Effects of intraabdominal CO2 insufflation in the piglet.

Adult intraabdominal surgery performed with the minimal-access technique has created a revolution in surgery. This technique has remained largely unused for pediatric surgical procedures because of concerns regarding its safety and efficacy. Presently, intraabdominal insufflation of CO2 is the preliminary step to performing minimal access surgery. In this study, an animal model was developed to determine the effects of intraabdominal CO2 insufflation in the infant. Eight piglets (4 to 6 kg; 14 to 19 days of age) were instrumented under fentanyl anesthesia to allow measurement of arterial blood pressure (BP), central venous pressure (CVP), heart rate (HR), cardiac index (CI), inferior vena cava pressure (IVCp), inferior vena cava flow (IVCf), mediastinal pressure (Mp), partial pressure of CO2 (PaCO2), and minute ventilation (VE) at baseline and during 1 hour of CO2 insufflation to a pressure of 15 mm Hg and again when ventilation was increased to control PaCO2 levels. Continuous recording of data allowed time-course analysis of 15-minute blocks to determine the rate of change of measured variables. A second group of 6 piglets (4 to 6 kg) underwent the same instrumentation, but their baseline values were compared with those during N2O insufflation to isolate the effects of increased intraabdominal pressure. During CO2 insufflation alone, PaCO2 increased by 31% (P < .0001). This increase occurred within the first 15 minutes of insufflation and then remained stable. The increase was likely the result of increased CO2 absorption from the peritoneal cavity because VE was unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Management of colonic and rectal injuries.

In managing a colonic or rectal injury the surgeon must decide whether it is acceptable to have feces passing over a suture line or anastomosis. If it is, resection and anastomosis or simple oversewing of the bowel can be done. If it is not, there are four choices: (a) closure of the wound, drainage and proximal diversion; (b) primary closure or resection and anastomosis of the wound with exteriorization; (c) formation of a double-barrelled colostomy; and (d) resection of the injured colon with formation of an end-colostomy and a mucosal fistula or a Hartmann procedure. The surgeon's choice should be dictated by the severity of the injury, the degree of fecal contamination and the general condition of the patient.

Management of hepatic injury.

Liver injuries may be due to either blunt or penetrating trauma to the thorax or abdomen. Specific treatment depends on the site and extent of hepatic injury. Following resuscitation with intravenous fluids and blood as needed, surgical therapy is directed to provide hemostasis, remove necrotic liver tissue and promote adequate external drainage in the postoperative period. While local measures are usually sufficient, complex hepatic wounds may require extensive resection and vascular ligature or repair.

Crohn's disease in an isolated rectal stump.

A case is reported which illustrates the development of Crohn's disease in an isolated rectal stump occurring four-and-a-half years after subtotal colectomy for multiple polyposis coli. There was no evidence of more proximal small-bowel or colonic Crohn's disease. To our knowledge no similar occurrence has been reported in the literature.

Human amniotic membrane: a versatile wound dressing.

Human amniotic membrane proved to be a versatile and useful temporary biologic dressing in studies involving 120 patients. Wounds, both traumatic and nontraumatic in origin, responded to a protocol that allowed coverage of tissues as diverse as exposed bowel, pleura, pericardium, blood vessels, tendon, nerve and bone. Wounds unresponsive to usual therapeutic measures responded to membrane application. Ease of availability, negligible cost and facilitated wound healing make this temporary biologic dressing generally superior to either cadaver skin allograft or pigskin xenograft. Human amniotic membrane dressings are therefore a useful adjunct in the care of the complicated wound.

Gastrointestinal complications of renal transplantation. 1. The upper gastrointestinal tract.

In 95 consecutive cases of cavaderic renal transplantation followed up for 1 to 83 months (mean 23.1 months) 17 complications developed in the upper gastrointestinal tract of 15 patients; these included duodenal ulcer in 12 and gastric ulcer, esophagitis, hemorrhagic gastritis, small-bowel obstruction and small-bowel perforation in 1 each. The occurrence of a complication was not related to the patient's age, sex, blood group or use of cigarettes or alcohol, the duration of hemodialysis before transplantation, the tissue match or the number of infusions of immunosuppressive medication. One patient died of the complication. The peptic ulcers that developed after transplantation were successfully managed conservatively in 69% of cases. Since surgical treatment in patients whose immune response has been suppressed is associated with an increased frequency of complications such as disruption of suture lines, it is preferable to reserve it for those in whom complications develop that are unresponsive to conservative measures.

Gastrointestinal complications of renal transplantation. 2. The colon.

In 95 consecutive cases of cadaveric renal transplantation followed up for 1 to 83 months (mean 23.1 months) seven colonic complications developed in seven patients; these included ischemic colitis in three, colonic perforation in two, fecal impaction in one and appendicitis in one. Except for appendicitis all the complications occurred within 2.5 months of transplantation and were not related to the patient's age, sex, blood group, or use of cigarettes or alcohol, the duration of hemodialysis before transplantation, the tissue match or the number of infusions of immunosuppressive medication. Two patients died, but not of the complication. In the management of free colonic perforation prompt resection or exteriorization, with avoidance of intraperitoneal suture lines, and continuous postoperative peritoneal lavage may be lifesaving. Early surgical intervention and creation of a colostomy in one of the cases of ischemic colitis proved helpful.

Dopaminergic receptor-mediated effects in the mesenteric vasculature and renal vasculature of the chronically instrumented newborn piglet.

OBJECTIVE: To determine the effects of stimulation of vascular dopaminergic receptor subtype 1 (dopamine-1) receptors in the renal and mesenteric vascular beds of a neonatal model. DESIGN: Prospective, unblinded, dose-response evaluation in an awake animal. SETTING: University research laboratory. SUBJECTS: Thirty newborn piglets, obtained and instrumented at 1 to 3 days of age and studied 48 hrs later. INTERVENTIONS: Animals were chronically instrumented with transit time ultrasound flow probes around the left renal and superior mesenteric arteries. They were then intravenously infused with either dopamine (2 to 32 micrograms/kg/min) or fenoldopam (1 to 100 micrograms/kg/min), which is a selective agonist of the dopamine-1 receptor. MEASUREMENTS AND MAIN RESULTS: Blood pressure was only significantly increased by the highest infusion rate of dopamine (32 micrograms/kg/min), from a mean of 78 mm Hg at baseline to 87 mm Hg. Mesenteric and renal vascular resistances were unchanged by dopamine at any dose. Dopamine at 32 micrograms/kg/min decreased renal blood flow by 16.6 +/- 19.6 (SD) % and increased renal vascular resistance by 39.6 +/- 41.1% (p < .05). Mesenteric blood flow increased by 15% at 32 micrograms/kg/min (p < .05) but mesenteric vascular resistance was not affected by dopamine. Fenoldopam reduced blood pressure at infusion rates of 5, 10, and 100 micrograms/kg/min. Fenoldopam had no effect on renal vascular resistance at any dose. Fenoldopam reduced mesenteric vascular resistance at 5 micrograms/kg/min and at all higher doses. CONCLUSIONS: These data demonstrate the absence of dopaminergic receptor-mediated vasodilation in the porcine neonatal renal vascular bed. In the mesenteric artery, dopamine-1 receptor-mediated vasodilation may be obtained. Dopamine itself, probably because of stimulation of other receptors, causes renal artery vasoconstriction and does not increase superior mesenteric artery blood flow.

Effects of a continuous epinephrine infusion on regional blood flow in awake newborn piglets.

OBJECTIVE: To determine the effects of a continuous epinephrine infusion on renal and mesenteric blood flow in both healthy newborn piglets and animals subjected to hemorrhagic shock. METHODS: Superior mesenteric artery (SMA) and left renal artery ultrasonic flow probes were implanted into 16 1- to 3-day-old piglets. Two days later, the effects of epinephrine on SMA and renal blood flow, mean arterial pressure (MAP) and central venous pressure were measured in conscious, non-sedated normovolemic piglets. Epinephrine doses of 0.2, 0.4, 0.8, 1.6 and 3.2 microg/kg.min were used in random order. Piglets were subsequently hemorrhaged (20 ml/kg) to mild hypotension and again received epinephrine infusion in the same doses. RESULTS: Doses of epinephrine less than 3.2 microg/kg.min had no significant effects on renal or mesenteric arterial flow. At 3.2 microg/kg.min of epinephrine during normovolemia, there was a significant decrease in SMA blood flow (34% [SD 42], p < 0.05) and increase in SMA vascular resistance (147% [SD 114], p < 0.05). Similar results were shown during hypovolemia, SMA flow decreased by 32% (SD 33), and SMA vascular resistance increased by 220.3% (SD 177). At 3.2 microg/kg.min renal artery flow decreased by 43% (SD 21) during normovolemia and a similar decrease occurred during hypovolemia, 37% (SD 31). Renal vascular resistance increased by about 200% at this dose (normovolemia 211% [SD 185], hypovolemia 186% [SD 150], p < 0.01). Low-to-moderate dose epinephrine caused no significant change in SMA or renal blood flow. During hypovolemia low dose epinephrine infusion was associated with a trend to increased SMA blood flow. CONCLUSION: Low-dose epinephrine does not cause vasoconstriction in the renal or mesenteric circulations during normovolemia or hypovolemia. High doses of epinephrine above 1.6 microg/kg.min may cause renal or mesenteric ischemia, in either the normovolemic or hypovolemic neonate.

Management of carcinoma of the extrahepatic bile ducts.

The records of 80 cases of carcinoma of the extrahepatic bile ducts were studied. The median duration of survival, in months, of patients who were treated by curative surgery, palliative surgery and radiation, palliative surgery alone and biopsy alone was 21.7, 9.3, 5.5 and 1, respectively. The best results were obtained by excision of the tumour, but only 10% of tumours were considered resectable. A more aggressive surgical approach to tumours still confined to the bile ducts might be expected to increase the resectability rate and improve survival. The use of a U tube is recommended because it ensures greater comfort even though survival is no longer than when a T tube is used. The roles of adjuvant radiotherapy and chemotherapy need further study. Because of some encouraging responses with the use of radiotherapy and the infusion of 5-fluorouracil the authors are currently evaluating these two methods of treatment.

Predicting nodal metastases in breast cancer by lymphoscintigraphy.

In a prospective trial, 89 women with breast lumps underwent bilateral axillary and internal mammary lymphoscintigraphy preoperatively, using technetium-99m antimony sulfide colloid. All scans were interpreted blindly by three separate observers. Breast biopsy was then performed; if the biopsy specimen showed malignant tumour, definitive therapy was performed with axillary dissection. The interpretation of the axillary and internal mammary lymphoscintigrams was subsequently compared with the histologic assessment of the axillary nodes. Of the 89 women, 54 had benign disease and 35 had cancer. The internal mammary lymphoscintigram was considered to show abnormality in only 1 of the 54 patients with benign disease. One patient with cancer was eliminated from the review. Sixteen of the remaining 34 patients had axillary node metastases. Of these, 8 had an abnormal internal mammary lymphoscintigram. Only 2 of the 18 patients with cancer but no axillary metastases had an abnormal internal mammary lymphoscintigram. One bilateral axillary lymphoscintigram in the 54 patients with benign disease was discarded for technical reasons. The axillary lymphoscintigram was accurate in 52 of the remaining 53 patients. Two such scintigrams in the 35 patients with breast cancer were discarded for technical reasons. The axillary lymphoscintigram indicated abnormalities in 12 of 16 patients with axillary nodal metastases but appeared normal in 13 of 17 patients without axillary metastases. Lymphoscintigraphy may play a valuable role in the staging of breast cancer in the future.

Caremap management for postoperative prostatectomy care at home: a comparative study.

OBJECTIVE: To evaluate early discharge from hospital with community-based care as an alternative to hospital-based care for patients who have undergone transurethral resection of the prostate (TURP). DESIGN: Prospective comparative study. SETTING: A major urban hospital and the urban community. PATIENTS: Of 198 patients who underwent TURP between Jan. 10, 1994 and Sept. 30, 1994, 81, discharged on postoperative day 1, received the caremap method of health care delivery at home. They were compared with 85 patients who were discharged on postoperative day 2 or 3 and received standard hospital-based care. MAIN OUTCOME MEASURES: Readmission to hospital, reuse of health care services, complications and patient satisfaction. RESULTS: Comparison of the 2 groups revealed no significant differences in readmissions to hospital, reutilization of health care services or complications. Following these initial results, the early discharge program was expanded to include all acute care hospitals and the surrounding community. CONCLUSIONS: Postoperative care for TURP can be delivered in the home. A critical success factor was the ability to provide quality care in the community without adverse effects.