Dystocia is the inability to expel neonates through the birth canal (O'Neill et al, 2018). The problem can manifest for a variety of reasons, such as anatomical abnormalities or the inability to perform contractions any longer. In the recent study by O'Neill et al (2018) of 18 758 bitches attending 50 veterinary clinics, there were 701 dystocia cases identified, giving a dystocia prevalence of 3.7%. The most common breeds diagnosed with dystocia cases were Chihuahua (10.7%), Staffordshire Bull Terrier (8.4%), Pug (6.1%), Jack Russell Terrier (6.1%) and crossbred (5.7%). The brachycephalic and toy breeds appeared to be at higher risk of dystocia.
Age was also shown in the O'Neill et al (2018) study to be a risk factor for dystocia: there was increased odds of dystocia among 3 to 6-year-old bitches compared with those aged under 3 years.
Mortality is a concern, and this has been indicated as 20% for the puppies and 1% for bitches. Dystocia therefore represents a major welfare issue for certain subsets of the domestic dog population. Veterinary nurses should be aware of all the issues described above.
This article will look at the bitch Caesarean, the effects the procedure has on the patient's body, and how to nurse the patient throughout the procedure to include the care of the neonates peri and post operatively.
The causes of dystocia in the bitch can be grouped into two categories: obstructive and non-obstructive (Table 1). Treatment, however, will depend on the individual patient, and the veterinary surgeon will decide the best treatment approach.
| Obstructive | Non obstructive |
|---|---|
| Pelvic trauma | Primary uterine inertia |
| Fetal presentation | Systemic illness |
| Uterine torsion | Secondary uterine inertia |
| Congenitally small pelvis, e.g. Welsh Corgi | Premature placental separation |
| Oversized fetus | Gestational diabetes |
Patient comfort on arrival
There are a number of reasons a whelping bitch will be asked to be brought to the veterinary practice, these include unproductive straining for more than 4 hours, if there is more than 2 hours between neonates, if she becomes systemically unwell or she has a foul smelling discharge or haemorrhage. There are some occasions when the situation will be treated as an emergency, in these cases there may be a fetal obstruction or malpresentation and surgery will be required immediately (O'Dwyer, 2014). This list is not exhaustive.
On arrival the owner will be seen by the veterinary surgeon (VS) who will complete a full clinical examination to include a vaginal examination to determine if the cervix is open or to feel for a neonate in the birth canal. When the bitch arrives in the preparation area she should be kept as calm and relaxed as possoble, as excitement and the increase in blood pressure will result in the release of catecholamines, which can then cause a decrease in uterine blood flow and could ultimately cause fetal hypoxia (Gendler, 2007).
The patient may present with dehydration, hypotension, lethargy/exhaustion, potentially haemorrhage and shock, depending on how long she has been in labour. It is advised to get baseline vital parameters at this point, this can be helpful when monitoring for fluctuations in the patient's respiratory and cardiovascular status, and when monitoring for any problems the patient may be having as outlined above.
Pre oxygenating the patient will assist with oxygen saturation — the weight of the gravid uterus on the diaphragm can cause respiratory difficulties, the lungs being unable to to fully ventilate. Be mindful not to cause further stress to the patient by holding a mask to her face. Robertson (2016) recommends pre oxygenation for 3–5 minutes with a mask prior to induction if it is well tolerated.
The VS may premedicate the patient. This will reduce the amount of anaesthetic required for induction and will help the patient with stress and anxiety levels. An opioid could be used as part of the pre anaesthesia medication; depending on the one chosen by the VS, it is useful to monitor the patient for emesis or aspiration pre and peri anaesthesia. Aspiration can be avoided by using the correct sized endotracheal tube. The patient will be eating little and often towards the end of the gestation period, this may result in stomach contents being present at the time of surgery (Thomas and Lerche, 2014). It is also common for the patient to have a decreased gastrointestinal mobility rate (Davidson, 2018), with the inclusion of the weight of the uterus this could also result in emesis. Use of an opioid such as methadone or bupranorphine would lower the risk of emesis (WSAVA, 2014).
The patient may also be dehydrated by the time they arrive at the surgery, this is however case specific. The VS will ascertain the dehydration status of the patient by completing a visual and clinical check of the patient. They will look for indications such as skin turgor, mucous membrane colour, sunken eyes and capillary refill time. The correct fluid rate can then be determined. Consideration should be given to any cardiac compromised patient as fluid therapy will assist with hypotension by increasing blood pressure, maintaining intravascular volume, and correcting any electrolyte abnormalities (Gendler et al, 2007). Crystalloids are commonly given to counteract the hypotensive nature of these patients, while they will also help with uterine blood flow. A more aggressive fluid therapy rate than the initial rate established for the individual may be needed if the patient is demonstrating changing clinical signs.
Prepare, prepare, prepare
The theatre should be prepared for the Caesarian section. A large surgical kit will be required with additional clamps to attach to the umbilical cords of the neonates. In addition, exploratory laparotomy swabs should be placed onto the tray; it is important to note these will need counting prior to surgery to ensure all have been removed before closure. It would also be advantageous to have a suction machine ready in case of any complications during surgery. The surgeon may want to lavage the abdomen if there has been any contamination during surgery.
The bitch may be placed in sternal recumbency while in the preparation room, or she may find a comfy position herself. Try to keep the chest elevated to relieve the pressure on the diaphragm. It is beneficial to try to clip the patient before she is induced as this can reduce induction to surgical closure time (Ebnar, 2016), and can therefore decrease the chance of fetal mortality and the risk the anaesthesia poses on the patient.
It is important to note that clipping while conscious should only take place if it does not cause further stress to the patient. The clip should cover the entirety of the abdomen length ways, but does not need to be very wide as nipple trauma from clippers will be uncomfortable when the bitch is feeding the puppies post operatively. When the patient has been clipped a first scrub using a chlorhexadine solution can be completed. Care must be taken not to stress the patient when clipping and handling as this may cause hypertension (Lloyd, 2017).
When the VS has induced the patient, she should be placed in dorsal recumbency. This will assist the decreased lung capacity and residual volume of the patient by reducing the pressure on the diaphragm. However, Robertson (2015) found there to be no immediate effect on blood pressure when the patient was being prepared in sternal recumbency as the gravid uterine horns would lie either side of major vessels. This is patient specific as giant breeds or those with higher numbers of puppies or large fetuses could compromise these major vessels when in dorsal recumbency.
Once the patient has been anaesthetised a second surgical scrub using a chlorhexadine solution can be performed. The patient's heart rate should be monitored — this can be done manually by palpating the lingual, pedal or digital arteries. A capnograph gives a useful indication of exhaled carbon dioxide levels and a pulse oximeter will measure oxygen saturation, both of these parameters give evidence of how the patient is coping under the anaesthetic. An oesophageal stethoscope can also be a good aid for monitoring the patient's heart rate as once in situ it can be left to be monitored through the ear pieces. Be mindful that these can cause regurgitation though. If available an electrocardiogram can be placed on the patient this will show the electrical activity of the heart and the heart rate, this would be a gold standard method of measuring the heart's activity.
Other methods of monitoring the patient would be to consider placing a doppler blood pressure monitor on the patient to establish if the patient was becoming hypotensive. The use of an oscillometric monitor would measure both systolic and diastolic readings and can be seen on a monitoring tower, therefore this may be the method used if available. It is gold standard to monitor mean arterial pressure during surgery and this would be completed using an invasive blood pressure monitoring method.
Monitoring the patient's temperature during the anaesthetic will give an early indication of hypothermia. Using a rectal thermometer is the easiest way of monitoring this and preventing the patient from becoming too cold; the placement of the thermometer can be difficult when the patient is underneath drapes therefore the use of an oesophageal stethoscope attached to a multi parameter monitor may be a more efficient way of monitoring temperature. The theatre table will require heat pads with blankets placed on top of these to prevent thermal burns. These should maintain the temperature of the patient; 38.3–39.2°C is considered the normal temperature (Cooper et al, 2015). Placing ‘hot hands’ with no protection between the patient and the glove can also cause trauma to the patient's skin, so this must be avoided also. Alternatives to these would be to use a bair hugger or ‘hot dog’; Phillips (2016) suggests active warming is gold standard for the patient. Warming of the intravenous fluids, by placing the giving set into an in-line warming device, could assist with maintaining normothermia (John et al, 2014); be mindful not to use a microwave as these can create hotspots which are damaging to tissues.
It is important to communicate with the VS regarding the number of expected puppies as this will enable the necessary preparations to be made. The following equipment is needed in preparation for the puppies:
Theatre
Once in theatre the VS will make a midline incision to the linea alba (Figures 2 and 3). The incision may be long to allow the neonates to be removed as quickly as possible. As this surgery is often performed out of hours there may be only one nurse performing both the anaesthesia and the revival of the puppies. If this is the case it is of paramount importance that all of the equipment is ready for both puppies and the bitch when the first incision is made. It would is beneficial, however, for other staff members to be available to assist when the VS opens up the uterine horns. The VS will place a puppy in the towel that is waiting ready in the hands of the nurse. The nurse will be required to briskly rub the puppy to provide warmth and to stimulate the puppy to breathe. At this point the neonate will have a small artery forcep clamp on its umbilical cord (Figure 4), and fetal membrane may need to be removed from around the nose and mouth. Once an open airway has been established and the puppy is seen to be breathing, and a heart rate and respiratory rate is established, the puppy can be placed into the prepared warm bedding. If the respiratory effort is absent then the cardiopulmonary resuscitation cycle should begin which consists of providing constant flow oxygen via a face mask for 1 minute, then positive pressure ventilations using a well fitted mask or an endotracheal tube and rebreathing bag (Davidson, 2016).
It used to be recommended to actively swing the puppy to remove any fluid from their respiratory system and stimulate them to breathe, but it is now not deemed best practice as it can cause accidental cerebral injury. Dugdale (2010) suggests holding the head down to alleviate any fluid build up in the airways if needed.
Any drug that can cross the blood brain barrier can also cross the placental barrier, this would include the anaesthetic drugs and any sedatives used. The induction agent used will reach the placenta resulting in the neonates becoming prone to hypotension (Ryan and Wagner, 2006).
During the anaesthetic the patient's cardiovascular system will have been under stress because of the increased uterine artery blood flow. The maternal blood volume will have increased compared with that in the non-pregnant bitch due to the presence of the puppies (Lopate, 2012). This will increase cardiac output, heart rate and stroke volume. During the anaesthetic it is important that the patient is monitored vigilantly. It is worth noting that induction apnoea can occur which will further cause a reduction in oxygen saturation (Chapman, 2011).
When the puppies have been removed the loss of pressure within the abdomen can cause hypotension in the bitch. This can be noted when a multi parameter monitoring system is in place, which is beneficial for these cases as discussed previously. Uterine laceration and haemorrhage during this procedure have also been recognised as potential complications (Aronson, 2015).
Recovery of the bitch
When the surgery is complete the patient should be placed in a kennel post extubation which has been pre prepared with bedding and heat pads, in a lateral recumbancy. Initial monitoring should consist of heart rate, pulse rate, temperature checks, mucous membrane colour and capillary refill time. The potential problems that this patient could face are anaemia, haemorrhage, wound dehiscence and peritonitis in the later stages of recovery (Slatter, 2002). Monitoring for these is important and regular checks should be carried out to ensure they are identified early on.
The surgical site should be checked for any infection, which would cause an increase in the patient's temperature and potentially cause a discharge. Any discharge or self trauma to the wound would be of concern and this should be checked by the nurse every 15 minutes initially. These checks should be demonstrated to the owner when they come to collect the patient and the puppies, so the owner can continue them at home. The home checks should continue hourly and decrease as the patient becomes more settled. Pain management of the bitch post operatively is important as this will encourage a shorter recovery period and allow her to take care of her puppies (Greer, 2014). The VS may choose to use an opioid to control pain.
Once the patient is conscious and ambulatory the puppies can be placed into the kennel with her to have their first feed. This is to prevent the patient from accidentally causing trauma to the puppies should there still be some levels of anaesthetic agent remaining systemically. Some surgeons may prefer to contact the owners and arrange for collection of the patient as soon as the patient is sitting up and stable and have her return home where she is familiar with surroundings and can nurse her puppies in her own nesting box. It is important to note the patient should be ambulatory before she is discharged.
Conclusion
Being faced with one of the more common elective/non elective surgeries seen in practice can be daunting. The bitch Caesarian section can provide many complications to her life and the puppies if the procedure is not managed with vigilant monitoring. It is important to remember the bitch's body is going through many changes from stress of parturition to hypotension and/or hypothermia, alongside many other side effects of anaesthesia.
Sometimes this procedure takes place out of hours when only a veterinary surgeon and a single veterinary nurse are available It is of paramount importance that all involved are organised and well versed in how the patient and puppies may react to a variety of situations.