The slope of thenar StO2 ascent after the ischaemic no-flow challenge (Srecovery) was used to quantify the post-ischaemic reoxygenation capabilities in the thenar muscle [27,28]. Our study shows that Srecovery www.selleckchem.com/products/dorsomorphin-2hcl.html was low in our PPH parturients at admission and improved towards levels measured in parturients with no PPH. As described above, the low Srecovery at admission cannot be explained by a high oxygen consumption in the thenar muscle of our parturients. Accordingly, the low Srecovery measured at admission is probably explained by an impaired post-ischaemic reserve of oxygen delivery in the thenar muscle at the time of admission for PPH.We have previously described a high incidence of increased cardiac troponin that was associated with low blood pressure, high heart rate, low haemoglobin level, T-wave inversions and echocardiography changes in severe PPH [4].

Several hypotheses, including subendocardial ischaemia due to a mismatch between myocardial oxygen supply and demand [29,30], have been proposed – but the mechanisms by which these features cause increases in cardiac troponin in the absence of acute coronary syndrome in PPH parturients remain uncertain. Our study revealed that increased cardiac troponin was strongly associated with muscular Srecovery <3%/second and not with baseline StO2 or with Socclusion. Muscular Srecovery <3%/second was even more strongly associated (odds ratio >10) with increased cardiac troponin than a high heart rate in our PPH parturients.

This might suggest – if the increased cardiac troponin was related to a mismatch between myocardial oxygen supply and demand, and if simultaneous impairments observed in the myocardium and in peripheral muscle were related to similar mechanisms – that increased cardiac troponin was rather due to an impaired myocardial oxygen supply than to an increased oxygen demand. This hypothesis needs further evaluation.In summary, our study confirmed the high incidence of increased cardiac troponin and demonstrated a simultaneous impairment in the reserve of oxygen delivery to the peripheral muscles in our severe PPH parturients when admitted with unstable haemodynamics. These data confirm that haemodynamic management in this patient subpopulation should focus on the early simultaneous restoration of both blood pressure and haemoglobin levels and, if possible, the reduction of tachycardia.

AbbreviationsICU: intensive care unit; AV-951 PPH: post-partum haemorrhage; Socclusion: slope of tissue haemoglobin oxygen saturation decrease; Srecovery: slope of tissue haemoglobin oxygen saturation ascent; StO2: tissue haemoglobin oxygen saturation.Competing interestsDP received honoraria from Hutchinson Company for lectures. The other authors declare that they have no competing interests.AcknowledgementsSupport was provided to DP by the Minist��re de l’Enseignement Sup��rieur et de la Recherche (EA 322) and a research Grant for Hutchinson Company.