"Needlescopic" sigmoid resection.

Minimally invasive surgical techniques and procedures continue to evolve with the trend toward fewer and smaller instruments. To our knowledge, this is the first reported case of sigmoid colon resection utilizing needlescopic technology. The patient was a 53-year-old woman diagnosed with a malignant lesion in the midsigmoid colon at 30 cm. A subsequent needlescopic sigmoid colon resection was performed and the patient was discharged home after an uneventful postoperative course. This case demonstrates that colon procedures that require major reconstruction may be performed needlescopically in selected patients.

Predicting infection in localized intraabdominal fluid collections: value of pH and pO2 measurements.

PURPOSE: To evaluate the use of pH, pO2, and the subjective opinion of the radiologist compared with bacterial culture in accurate diagnoses of bacterial infection in intraabdominal fluid collections. MATERIALS AND METHODS: Prospectively, 79 patients who were suspected of having an intraabdominal fluid collection underwent diagnostic fluid aspiration. The aspirate was cultured and measured for pH and pO2. A pH < or = 7.1 and a PO2 < or = 49 mm Hg were threshold values used to separate infected from sterile fluid collections. RESULTS: pH alone had a 92% sensitivity and 79% specificity, whereas PO2 alone had a 51% sensitivity and 79% specificity. pH or pO2 combined yielded a 92% sensitivity and 60% specificity. The radiologist's opinion produced a 83% sensitivity and 92% specificity. pH and the radiologist's opinion combined produced a 78% sensitivity and 96% specificity. pH or the radiologist's opinion combined had a 95% sensitivity and a 63% specificity. CONCLUSION: pH is the most sensitive indicator of infection and the radiologist's opinion is the most specific. We recommend proceeding to drainage if the radiologist believes the collection to be infected and performing pH analysis if not. If the pH < or = 7.04, proceed to drainage. If neither of the above criteria are met, drainage could be delayed, pending the results of culture.

Is outpatient surgery safe for the higher risk patient?

The trend toward outpatient surgery led to this study to determine the safety of elective outpatient laparoscopic surgery for the higher risk patient. One hundred consecutive higher risk patients from all patients scheduled for elective outpatient laparoscopic surgery were studied prospectively in a 256-bed community hospital. Seventeen percent of patients required admission. In each instance the need was readily evident in the perioperative observation period. Eighty-three percent of patients were stable and were successfully treated as outpatients. No patient who remained stable decompensated later, and none required readmission to treat complications resulting from outpatient status. The 2% readmission rate (for unrelated reasons) was comparable to the 2% readmission rate for low-risk patients. It was concluded that routine outpatient laparoscopic surgery is safe for elective higher risk patients. Problems requiring admission are readily evident during the period of observation and no patient who remains stable decompensates later.

Distribution of free and liposomal cefoxitin in plasma and peritoneal fluid in a porcine intra-abdominal sepsis model.

The plasma and peritoneal fluid pharmacokinetic parameters obtained after the intravenous administration of free and liposomal cefoxitin were studied in a porcine model of intraabdominal sepsis. No prior assumptions were made to predict the number of compartments pertaining to drug clearance from the administration of either cefoxitin formulation. The experimental data obtained were applied to fit mathematical models of multiexponential drug clearance and the pharmacokinetic data were found to best fit a two-compartment open model. Liposomal encapsulation significantly altered the plasma drug distribution pattern resulting in changes in the magnitude of a number of pharmacokinetic parameters examined. The mean post-distributive half-life of liposomal cefoxitin was substantially longer than that of free cefoxitin by at least 3 times. The peritoneal cavity appeared to provide a reservoir for the initial distributive phase of rapid drug clearance from the plasma compartment followed by a less-rapid post-distributive phase. The cumulative drug level, as determined by the area under the concentration curve (AUC) as a function of time, in the plasma of animals treated with liposomal cefoxitin was about 3-4 fold as high as that of animals treated with free cefoxitin. The differences in pharmacokinetic parameters appeared to account for the improved therapeutic efficacy of liposomal cefoxitin in this animal model.

Strategies of invasive ventilatory support in ARDS.

Acute respiratory distress syndrome is a common cause of morbidity and mortality in intensive care units. For the most part, the mortality of this syndrome has arguably not decreased since the syndrome was originally described. One of the major reasons for this lack of reduction in mortality may be related to adherence to more traditional ventilatory strategies that have the potential to cause ventilator-induced lung injury. Ventilator strategies that attempt to limit ventilator-induced lung injury and accept permissive hypercapnia have successfully demonstrated a marked reduction in mortality in uncontrolled settings. So encouraging are these reductions that there has been a subtle shift in philosophy of mechanical ventilation toward using lung-protective ventilatory strategies at all times. With broad acceptance of this shift in philosophy, and the use of recently standardized clinical definitions for controlled studies, we optimistically anticipate improved mortality rates for acute respiratory distress syndrome.

Liposomal cefoxitin in a porcine model of intra-abdominal sepsis: hemodynamic changes.

The effects of free versus liposomal cefoxitin on various physiological parameters in a porcine model of Gram-negative intra-abdominal sepsis were evaluated. Four different doses of Escherichia coli inoculum mixed with sterile pig feces were used (10(8), 10(9), 10(10), and 10(11) cfu/animal), and the most consistent hemodynamic changes were observed with an inoculum of approximately 10(11) bacteria/20 kg animal. Two treatment groups were established as follows: free cefoxitin (n = 9) and liposomal cefoxitin (n = 9). All animals were maintained under anesthesia for the duration of the study, and then euthanized 24 h following intra-abdominal inoculation. The inoculated and nontreated animals showed increases in heart rate, mean pulmonary arterial pressure, systemic and pulmonary vascular resistance, and decreases in mean systemic arterial pressure and cardiac index. These changes were significant (p < .05) compared with a control group injected with normal saline. Liposomal cefoxitin-treated animals showed significantly lower decreases in mean systemic arterial pressure and increases in heart rate (p < .05) compared with both the inoculated nontreated and free cefoxitin-treated groups. Both liposomal and free cefoxitin significantly modulated the mean pulmonary arterial pressure compared with the inoculated nontreated animals (p < .05). Acidosis that developed during intra-abdominal infection diminished 6 h following the first dose of liposomal cefoxitin (p < .05). The results of these experiments demonstrate that liposomal cefoxitin exerts a beneficial modulation of some of the hemodynamic disturbances during intra-abdominal Gram-negative sepsis.

Liposomal cefoxitin in a porcine model of intra-abdominal sepsis: bactericidal efficacy.

The bactericidal effect of free versus liposomal cefoxitin was evaluated in the major reticuloendothelial organs in a porcine model of intra-abdominal sepsis. Yorkshire Landrace pigs were inoculated with 3.2 x 10(10) (n = 5) or 1.4 x 10(11) (n = 7) cfu of Escherichia coli mixed in sterile feces/animal. Two treatment groups inoculated with 1.4 x 10(11) cfu were established: free cefoxitin (n = 9) and liposomal cefoxitin (n = 9). All animals were maintained under anesthesia and euthanized after 24 h. The number of E. coli recovered in the liver, lungs, and spleen was significantly affected by inoculum size (p < .05). The liver had significantly higher numbers of bacteria (p < .05) compared with the other organs, regardless of the inoculum size. The liver and the lung of the liposomal cefoxitin-treated group showed significantly lower numbers of E. coli (5.0 x 10(4) and 6.3 x 10(2), respectively) compared with the untreated (liver, 6.3 x 10(7); lung, 2.0 x 10(6)) and free cefoxitin (liver, 5.0 x 10(6); lung, 7.9 x 10(4))-treated groups (p < .05). At 2 h following the injection of free and liposomal cefoxitin, the decrease of E. coli in peritoneal fluid compared with the nontreated septic group was significant (p < .05). No growth was observed from blood cultures taken 24 h after sepsis induction. All control experiments yielded negative cultures. The results of these experiments demonstrated that liposomal cefoxitin exerts an enhanced bactericidal effect in liver and lungs during Gram-negative sepsis.

Emergency embolization of a ruptured aneurysm of the pancreaticoduodenal arcade.

Inferior pancreaticoduodenal aneurysms are uncommon. A 77-year-old woman was seen with a 1-week history of sharp pain in the right lower abdominal quadrant radiating to the back, associated with malaise, anorexia, vomiting and nonbloody diarrhea. Appendicitis was diagnosed, but at laparotomy a large retroperitoneal hematoma was found; no aneurysm was identified. The abdomen was closed and aortography was done. An aneurysm of the inferior pancreaticoduodenal artery arcade was demonstrated, with occlusion of the celiac artery at its origin. The arc of Buehler was patent and enlarged and supplied the hepatic and splenic arteries. Embolization with Gianturco coils placed proximal to the aneurysm was successful.

Pneumatosis intestinalis with free air mimicking intestinal perforation in a bone marrow transplant patient.

A case of pneumatosis intestinalis with perforation is reported in a patient after bone marrow allograft for chronic myeloid leukemia. Risk factors included the transplant, prolonged immunosuppression and neutropenia, graft-versus-host disease, extended use of corticosteroids, infection and lower gastrointestinal endoscopic biopsy. The literature is reviewed and a management plan for patients presenting with this complication is discussed.

Deferoxamine induces hypotension in experimental gram-negative septicemia.

Multiple organ system failure may result from tissue damage caused by activated neutrophils or endotoxin. A significant part of this tissue damage is due to peroxidation induced by oxygen-free radicals and requires iron as a co-factor. Iron chelation has been shown to prevent tissue damage in some models. This experiment was carried out to determine whether iron chelation with deferoxamine (DFO) would prevent lung damage in a swine model of Gram-negative septicemia. Fifteen animals were randomized to control, Pseudomonas aeruginosa infusion at a rate of 2 x 10(7) colony forming units/20 kg/min (septic group), or Pseudomonas infusion combined with DFO pretreatment at a dose of 80 mg/kg/h (septic-treated group). Three of six septic-treated animals became severely hypotensive and died during the course of the experiment as opposed to none of six septic animals. Surviving septic-treated animals were significantly hypotensive (60 +/- 24 mmHg mean arterial pressure) compared to septic (122 +/- 9 mmHg) and control (109 +/- 8 mmHg) animals. DFO did not improve respiratory function (e.g., pO2) or morphology in septic animals. We conclude that iron-chelation therapy with DFO at the above dosage results in a significant deterioration in cardiovascular function in septic swine. Lung damage was not prevented.

Steroids, APACHE II score, and the outcome of abdominal infection.

OBJECTIVE: To compare the outcome of abdominal infection in patients with or without previous systemic glucocorticoid therapy and to determine the effect of steroid administration on the relationship between APACHE II (Acute Physiology and Chronic Health Evaluation) scores and mortality. HYPOTHESIS: Steroid therapy leads to greater mortality and relatively lower APACHE II scores. DESIGN: Prospective cohort study. SETTING: University hospital. PATIENTS: Two hundred ninety-seven consecutive adult patients with abdominal infection treated by surgical or percutaneous drainage. Treatment was at the clinician's discretion. Seventy-one patients received systemic steroid therapy. OUTCOME MEASURES: APACHE II score, clinical course, and death in hospital; relationship between APACHE II score and mortality in the steroid and no steroid groups. RESULTS: Thirty-three patients receiving steroid therapy (46%) died vs 55 (24%) of 226 patients not receiving steroid therapy. The APACHE II score (P < .0001) and steroid administration (P = .04) were each independently associated with death. Steroid-treated patients had the same probability of dying as "nonsteroid" patients with an APACHE II score a mean of 3.7 points higher (95% confidence limits, 0.03 and 7.7). The confidence that 2, 3, or 4 extra APACHE II points is the appropriate correction for steroid-treated patients is 80%, 60%, or 40%, respectively. CONCLUSIONS: Patients receiving steroid therapy appear to be at higher risk of dying of abdominal infection than predicted by APACHE II scores. The number of patients receiving cancer chemotherapy was too small to determine whether this was an additional risk factor. In the design of clinical trials stratified by APACHE II scores, steroid-treated patients should either be excluded or assigned two extra APACHE II points.

Visceral infarction caused by cocaine abuse: a case report.

Cocaine abuse is now known to result in a wide variety of medical illnesses. We report our experience with one patient who had abdominal pain and was found to have near-total infarction of all abdominal viscera. The cause of this and other medical complications of cocaine abuse (i.e., extreme vasoconstriction) is discussed in detail. Physicians should maintain a high index of suspicion when dealing with complaints of abdominal pain by cocaine users.

Automated recognition of corrupted arterial waveforms using neural network techniques.

A data acquisition system that automatically discards corrupted or undesirable signals would save untold hours of drudgery for researchers. Continuous recording of variables to provide detailed behavior patterns generates huge amounts of raw data. Unfortunately waveforms usually require visual inspection for isolating desired behavior or validating signal integrity. This tedious and time-consuming step can potentially be eliminated using a novel computer science technique. We have trained a simulated neural network to recognize corrupted arterial pressure waveforms. Our system can now evaluate the validity of the arterial waveform without human intervention with an average false positive error rate of 2.2% and an average false negative error rate of 12.6%.

Pneumonia complicating abdominal sepsis. An independent risk factor for mortality.

Nosocomial pneumonia (NP) is associated with a significant mortality, 66% in a previous retrospective study of NP complicating intra-abdominal sepsis (IAS). We prospectively compared the outcome of NP complicating IAS with that of recurrent IAS (R-IAS) in the absence of NP. Data were collected prospectively on 300 patients with IAS; 34 patients who presented with pneumonia were excluded from the analysis (44% mortality). One hundred seventy-one patients with no NP and no R-IAS (group 1) had a hospital mortality of 20% (34 patients); 36 without NP in whom R-IAS developed (group 2) had a 17% mortality (six patients); and 47 with NP but no R-IAS (group 3) had a 53% mortality (25 patients). Finally, 12 patients who had both NP and R-IAS suffered a 75% mortality (nine patients). We examined the relationships among the following putative risk factors and mortality: APACHE (acute physiology and chronic health evaluation) II score (at initial presentation with IAS), the need for mechanical ventilatory assistance following initial treatment for peritonitis, steroid requirement, generalized peritonitis vs abscess, and the need for surgical as opposed to percutaneous treatment. Using mortality as the dependent variable, group 2 vs 3 as the explanatory variable, and the risk factors as confounders, logistic regression analysis indicated that the group difference was significant after controlling for confounders. We conclude that NP complicating IAS is an independent risk factor associated with a significant mortality compared with R-IAS. These data challenge the notion that death in IAS is usually due to recurrent or persistent intra-abdominal infection.

A critical look at scheduled relaparotomy for secondary bacterial peritonitis.

Scheduled relaparotomy is attracting interest as a means of treating intra-abdominal sepsis. It is the subject of several studies to evaluate its role in the management of peritoneal infection. However, indications for this procedure are not clear and current knowledge does not allow for adequate scientific evaluation. Many trials lack control groups and historical control groups cannot be evaluated on criteria, such as illness severity, concomitant health problems or even surgical technique. Indicators of outcome are generally described in insufficient detail; only death or survival are reported and important morbidity and resource utilization data are not included. A randomized, prospective, multicenter clinical trial using standardized techniques is necessary to determine the usefulness of scheduled relaparotomy performed on different patients.

Failure of therapy with 2,3-dihydroxybenzoic acid to modify the course of sepsis-induced lung injury.

Oxidant-induced injury of the pulmonary microvasculature reportedly contributes to an increase in microvascular permeability and pulmonary hypertension, both of which are principal features of acute lung injury (ALI). We tested the hypothesis that antioxidant therapy with 2,3-dihydroxybenzoic acid (DHB), initiated in awake sheep after the development of sepsis-induced ALI, would ameliorate the progression of these lesions. DHB has many actions that suggested to us the potential for demonstrating benefit in ALI complicating sepsis; it is a nontoxic hydroxyl-radical scavenger that also inhibits the cyclooxygenase pathway and acts as a weak iron chelator. In preliminary experiments, we demonstrated that pretreatment with DHB prevented an increase in mean pulmonary arterial pressure, plasma thromboxane A2, measured as its metabolite thromboxane B2, and lymph total protein clearance that otherwise followed an infusion of zymosan-activated plasma (ZAP) in sheep. In subsequent experiments, 12 additional sheep were rendered septic by cecal ligation and perforation. Twenty-four to 36 h after cecal ligation and perforation, an increase in lung microvascular permeability was confirmed, because pulmonary lymph flow had increased by 82% while the mean lymph-to-plasma total protein ratio was unchanged from baseline. At this point, six sheep were then treated with parenteral DHB and six with DHB vehicle for the subsequent 24 h. In contrast to the demonstrated benefit of DHB pretreatment in preventing ALI secondary to an infusion of ZAP, the progressive increase in lymph total protein clearance that complicated septic lung injury in the DHB vehicle group throughout this 24-h study period was not ameliorated in the DHB treatment group. However, DHB did prevent a modest increase in mean pulmonary arterial pressures that was demonstrated in the DHB vehicle group throughout this 24-h treatment period. Although pretreatment prevented ALI after a ZAP infusion, we conclude that DHB only incompletely modified disease progression when administered after the onset of sepsis-induced ALI because it ameliorated the pulmonary hypertensive response without concurrently modifying an increase in lung microvascular fluid flux.

PC-based system for collection and analysis of physiological data.

A personal computer based system for data acquisition and analysis appropriate to physiological experiments is described in detail. The system is independent of the details of the analog signal generation. The software, written in C, is modular and easily portable to other PC systems. The system is capable of: (a) sampling many analog signals at an appropriate rate (100 Hz), (b) storing large quantities of digitized data, (c) analysing digitized waveforms to obtain signal parameters, and (d) storing signal parameters in a format suitable for statistical analysis. Computer processed cardiopulmonary data are compared with data derived from standard ICU equipment.

Development of an intravenous desferrioxamine mesylate treatment protocol for swine: monitoring of desferrioxamine and metabolites by high-performance liquid chromatography.

Desferrioxamine (DFO) metabolism and its pharmacokinetics were studied in a swine model using high-performance liquid chromatography. DFO and three iron-binding metabolites occurred in plasma. Interindividual differences in pharmacokinetics and metabolism were observed. Urine analysis in 4 pigs showed three iron-binding metabolites. The mean percent dose excreted in urine in the form of the parent drug was 45 +/- 10% and 10 +/- 2% (means +/- SD) in the form of metabolites. Of the total amount of the parent drug infused, 3 h after initiation, 87% was in the form of DFO, whereas 13% was present as the DFO-iron III complex which represented 45 mg of urinary iron elimination. The described DFO infusion protocol provides for sufficient DFO to chelate significant amounts of ferric iron in excess of normal levels, thus allowing experimental studies of iron chelation in a variety of disease states.