Cardiopulmonary exercise testing for preoperative risk assessment before pancreaticoduodenectomy for cancer.

OBJECTIVE: Pancreaticoduodenectomy is the standard of care for tumors confined to the head of pancreas and can be undertaken with low operative mortality. The procedure has a high morbidity, particularly in older patient populations with preexisting comorbidities. This study evaluated the role of cardiopulmonary exercise testing to predict postoperative morbidity and outcome in high-risk patients undergoing pancreaticoduodenectomy. METHODS: In a prospective cohort of consecutive patients undergoing pancreaticoduodenectomy, those aged over 65 years (or younger with comorbidity) were categorized as high risk and underwent preoperative assessment by cardiopulmonary exercise testing (CPET) according to a predefined protocol. Data were collected on functional status, postoperative complications, and survival. RESULTS: A total of 143 patients underwent preoperative assessment, 50 of whom were deemed to be at low risk for surgery per study protocol. Of 93 high-risk patients, 64 proceeded to surgery after preoperative CPET. Neither anaerobic threshold (AT) nor maximal oxygen consumption ([Formula: see text] O 2 MAX) predicted patient mortality or morbidity. However, ventilatory equivalent of carbon dioxide ([Formula: see text] E/[Formula: see text] CO 2) at AT was a predictive marker of postoperative mortality, with an area under the curve (AUC) of 0.84 (95 % confidence interval [CI] 0.63-1.00, p = 0.020); a threshold of 41 was 75 % sensitive and 95 % specific (positive predictive value 50 %, negative predictive value 98 %). Above this threshold, raised [Formula: see text] E/[Formula: see text] CO 2 predicted poor long-term survival (hazard ratio 2.05, 95 % CI 1.09-3.86, p = 0.026). CONCLUSIONS: CPET is a useful adjunctive test for predicting postoperative outcome in patients being assessed for pancreaticoduodenectomy. Raised CPET-derived [Formula: see text] E/[Formula: see text] CO 2 predicts early postoperative death and poor long-term survival.

Peripheral oxygen extraction in patients with malignant obstructive jaundice.

Malignant obstructive jaundice is associated with poor aerobic capacity. We measured oxygen consumption and oxygen extraction (arterial-venous oxygen content) in the legs of nine patients during cardiopulmonary exercise testing before pancreaticoduodenectomy. The median (IQR [range]) peak oxygen consumption was 67 (49-77 [32-84])% of predicted. Normal patterns of oxygen extraction were seen with increasing power towards lactate threshold. Near maximal oxygen extraction occurred at peak exercise. Femoral venous oxygen pressure and saturation exceeded baseline values whilst recovering from exercise. These findings suggest that peripheral oxygen extraction is normal during exercise in patients with malignant obstructive jaundice. The primary limitation in oxygen consumption is reduced oxygen delivery.

Cardiopulmonary exercise testing for preoperative risk assessment before hepatic resection.

BACKGROUND: Contemporary liver surgery practice must accurately assess operative risk in increasingly elderly populations with greater co-morbidity. This study evaluated preoperative cardiopulmonary exercise testing (CPET) in high-risk patients undergoing hepatic resection. METHODS: In a prospective cohort referred for liver resection, patients aged over 65 years (or younger with co-morbidity) were evaluated by preoperative CPET. Data were collected prospectively on functional status, postoperative complications and survival. RESULTS: Two hundred and four patients were assessed for hepatic resection, of whom 108 had preoperative CPET. An anaerobic threshold (AT) of 9·9 ml O(2) per kg per min predicted in-hospital death and subsequent survival. Below this value, AT was 100 per cent sensitive and 76 per cent specific for in-hospital mortality, with a positive predictive value (PPV) of 19 per cent and a negative predictive value (NPV) of 100 per cent: no deaths occurred above the threshold. Age and respiratory efficiency in the elimination of carbon dioxide (VE/VCO(2)) at AT were statistically significant predictors of postoperative complications. Receiver operating characteristic (ROC) curve analysis showed that a threshold of 34·5 for VE/VCO(2) at AT provided a specificity of 84 per cent and a sensitivity of 47 per cent, with a PPV of 76 (95 per cent confidence interval (c.i.) 58 to 88) per cent and a NPV of 60 (48 to 72) per cent for postoperative complications. Long-term survival of those with an AT of less than 9·9 ml O(2) per kg per min was significantly worse than that of patients with a higher AT (hazard ratio for mortality 1·81, 95 per cent c.i. 1·04 to 3·17; P = 0·036). CONCLUSION: CPET provides a useful prognostic adjunct in the preoperative assessment of patients undergoing hepatic resection.