Methicillin-resistant Staphylococcus aureus infections following esophageal surgery in patients with impaired defense mechanisms

Digest

For his first digest of 1994 Professor Yoshio Mishima, Editor-in-Chief of Surgery Today (The Japanese Journal of Surgery), has selected from the October to December 1993 issues. A summary of BJS articles for the same period appears in the March issue of the Japanese journal.

Influence of early postoperative enteral nutrition versus placebo on cell-mediated immunity, as measured with the Multitest CMI

BACKGROUND

Patients who become anergic after surgery have a very high death rate, mainly due to infectious complications. It has earlier been shown that preoperative skin testing has predictive value for the clinical outcome in gastrointestinal surgery. This study investigated the effect of early postoperative enteral nutrition versus placebo on cell-mediated immunity with the Multitest CMI and correlated the results to the clinical outcome and to the preoperative nutritional status.

METHODS

Sixty patients were randomized to receive either enteral nutrition or placebo. All patients were stratified in accordance with preoperative nutritional status. CMI tests were applied 2 days before surgery and days 1 and 5 postoperatively. All tests were applied and recorded by the same investigator.

RESULTS

No significant differences in the score were seen between the groups. Nine patients were malnourished. No significant difference was seen preoperatively with regard to nutritional status, but the malnourished patients had a lower median value on the 3rd postoperative day. In patients with complications the preoperative median CMI score was 17.0 mm (95% confidence limits, 10.5-24 mm), and in patients without complications 9.5 mm (95% confidence limits, 5.5-16 mm). This result is significant and unexpected. Ten patients were anergic preoperatively, and three of these developed complications (30%). The overall complication rate was 27 of 60 (45%). A change in immunologic status from responding preoperatively to anergy postoperatively was significantly associated with severe complications (P = 0.043).

CONCLUSIONS

Early enteral nutrition does not influence the CMI score. Preoperative anergy was not related to increased mortality/morbidity, whereas the change in CMI response towards anergy was significant.

IgG2 deficiency in methicillin-resistant Staphylococcus aureus infections after esophageal surgery

We previously reported the selective development of methicillin-resistant Staphylococcus aureus (MRSA) infections following esophageal surgery in patients with a reduced ability to produce anti-pneumococcal polysaccharide (PPS) IgG. Since the response to the PPS vaccine is correlated to the serum IgG2 levels, we measured IgG2 in the same series of esophageal cancer patients. IgG subclasses were determined in 21 patients, 8 of whom developed MRSA infections. IgG2 was thus found to be significantly lower (P < 0.01) in patients with MRSA infections (453 mg/dl) than in those without such infections (666 mg/dl). There was also a significantly positive correlation (r = 0.61) between anti-PPS IgG and serum IgG2. Therefore, the preoperative measurement of serum IgG2 is considered to be useful in detecting patients who are at risk for developing an MRSA infection after esophageal surgery.