Recognising the deteriorating woman
The most recent confidential enquiries into maternal death in the UK have identified that practitioners fail to recognise the deteriorating woman. This has far reaching consequences for the woman and her family because this failure can result in severe morbidity or mortality. In order to recognise the deteriorating woman, it is essential to understand and recognise the different stages of shock (Figure 57.1). Childbearing women generally compensate for shock very well, because they are (usually) young and fit their bodies physiologically adapt to cope well with shock, but will show subtle signs that they are becoming unwell. In order to recognise the deteriorating woman, the different stages of shock must be understood. Effective history taking antenatally will help to identify women who may have known risk factors that predispose them to shock and so allow decisions to be made through discussion with the multiprofessional team about appropriate place of birth.
Physiological shock occurs when there is a deficit in the oxygen available compared to the oxygen that is required by the cells to allow normal cell function. In childbearing women, the most common type of shock is hypovolaemic shock following an antepartum or postpartum haemorrhage, where the cells do not receive enough oxygen because there is not enough blood volume to get the oxygen to all cells. In septic shock, bacterial infection causes an acute inflammatory response that results in vasodilation and hypotension; again there is inadequate blood pressure to circulate oxygen to where it is needed. In midwifery care, we see neurogenic shock during a uterine inversion as the stretching of broad ligaments that support the uterus normally disrupts the sympathetic nervous system, which means that compensatory mechanisms cannot take place and the pulse and blood pressure will drop rapidly. Anaphylactic shock and cardiogenic shock are rare in maternity but the midwife should consider them if a woman has had a new drug administered (particularly an antibiotic or anti-D) or if she has a known cardiac disorder.
The initial stage of shock occurs in the absence of a sufficient oxygen supply, when cells begin to respire anaerobically. A by-product of this anaerobic respiration is lactic acid (measured as serum lactate in blood tests). At this early stage it is unlikely that the practitioner will be able observe changes.
In the compensatory stage of shock, the body’s compensatory mechanisms begin to function. Hyperventilation reduces carbon dioxide levels and neutralises the acidic conditions that have begun to occur. Hyperventilation also serves to increase the oxygen levels that are available for cell function. Catecholamine release is triggered by hypotension and serves to increase the heart rate and blood pressure to maintain it at normal levels. Vasopressin is released and triggers fluid retention and vasoconstriction. This means that the first observations that the midwife will make indicating change are an increased respiration rate and a degree of vasoconstriction that may manifest as an increased peripheral capillary refill time. Anecdotally, these observations are often routinely omitted in practice so the opportunity to recognise the compensatory stage of shock is missed.
The progressive stage of shock occurs when shock is not corrected and compensatory mechanisms begin to fail. At this stage, the practitioner will observe an increasing pulse rate, a drop in blood pressure and a drop in oxygen saturation levels. It is essential that the severity of these observations are noted, reported and action taken if it has not been initiated already. A rising pulse rate, dropping blood pressure and oxygen saturation levels indicate a critically unwell woman and immediate action should be taken.
The refractory stage of shock occurs when organ failure begins due to the inability of cells to function effectively. Kidney function is the most sensitive to hypoxia, so although some women will have a reduced urine output if they are dehydrated, the midwife must consider reduced urine output may indicate a degree of renal failure. If the shock is not managed effectively, and more than one organ fails, then the woman will die because she cannot survive with multiple organ failure.
Regular observations are essential in recognising the deteriorating woman. In addition to changes in these observations, the midwife needs to consider the woman holistically, and extended assessment (ABCDE) is helpful (Figure 57.2). Her general appearance and cognitive function need to be considered. Once the deterioration has been recognised, prompt referral to senior midwifery and medical colleagues needs to be prioritised; failure to do this increases maternal mortality and morbidity. Immediate treatment of the deterioration will require input from the multiprofessional team. Early referral to a high-dependency or intensive care unit will also improve the outcome for the critically unwell woman.
High-flow facial oxygen needs to be applied and combined with intravenous access for blood tests and fluid replacement until the cause of the deterioration is identified and managed appropriately. An indwelling urinary catheter will allow accurate assessment of urine output and recording of fluid balance. A complete set of observations, including respiration rate, pulse rate, blood pressure, oxygen saturations and peripheral capillary refill should be repeated every 3 to 5 minutes to monitor deterioration until her condition stabilises.
- Record a full set of observations, including respirations and capillary refill regularly.
- Document your findings on a Modified Early Obstetric Warning Score (MEOWS) or High Dependency Unit (HDU) chart.
- Look for trends in observations.
- Early referral to senior colleagues is essential.