- Email: [email protected]
Anaesthetic management of a parturient with Laron syndrome
344
Laron syndrome
preparation methods and of blood films with histology. J Clin Microbiol 2003;41:1370–4. 13. Wedel D, Horlocker T. Regional anesthesia in the febrile or infected patient. Reg Anesth Pain Med 2006;31:324–34. 14. Cook TM, Counsell D, Wildsmith JAW. Major complications of central neuraxial block: report on the Third National Audit Project
of the Royal College of Anaesthetists. Br J Anaesth 2009;102: 179–90. 15. Choi S, Brull R. Neuraxial techniques in obstetric and nonobstetric patients with common bleeding diatheses. Anesth Analg 2009;109:648–60.
0959-289X/$-see front matter c 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.ijoa.2011.06.003
Anaesthetic management of a parturient with Laron syndrome K. Bhatia, R. Cockerham Department of Anaesthetics, St. Mary’s Hospital & Manchester Royal Infirmary, Manchester, UK ABSTRACT We report a case of a parturient with Laron syndrome, a rare form of dwarfism which results from an inability to generate insulinlike growth factor 1. In addition to dwarfism these patients may have craniofacial abnormalities, atlantoaxial instability, spinal stenosis and metabolic, musculoskeletal and genitourinary abnormalities. The patient underwent an urgent caesarean section using combined spinal-epidural anaesthesia. Laron syndrome is reviewed and its anaesthetic implications discussed. c 2011 Elsevier Ltd. All rights reserved.
Keywords: Anaesthesia; Combined spinal-epidural; Laron syndrome
Introduction Laron syndrome (LS) is an autosomal recessive disease caused by deletions1 or mutations in the growth hormone receptor gene.2,3 Defects in growth hormone signal transmission lead to an inability to generate insulin-like growth factor 1 (IGF-1)4 so affected patients fail to respond to growth hormone of either exogenous or endogenous origin resulting in proportionate dwarfism. The exact incidence is not known but around 250 cases have been reported worldwide mostly of Mediterranean or Middle Eastern origin.5 The male-to-female ratio for LS varies from 0.5–1.5:1.6 We describe our anaesthetic management for caesarean section (CS) in a patient with LS with preeclampsia and thrombocytopenia.
Case report A 26 year old primigravida (height 110 cm; body mass index 41.3 kg/m2) was booked for elective CS due to cephalopelvic disproportion. She had previously been diagnosed with LS and had well-controlled asthma but she was not referred for antenatal anaesthetic assessment. She was admitted as an emergency at 37 weeks of gestation with preeclampsia, headache, photophobia and proteinuria Accepted June 2011 Correspondence to: Dr. R. Cockerham, Department of Anaesthetics, St. Mary’s Hospital, Oxford Road, Manchester M13 9WL, UK. E-mail address: [email protected]
300 mg/dL. Her blood pressure (BP) was 180/90 mmHg which was stabilised with oral labetalol 100 mg. Two hours after admission she went into labour and an urgent CS was planned. Paediatric notes revealed that two consultant paediatric anaesthetists had struggled to intubate the patient’s trachea (Cormack and Lehane grade 3 laryngoscopy, 6.0mm tracheal tube passed on the third attempt with the aid of a bougie and external laryngeal pressure) when she was anaesthetised for grommet insertion at age 13 years. Anaesthetic assessment revealed a high pitched voice, small mouth with a Mallampati class 3 airway and a short neck with a thyromental distance of 6 cm. Admission blood results revealed a haemoglobin (Hb) 9.6g/dL, white cell count 5.6 · 109/L, platelet count 133 · 109/L and serum uric acid 0.36 mmol/L. After discussion with the patient of the potential risks and benefits of general (GA) compared with neuraxial anaesthesia, it was decided to perform the operation under combined spinal-epidural (CSE) anaesthesia. A 16-gauge peripheral intravenous cannula, electrocardiogram, pulse oximetry and invasive arterial BP monitoring were established in theatre. With the patient in the sitting position, the epidural space was detected at 5 cm with a 16-gauge Tuohy needle using a loss-of-resistance to saline technique at the L3–4 intervertebral space. After apparent aspiration of cerebrospinal fluid (CSF) through a 26-gauge Whitacre needle, 0.5% hyperbaric bupivacaine 4 mg and fentanyl 15 lg were injected. The epidural catheter was easily threaded into the epidural space and the patient transferred to the supine wedged position.
K. Bhatia, R. Cockerham After 20 min, there was no detectable sensory or motor block in the lower limbs and the sacral dermatomes. She was returned to a sitting position and using a 27-gauge Whitacre needle in the L4-5 interspace, a repeat intrathecal injection of 0.5% hyperbaric bupivacaine 4 mg and fentanyl 15 lg was given. Within 5 min the patient had a sensory block of T4 bilaterally. Surgery was commenced and after 5 min a healthy female infant weighing 2.6 kg was delivered. Blood loss was estimated at 300 mL and one litre of crystalloid was infused intravenously. Surgery was completed uneventfully, the epidural catheter removed and the patient given intravenous morphine patient-controlled analgesia. She was transferred to the obstetric high-dependency unit for postoperative monitoring. After surgery, we discovered that the platelet count was not 133 · 109/L as conveyed to us on the telephone but 33 · 109/L. Pseudothrombocytopenia was excluded using a citrated sample. Results from repeat samples were Hb 7.6 g/dL, white cell count 6.4 · 109/L, platelets 90 · 109/L and a normal coagulation profile. She was closely monitored but did not develop neurological symptoms and was discharged home on the tenth day; the delay due to social reasons.
Discussion We believe this is the first reported case of CS in a patient with LS. The syndrome was first described in Table 1
345 1966 and again in 1968 in a group of Oriental Jewish patients. The clinical features are indistinguishable from those of untreated isolated growth hormone deficiency, but patients with LS have high levels of growth hormone and undetectable levels of serum IGF-1.7,8 Two types of dwarfism are described in the literature: proportionate, such as LS where there is a normal trunk-limb ratio; and disproportionate including achondroplasia, where the trunk is short in relation to the limbs or short limbs in relation to the trunk. The significant manifestations of LS with their anaesthetic implications are summarised in Table 1.6,9–12 Our patient was keen to be awake for the procedure and with co-morbities of morbid obesity, preeclampsia, asthma and a potentially difficult airway, we considered neuraxial anaesthesia preferable. Choosing an adequate intrathecal local anaesthetic dose is difficult in this group of patients. Under dosage results in inadequate anaesthesia for CS and over dosage may result in a high spinal. We therefore opted for a CSE allowing placement of a small intrathecal dose of local anaesthetic and opioid to initiate the block, the final height of which could then be titrated using the epidural. Alternative neuraxial techniques would be either continuous spinal anaesthesia; however, we had no experience of this technique; or titrated de novo epidural anaesthesia, but this technique has a significant failure rate.13 There are case reports of achondroplastic dwarves developing a bilat-
Laron syndrome: manifestations and anaesthetic implications Manifestations
Central Nervous System Cerebellar atrophy Lacunar infarcts Spinal stenosis Airway
Large head Narrow oropharynx Sleep apnoea Atlanto-odontoid joint degeneration and os odontoideum. (dens separation from axis body)
Anaesthetic implications Preoperative assessment for neurological symptoms and signs
Consider flexion/extension radiographs of cervical spine with MRI of spine Anticipate difficult intubation and have necessary equipment available Consider awake fibre-optic intubation
Cardio-respiratory
Exaggerated respiratory embarrassment from gravid uterus and severe aortocaval compression
Cardio-respiratory compromise may warrant early delivery Consider invasive blood pressure monitoring
Metabolic
Asymptomatic hypoglycaemia, hypercholesterolemia and osteoporosis
Monitor blood sugar, appropriate positioning during surgery
Genital Tract
Small pelvis
Increased rates of miscarriage, stillbirths and a higher rate of CS
Musculo-skeletal
Reduced interpedencular distances
Increased technical difficulty with neuraxial anaesthesia Possible increased risk of neurological damage during neuraxial anaesthesia Consider spinal MRI to assess the lower level of spinal cord
Degenerative changes in the spine. (more in disproportionate dwarves)
MRI magnetic resonance imaging.
346 eral T4 block following spinal anaesthesia with of 0.5% hyperbaric bupivacaine 1–1.3 mL.14,15 No recommendations for dosing exist for dwarves or adults less than 148 cm tall. Disproportionate dwarves have a relatively longer trunk so may require relatively larger doses of local anaesthetic than might be expected for their height. Our patient was proportionate and shorter, so we selected 0.5% hyperbaric bupivacaine 0.8 mL. We were concerned about using long-acting neuraxial opioids since there are no recommendations on dosing in dwarfism so we added the short-acting intrathecal fentanyl to improve the quality of the block and did not use the epidural catheter for administration of postoperative opioids. The uncertainty regarding dose–response relationship with neuraxial opioids necessitates a high level of postoperative monitoring for at least 24 h. The first spinal anaesthetic failed to demonstrate any sensory block 20 min after the injection. Possible reasons for such failure have been comprehensively reviewed.16–18 In our case, we feel that we mistook saline injected during location of the epidural space, for CSF and deposited the drug epidurally, although we cannot rule out an anatomical abnormality as a cause as magnetic resonance imaging was not done. After the failure of the first spinal anaesthetic we decided not to top-up the epidural because should it fail in this case we would have to convert to GA, which we were keen to avoid. There was no fetal distress, so the spinal was repeated. If our second spinal had failed we would have then topped-up her epidural. Thrombocytopenia occurs in 50% of preeclamptic patients and occasionally precedes other manifestations of the disease.19 There was no excessive bleeding during surgery and the platelet count was 90 · 109/L on repeat sample 5 h later. Fortunately there were no neurological sequelae postoperatively. Whilst neuraxial block has been reported in patients with thrombocytopenia,20–23 we are not recommending this technique at such low platelet counts. If we had known the platelet count was <50 · 109/L we would have transfused platelets to cover the CS and a decision regarding neuraxial anaesthesia would have been made after a risk-benefit discussion with the patient This case report highlights the problems associated with LS, successful use of neuraxial anaesthesia and the need for effective communication between the anaesthetist, haematologist and obstetrician while dealing with a complex patient.
References 1. Godowski PJ, Leung DW, Meacham LR, Galgani JP, Hellmiss R, Keret R. Characterisation of the human growth receptor gene and demonstration of partial gene deletion in 2 patients with Laron type dwarfism. Proc Natl Acad Sci USA 1989;86:8083–7. 2. Rosenfeld RG, Rosenbloom AL, Guevara-Aguirre J. Growth hormone (GH) insensitivity due to primary GH receptor deficiency. Endocr Rev 1994;15:369–90.
Laron syndrome 3. Amsalem S, Sobrier ML, Dastot F, Duquensnoy O, Duriez B, Goossens M. Molecular basis of inherent growth hormone resistance in childhood. Baillieres Clin Endocrinol Metab 1996;10:353–9. 4. Laron Z, Pertzelan A, Karp M, Kowadlo-Silbergeld A, Daughaday WH. Administration of growth hormone to patients with familial dwarfism with high plasma immunoreactive growth hormone. Measurement of sulfation factor, metabolic and linear growth responses. J Clin Endocrinol Metab 1971;33:332–42. 5. Laron Z. Laron – type dwarfism (hereditary somatomedin deficiency): a review. In: Frick P, Von Harnack GA, Kochsiek A, Prader A, editors. Advances in internal medicine and paediatrics. Berlin, Heidelberg: Springer Verlag; 1984. p. 117–50. 6. Wetterau AL, Armando F. Laron syndrome. http://emedicine.medscape.com/article/922902-overview; 2009 [accessed Jan 10]. 7. Laron Z, Pertzelan A, Mannheimer S. Genetic pituitary dwarfism with high serum concentration of growth hormone: a new inborn error of metabolism? Isr J Med Sci 1966;2:152–5. 8. Laron Z, Pertzelan A, Karp M. Pituitary dwarfism with high level of growth hormone. Isr J Med Sci 1968;4:883–94. 9. Laron Z. Growth hormone insensitivity (Laron Syndrome). Rev Endocr Metab Disord 2002;3:347–55. 10. Fuller AJ, Ratner EF, Cohen SE. Parturients of short stature. In: Gambling D, Douglas J, Robert S, Mackay F, editors. Obstetric anaesthesia and uncommon disorders. Philadelphia: Cambridge University Press; 2008. p. 115–28. 11. Kornreich L, Horev G, Schwarz M, Karmazyn B, Laron Z. Laron syndrome abnormalities: spinal stenosis, os odontoideum, degenerative changes of the atlanto-odontoid joint, and small oropharynx. Am J Neuroradiol 2002;23:625–31. 12. Allanson JE, Hall JG. Obstetric and gynecolologic problems in women with chondrodystrophies. Obstet Gynecol 1986;67:74–8. 13. Obstetric Anaesthesia Association. Epidural information card. http://www.oaa-anaes.ac.uk/assets/_managed/editor/File/ Info%20for%20Mothers/EIC/2008_eic_english.pdf;2009 [accessed Jan 10]. 14. Ravenscroft AJ, Govender T, Rout C. Spinal anaesthesia for emergency caesarean section in an achondroplastic dwarf. Anaesthesia 1998;53:1236–7. 15. Crawford M, Dutton DA. Spinal anaesthesia for caesarean section in an achondroplastic dwarf. Anaesthesia 1992;47:1007. 16. Drasner K, Rigler M. Repeat injection after a ‘‘failed spinal’’: at times a potentially unsafe practice. Anesthesiology 1991;75:713–4. 17. Hoppe J, Popham P. Complete failure of spinal anaesthesia in obstetrics. Int J Obstet Anesth 2007;16:250–5. 18. Fettes PDW, Jansson JR, Wildsmith JAW. Failed spinal anaesthesia: mechanisms, management, and prevention. Br J Anaesth 2009;102:739–48. 19. Kam PCA, Thompson SA, Liew ACS. Thrombocytopenia in the parturient. Anaesthesia 2004;59:255–64. 20. Tobias MB, Krzystof MK, Benumof JL. Uneventful epidural labor analgesia in a parturient with immune thrombocytopenic purpura and platelet count of 26000/mm3 which was unknown pre-operatively. J Clin Anesth 2004;16:51–3. 21. Rasmus KT, Rottman RL, Kotelko DM, Wright WC, Stone JJ, Rosenblatt RM. Unrecognised thrombocytopenia and regional anaesthesia in parturients: a retrospective review. Obstet Gynecol 1989;73:943–6. 22. Beilin Y, Zahn J, Comerford M. Safe epidural analgesia in thirty parturients with platelet counts between 69000 and 98000/mm3. Anesth Analg 1997;85:385–8. 23. Frenk V, Camann W, Shankar KB. Regional anesthesia in parturients with low platelet counts. Can J Anesth 2005;52:114.
0959-289X/$-see front matter c 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.ijoa.2011.06.005
Laron syndrome
preparation methods and of blood films with histology. J Clin Microbiol 2003;41:1370–4. 13. Wedel D, Horlocker T. Regional anesthesia in the febrile or infected patient. Reg Anesth Pain Med 2006;31:324–34. 14. Cook TM, Counsell D, Wildsmith JAW. Major complications of central neuraxial block: report on the Third National Audit Project
of the Royal College of Anaesthetists. Br J Anaesth 2009;102: 179–90. 15. Choi S, Brull R. Neuraxial techniques in obstetric and nonobstetric patients with common bleeding diatheses. Anesth Analg 2009;109:648–60.
0959-289X/$-see front matter c 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.ijoa.2011.06.003
Anaesthetic management of a parturient with Laron syndrome K. Bhatia, R. Cockerham Department of Anaesthetics, St. Mary’s Hospital & Manchester Royal Infirmary, Manchester, UK ABSTRACT We report a case of a parturient with Laron syndrome, a rare form of dwarfism which results from an inability to generate insulinlike growth factor 1. In addition to dwarfism these patients may have craniofacial abnormalities, atlantoaxial instability, spinal stenosis and metabolic, musculoskeletal and genitourinary abnormalities. The patient underwent an urgent caesarean section using combined spinal-epidural anaesthesia. Laron syndrome is reviewed and its anaesthetic implications discussed. c 2011 Elsevier Ltd. All rights reserved.
Keywords: Anaesthesia; Combined spinal-epidural; Laron syndrome
Introduction Laron syndrome (LS) is an autosomal recessive disease caused by deletions1 or mutations in the growth hormone receptor gene.2,3 Defects in growth hormone signal transmission lead to an inability to generate insulin-like growth factor 1 (IGF-1)4 so affected patients fail to respond to growth hormone of either exogenous or endogenous origin resulting in proportionate dwarfism. The exact incidence is not known but around 250 cases have been reported worldwide mostly of Mediterranean or Middle Eastern origin.5 The male-to-female ratio for LS varies from 0.5–1.5:1.6 We describe our anaesthetic management for caesarean section (CS) in a patient with LS with preeclampsia and thrombocytopenia.
Case report A 26 year old primigravida (height 110 cm; body mass index 41.3 kg/m2) was booked for elective CS due to cephalopelvic disproportion. She had previously been diagnosed with LS and had well-controlled asthma but she was not referred for antenatal anaesthetic assessment. She was admitted as an emergency at 37 weeks of gestation with preeclampsia, headache, photophobia and proteinuria Accepted June 2011 Correspondence to: Dr. R. Cockerham, Department of Anaesthetics, St. Mary’s Hospital, Oxford Road, Manchester M13 9WL, UK. E-mail address: [email protected]
300 mg/dL. Her blood pressure (BP) was 180/90 mmHg which was stabilised with oral labetalol 100 mg. Two hours after admission she went into labour and an urgent CS was planned. Paediatric notes revealed that two consultant paediatric anaesthetists had struggled to intubate the patient’s trachea (Cormack and Lehane grade 3 laryngoscopy, 6.0mm tracheal tube passed on the third attempt with the aid of a bougie and external laryngeal pressure) when she was anaesthetised for grommet insertion at age 13 years. Anaesthetic assessment revealed a high pitched voice, small mouth with a Mallampati class 3 airway and a short neck with a thyromental distance of 6 cm. Admission blood results revealed a haemoglobin (Hb) 9.6g/dL, white cell count 5.6 · 109/L, platelet count 133 · 109/L and serum uric acid 0.36 mmol/L. After discussion with the patient of the potential risks and benefits of general (GA) compared with neuraxial anaesthesia, it was decided to perform the operation under combined spinal-epidural (CSE) anaesthesia. A 16-gauge peripheral intravenous cannula, electrocardiogram, pulse oximetry and invasive arterial BP monitoring were established in theatre. With the patient in the sitting position, the epidural space was detected at 5 cm with a 16-gauge Tuohy needle using a loss-of-resistance to saline technique at the L3–4 intervertebral space. After apparent aspiration of cerebrospinal fluid (CSF) through a 26-gauge Whitacre needle, 0.5% hyperbaric bupivacaine 4 mg and fentanyl 15 lg were injected. The epidural catheter was easily threaded into the epidural space and the patient transferred to the supine wedged position.
K. Bhatia, R. Cockerham After 20 min, there was no detectable sensory or motor block in the lower limbs and the sacral dermatomes. She was returned to a sitting position and using a 27-gauge Whitacre needle in the L4-5 interspace, a repeat intrathecal injection of 0.5% hyperbaric bupivacaine 4 mg and fentanyl 15 lg was given. Within 5 min the patient had a sensory block of T4 bilaterally. Surgery was commenced and after 5 min a healthy female infant weighing 2.6 kg was delivered. Blood loss was estimated at 300 mL and one litre of crystalloid was infused intravenously. Surgery was completed uneventfully, the epidural catheter removed and the patient given intravenous morphine patient-controlled analgesia. She was transferred to the obstetric high-dependency unit for postoperative monitoring. After surgery, we discovered that the platelet count was not 133 · 109/L as conveyed to us on the telephone but 33 · 109/L. Pseudothrombocytopenia was excluded using a citrated sample. Results from repeat samples were Hb 7.6 g/dL, white cell count 6.4 · 109/L, platelets 90 · 109/L and a normal coagulation profile. She was closely monitored but did not develop neurological symptoms and was discharged home on the tenth day; the delay due to social reasons.
Discussion We believe this is the first reported case of CS in a patient with LS. The syndrome was first described in Table 1
345 1966 and again in 1968 in a group of Oriental Jewish patients. The clinical features are indistinguishable from those of untreated isolated growth hormone deficiency, but patients with LS have high levels of growth hormone and undetectable levels of serum IGF-1.7,8 Two types of dwarfism are described in the literature: proportionate, such as LS where there is a normal trunk-limb ratio; and disproportionate including achondroplasia, where the trunk is short in relation to the limbs or short limbs in relation to the trunk. The significant manifestations of LS with their anaesthetic implications are summarised in Table 1.6,9–12 Our patient was keen to be awake for the procedure and with co-morbities of morbid obesity, preeclampsia, asthma and a potentially difficult airway, we considered neuraxial anaesthesia preferable. Choosing an adequate intrathecal local anaesthetic dose is difficult in this group of patients. Under dosage results in inadequate anaesthesia for CS and over dosage may result in a high spinal. We therefore opted for a CSE allowing placement of a small intrathecal dose of local anaesthetic and opioid to initiate the block, the final height of which could then be titrated using the epidural. Alternative neuraxial techniques would be either continuous spinal anaesthesia; however, we had no experience of this technique; or titrated de novo epidural anaesthesia, but this technique has a significant failure rate.13 There are case reports of achondroplastic dwarves developing a bilat-
Laron syndrome: manifestations and anaesthetic implications Manifestations
Central Nervous System Cerebellar atrophy Lacunar infarcts Spinal stenosis Airway
Large head Narrow oropharynx Sleep apnoea Atlanto-odontoid joint degeneration and os odontoideum. (dens separation from axis body)
Anaesthetic implications Preoperative assessment for neurological symptoms and signs
Consider flexion/extension radiographs of cervical spine with MRI of spine Anticipate difficult intubation and have necessary equipment available Consider awake fibre-optic intubation
Cardio-respiratory
Exaggerated respiratory embarrassment from gravid uterus and severe aortocaval compression
Cardio-respiratory compromise may warrant early delivery Consider invasive blood pressure monitoring
Metabolic
Asymptomatic hypoglycaemia, hypercholesterolemia and osteoporosis
Monitor blood sugar, appropriate positioning during surgery
Genital Tract
Small pelvis
Increased rates of miscarriage, stillbirths and a higher rate of CS
Musculo-skeletal
Reduced interpedencular distances
Increased technical difficulty with neuraxial anaesthesia Possible increased risk of neurological damage during neuraxial anaesthesia Consider spinal MRI to assess the lower level of spinal cord
Degenerative changes in the spine. (more in disproportionate dwarves)
MRI magnetic resonance imaging.
346 eral T4 block following spinal anaesthesia with of 0.5% hyperbaric bupivacaine 1–1.3 mL.14,15 No recommendations for dosing exist for dwarves or adults less than 148 cm tall. Disproportionate dwarves have a relatively longer trunk so may require relatively larger doses of local anaesthetic than might be expected for their height. Our patient was proportionate and shorter, so we selected 0.5% hyperbaric bupivacaine 0.8 mL. We were concerned about using long-acting neuraxial opioids since there are no recommendations on dosing in dwarfism so we added the short-acting intrathecal fentanyl to improve the quality of the block and did not use the epidural catheter for administration of postoperative opioids. The uncertainty regarding dose–response relationship with neuraxial opioids necessitates a high level of postoperative monitoring for at least 24 h. The first spinal anaesthetic failed to demonstrate any sensory block 20 min after the injection. Possible reasons for such failure have been comprehensively reviewed.16–18 In our case, we feel that we mistook saline injected during location of the epidural space, for CSF and deposited the drug epidurally, although we cannot rule out an anatomical abnormality as a cause as magnetic resonance imaging was not done. After the failure of the first spinal anaesthetic we decided not to top-up the epidural because should it fail in this case we would have to convert to GA, which we were keen to avoid. There was no fetal distress, so the spinal was repeated. If our second spinal had failed we would have then topped-up her epidural. Thrombocytopenia occurs in 50% of preeclamptic patients and occasionally precedes other manifestations of the disease.19 There was no excessive bleeding during surgery and the platelet count was 90 · 109/L on repeat sample 5 h later. Fortunately there were no neurological sequelae postoperatively. Whilst neuraxial block has been reported in patients with thrombocytopenia,20–23 we are not recommending this technique at such low platelet counts. If we had known the platelet count was <50 · 109/L we would have transfused platelets to cover the CS and a decision regarding neuraxial anaesthesia would have been made after a risk-benefit discussion with the patient This case report highlights the problems associated with LS, successful use of neuraxial anaesthesia and the need for effective communication between the anaesthetist, haematologist and obstetrician while dealing with a complex patient.
References 1. Godowski PJ, Leung DW, Meacham LR, Galgani JP, Hellmiss R, Keret R. Characterisation of the human growth receptor gene and demonstration of partial gene deletion in 2 patients with Laron type dwarfism. Proc Natl Acad Sci USA 1989;86:8083–7. 2. Rosenfeld RG, Rosenbloom AL, Guevara-Aguirre J. Growth hormone (GH) insensitivity due to primary GH receptor deficiency. Endocr Rev 1994;15:369–90.
Laron syndrome 3. Amsalem S, Sobrier ML, Dastot F, Duquensnoy O, Duriez B, Goossens M. Molecular basis of inherent growth hormone resistance in childhood. Baillieres Clin Endocrinol Metab 1996;10:353–9. 4. Laron Z, Pertzelan A, Karp M, Kowadlo-Silbergeld A, Daughaday WH. Administration of growth hormone to patients with familial dwarfism with high plasma immunoreactive growth hormone. Measurement of sulfation factor, metabolic and linear growth responses. J Clin Endocrinol Metab 1971;33:332–42. 5. Laron Z. Laron – type dwarfism (hereditary somatomedin deficiency): a review. In: Frick P, Von Harnack GA, Kochsiek A, Prader A, editors. Advances in internal medicine and paediatrics. Berlin, Heidelberg: Springer Verlag; 1984. p. 117–50. 6. Wetterau AL, Armando F. Laron syndrome. http://emedicine.medscape.com/article/922902-overview; 2009 [accessed Jan 10]. 7. Laron Z, Pertzelan A, Mannheimer S. Genetic pituitary dwarfism with high serum concentration of growth hormone: a new inborn error of metabolism? Isr J Med Sci 1966;2:152–5. 8. Laron Z, Pertzelan A, Karp M. Pituitary dwarfism with high level of growth hormone. Isr J Med Sci 1968;4:883–94. 9. Laron Z. Growth hormone insensitivity (Laron Syndrome). Rev Endocr Metab Disord 2002;3:347–55. 10. Fuller AJ, Ratner EF, Cohen SE. Parturients of short stature. In: Gambling D, Douglas J, Robert S, Mackay F, editors. Obstetric anaesthesia and uncommon disorders. Philadelphia: Cambridge University Press; 2008. p. 115–28. 11. Kornreich L, Horev G, Schwarz M, Karmazyn B, Laron Z. Laron syndrome abnormalities: spinal stenosis, os odontoideum, degenerative changes of the atlanto-odontoid joint, and small oropharynx. Am J Neuroradiol 2002;23:625–31. 12. Allanson JE, Hall JG. Obstetric and gynecolologic problems in women with chondrodystrophies. Obstet Gynecol 1986;67:74–8. 13. Obstetric Anaesthesia Association. Epidural information card. http://www.oaa-anaes.ac.uk/assets/_managed/editor/File/ Info%20for%20Mothers/EIC/2008_eic_english.pdf;2009 [accessed Jan 10]. 14. Ravenscroft AJ, Govender T, Rout C. Spinal anaesthesia for emergency caesarean section in an achondroplastic dwarf. Anaesthesia 1998;53:1236–7. 15. Crawford M, Dutton DA. Spinal anaesthesia for caesarean section in an achondroplastic dwarf. Anaesthesia 1992;47:1007. 16. Drasner K, Rigler M. Repeat injection after a ‘‘failed spinal’’: at times a potentially unsafe practice. Anesthesiology 1991;75:713–4. 17. Hoppe J, Popham P. Complete failure of spinal anaesthesia in obstetrics. Int J Obstet Anesth 2007;16:250–5. 18. Fettes PDW, Jansson JR, Wildsmith JAW. Failed spinal anaesthesia: mechanisms, management, and prevention. Br J Anaesth 2009;102:739–48. 19. Kam PCA, Thompson SA, Liew ACS. Thrombocytopenia in the parturient. Anaesthesia 2004;59:255–64. 20. Tobias MB, Krzystof MK, Benumof JL. Uneventful epidural labor analgesia in a parturient with immune thrombocytopenic purpura and platelet count of 26000/mm3 which was unknown pre-operatively. J Clin Anesth 2004;16:51–3. 21. Rasmus KT, Rottman RL, Kotelko DM, Wright WC, Stone JJ, Rosenblatt RM. Unrecognised thrombocytopenia and regional anaesthesia in parturients: a retrospective review. Obstet Gynecol 1989;73:943–6. 22. Beilin Y, Zahn J, Comerford M. Safe epidural analgesia in thirty parturients with platelet counts between 69000 and 98000/mm3. Anesth Analg 1997;85:385–8. 23. Frenk V, Camann W, Shankar KB. Regional anesthesia in parturients with low platelet counts. Can J Anesth 2005;52:114.
0959-289X/$-see front matter c 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.ijoa.2011.06.005