operative intestinal obstruction between BAR (n = 3) and SSA (n = 8) groups; none of the BAR patients required re-operation. The average length of time for return of bowel function was not significantly different (P = 0.197) between BAR (4.3 days) and SSA (5.8 days) groups.

CONCLUSIONS

The 25 mm BAR may be used in the repair of traumatic small bowel injury, based upon comparable outcomes when compared with sutured and stapled anastomoses.

Effects of pentafraction administration on microvascular permeability alterations induced by graded thermal injury

BACKGROUND

Pentafraction is a pentastarch derivative hypothesized to limit burn edema by "sealing" damaged capillaries, restoring a barrier to fluid translocation and macromolecular (protein) flux.

METHODS

Canine hind paw lymph flow (QL) and lymph (CL) and plasma (CP) protein concentrations were measured before and for 6 hours after (1) 5-second 100 degrees C (n = 6) or 80 degrees C (n = 6) foot paw scald, (2) 100 degrees C (n = 5) or 80 degrees C (n = 5) foot paw scald followed 30 minutes later by a 4 cc/kg bolus of 6% pentafraction, or (3) pentafraction infusion without scald (n = 5). Before scald or pentafraction infusion, hind paw venous pressure was elevated and maintained by outflow restriction until a steady state, minimal CL/CP was reached. The reflection coefficient, sigma d, was determined as 1-CL/CP, and the (fluid) filtration coefficient (Kf) was calculated.

RESULTS

Scalding uniformly produced statistical (p < 0.05, ANOVA) increases in QL, CL/CP, sigma d, Kf, and paw weight gain. Postburn pentafraction infusion produced no enduring alterations in any measured parameter as compared with those of animals who received a matched severity scald without pentafraction.

CONCLUSIONS

Pentafraction does not appreciably ameliorate the adverse microcirculatory consequences observed at the site of burn injury.

Analysis of regional hemodynamic regulation in response to scald injury

Ultrasonic probes were placed around dog femoral arteries to record blood flow. Hind paw scalding with boiling water (5 s) caused a marked increase in ipsilateral femoral blood flow that persisted for the 2-h observation period. Contralateral femoral blood flow and systemic and pulmonary vascular resistances were unchanged. Compared to scald only animals, methysergide pretreatment diminished and shortened the femoral vasodilator response to scald (109 +/- 14 vs 243 +/- 27 ml/min at 5 min; 59 +/- 14 vs 191 +/- 31 ml/min at 2 h). Pretreatment with ritanserin, BW A1433U83, atropine, ICI 118551, diphenhydramine, ranitidine, meclofenamate, L-nitro-arginine methyl ester, 3-amino-1,2,4-triazine, and U 37883A had no effect on the increased femoral blood flow response to scald, suggesting this vasodilator response is not dependent upon activation of serotonergic2, adenosineA1, muscarinic, beta 2-adrenergic, histaminergic1 or histaminergic2 receptors, on cyclooxygenase products, endothelium-derived relaxing factor derived from nitric oxide (NO) synthase III, NO derived from NO synthase II, or KATP channels, respectively. Methysergide given after burn immediately reduced the augmented femoral blood flow to preburn levels, suggesting the vasodilator response to scald is mediated through continual activation of local serotonergic1-like receptors, which may be target site(s) for therapeutic interventions to influence burn-induced hemodynamic alterations.

A convincing case for primary repair of penetrating colon injuries

Over the past 14 years, 146 patients with penetrating colon trauma were managed by primary repair with/without resection (PR, n = 55), and by diverting colostomy (DC, n = 91). These groups did not differ in terms of age, ISS (Injury Severity Scale), PATI (Penetrating Abdominal Trauma Index), a-AIS (abdominal Abbreviated Injury Scale), or preoperative hypotension. No intergroup differences were manifested in intra-abdominal complications (fistula/leak, abscess, pancreatitis, intestinal obstruction, wound dehiscence). The percentage of patients who experienced at least one major intra-abdominal complication did not differ statistically when the two groups were compared--12.7% in PR versus 11% in DC--although risk in both groups increased with the additional number of organs injured. Wound infection was significantly higher (p < 0.05) in the PR group (19.6%) compared with the DC group (9.4%). Mortality in the PR and DC groups was 0% and 3.6%, respectively. One hundred and ten patients who underwent elective colostomy closure following trauma had a 9.1% intra-abdominal complication rate and a 3.6% wound infection rate. These risks should be considered when colostomy is selected to manage patients with penetrating colon injury. These data support primary repair of all colon injuries, reserving skin closure for patients with limited collateral damage.

Impact of mandatory nonoperative training on surgical critical care

Since the development of surgical critical care (SCC) as a discrete body of knowledge and its recognition by the American Board of Surgery (ABS), it has been beset by several controversies. One controversy is that the Residency Review Committee (RRC) for Surgery mandated that approved SCC training be 1 year long with no operative experience. A survey was conducted to determine the opinions and experiences on this controversy and others of 498 surgeons who regularly practice SCC. Seventy percent (349) responded and 100% of these held a Certificate of Added Qualifications in SCC. Only 35% of the respondents had completed a critical care fellowship and 61% were either the director or associate director of an ICU. An overwhelming majority (> 90%) believed that SCC should be considered one of the essentials in training surgeons and that the ABS should continue to offer a Certificate of Added Qualifications. Two thirds disagreed with the RRC's ban on operative experience during SCC fellowships and 71% believed that this prohibition limited the pool of surgical applicants to SCC programs. There were no significant differences in the responses between any of the major subgroups. Interestingly, 50% of the respondents who had completed RRC-approved SCC fellowships stated that their fellowship included operative experience.(ABSTRACT TRUNCATED AT 250 WORDS)

Irrigation of the abdominal cavity in the treatment of experimentally induced microbial peritonitis: efficacy of ozonated saline

Ozone is an oxidizing agent possessing potent in vitro microbicidal capacity. This study was designed to address the extent to which irrigation of the contaminated abdominal cavity using a saline solution primed with ozone is effective in reducing morbidity and mortality. Gelatin capsules containing different quantities of a premixed slurry of filtered human fecal material were implanted in the peritoneal cavities of a preliminary series of rats. Three inocula concentrations were selected for later experiments, based upon their ability to produce morbid consequences: (1) high (100% 1-day mortality), (2) medium (70% 3-day mortality, 100% abscess rate in survivors), and (3) low (100% 10-day survival, 100% abscess rate). Fecal and abscess bacteriology were similar in all rats. The peritoneal cavities of 240 rats then underwent fecal-capsule implantation (three groups of 80 rats/inoculum concentration). At celiotomy 4 hours later, equal numbers of rats from each group were randomly assigned to one of four protocols: (1) no irrigation, (2) normal saline irrigation, (3) saline-cephalothin irrigation, and (4) ozonated saline irrigation. Each treatment lasted 5 minutes, using 100 ml of irrigation fluid. Mortality was significantly reduced when, in lieu of no irrigation, any of the irrigation solutions were used. Additionally, ozonated saline statistically proved the most effective irrigating solution for reducing abscess formation in survivors.

The role of endoscopic retrograde cholangiopancreatography: sphincterotomy versus common bile duct exploration as a primary technique in the management of choledocholithiasis

253 patients underwent diagnostic or therapeutic intervention for a presumed diagnosis of choledocholithiasis. In 104 (mean age, 60 years) the diagnosis was confirmed by endoscopic retrograde cholangiopancreatography (ERCP) or common bile duct exploration (CBDE). Of this group, 70 patients first underwent a total of 102 attempts at endoscopic sphincterotomy (ERCP-S). Success (clearing the common duct of stones) was achieved in 43 patients (61%), though an average of 1.5 ERCP-S/patient was required (maximum of four per patient). Of the 27 in whom ERCP-S failed, 20 went on to CBDE, which was successful in 18. Significant morbidity occurred in 12 (17%) ERCP-S patients, including hemorrhage. There were no deaths. Of the 34 patients who first underwent CBDE, 30 were cleared of common duct stones (88%). ERCP-S was subsequently employed to retrieve retained stones in three patients. Significant morbidity was documented in three (9%). No patients required perioperative blood transfusion. There were no deaths. While there is, as expected, a lower initial success rate with ERCP-S than with CBDE, the fact that ERCP-S is a less invasive procedure than is CBDE justifies its preferential utilization. However, patients must be informed that successful ERCP-S may require multiple visits to the endoscopy suite. Furthermore, the morbid consequences of ERCP-S, particularly hemorrhage, cannot be understated.

Prospective alterations in therapy for penetrating abdominal trauma

In a double-blind, randomized study, 170 patients with traumatic perforation of the gastrointestinal tract were administered an advanced-generation cephalosporin. Patients were divided into infection risk groups (< or = 40%, low; 40% to 70%, mid; and > 70%, high) at surgical closure using a logistic regression formula based on four proved risk factors--age, blood replacement, ostomy, and the number of organs injured. Patients in the low group received 2 days of antibiotic therapy; those in the mid to high group received 5 days of antibiotic therapy. Those patients in the low to mid group had primary wound closure; those in the high group had their wounds packed open and closed later. Most of the patients (144 [85%]) were in the low group. Their major and minor infection rates (10% and 12%, respectively) were not significantly different from 145 historic control subjects receiving 5 days of antibiotic therapy (9% major; 14% minor). Patients in the mid to high group showed a greater incidence of major infections (46%) but a similar incidence of minor infections (12%). The results indicate that risk factors can be used to identify low-risk patients who require only short-term antibiotic therapy and primary wound closure. The remaining patients are at greater risk for infection despite prolonged antibiotic therapy and delayed wound closure.