‘Labour pain is not associated with pathology but with the most basic and fundamental of life's experiences’ (Lowe, 2002: 16).
An integral part of the labour process, pain poses challenges to both women and midwives despite the position of normality it holds in the maternity context. Pain is most commonly defined as ‘an unpleasant sensory and/or emotional experience associated with perceived or actual tissue damage’ (International Association for the Study of Pain (IASP), 2014). Because of the subjectivity, perception variations and phenomenological nature of labour pain, it may be useful to employ McCaffery's consideration that within the context of nursing sciences pain is ‘whatever the experiencing person says it is, existing whenever he or she says it does’ (1979: 11). Labour is arguably one of the only contexts in which pain is a normal, physiological process, rather than pathological in nature; nevertheless it challenges women emotionally, psychologically and physiologically. It is the midwife's role to support and enable women to make their individual choice for passage through the terrain of pain management options. The exploration of advantages and disadvantages of pain management strategies in labour is often perceived from the pharmacological perspective. However, in order to facilitate womancentred care, midwives must work in a holistic rather than institutionalised manner, appreciating the diversity of the women in their care. This demands a wider perception and contemplation of the benefits and drawbacks of pain management; considering each woman's psychospiritual and physiological clinical picture, birth location and environment, and the impact that each strategy can have on the individual experience.
Ideally, an individualised discussion about intrapartum pain management should be facilitated and documented antenatally, enabling women to make the right choice for their needs before the intrapartum period (Nursing and Midwifery Council (NMC), 2012). Midwives endeavour to ensure that women understand the importance of retaining a flexible outlook on labour pain management strategies. As autonomous practitioners, midwives need confidence in discussing options with women (Royal College of Midwives (RCM), 2012a; NMC 2008), especially considering the fragmented nature of carer continuity currently practiced within the UK (Walsh, 2012). Women often underestimate the pain of labour (Lally et al, 2008), and therefore may be unprepared to consider options for labour pain management. Midwives are well-placed to address the mismatch between expectations of labour pain and the lived experience (Lally et al, 2008; Williams et al, 2013).
It is essential to acknowledge that midwives’ perceptions of pain are influenced by their personal experiences, and thus parturient pain levels may be underestimated (Williams et al, 2013). The National Institute for Health and Care Excellence (NICE, 2007; 2008) recognise that midwives should consider how their own values impact on their perceptions and attitudes towards the pain of labouring women, ensuring that care remains unbiased and womancentred. Indeed, it has been suggested that the mother–caregiver relationship may be as important as the choice of analgesia (Hodnett, 2002), and women who receive continuous support in labour are less likely to have an instrumental delivery or a caesarean section (Hodnett et al, 2011).
Midwives must understand how pain operates in order to support women in labour to the best of their capabilities, normalising and facilitating physiological and psychological responses to labour pain, enabling women to focus on the process they are undergoing (Roberts et al, 2010). The experience of pain during labour can result in stress responses, especially when accompanied by fear and anxiety (Simkin and Ancheta, 2011a). If pain is well-managed these physiological responses remain unproblematic but if not, increased levels of maternal catecholamines can give rise to hypertension, tachycardia, and increased oxygen consumption (Mander, 2011).
Pain management strategies
Pain management options for labour are frequently visualised as a ladder, ascending in pharmacological strength and perceived efficacy, but also becoming increasingly interventionistic. However, this linear model overlooks the shifting dynamics of labour pain. Opining that one technique is superior to another denies women's individuality and fluctuating labour needs. Individualised midwifery guidance (NICE, 2007), rather than a ‘menu’ model of analgesic interventions (Leap, 1997), empowers fully informed choice, in which women can access any strategy at any point in labour in whichever order they prefer, creating woman-led pain management. Often emphasis is placed on the midwifery and obstetric analgesia provision, rather than strategies women can self-generate while in control of their own birth experience (Karlsdottir et al, 2013).
Self-generated and complementary/alternative therapies
Techniques including hypnotherapy, hypnobirthing, meditation/visualisation, biofeedback, and relaxation practices including breathing and music therapy are often the first coping mechanisms used in labour, especially in the early and latent phases. It is well understood that control and self-efficacy is central to positive maternal satisfaction in a labour context (Hodnett, 2002). Thus, midwives should be supportive and facilitative of women's choices to use these aids, being key in the creation of a conducive milieu in which women feel comfortable (Watson et al, 2007). To limit these options to the early stages of labour is short-sighted, as for some women these alone will be sufficient, and midwives offering the ‘menu’ of analgesia can undermine and interrupt their coping process (Leap and Anderson, 2008).
Indeed, there has been a sharp rise in the use of complementary/alternative therapies (CAT) in recent years (Williams and Mitchell, 2007).CATs include homeopathy, acupuncture and acupressure, reflexology and aromatherapy, amongst others. Although evidence-base is not yet well established (Smith et al, 2006), midwives are often faced with women hesitant to access analgesic methods of pain management, preferring a less interventionist approach (Smith et al, 2011). It has been suggested that midwives are highly receptive to their integration into clinical practice (Williams and Mitchell, 2007), although caution should be exercised when seeking to incorporate CATs into practice without the appropriate training and institutional support (NICE, 2007). The majority of these techniques are not currently provided by health professionals, but women independently choosing to access CATs should not be prevented from doing so. This can be challenging for both women and midwives, especially in the presence of a midwife qualified in one of the CAT fields.
Suggested benefits of CATs include increased maternal relaxation and satisfaction, promotion of normality and a reduction of intervention; both medically and pharmacologically (Williams and Mitchell, 2007; Smith et al, 2006). Their use in clinical practice therefore warrants further exploration.
Tactile pain management strategies
Physical contact in labour is thought not only to relieve pain, but to assist in relaxation and reduce emotional stress (Simkin and Bolding, 2004; Kimber et al, 2008; Gallo et al, 2013). Tactile methods include massage, which may contain hot or cold elements, and the use of transcutaneous electrical nerve stimulation (TENS) machines. These strategies often emerge as labour intensifies and heightened pain sensations necessitate physiological support.
The physiological mechanism underpinning tactile methods is poorly understood, but is largely thought to complement the gate control theory of pain (Melzack and Wall, 2008), proposing that when the lower back is stimulated, this excites afferent nerves, thus inhibiting the transmission of pain arising from labour (Augustinsson et al, 1977). Additionally. TENS is hypothesised to complement the release of endogenous endorphins (Lechner, 1991). TENS has been used in labour since the 1970s (Augustinsson, 1977), and as such various TENS models are available, consisting of a handheld device connected to electrodes which are then usually applied to the skin of the lower back on either side of the spine at vertebral positions T10 and S2. The unit then emits low-voltage impulses, the frequency and intensity of which are controlled by the labouring woman (Simkin and Bolding, 2004; Bedwell et al, 2011).
The efficacy of TENS machines has been widely debated. Bedwell et al (2011) found that although there was some evidence that women using TENS were less likely to report severe pain, evidence was neither strong nor consistent, and use did not reliably reduce uptake of pharmacological management. NICE (2007) do not recommend the offering of TENS in established labour, although if women choose to use TENS, midwives should offer their full support (Bedwell, 2011). Although Bedwell et al (2011) did not find that TENS consistently increased maternal satisfaction, for some women it may enhance feelings of control and therefore reduce anxiety and pain (Simkin and Bolding, 2004).
Massage is an easily accessible intrapartum tool, potentially reducing reliance on pharmacological interventions. Therefore it is appropriate for midwives to encourage the use of massage in labour (Gallo et al, 2013), as it is unlikely to have detrimental effects. This in turn can also facilitate the integration of a birth partner's role in the labour scenario.
Water immersion
Hydrotherapy as a therapeutic intervention for physical and psychological illness has been used for many years (Reid-Campion, 1997), and it's use in labour for relaxation and pain management has dramatically increased in recent decades (Tournaire and Theau-Yonneau, 2007). NICE (2007) and RCM (2005, 2012b) advocate water immersion in labour as a means of normalising birth and empowering women. Water immersion typically refers to the immersion of a woman at any stage of labour, where the woman's abdomen is entirely submerged in water, and therefore necessitates a pool larger than a normal sized bath (Cluett and Burns, 2009).
Intrapartum water immersion is thought to have a number of physiological and psychological benefits. Buoyancy in water increases mobility, enabling the women to adopt positions that maximise pelvic diameters. This in turn encourages fetal flexion, optimising fetal positioning (Ohlsson et al, 2001; Simkin and Ancheta, 2011b). Due to increased maternal comfort and pain alleviation in water, endogenous endorphins and oxytocin are released, supporting enhanced labour progress (Ginesi and Niescierowicz, 1998a; Ginesi and Niescierowicz, 1998b). Cluett and Burns (2009) suggest that immersion in water during labour significantly reduces the incidence of epidural or spinal analgesia and does not adversely affect duration of labour or neonatal wellbeing (Cluett and Burns, 2009). Water immersion is also thought to increase maternal satisfaction and a lead to a heightened sense of control (Richmond, 2003).
Midwives should be confident and competent in the care of women choosing to labour in water, including regularly checking maternal and pool temperature to ensure the mother does not become pyrexial; water temperature should not exceed maternal body temperature, or 37.5°C, with two midwives being present for birth (NICE, 2007; Cluett and Burns, 2009). The water pool becomes an intimate site for privacy, enabling women to surrender to the natural rhythms of labour, becoming fully immersed in the process.
Paracetamol is suggested to be the most commonly used drug worldwide
All pharmacological methods of pain management have side effects and contraindications (NICE, 2007; NMC, 2007; RCM, 2012a), which the midwife must fully inform the woman of so she is able to make an educated choice. How feasible is it for midwives to inform women to a sufficient level while they are in the midst of intense labour? Women who have reached a level of labour discomfort which prompts them to seek out pharmacological interventions, potentially having not considered them before labour, may not be in an emotionally rational state to consider the implications of their choices. The midwife therefore becomes essential in advising and supporting women to make sensitive choices appropriate for their stage of labour. Indeed, midwifery expertise in the recognition of method advantages and limitations, and intuitively recognising when to move on from a particular method, is key to enabling informed choice and woman-centred care. Midwives must risk-assess the wellbeing of the mother and the baby before, during and after the administration of any drug, as well as the efficacy of each method, in-keeping with NMC Standards (2007).
Paracetamol
Paracetamol is suggested to be the most commonly used drug worldwide (Sharma and Mehta, 2014), being extensively used for its analgesic and antipyretic effects (Malaise et al, 2007). Paracetamol is predominantly used in the latent phase of labour due to its availability over the counter, financial accessibility and excellent safety profile (Graham et al, 2005; Sharma and Mehta, 2014). The usual dose of oral paracetamol is 0.5-1g 4-6 hourly, with a maximum dose of 4g daily (Joint Formulary Committee (JFC), 2014). Paracetamol, as with all non-opioid analgesics, is thought to have a ceiling effect. That is to say, there is an upper limit to the pain relief that can be achieved, and taking further doses will not provide any further analgesia once this limit has been reached (Evron and Ezri, 2007; Othman et al, 2012). Lending itself to mild–moderate pain, such as that of early labour, the analgesic effect of paracetamol may not be sufficient once labour is established and pain severe. However, a recent study comparing the intrapartum use of paracetamol and pethidine intravenously suggests that paracetamol may be as effective as pethidine, with additional benefits of having far fewer maternal and fetal/neonatal side effects (Elbohoty et al, 2012). Further research would be beneficial on a larger scale in order to ascertain whether paracetamol could be considered a viable and potentially superior future option for intrapartum pain management.
| Methods | Benefits | Drawbacks |
|---|---|---|
| Self-generated/Complimentary and alternative therapies | Increased control and self-efficacy | May only offer short-term relief |
| Non-reliance on pharmacological methods | Can be expensive, may require additional midwifery training | |
| Tactile methods | Birth partner involvement | Difficulty to maintain for long periods of time |
| Physiologically working with pain gate theory | Varying levels of efficacy | |
| Water immersion | Increased positional mobility | Often only offered to low risk women |
| Enables a conducive intimate laboring environment | Additional midwifery attendance has implications on staff availability | |
| Paracetamol | Favourable safety profile | Potentially has a ceiling effect |
| Possibility of using intravenously | Often not considered in the labour context | |
| Entonox | Self-administered, heightening sense of control | Side effects can be unpleasant |
| Rapid excretion from the body | Excessively prolonged use can be detrimental to maternal and fetal wellbeing | |
| Opioids | Relaxation and sedation effects | Detrimental effects to the neonate including respiratory depression |
| Relatively inexpensive | Poor pain relief effect | |
| Epidural | Can eliminate all discomfort | Expensive, leading potentially to increased rates of intervention |
| Potential for reduced adrenaline and catecholamine levels | Limits maternal control |
Entonox
Entonox, 50% Nitrous Oxide (N2O) and 50% Oxygen (O2), is the most widely used form of inhalation analgesia in modern midwifery practice (Jones et al, 2013), and is frequently perceived as the first step on the ladder of analgesic options. Entonox is thought to have such wide uptake due to women's ability to easily self-administer, its rapid analgesic onset and swift elimination from the woman and baby. Furthermore, Entonox is non-offensive, and has not been shown to have any adverse effect on uterine contractions, with minimal toxicity and depression of the cardiovascular system (Rosen, 2002; Jones et al, 2013). Analgesic effect is dependent on achieving sufficient blood concentration by the peak of uterine contraction (Pang and O'sullivan, 2008). The mechanism of action remains unclear, although Maze and Fuginaga (2000) hypothesize that N2O induces the release of endogenous opioids.
Entonox is usually self-administered via a demand valve connected to a face-mask or mouthpiece, opening only on user inspiration (Pang and O'sullivan, 2008). The recommended administration of Entonox is intermittent, with women advised to begin inhaling when they first feel the contraction, and to stop when the peak of the contraction has passed (Pang and O'sullivan, 2008). This is thought to ensure adequate analgesic effect, while reducing prolonged exposure, associated with adverse outcomes including loss of fertility and miscarriage. As such, Entonox should not be used for more than 24 hours (British Oxygen Company Group, 2011). A systematic review on the efficacy of Entonox (Rosen, 2002) indicates a moderate level of evidence to support use in labour, being effective for some women (Pang and O'sullivan, 2008). However, side effects can include maternal drowsiness, hallucinations, vomiting, hyperventilation and it has been suggested that with excessively prolonged use comes a risk of maternal or fetal hypoxia (Jones et al, 2013).
Despite its rapid excretion from the body, Entonox is a pharmacological intervention with potentially unpleasant side effects and varying analgesic effect, yet often is perceived as innocuous. The role of the midwife in properly educating women is therefore vital. If midwives minimise the pharmaceutical nature of Entonox, not disclosing the extent of drawbacks, but rather emphasising advantages, informed consent is not achieved.
Opioids
Opioids including pethidine (also known as Meperidine or Demerol) and diamorphine are used in labour for their relaxation, sedation and analgesic effects (Jordan, 2010). This relatively inexpensive group of drugs are routinely available in obstetric units, with midwives being able to administer both pethidine and diamorphine during labour in line with midwives exemptions (Medicines and Healthcare Products Regulatory Agency, 2014). The maximum dose of pethidine in a 24 hour period is 400 mg (JFC, 2014), but this would be far above that which is ordinarily used, with most practitioners administering between 50–100 mg intramuscularly, repeated after 1–3 hours if needed (JFC, 2014). Diamorphine is often prescribed as 5 mg via intramuscular injection, repeated every 4 hours as necessary (JFC, 2014).
Because 34% of women use some type of opioid in birth settings (Ullman et al, 2011), it is imperative that midwives have a comprehensive understanding of the labour implications for introducing this type of pharmacological intervention, and that these are relayed to the women in their care. Chemically aking to the body's natural hormones, opioid analgesics act on those receptors which normally respond to endogenous endorphins (Jordan, 2010). Women may feel euphoric or dysphoric after administration, with extensive side effects including restlessness and delirium. Although possibly aiding relaxation, parenteral opioids offer only moderate success in relieving intrapartum pain (NICE, 2007; Ullman et al, 2011). With analgesic effects lessening dramatically after the first 2 hour period following administration, efficacy needs frank and transparent discussion with women to ensure that expectations are realistically managed.
Women may experience protracted stages of labour (Mander, 2011), with drowsiness limiting their abilities to utilise active birth positioning, itself perpetrating an array of subsequent sequelae (Lawrence et al, 2009). In addition, pethidine limits the access to other management strategies such as water immersion (NICE, 2007). Because of the impairment on consciousness levels, it is important to consider the impact of opioids on women's decision-making capabilities. Reduced sensitivity of the respiratory centre to carbon dioxide occurs with any opioid, necessitating vigilant respiratory monitoring (Gutstein and Akil, 2006). A thorough medical history is essential to rule out any underlying respiratory issues, especially with pethidine which additionally depresses the cough reflex. Midwives may administer an anti-emetic as recommended by NICE (2007) due to prevalence of nausea and vomiting side effects. Delayed gastric emptying could indicate the need for anticipatory administration of antacid drugs, although this could be considered to be overtly pre-emptive.
Opioids transfer rapidly across the placental barrier, with fetal tachycardia/bradycardia detected via fetal scalp electrodes within 7 minutes of administration via an intramuscular route (Jordan, 2010; Wee et al, 2011). Therefore, timing of administration needs careful midwifery assessment to avoid respiratory depression in the neonate. If delivery occurs within the first hour following administration there will be little impact as the drug will not have had time to cause an established effect. Maximum exposure time for the unborn baby is 2–3 hours after administration (Jordan, 2010), often putting midwives in the difficult position of weighing up maternal analgesic options while assessing delivery time frames. Short-term behavioural responsiveness can be affected in the neonate, with 3-6 day excretion rate having implications for feeding (Hogg et al, 1977; Nissen et al, 1995). A proactive midwifery approach to ensure the establishment of effective latch and milk transfer at the outset of the feeding relationship is essential.
Perhaps as Shoorab et al (2013)suggest, if opioids are to be used, the consideration of superior analgesic drugs such as remifentanil or fentanyl via a non-axial route could be explored. Administered intravenously, fentanyl is found to be an effective fast-acting analgesic, with decreased side-effects including less nausea and normal neonatal neurological capabilities within 2 hours following delivery. If opiates offer such a poor analgesic effect, and are primarily used by midwives for their relaxation qualities, the numerous side-effects and possible implications for the mother and baby diad should prompt midwives to discuss alternative non-pharmacological relaxation methods.
Epidural
The rate of accessing epidural analgesia has increased rapidly over recent years (Walsh, 2009; Tamagawa and Weaver, 2012; Health and Social Care Information Centre, 2013) despite the long list of potential side effects and maternal/neonatal morbidities (Jones et al, 2013).
Epidural anaesthesia is comprised of the administration of anaesthetic and/or opiates into the epidural space in the spinal column (Charles, 2013), effectively numbing the pain felt in labour. Epidurals are often the final and arguably the most invasive option of the intrapartum analgesia spectrum, promising the possibility of eliminating all maternal discomfort. Although highly effective when working well, if not correctly sited, epidural anaesthesia can leave women experiencing an uneven block (Carvalho and Cohen, 2013) with pain sensations being effectively removed down one side of the body but not the alternate side. Even when working, epidurals have detrimental effects on labour progress. The anaesthetising effect on the musculature of the pelvic floor, impacts fetal positioning (Simkin and Ancheta, 2011c) thereby altering the midwifery management of the second stage. Women's ability to push effectively potentially becomes impaired in the absence of spontaneous pushing sensations, and labour becomes progressively more interventionist with increased catheterisation, increased maternal observations, continuous fetal monitoring, and an increased incidence in oxytocin augmentation (Anim-Somuah et al, 2011).
NICE (2007) states that women should be advised of the positive and negative ramifications and implications of choosing epidural analgesia. Anim-Soumuah et al (2011) found that the use of epidural increased risk of instrumental birth, prolonged second stage and hypotension; and although not directly related to an increase in caesarean section, findings reported an increase of fetal distress resulting in caesarean section. The association of epidural and instrumental deliveries is well established (Nguyen et al, 2010; Eriksen et al, 2011; Jones et al, 2013), with maternal morbidities including dural headache. Neonatal morbidities include sequelae of instrumental delivery, and detrimental impact on breastfeeding (Jordan et al, 2009; Wiklund et al, 2009).
It is unquestionable that for some women epidural is the preferred and only option for labour analgesia, and this decision must be respected, yet necessitates women being in full receipt of the current evidence-base and holding a fully informed position in order to appropriately consent. Epidurals also have significant impact on midwifery care delivery, with the shift away from observing normality into an increasingly directive role. This requires great skill from the midwife to ensure women retain control and engagement in the experience of their own labour rather than becoming a passive participant of the process receiving direction, instead of midwifery facilitation. This subsequent shift in midwifery management needs to be clearly imparted to women, and the impact this may have on their birthing plans.
Conclusion
The advantages and disadvantages of labour pain management options are not straightforwardly defined. Rather, they demand an in depth and continually changing consideration of the individualistic dynamic continuum of each woman's labour. Working in a pharmacologically centric manner is to deny the physiological nature of normal birth and its inherent pain. Midwifery guidance and facilitation are centrally placed to enable women to make truly informed choices and conscious subsequent action plans for pain management. Birthing with a ‘level of low anxiety’ can be achieved if a woman's fear about coping with labour is assuaged (Odent, 2011: 75), placing antenatal communication at the forefront of high quality clinical practice, while intrapartum flexibility and the therapeutic environment are maintained.
The psychosocial ramifications of maternal control and satisfaction with labour pain management expectations (Hodnett, 2002) have extensive and far reaching effects on the wider family unit (Carvalho and Cohen, 2013). Any opportunity to empower women in their innate abilities to negotiate their birth experience with the care and methods appropriate to their social and cultural needs should be seized. It may be appropriate for midwives to consider labour pain as a process to be gone through, not a problem to be solved, and that managing and working with labour pain is superior to anaesthetising the birth experience (Leap and Anderson, 2008). The very essence of skilled midwifery practice within intrapartum pain management is the utilisation of an expansive, unlimited toolkit of strategies, intuitively pairing each individual woman with the methodology that best suits her changing labour needs.