Computer-derived equations for predicting survival postoperatively. Their usefulness and limitations

We used multivariate analysis to determine whether survival following perforations of the gastrointestinal tract could be accurately predicted from preoperative data. Of 12 variables tested, four were found to have predictive value. These were age, pulmonary disease, preoperative shock, and the attending surgeon. When these four variables were employed in a logistic regression equation on 42 patients, it correctly predicted which 21 patients died before leaving the hospital. To produce an equation useful for other hospitals, we recalculated it without the attending surgeon variable. Again, the equation was used to predict survival. The correlation of predicted vs observed outcome remained high, and, using a 2 x 2 chi 2 test, the correlation was significant. We then cross validated the three-variable model on data from a second hospital. The model accurately predicted the new data equally well. We believe that predictive models can identify risk factors in a variety of patient populations and can determine who is likely to benefit from specific treatment modalities.     

Hydatid cyst of gall bladder.

Gall bladder hydatid cyst is a rare entity. Concurrent occurrence of gall blader hydatid cysts along with liver cysts, especially with the biliary channels clear of cysts, is very rare. We report a 27-year-old man with a gall bladder hydatid cyst that was diagnosed only after opening the resected specimen of the gall bladder.     

Effect of fibronectin-rich human cryoprecipitate on fluid volume requirements in sheep during postoperative sepsis

Septic surgical patients often require fluid administration to maintain cardiovascular stability due, in part, to the sepsis-induced increase in vascular permeability and associated plasma volume depletion. Plasma fibronectin deficiency exists in such septic patients. We determined if maintenance of fibronectin levels by administration of fibronectin-rich human plasma cryoprecipitate would lower the resuscitative fluid volume needed for support of arterial pressure in septic postoperative sheep which were experimentally depleted of plasma fibronectin. Following a 2-hr postoperative baseline period, denatured collagen (gelatin, 8.7 mg/kg), which has a high affinity for fibronectin, was infused into both control and experimental sheep in order to acutely deplete plasma fibronectin. Sheep were then challenged both intraperitoneally and intravenously with live Pseudomonas (5 x 10(10) bacteria IP; 5 x 10(9) bacteria IV). Experimentals were given fresh plasma cryoprecipitate intravenously at a dose of 4 units bolus, followed by 3 units/hr for 5 hr. Controls received plasma cryoprecipitate selectively depleted of fibronectin by affinity chromatography. Bacterial challenge rapidly resulted in severe systemic hypotension. Ringer's lactate was infused intravenously into both groups at a rate sufficient to maintain a systemic arterial pressure of approximately 50 mm Hg with a maximum pulmonary artery wedge pressure of 15-18 mm Hg. Its rate of infusion was periodically adjusted to maintain this hemodynamic status. Comparison was made of the volume of Ringer's lactate required to maintain an arterial pressure of 50 mm Hg in both groups. Net fluid requirement was significantly (p less than 0.05) less in postoperative septic sheep (47.4 +/- 6.2 mg/kg/hr) treated with fibronectin-rich cryoprecipitate compared to the fluid requirement (71.7 +/- 4.7 mg/kg/hr) for postoperative septic sheep receiving fibronectin-deficient cryoprecipitate. Thus elevation of plasma fibronectin concentration lowers the fluid requirements needed for hemodynamic support in postoperative Gram-negative sepsis.     

Perurethral ultrasound-guided ovum pickup

Either a percutaneous-transvesical, a transvaginal, or a perurethral-transvesical approach can be used for oocyte recovery under ultrasound guidance in an in vitro fertilization and embryo transfer program. After having experienced these three different approaches in our program, we preferentially used the perurethral-transvesical approach as our routine technique for oocyte recovery under ultrasound guidance. We feel that this method is easier to perform and also carrier less risk for contamination. From January to December 1986, 186 oocyte retrievals under ultrasound guidance were performed. In 7 cases no oocytes were found despite normal ovarian stimulation. A total of 767 oocytes was collected; the fertilization rate was 71.8%. Forty pregnancies were achieved (21.5% per attempt or 27.7% per embryo replacement). Except for transient hematuria, no complications were observed.     

Neurogenic bladder in acquired immune deficiency syndrome (AIDS).

This is the first report of incidence of neurogenic bladder in patients with acquired immune deficiency syndrome (AIDS) and emphasizes that it is a significant cause of various voiding dysfunctions in these patients. Neurologic disease occurs in about one third of patients with AIDS. Both central and peripheral nervous systems may be involved. Urodynamic evaluation is necessary for assessment and management of neurogenic voiding disorders in this group of patients.     

Diminution in Kerosene-Mediated Induction of Drug Metabolizing Enzymes by Asbestos in Rat Lungs

Abstract: In order to determine the pulmonary toxicity of kerosene and its ignition product (soot) in asbestos exposed subjects, the activities of phase I and phase II drug metabolizing enzymes in rat lungs after single intratracheal coexposure to Indian chrysotile asbestos and kerosene or its soot and Indian chrysotile were assayed. Exposure to kerosene or its soot resulted in a significant increase in the level of microsomal cytochrome P-450 and the activity of P-450 dependent monooxygenase, benzo(a)pyrene hydroxylase, as well as in the activities of microsomal epoxide hydrase and cytosolic glutathione-S-transferase (GST). However, in chrysotile exposed animals a reverse pattern in these parameters was recorded. The co-exposure to chrysotile and kerosene or chrysotile and soot led to a significant depletion in cytochrome P-450 level and a decrease in the activities of benzo(a)pyrene hydroxylase, epoxide hydrase and GST when compared to kerosene and soot controls, respectively. These results suggest that asbestos by altering the pulmonary drug metabolizing enzyme system may increase the toxic potential of kerosene and its ignition product in the respiratory system.     

Gastric carcinoma--a study of 100 cases in northern Pakistan.

We describe 100 consecutive patients with histologically proven gastric carcinoma who were admitted to various hospitals in Northern Pakistan. Twenty-six per cent of patients were under 40 years of age. In a majority of patients the tumour was of a morphological type associated with poor prognosis. In most cases the disease was already at an advanced stage at the time of diagnosis, and most patients died within one year.     

Effect of dietary fish oil supplementation on the antigen-induced late-phase response in the skin.

We have studied the effect of dietary fish oil supplementation (3.2 gm/day of eicosapentaenoic acid and 2.2 gm/day of docosahexaenoic acid) for 10 weeks on the antigen-induced, cutaneous late-phase response (LPR) in 16 atopic individuals. All subjects developed an LPR to intradermal allergen injection. The mean +/- SEM area of induration at 6 hours was 1840 +/- 472 mm2. A biopsy was performed at the LPR site at 6 hours. Subjects were then randomized to receive fish oil or placebo olive oil in a double-blind, parallel fashion, for 10 weeks. After the diet, there were no significant differences between fish oil and placebo treatment in the size of the immediate wheal-and-flare response or the extent of induration at 4 and 6 hours, as compared with prediet values in each group. Histologically, at 6 hours, there was a significant infiltrate into the allergen site compared with that of the control diluent site of total inflammatory cells (p less than 0.002) as well as of eosinophils (p less than 0.001). However, there were no significant differences when pre- and postdiet values were compared. Hence, we conclude that dietary fish oil supplementation does not inhibit the cutaneous LPR clinically or histologically.     

Nimodipine treatment in poor-grade aneurysm patients. Results of a multicenter double-blind placebo-controlled trial

A multicenter, randomized placebo-controlled double-blind trial of nimodipine in poor-grade aneurysm patients was carried out in 17 Canadian hospitals. Of 188 patients enrolled in the trial, 32 were excluded for protocol violations and two were excluded due to statistical considerations, leaving 154 patients for valid outcome analysis. Nimodipine treatment was associated with a significantly better outcome (p less than 0.001): 21 (29.2%) of 72 nimodipine-treated patients had a good outcome at 3 months after subarachnoid hemorrhage (SAH) compared to eight (9.8%) of 82 placebo-treated patients. Delayed ischemic deficits from vasospasm alone were significantly less frequent in the nimodipine group (p less than 0.05) with permanent deficits occurring in five nimodipine-treated patients (6.9%) and in 22 placebo-treated patients (26.8%). Improvement in the good outcome rate and reduction in delayed ischemic deficits from vasospasm alone occurred in both Grade 3 and 4 patients, with no difference between nimodipine- and placebo-treated patients being found in Grade 5 patients. Repeat angiography after Day 4 was carried out in 124 patients. There was no significant difference in the incidence of moderate or severe diffuse spasm, which was seen in 64.3% of nimodipine-treated patients and 66.2% of placebo-treated patients. The authors conclude that nimodipine treatment in poor-grade patients with SAH results in an increase in the number of good outcomes and a reduction in the incidence of delayed neurological deterioration due to vasospasm. This effect occurs by a mechanism other than prevention of large-vessel spasm as visualized on angiography.