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Overcoming anaesthetic challenges in a pregnant woman with pituitary apoplexy undergoing endoscopic trans-sphenoidal resection of the pituitary tumour
  1. Priya Thappa,
  2. Charu Sharma,
  3. Ashwini Reddy and
  4. Amiya Kumar Barik
  1. Anaesthesia and Intensive Care, PGIMER, Chandigarh, India
  1. Correspondence to Dr Amiya Kumar Barik; amiyabarik.scb{at}gmail.com

Abstract

Pituitary apoplexy is a rare condition that occurs due to acute haemorrhage in the pituitary gland and usually presents with features of acute hypopituitarism, visual defects and ophthalmoplegia. Pregnancy is one of the risk factors for pituitary apoplexy. Medical management is the first line of management in pregnancy irrespective of the gestational age. However, acute neuro-ophthalmological deterioration might warrant an urgent surgical decompression. Preoperative corticosteroids have dual benefits of providing hormonal replacement in the mother and also promoting fetal lung maturity in the offspring. Uterine contractions should be monitored and tocolysis provided as per requirements in a post-viable fetus.

  • Pituitary disorders
  • Neuroanaesthesia
  • Neuroendocrinology
  • Pregnancy

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Background

Pituitary apoplexy is an endocrine emergency that can occur due to haemorrhagic infarction of a pre-existing pituitary adenoma or even in a physiologically enlarged gland. It is characterised by an abrupt-onset headache, and endocrinological and neuro-ophthalmological deterioration. Acute hypercortisolism can cause nausea, hyponatraemia and severe hypotension. If the tumour capsule and arachnoid membrane are breached, the patients can present with meningism, neck stiffness and photophobia. Hypothalamic involvement can cause cardiac arrhythmia and lead to cardiovascular collapse, respiratory disturbances, temperature dysregulations and diabetes insipidus. The visual disturbances include ophthalmoplegia and visual field defects. The prevalence of pituitary apoplexy is around 1/10 000 pregnancies at term and the mean gestational age of occurrence is 24 weeks.1 2 Early symptoms in a parturient especially the visual symptoms may be overlooked due to physiological changes or obstetric complications like pre-eclampsia. We describe a case of pituitary apoplexy in a pregnant patient undergoing endoscopic trans-sphenoidal surgery (TSS) and discuss the various anaesthetic concerns in such patients.

Case presentation

A patient in her 20s with no known comorbidities at 30-week period of gestation presented to the outpatient department with headache for 3–4 months, and visual disturbances in the form of blurring of vision and visual field defects for 1 month, which had worsened for the last 1 day. There was no history of nausea, vomiting, fever, trauma, galactorrhoea, stria over the abdomen or loss of consciousness. On examination, she had a Glasgow Coma Scale E4V5M6, with normal vitals. Her visual acuity was 6/6 and 6/60 in the right and left eyes, respectively. Perimetry suggested the presence of a bitemporal field defect and funduscopy revealed normal discs. She had a normal range of movements for extraocular muscles, no sensorimotor deficits or cranial nerve palsies. Her hormonal profile was normal (serum cortisol at 08:00: 198 nmol/L (138–635 nmol/L) and 16:00: 106 nmol/L (83–359 nmol/L), serum thyroid-stimulating hormone: 2.52 μIU/mL (0.27–4.2 μIU/mL), serum T4: 7.47 μg/dL (4.8–12.7 µg/dL), serum T3: 1.23 ng/mL (0.8–2 ng/mL)) except for raised prolactin (42.3 ng/mL) levels (normal value is <25 ng/mL). MRI showed the presence of a lesion in the sellar region with the size of 23×17×21 mm with a fluid level suggestive of haemorrhage (figure 1). A diagnosis of prolactinoma with pituitary apoplexy was made and the patient was started on the tablet cabergoline 0.5 mg two times per week and injection of hydrocortisone 100 mg three times a day with strict haemodynamic and neuro-ophthalmological examinations. But in view of the deteriorating visual status, the decision for an urgent endoscopic trans-sphenoidal resection of the tumour was made. A multidisciplinary team including a neurosurgeon, neurologist, obstetrician, endocrinologist and anaesthesiologist was involved in the management of the patient.

Figure 1

(A) T1-weighted MRI (axial section) showing mildly hyperintense lesion in the sellar region. (B) T2-weighted MRI (coronal section) showing hyperintense cystic lesion in the sella extending to the suprasellar cistern and causing compression and displacement of the optic chiasm. (C) T2-weighted MRI (sagittal section) hyperintense cystic lesion in the sella with fluid–fluid level within the mass suggestive of haemorrhage.

The patient was given an injection of dexamethasone and progesterone 250 µg preoperatively. Fetal heart rate (FHR) monitoring was done preoperatively by an obstetrician and the parturient was explained the risk to the fetus and may require an emergency caesarean delivery. After taking written informed consent, the patient was premedicated with an injection of ranitidine 150 mg and an injection of metoclopramide 10 mg. The patient was shifted to the operation theatre table with a 15° wedge placed under her right hip to maintain the left uterine displacement. Preoperative standard American Society of Anesthesiologists monitors like ECG, non-invasive blood pressure, pulse oximetry, alongside neuromuscular monitoring (NMT) and bispectral index (BIS), were attached. Difficult airway cart was kept ready. She was pre-oxygenated for 3 min with a target end-tidal oxygen of 90%. Modified rapid sequence induction was carried out with fentanyl 1.5 µg/kg, propofol 1.5 mg/kg and succinylcholine 1 mg/kg and intubated with a 7.0 mm internal diameter (ID)/ polyvinyl chloride (PVC)/cuffed endotracheal tube (ETT) while maintaining cricoid pressure. The tube was secured at the left corner of the mouth and an 18 G Ryle’s tube was inserted orally for stomach deflation. The hypopharynx of the patient was gently packed with soft and moist gauze. The left radial artery was cannulated using a 20 G cannula for invasive blood pressure monitoring and arterial blood gas sampling. The patient was maintained with an air oxygen mixture (1:1), propofol infusion titrated to BIS of 40–60, fentanyl 80 µg boluses every hour, an atracurium 25 mg bolus followed by 5 mg guided by NMT values. Because of the raised blood pressure, the surgical field was obscured with blood. Hence, the blood pressure of the parturient was decreased to normal values using dexmedetomidine infusion (0.2–0.4 µg/kg/hour) and labetalol (20 mg). Goal-directed intravenous fluid (0.9% sodium chloride) infused with target pulse pressure variation <13% was also administered. Continuous electronic FHR and uterine contractions monitoring was done by the obstetrician. Normothermia, mild hypocapnia (target arterial carbon dioxide pressure (PaCO2): 28–32 mm Hg) and normoglycaemia were maintained. Towards the end of the surgery, propofol infusion was decreased to target BIS of 60 and dexmedetomidine continued at 0.2 µg/kg/hour. After the surgery, the anaesthesia was stopped, endotracheal lidocaine was given to prevent cough and neuromuscular blockade was reversed with neostigmine 50 µg/kg and glycopyrrolate 10 µg/kg. The patient was extubated when she became conscious and obeyed commands. Postoperatively, analgesia was maintained with intravenous acetaminophen 1 g 8 hourly and fentanyl 0.5 µg/kg as and when required. Continuous FHR and uterine contractions monitoring was performed for 6 hours followed by intermittent monitoring. She was started on thyroxine, and hydrocortisone was continued for 3 days and tapered off gradually. On postoperative day (POD) 3, she developed diabetes insipidus and was put on tablet desmopressin 0.1 µg once daily, which got resolved by POD 7, and the patient was discharged from the hospital.

Outcome and follow-up

She was discharged from the hospital on POD 7 and was advised to continue tablet hydrocortisone 5 mg three times a day and was kept on follow-up. The patient underwent a lower-segment caesarean section on the 39th week of gestation.

Discussion

Pituitary apoplexy is a potentially life-threatening condition that usually occurs in patients with pituitary adenomas. Systemic hypertension, major surgery, dynamic hormonal testing, oestrogen therapy, radiation therapy, coagulopathies and pregnancy are known to be the precipitating factors of apoplexy. During pregnancy, the pituitary gland increases in size by two to threefold due to high oestradiol levels.3 The increase in the size of the pituitary gland, hormonal changes and haemodynamic changes associated with pregnancy predispose the patient to apoplexy.4 Dopamine agonists have shown a good tumour reduction for prolactinomas as well as good safety profile for the fetus.5 Hence, medical management remains the first line of management. Surgical indications in the case of apoplexy during pregnancy include a deteriorating level of consciousness or a significant or progressive neuro-ophthalmological deficit. In a case series, it was found that 61% of patients required hormonal replacement, while 42% of patients required surgery during pregnancy.1 Non-contrast MRI does not increase the risk of adverse fetal outcomes at any trimester of the pregnancy and is considered safe as there is no exposure to ionising radiation.6 7

Maintenance of normal hormonal milieu and haemodynamics of the patient forms the cornerstone of the management of pituitary apoplexy. The pregnancy gives us an additional target to maintain the uteroplacental circulation along with maintaining the cerebral perfusion pressure of the patient. Early multidisciplinary involvement becomes vital for the management of the patient. The first concern in such a patient would be the preoperative hormonal replacement and haemodynamic and metabolic stabilisation. The patients can have altered sensorium, refractory hypotension and dyselectrolytaemia, which responds to injection of hydrocortisone 100 mg bolus followed by 50–100 mg 6 hourly. Preoperative assessment by an obstetrician is also strongly recommended and the risk of fetal teratogenesis and neurotoxicity should be explained to the patient. Second trimester onwards, the airway aspiration risk becomes considerable due to physiological changes in lower oesophageal sphincter tone and should be dealt with using adequate anti-aspiration prophylaxis. Also, 16th week onwards, the gravid uterus can cause inferior vena cava compression leading to hypotension, and cerebral and placental hypoperfusion. Hence, the patients should be positioned in the supine position with a wedge under the right hip to lift off the weight of the uterus. Third, the upper airway mucosal congestion along with friability pose a risk of bleeding during intubation and throat packing and therefore should be done gently. Also, the friable nasal mucosa can pose a challenge for the surgeon concerning the quality of the surgical field. Reduced functional residual capacity and increased oxygen consumption in the parturient decrease apnoea time. Therefore, difficult airway carts should be kept ready with the availability of small-sized ETTs.

Regarding intraoperative haemodynamics, the induced hypotension generally done in TSS patients is not done in pregnant patients and normotension should be targeted. However, in patients with hypertensive disorders of pregnancy, normotension can be maintained using the beta-blockers, dexmedetomidine, hydralazine, nifedipine, diazoxide and nicardipine, especially during the vasoconstrictor instillation. The ventilatory management should be adjusted to maintain the normal maternal range PaCO2 of 28–32 mm Hg. Permissive hypercapnia usually employed for improving the visualisation of the tumour is not an attractive option for the pregnant patient. Maternal hypercapnia quickly results in fetal respiratory acidosis, which shifts the fetal oxygen dissociation curve to the right, decreasing the ability to bind oxygen to fetal haemoglobin.8 The anatomical difficulties, increased risk of traumatic tap and technical difficulties of positioning the patient can make the lumbar drain placement a tedious job. Simultaneously, FHR monitoring based on the gestational age has to be ensured. A pre-procedural and post-procedural FHR documentation using a Doppler is sufficient for a pre-viable fetus; however, for a viable fetus, FHR should be monitored along with uterine contractions.9 Intraoperative steroid (2–4 mg/hour) cover should be continued throughout the surgery for 24 hours. Adequate hydration, haemoglobin levels and temperature have to be strictly maintained. Prophylactic corticosteroids are beneficial for fetal lung maturation and prophylactic hormonal support is usually given. Tocolytics could be administrated during the third trimester in the case of contractions.4 A hawk’s eye must be kept on the hourly urine output and serum sodium levels for prompt diagnosis and management of diabetes insipidus. During extubation, a smooth and rapid emergence should be done with avoidance of coughing over the tube which can be prevented by continuing the dexmedetomidine infusion and giving endotracheal lidocaine, intravenous lidocaine and esmolol boluses.

Postoperatively, neuro-ophthalmological status, urine output, serum electrolytes and postoperative cerebrospinal fluid leak should be checked. As postoperative pain and stress can precipitate labour, the provision of adequate analgesia is important. Scheduled acetaminophen usually suffices for postoperative analgesia and non-steroidal anti-inflammatory drugs should be avoided. The patient’s hormonal status has to be monitored and the steroid replacement adjusted accordingly.

Xia et al have reported a similar case of anaesthetic management of a pregnant patient undergoing endoscopic trans-sphenoidal resection of a macroprolactinoma during her second trimester. However, the patient in the above-mentioned study underwent a scheduled surgery and had no evidence of pituitary apoplexy unlike ours.10

Patient’s perspective

I was very disturbed initially and I thought I will lose my eyesight. But I am grateful to the team of doctors who treated me. Now, I am relieved and happy about my baby. Thank you so much.

Learning points

  • Anaesthetic management of a pregnant patient with pituitary apoplexy is quite a challenge as there are three main targets of concern: mother, fetus and pituitary gland.

  • A thorough knowledge of the physiological changes of pregnancy, endocrine physiology, understanding of the disease, meticulous planning, multidisciplinary approach and execution is required to conduct a successful case.

  • While anaesthetic management is challenging, the goals are clear, which include acute hormonal, haemodynamic and metabolic stabilisation of the patient, management of anticipated difficult airway, and the standard goals of maintaining normotension, normovolaemia, normothermia and mild hypocapnia to ensure adequate uteroplacental perfusion and appropriate fetal monitoring.

  • The perioperative urine output and sodium levels should be carefully monitored due to the risk of diabetes insipidus.

Ethics statements

Patient consent for publication

References

Footnotes

  • Contributors The following authors were responsible for drafting of the text, sourcing and editing of clinical images, investigation results, drawing original diagrams and algorithms, and critical revision for important intellectual content—PT, CS and AKB. The following authors gave final approval of the manuscript—AKB and AR.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Case reports provide a valuable learning resource for the scientific community and can indicate areas of interest for future research. They should not be used in isolation to guide treatment choices or public health policy.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.