John F. Stremple

Risk adjustment of the postoperative morbidity rate for the comparative assessment of the quality of surgical care : Results of the National Veterans Affairs Surgical Risk Study

BACKGROUND The National Veterans Affairs Surgical Risk Study was designed to collect reliable, valid data on patient risk and outcomes for major surgery in the Veterans Health Administration and to report comparative risk-adjusted postoperative mortality rates for surgical services in Veterans Health Administration. STUDY DESIGN This cohort study was conducted in 44 Veterans Affairs Medical Centers. Included were 87,078 major noncardiac operations performed under general, spinal, or epidural anesthesia between October 1, 1991, and December 31, 1993. The main outcomes measure was all-cause mortality within 30 days after the index procedure. Multivariable logistic regression risk-adjustment models for all operations and for eight surgical subspecialties were developed. Risk-adjusted surgical mortality rates were expressed as observed-to-expected ratios and were compared with unadjusted 30-day postoperative mortality rates. RESULTS Patient risk factors predictive of postoperative mortality included serum albumin level, American Society of Anesthesia class, emergency operation, and 31 additional preoperative variables. Considerable variability in unadjusted mortality rates for all operations was observed across the 44 hospitals (1.2-5.4%). After risk adjustment, observed-to-expected ratios ranged from 0.49 to 1.53. Rank order correlation of the hospitals by unadjusted and risk-adjusted mortality rates for all operations was 0.64. Ninety-three percent of the hospitals changed rank after risk adjustment, 50% by more than 5 and 25% by more than 10. CONCLUSIONS The Department of Veterans Affairs has successfully implemented a system for the prospective collection and comparative reporting of risk-adjusted postoperative mortality rates after major noncardiac operations. Risk adjustment had an appreciable impact on the rank ordering of the hospitals and provided a means for monitoring and potentially improving the quality of surgical care.

Relation of Surgical Volume to Outcome in Eight Common Operations : Results From the VA National Surgical Quality Improvement Program

OBJECTIVE To examine, in the Veterans Health Administration (VHA), the relation between surgical volume and outcome in eight commonly performed operations of intermediate complexity. SUMMARY BACKGROUND DATA In multihospital health care systems such as VHA, consideration is often given to closing low-volume surgical services, with the assumption that better surgical outcomes are achieved in hospitals with larger surgical volumes. Literature data to support this assumption in intermediate-complexity operations are either limited or controversial. METHODS The VHA National Surgical Quality Improvement Program data on nonruptured abdominal aortic aneurysmectomy, vascular infrainguinal reconstruction, carotid endarterectomy (CEA), lung lobectomy/pneumonectomy, open and laparoscopic cholecystectomy, partial colectomy, and total hip arthroplasty were used. Pearson correlation, analysis of variance, mixed effects hierarchical logistic regression, and automatic interaction detection analysis were used to assess the association of annual procedure/specialty volume with risk-adjusted 30-day death (and stroke in CEA). RESULTS Eight major surgical procedures (68,631 operations) were analyzed. No statistically significant associations between procedure or specialty volume and 30-day mortality rate (or 30-day stroke rate in CEA) were found. CONCLUSIONS In VHA hospitals, the procedure and surgical specialty volume in eight prevalent operations of intermediate complexity are not associated with risk-adjusted 30-day mortality rate from these operations, or with the risk-adjusted 30-day stroke rate from CEA. Volume of surgery in these operations should not be used as a surrogate for quality of surgical care.

Perioperative total parenteral nutrition in patients with gastrointestinal cancer

Forty-one male surgical patients with gastrointestinal cancer were randomized into three groups on the basis of preoperative weight loss: Group I (20 patients)—mean age 64.1 ± 11.0 years, less than 10-lb weight loss, no TPN; Group II (9 patients)—mean age 65.8 ± 12.0 greater than 10 pound weight loss, no TPN; Group III (12 patients)—mean age 63.7 ± 10.7 years, greater than 10-lb weight loss, TPN. Group III received greater than 2000 cc of D25/4.25% Travasol for at least 5 days preoperatively and 8 days postoperatively. Major postoperative complications included abscess, anastomotic leak, or wound infection. Results: Preoperative immunocompetence was no different between any group (P > 0.05). Postoperative weight loss was significantly greater in Group I than in Group III (P 0.05). Rate of major complications was not significantly different between any of the groups (P > 0.05). Mortality was 10% in Group I, 0% in Group II, and 0% in Group III. Conclusion: An 18-day duration of perioperative TPN in comparable randomized patients based on preoperative weight loss does not alter the rate of major postoperative complications or mortality, but allows patients to maintain weight.

The stress ulcer syndrome

Summary o 1. In 3% of 2,297 men who sustained intracranial, spinal cord and intra-abdominal combat wounds gastrointestinal bleeding developed. 2. Gastrointestinal bleeding was more common following intra-abdominal trauma than intracranial trauma. 3. Subtotal gastric resection and vagotomy and removal of localized deep ulcer craters controlled gastrointestinal bleeding, if nonoperative management failed. The indication for and type of operation should be tailored to the overall clinical condition of the patient and pathologic lesion encountered. 4. The stress ulcer of the stomach or duodenum has been the dominant grossly visible clinical feature to the surgeon. The gross and microscopic pathologic lesions that we encountered included several related stages of what has been called the stress ulcer syndrome. These included microscopic epithelial necrosis; grossly visible superficial erosion and deep ulceration of stomach, small bowel or colon; and hemorrhagic necrosis of the entire gut. Because of the varied and generalized nature of these pathologic lesions, we prefer to use the descriptive term “acute gastrointestinal focal necrosis syndrome” (AGFNS), rather than the commonly used term “stress ulcer.” 5. That the AGFNS is probably initiated very early following trauma is suggested by the advanced chronic inflammatory histopathologic changes found in operative specimens. 6. No increase in urinary steroid excretion was found following trauma, which speaks against the role of the adrenals in initiating gastrointestinal lesions of stress. 7. Net acid output was below normal in the first 24 hours, perhaps due to initiation of back diffusion of hydrogen ions immediately following trauma. This acid output increased gradually on subsequent post-trauma days in all patients in whom prospective measurements were made. Therefore, prophylactic antacid therapy may be important to protect against initial acid back diffusion and subsequent increased net acid output. 8. A serum protein leak into the gastric content was found in all patients following trauma, but was greater in those who oozed larger amounts of blood into the stomach lumen or who bled grossly. This suggests all of our patients had some degree of permeability derangement of the gastrointestinal mucosal barrier. 9. No decrease in gastric sialic acid and other oligosaccharides was found following trauma, which suggested that the previously postulated deficiency of the gastric mucus barrier was not a primary causative factor. 10. The output of SGP and NSGP showed a gradual increase after trauma. This was the largest in grossly bleeding patients, in those oozing blood into the stomach and just prior to bleeding. Also, the output of individual carbohydrates (fucose, hexosamines, sialic acid) increased just prior to the bleeding. These findings can be considered as a manifestation of focal necrosis of the gastric surface epithelium preceding the bleeding and associated with shedding of mucous cells into the lumen. The focal denudation of the gastric mucosa from protective mucus layer at the time of increased gastric output in turn may contribute to a potentiation of existing gastric mucosal damage due to trauma of multifactorial pathogenesis. The less marked increase in the carbohydrate content of gastric juice which occurs at a later date in nonbleeding patients may be related in part to mucosal cell regeneration seen at that time histologically. 11. Clinically evident gastrointestinal bleeding is only a partial manifestation of the AGFNS. In a large portion of post-trauma patients in whom no gross bleeding was recognized, the chemical assay of heme in gastric juice showed the presence of 5–60 ml of blood/L of gastric content. The mechanism appears to be similar to that of gross bleeding as shown by its association with serum protein leakage and changes in gastric mucosubstances. It should be recognized as an equivalent of gross gastrointestinal bleeding and searched for and managed accordingly. 12. Bile reflux was associated in our patients with blood entry into the stomach. However, clinically significant gastrointestinal bleeding and increased serum protein leak into the stomach did not correlate with the presence of bile in gastric contents.

Comparison of postoperative mortality in VA and private hospitals.

OBJECTIVE This study compared unselected VA (Department of Veterans Affairs) and private multi-hospital postoperative mortality rates. In the absence of national standards for postoperative mortality rates and in view of the unique volume and range of surgical procedures studied, the second objective is to help establish national standards through the dissemination of these postoperative mortality norms. SUMMARY BACKGROUND DATA Public Law 99-166, Section 204, enacted by Congress December 3, 1985, required that the VA compare postoperative mortality and morbidity rates for each type of surgical procedure it performs with the prevailing national standard and analyze any deviation between such rates in terms of patient characteristics. METHODS The authors compared postoperative mortality in the VA to that in private hospitals, adjusting for the patient characteristics of age, diagnosis, comorbidity, or severity of illness. We used a total of 830,000 patients discharge records (323,000 VA and 507,000 private patients) from 1984 through 1986 among 309 individual surgical procedures within 113 comparison surgical procedures or procedure groups. RESULTS The authors found no significant differences in postoperative mortality rates between the VA and private hospital systems for 105 of the 113 surgical procedures or procedure groups. VA postoperative mortality rates that were higher than those in private hospitals were found for suture of ulcer, revision of gastric anastomosis, small-to-small intestinal anastomosis, appendectomy, and reclosure of postoperative disruption of abdominal wall (p = 0.05). Vascular bypass surgery, portal systemic venous shunt, and esophageal surgery showed a significantly lower postoperative mortality in the VA as compared with that in private hospitals (p = 0.05). CONCLUSIONS VA postoperative mortality in 113 surgical procedures or procedure groups is comparable to that in private hospitals.

Lower esophageal sphincter pressure during the normal menstrual cycle

Lower esophageal sphincter pressure (LESP), basal gastric pH, and plasma levels of gastrin, estradiol, and progesterone were determined in ten women known to have normal menstrual cycles. All determinations were performed both during the follicular phase (Days 2 to 8) and during the luteal phase (Days 20 to 30). In addition, an intraluminal pH probe placed 5 cm. above the lower esophageal sphincter was used to test for the presence of acid reflux in response to three provocative procedures. LESP during the follicular phase was 19.0 +/- 1.5 mm. Hg (mean +/- S.E.M.) and during the luteal phase 16.5 +/- 1.3 mm. Hg (p less than 0.01). Basal gastric pH and plasma gastrin levels were similar at both times. Plasma estradiol in the follicular phase (76.1 +/- 7.0 pg. per milliliter) increased twofold during the luteal phase (159.0 +/- 6.0) (p less than 0.01). Plasma progesterone increased from a level of 1.5 +/- 0.8 ng. per milliliter during the follicular phase to 19.2 +/- 4.2 during the luteal phase. Coincident with these changes in LESP and increases in steroid levels, acid reflux was detected in five women during the luteal phase but was present in only one during the follicular phase.

Lower esophageal sphincter pressure in cirrhotic men with ascites: before and after diuresis.

Lower esophageal sphincter pressure (LESP) was measured in 10 biopsy-proved cirrhotics with esophageal varices and tense ascites before and after diuresis to evaluate of ascites might play in the development of variceal bleeding. In the 10 cirrhotic men studied, basal LESP was 30.9 +/- 1.7 mm Hg before and 22.7 +/- 1.3 mm Hg (P less than 0.01) after a diuresis which resulted in a mean 12-kg weight loss. LESP responses to abdominal compression were also evaluated. The change in LESP in response to a standard degree of abdominal compression was greater in the presence of ascites (8.5 +/- 0.4) than in its absence (6.3 +/- 0.4) (P less than 0.01). Basal gastric pH and fasting plasma gastrin concentrations did not differ during the two testing periods. Based on these data and the rarity with which cirrhotic patients with ascites complain of heartburn, it is concluded that reflux esophagitis caused by failure of the lower esophageal sphincter to remain competent is unlikely to be a significant etiological factor in the development of variceal bleeding.

Serum gastrin levels in the differential diagnosis of recurrent peptic ulceration due to retained gastric antrum.

If recurrent peptic ulceration follows partial gastrectomy with Billroth II reconstruction, retained antrum on the duodenal stump may be the culprit. Moderate hypergastrinemia and a high basal acid output (BAO) to maximal acid output (MAO) ratio on gastric analysis should alert the clinician. Careful filling of the afferent loop on barium meal or technetium 99m scanning may verify the diagnosis. The secretin provocative test may be helpful in distinguishing retained antrum from the Zollinger-Ellison syndrome by eliciting a decrease in serum gastrin levels in patients with retained antrum and an increase in serum gastrin levels in patients with Zollinger-Ellison syndrome.

Prospective studies of gastric secretion in trauma patients

Patients who had cranial injuries and those who were less severely injured had a normal gastric acid output. Pepsin output decreased throughout the first 72 hours after trauma. Gastric juice protein output was slightly increased. Gastric mucosal cell renewal as estimated by gastric juice DNA was increased. Patients who were more severely injured and those with intra-abdominal trauma had markedly increased gastric acid, pepsin, and protein output after increased gastric mucosal cell exfoliation but a relatively decreased gastric mucosal cell renewal between 36 and 72 hours after trauma. It is concluded that the gastric mucosa must be protected by antacids and/or gastric aspiration before 24 hours after trauma and continued through at least 72 hours. This study supports the importance of acid-pepsin damage during gastric mucosal cell exfoliation and decreased renewal in trauma patients and indicates the timing and value of prophylactic treatment.

A new operation for the anatomic correction of chronic intermittent gastric volvulus

Abstract A case of chronic intermittent gastric volvulus occurring in a twenty-one year old woman is reported and a new and successful operation described. The clinical occurrence may not be as rare as previously recorded in the literature.