A reply

Abstract

We thank Drs Sagadai et al. for their interest in our article. We understand their concerns, but we would like to justify our views. We did not give the details of radiotherapy or chemotherapy received by the patients as there are articles to support the statement that cancer patients are at a greater risk of infection, even without chemotherapy or radiotherapy. Patients with malignancy have a systematic suppression of the host immune function and have a significantly increased risk for infection in comparison with patients without malignancy [1]. The group with absolute neutrophil count greater than 500 per microlitre and no immunosuppressive therapy represents the least immunosuppressed patients with cancer, but some level of risk of infection may still exist [2]. Patients undergoing surgery for malignancies are also at risk as a result of anatomic factors. Patients undergoing head and neck surgery are at higher risk for aspiration pneumonia and infections by skin and oral mucosal flora [2, 3]. Patients with biliary tract obstruction are usually treated with stents or diverting procedures that enable colonisation of the biliary tract with intestinal flora which increases the risk of postoperative infection. Direct invasion through the colonic mucosa is associated with local abscess formation and sepsis by enteric flora. Streptococcus bacteraemia is associated with colon cancer [2]. Other factors specific to oncology patients which increase the risk of infection include tumour obstruction of hollow viscera, infection of necrotic tumour, extensive debulking, nodal dissection, prolonged use of surgical drains, catheter-related sepsis, ventilator-associated pneumonia and malnutrition [2]. In our study, laparotomies were done for gastric, oesophageal, colorectal, pancreatic, cervical cancers, soft tissue tumours, ovarian tumours and renal cell carcinomas. Thoracotomies were performed for pulmonary metastases and chest wall tumours. Thoraco-abdominal procedures were performed for oesophageal cancers. Lower limb procedures were done for squamous cell carcinomas and soft tissue sarcomas involving the limbs. Head and neck operations included those for carcinoma of buccal mucosa, tongue, alveolus, maxilla, etc. The ‘miscellaneous’ procedures included mastectomies with breast reconstruction, penile amputations with ilio-inguinal lymph node dissections, pelvic chondrosarcomas, soft tissue sarcomas involving gluteal region, flank, groin, anterior abdominal wall, etc. We have conducted a study to compare epidural morphine analgesia with intravenous morphine for oral cancer surgery with pectoralis major myocutaneous flap reconstruction [4]. These catheters were sited at T 8/9 level. Two epidural catheters tips were positive for bacterial culture in these patients. However, there were no epidural space or central nervous system infections in any of these patients, although oral cancer patients who undergo procedures that breach the upper aerodigestive tract mucosa are at significant risk for infection and even thoracic epidural catheters have been reported to have a greater rate of infection when compared with catheters sited at other levels.