Pheochromocytoma and pregnancy: a case report and review of anesthetic management

PURPOSE: To describe a patient diagnosed with pheochromocytoma in the third trimester of pregnancy and discuss the perioperative and anesthetic management. CLINICAL FEATURES: A 32-yr-old previously healthy woman (gravida 4, para 2) presented to our tertiary care obstetrical hospital at 34 weeks five days gestation with a history of labile blood pressure and severe hypertension. A week prior to admission she began having episodes of severe headache, dizziness, sweating and nausea. On a routine obstetric visit she was noted to be severely hypertensive with a blood pressure of 200/120 mmHg. Biochemical investigations confirmed the diagnosis of pheochromocytoma and magnetic resonance imaging demonstrated a 3 cm x 3 cm right adrenal mass. The patient was invasively monitored in the intensive care unit and treated with alpha- followed by beta-blockade with phenoxybenzamine and metoprolol. A multidisciplinary conference was organized involving endocrinology, anesthesiology, general surgery and obstetrics to determine the most appropriate management of the patient. An uncomplicated laparoscopic adrenalectomy was performed following a period of recovery after an uneventful elective Cesarean delivery. CONCLUSIONS: The primary goals in the management of pheochromocytoma in pregnancy are early diagnosis, avoidance of a hypertensive crisis during delivery and definitive surgical treatment. Timing of surgical resection will depend on the gestational age at which diagnosis is made. Cesarean section is the preferred mode of delivery when the tumour is still present. This case illustrates that with antenatal diagnosis, advanced methods of tumour localization, adequate preoperative adrenergic blockade and team planning, pheochromocytoma in pregnancy can be treated successfully.     

P07Reduction of Allogeneic Red Cell Transfusion using Autologous Blood Cell Salvage in Knee Arthroplasty

Recent Hospital Transfusion Committee (HTC) audit at the Royal Bournemouth Hospital (RBH) confirmed an allogeneic red cell transfusion rate of 20% for primary Total Knee Replacement (TKR). Current policy at RBH states that when blood stocks reach 67% of normal (amber alert) then surgery with a >20% likelihood of blood transfusion will be cancelled. At current transfusion rates this would include primary TKR. Recent studies have shown a reduction in allogeneic transfusion rates when autologous transfusion drains are utilized. The purpose of this study was to see whether the current rate of allogeneic transfusion could be reduced with the introduction of the CellTransTM Autologous Knee Drainage Blood Transfusion System (ABT) in TKR at RBH. Over a 3 month period all patients undergoing primary, bilateral or revision knee arthroplasty received an ABT. Demographic data was collected from the orthopaedic pre‐assessment clinic. Following surgery further data was collected relating to volume of blood loss into the drain, volume of autologous blood re‐transfused, units of allogeneic blood required and the transfusion trigger, postoperative haemoglobin levels, infection rates and length of stay in hospital. We then compared this data set with retrospective data. Of 170 patients undergoing knee arthroplasty 141 received the ABT. The data collected was compared retrospectively with 169 patients from the previous 3 month period. We demonstrated a reduction in transfusion rates of 13% for primary TKR, 42% for bilateral TKR and 57% for revision TKR with the use of the ABT. In addition we demonstrated a reduction in total allogeneic blood use (99 units to 26 units) and a reduction in mean length of stay in hospital (8.6 days to 7.5 days) with the ABT. Further analysis of the data collected showed a 46% reduction in the allogeneic transfusion rate and a reduction in total allogeneic blood usage (99 units to 9 units) of anaemic patients presenting for surgery. This study has demonstrated a dramatic reduction in allogeneic blood transfusion rates with the use of the CellTransTM Autologous Blood Transfusion System. We have also shown a reduction in length of stay in hospital. Prior to the study primary total knee replacement would have been cancelled during times of limited blood availability (amber alert). The use of the ABT is good for the patient in reducing the need for allogeneic blood, and in addition has demonstrated a significant cost saving due to the reduced blood usage and potential prevention of cancelled operation lists.     

The nigral projection to predorsal bundle cells in the superior colliculus of the rat.

Predorsal bundle cells give rise to the major efferent pathway from the superior colliculus to the premotor centers of the brainstem and spinal cord responsible for initiating orienting movements. The activity of predorsal bundle cells is profoundly influenced by an inhibitory pathway from substantia nigra pars reticulata that uses gamma aminobutyric acid (GABA) as a neurotransmitter. The present study examines the morphological basis for this influence of substantia nigra on predorsal bundle cells in the rat. In the first experiments, the laminar distributions of the nigrotectal tract terminals and the predorsal bundle cells were compared. The predorsal bundle cells were labeled by the retrograde axonal transport of horseradish peroxidase from either the decussation of the predorsal bundle or the cervical spinal cord, while the terminations of the pathway from substantia nigra pars reticulata were labeled by anterograde axonal transport from the substantia nigra. Either horseradish peroxidase, wheat germ agglutinin conjugated to horseradish peroxidase, or Phaseolus vulgaris leucoagglutinin were used as anterograde tracers. The results showed that the distributions of both the predorsal bundle cells and the nigrotectal terminals are restricted almost entirely to the intermediate grey layer and that they overlap extensively. Predorsal bundle cells varied in size. Within the areas of maximum overlap, the majority, regardless of size, was closely apposed by nigrotectal terminals. In a second series of experiments, the synaptic contacts between nigrotectal terminals and the tectospinal component of the predorsal bundle were examined in tissue in which both the terminals and the tectospinal cells were labeled for electron microscopy. In the final experiments, the distribution and fine structure of the nigrotectal terminals were compared to those of terminals that had been labeled immunocytochemically with an antibody to glutamic acid decarboxylase, the synthesizing enzyme for GABA. The results showed that nigrotectal terminals contain large numbers of mitochondria and pleomorphic vesicles, and form synaptic contacts with the somas and proximal dendrites of tectospinal cells. These synapses have modest postsynaptic densities. In both their distribution and fine structure, these terminations resemble the glutamic acid decarboxylase immunoreactive terminals that contact tectospinal cells. Taken together, these results support the view that the nigrotectal tract is an important source of GABAergic input to most, if not all, predorsal bundle cells.     

Modulation of fluoroaluminate-induced inositol phosphate formation by increases in tissue cyclic AMP content in bovine tracheal smooth muscle.

1. The effect of fluoroaluminate complexes (AlCl3 plus NaF) upon smooth muscle tone, [3H]-inositol phosphate accumulation and [3H]-cyclic AMP accumulation has been investigated in slices of bovine tracheal smooth muscle. 2. Fluoroaluminate (10 microM AlCl3 + various concentrations of NaF) elicited concentration-dependent contractions of bovine tracheal smooth muscle strips at concentrations of NaF in the range 1-10 mM. The resultant contractile response was reversed by isoprenaline (50 nM) and was preserved in calcium-free medium. 3. Fluoroaluminate stimulated [3H]-inositol phosphate formation at concentrations of NaF over 1 mM. The response to 20 mM NaF + 10 microM AlCl3 was 164 +/- 29% of the response to 1 mM histamine. Fluoroaluminate also increased the incorporation of [3H]-myo-inositol into membrane phospholipids. 4. Fluoroaluminate produced a small rise in [3H]-cyclic AMP levels (2.1 fold increase over basal with 20 mM NaF). The response to forskolin (1 microM, 8.6 fold over basal) was reduced by fluoroaluminate in a concentration-dependent manner, but still remained significantly (P less than 0.05) elevated over the response to fluoroaluminate alone. 5. The [3H]-inositol phosphate response to fluoroaluminate was inhibited by salbutamol (maximum inhibition 60%, IC50 = 0.08 microM), forskolin (1 microM, 46% inhibition) and isobutylmethylxanthine (1 mM, 73% inhibition). 6. These data suggest that inhibition of agonist-induced inositol phospholipid turnover by cyclic AMP in this tissue can occur at the post-receptor level.     

The sonographic appearances in postpartum thyroiditis.

During the postpartum period about 50% of women with circulating thyroid autoantibodies develop a transient autoimmune thyroiditis. To determine the sonographic appearances in postpartum thyroiditis (PPT), serial ultrasound (US) scans of the thyroid were performed in 135 postpartum women who were divided into three clinical groups: Group 1, 37 antibody positive subjects who developed PPT; Group 2, 28 antibody positive subjects in whom thyroid function remained normal; Group 3, 70 antibody negative controls. Thyroid hypoechogenicity was observed in 14/31 patients (45%) who were scanned between 4 and 8 weeks postpartum and who subsequently developed PPT (Group 1) compared with 4/24 patients (17%) in Group 2 (P less than 0.05) and 1/65 patients (1.5%) in Group 3 (P less than 0.001). In antibody positive patients, the positive predictive value of an abnormal scan during this period was 78%. Between 15 and 25 weeks postpartum thyroid hypoechogenicity was present in 32/37 patients (86%) in Group 1 compared with 11/28 patients (39%) in Group 2 (P less than 0.001) and 2/70 patients (3%) in Group 3 (P less than 0.001). Sonographic abnormality persisted beyond 32 weeks postpartum in 36/41 antibody positive patients (87%) who had exhibited thyroid hypoechogenicity earlier during the study and who had late scans. The characteristic US appearance in PPT is thyroid hypoechogenicity. The role of sonography in the prediction, diagnosis and follow up of patients with PPT is discussed.     

Insulin regulates the 35 kDa IGF binding protein in patients with diabetes mellitus

The serum levels of the low molecular form of insulin-like growth factor binding protein (IGFBP) was determined in 56 outpatients with diabetes mellitus by a radioimmunoassay developed for amniotic 35 kDa IGFBP. The mean level of 35 kDa IGFBP was found to be threefold higher in insulin dependent diabetes mellitus (IDDM), 112 +/- 13 ng/ml, than in age matched controls, 37 +/- 2 ng/ml, while the mean level in non-insulin dependent diabetes mellitus (NIDDM), 16 +/- 2 ng/ml, was decreased. In hospitalized IDDM patients there was a significant correlation (r = 0.91, p less than 0.01) between fasting blood-glucose and 35 kDa IGFBP levels, not found in NIDDM patients. During insulin infusion the 35 kDa IGFBP levels declined with a half-life of 60-120 min. The decline in IGFBP continued even after the establishment of steady state B-glucose at 4.7 mmol/l. In conclusion, the elevated 35 kDa IGFBP levels in IDDM can be attributed to insulin deficiency and may reflect a reduced bioavailability of the IGFs at the target cells.     

Nerve growth factor effects on inhibition by submandibular gland ablation or autonomic denervation of activity-induced parotid growth.

Present data confirm our earlier report that an increase in [3H]thymidine incorporation into DNA of parotid gland occurs with reintroduction of solid chow to rats previously maintained on liquid diet; if, however, the submandibular-sublingual glands are removed prior to the dietary substitution, the increase is prevented (present data and [19]). In addition, present data show that administration of nerve growth factor (NGF) to partially sialoadenectomized rats during the 2-day period of dietary change from liquid to solid diet restores thymidine values to the high levels observed following the dietary change in intact animals. However, the increase in gland size that accompanied the change in dietary consistency was not prevented by prior submandibular gland ablation, and administration of NGF had no influence on gland size or cell size. The removal of both the sympathetic and parasympathetic nerves to the parotid gland prior to the dietary manipulation also suppressed [3H]thymidine incorporation into parotid, and values did not differ from chow controls. The data show that NGF, a submandibular growth factor, has a prominent role in regulation of the autonomically-mediated hyperplastic response. However, neither the submandibular gland nor NGF has an important role in regulation of the increase in gland size that also accompanies the dietary change.