Anti-infective treatment in the perioperative period
HIV mainly invades and destroys CD4 T lymphocytes, causing CD4 counts to gradually decrease. In consequence of their significantly impaired immune function when the,CD4 count is below 350 cell/μL, HIV-infected patients are likely to get opportunistic infections and cancers and their mortality is then usually high[16]. At this stage ART is used, and usually includes two kinds of nucleosides and one kind of protease inhibitor. Patients using ART who undergo surgery need to continue ART use during the perioperative period[17]. Even if patients are undergoing gastrointestinal surgery and need to fast, they can take antiviral drugs. When a patient's, CD4 count is below 200 cell/μL, there is an additional high risk of acquiring fungal infections such as Pneumocystis carinii pneumonia which bring a marked increase in mortality[18, 19]. Therefore SMZ and fluconazole are conventionally added to ART during the perioperative period to prevent P. carinii pneumonia and other fungal infections. If tuberculosis, cryptococcosis, candidiasis or similar infections have been found before surgery, anti-TB or antifungal treatments are clearly required to control the disease. In summary, HIV patients undergoing emergency surgery need prophylactic anti-infective drugs based on doctor/clinical experience, and effective anti-infective treatments are to be applied according to the results of resection of lesions and blood culture[20, 21].
Prophylactic antibiotics
To reduce the incidence of surgical site infection, prophylactic antibiotics are generally used during the perioperative period. Because of the weakened immune function, HIV-infected patients are even more likely to need prophylactic antibiotics[22]. However, there are no reports specifically about how to use antibiotic in surgical patients who are HIV infected. We found that preoperative CD4 lymphocytes, WBC and hemoglobin are independent risk factors for sepsis. CD4 counts cannot be implied from white blood cell counts. Decline in CD4 T lymphocyte counts is often accompanied by decline in hemoglobin. Our principle in using prophylactic antibiotics was to use those antibiotics which can cover the most common infections according to surgical incision site and type of surgery. We took into account the likelihood of Gram-negative bacilli (enteric bacteria), gram-positive cocci (Staphylococcus aureus) and anaerobic bacteria, and chose between two kinds of antibiotic combinations. We usually selected first-generation cephalosporins on clean wound surgery. For nine patients who were undergoing excision of thyroid tumor or breast tumor, we did not use any antibiotics and no SSI arose. In all, 82 patients underwent clean wound surgery and 81 had healing wounds. In future we may try not using any antibiotic for classIminor incisions. For giant splenectomy with cirrhosis and for internal fixation of femoral fractures, we still need prophylactic antibiotics, and they should be used longer than for normal surgery. We generally use antibiotics until wound have healed. The first-generation cephalosporins have a strong bactericidal activity for Gram-positive S. aureus, but for Gram-positive intestinal bacteria its bactericidal activity is less than second- and third-generation cephalosporins (ceftriaxone, etc.). Second-generation cephalosporins have advantages in the prevention of wound infection for class-IIincisions and gastrointestinal tract surgery, but its bactericidal activity is less than third-generation cephalosporins in the prevention of intra-abdominal infection. Prophylactic antibiotics should also cover common anaerobic bacteria for lower gastrointestinal surgery where there is significant pollution. Antibiotics such as piperacillin, cefoxitin, cefotetan, etc., can cover gram-negative enteric bacilli as well as anaerobic bacteria. Metronidazole and clindamycin should be included when other antibiotics do not have activity against anaerobic bacteria.
Antibiotics for therapy
Therapeutic drugs should be used for intra or postoperative infections. According to our statistical analysis of the clinical data, the lower the preoperative CD4 counts, the higher the incidence of sepsis. Our data also show that SSIs were frequent and differed widely by wound class. The incidence of SSIs is high for Class II incisions because our study included many anal warts excision patients and these usually develop SSIs after surgery. Clearly, we should maintain clean wounds for superficial surgical site infections to reduce sepsis; our data show that the incidence of sepsis in the SSIs group was significantly higher than in the non-SSIs group. Therefore effective treatment should also be used for surgical site infection. Effective anti-infection treatment involves a multi-disciplinary knowledge for HIV-infected patients who may have tuberculosis, fungal infections and surgical site infections.
Surgical risk and prognosis
HIV-infected patients have a higher incidence of surgical complication and mortality than normal patients. Jeremiah L et al.[23] reported that the incidence of postoperative infectious complications was 55% and the 30-day mortality rate after surgery was 30% for HIV-infected patients. Our institution is a designated tertiary care university hospital for treatment of HIV-infected patients, so we have accumulated much perioperative anti-infection treatment experience. The mortality of HIV-infected patients undergoing abdominal surgery in our hospital was 7.7% which is significantly lower than previously reported data. Surgeons should pay attention to occupational exposure and aseptic technique in order to reduce SSIs and surgical trauma.
Limitations of the study
One of the limitations of the study was possible information biases due to the retrospective nature of the study design. Another was that the study did not control for possible confounders other than those investigated.
In conclusion, in order to reduce the incidence of infection complications and mortality, surgeons should combine multidisciplinary knowledge and carry out reasonable anti-infection treatments.
Ethical approval
The study was approved by the Ethical Committee of Shanghai Public Health Clinical Center, Fudan University, Shanghai, China. (International index IORG0006364).