{'fraction_non_alphanumeric': 0.05224304372515616, 'fraction_numerical': 0.043725156161272004, 'mean_word_length': 4.575949367088608, 'pattern_counts': {'":': 0, '<': 4, '<?xml version=': 0, '>': 3, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Veno‐arterial carbon dioxide and pH gradients and survival in critical illness

Abstract. Recent studies have shown that the veno‐arterial gradient for carbon dioxide (dVVApCO2) is increased in the case of low cardiac index (CI). In order to further investigate this matter 220 haemody‐namic measurements from 34 patients with septic shock and from 28 patients in the post‐operative state without sepsis were evaluated. The arterio‐venous gradient for pH (dAVVpH) was also evaluated. CI was found to be inversely correlated to both dVVApCO2 and dAVVpH when the two groups of patients were analysed separately (r= ‐0.76 and r= ‐0.78, P< 0.001 for the relationship between CI and dVVApCO2, r = ‐0.58 and r = ‐0.69 P<0.001 for the relationship between CI and dAVVpH). When volume loading over 2 h was used to increase CI, 58–66% of_the patients in the two groups showed a decline in dVVApCO2 > 10% when CI was increased by > 10%. The corresponding values for a reduction in dAVVpH> 10% during volume loading was 36–52%. While dAVVpH was found to be increased in non‐survivors (n= 27) when compared to survivors (0.32 ± 0.01 vs. 0.24±0.1, P<0.05) at the second day in the IUC, dVVApCO2 was not a significant predictor of mortality despite the fact that CI was found to be decreased in the non‐survivors (3.5 ±0.94 vs. 4.3±1.0 L min‐1 m‐2, P<0.01). In conclusion, the veno‐arterial carbon dioxide gradient was found to be inversely correlated to cardiac performance in patients both in patients with septic shock and in non‐septic post‐operative patients. The arterio‐venous gradient for pH was increased in low flow states, but this association was weaker. However of these two indices evaluated, only a raised dAVVpH was a significant predictor of later mortality.