Inhibition of the fetal stress response improves cardiac output and gas exchange after fetal cardiac bypass

Circulatory responses to maternal hyperoxaemia and hypoxaemia assessed non‐invasively in fetal sheep at 0.3–0.5 gestation in acute experiments

“…Ketamine is known to increase maternal blood pressure (7%), cardiac output (16%), cerebral ow and circulating epinephrine 23 , but is still much used for acute experiments. The reason for this popularity is that ketamine hardly affects respiratory re¯exes and exerts a relatively mild effect on hypoxic and acidaemic responses 24,25 . A possible effect of ketamine in our study would be to counteract the bradycardia and¯ow reduction.…”

Anaesthesia for pregnant animals

“…Maternal stress leads to fetal stress, so care of the dam is essential to fetal wellbeing. Fenton et al (1994) showed that it is prevention of fetal stress rather than the type of anaesthetic that determines fetal survival. Sugino et al (1994) demonstrated that in the pregnant rat chronic restraint stress led to fetal loss.…”

“…Most of these have shown the techniques to be as minimally depressant as generally believed (Guay et al 1992), but Vincent et al (1992 showed that epidural anaesthesia worsens uterine blood flow and fetal oxygenation during haemorrhage. Fenton et al (1994) convincingly demonstrated the benefit of preventing the fetal stress response during major fetal surgery in preventing post operative fetal distress and abortion.…”

“…Pregnant cows have also been studied ) but sheep have now been used most frequently to study fetal physiology and pharmacology as a model for pregnant women (Vincent et al 1994). The outcome of surgery on the fetus has also been studied in this way (Canady et al 1994;Fenton et al 1994;Meuli et al 1995). Some investigations have been conducted expressly to examine the effects of anaesthesia on the fetus.…”

In‐utero intervention for hypoplastic left heart syndrome — a perinatologist's perspective

“…Studies have provided guidance for incorporating inotropic medications, correction of acidosis and, when needed, fetal transfusion 32 . Researchers in this area have greatly enhanced our knowledge of the stress response in the fetus and the modalities applicable to inhibit pain and fetal catecholamine response during fetal interventions 33 . Work evaluating the cortisol responses, hemodynamic changes and noradrenaline responses during fetal needling procedures emerged during the 1990s, leading to the advocation of the administration of fetal fentanyl prior to intervention procedures 34 -37 .…”