Tuesday, 12 January 2010

ARDS in pregnancy

What is ARDS?

It is form of acute respiratory failure
characterized by (i) alveolar hypoxemia (ii) increased capillary permeability
resulting from diffuse & ongoing pulmonary inflammation.

Current definition
(i)acute onset
(ii) a PaO2/FIO2 ratio, or hypoxia score,of <=200, regardless of positive end expiratory pressure (iii) bilateral infiltrates on chest radio graph (iv) a pulmonary artery occlusion pressure of <=18 mm Hg or the absence of clinical evidence of left atrial hypertension. 4phases
(i)exudative phase-increased capillary permeability resulting in alveoli filled with fluid.(0-4days)
(ii)proliferative phase(4-8days)
(iii)fibrotic phase(>8 days)

2 type of causes

(i) Direct-(pulmonary causes)direct lung injury Example: Aspiration
(ii)Indirect(extrapulmonary causes) Ex:Acute pancreatitis in pregnancy

3 categories in pregnancy
(A)Pathogeneses Minimally Affected by Pregnancy (i)Sepsis with prolonged hypotension
(B)Pathogeneses Affected by pregnancy (i)aspiration (ii)acute pyelonephritis
(C)Pathogeneses unique to pregnancy (i)preeclampsia

Differential diagnosis

(i)Cardiogenic pulmonary odema
(ii)volume overload

Multidisciplinary management involving Obstetrician, Intensivists, Anaesthetists and Neonatologist.

3 aspects of management
(i)initial stabilization
(ii)confirming the diagnosis & identifying the aeitiology
(iii)assessing fetal well being & making the delivery plan

Treatment principles
(A) treat primary problem
(B)physiological support(lungs & other organs)
(C) avoid complications

Different methods of ventilatory support
(i)Noninvasive Positive-Pressure Ventilation-There is limitation in pregnancy due to raised risk of air way compromise & aspiration.
(ii)Lung-Protective Conventional Ventilation-(endotracheal intubation)

Advanced options :
(a)airway pressure-release ventilation (APRV)
(b)high-frequency oscillatory ventilation(HFOV)
(c)lung recruitment maneuvers(LRMs)
(d) prone positioning
(e) inhaled nitric oxide

Timing & mode of delivery
The available evidence is limited,so timing & mode of delivery should be as per standard obstetric practice.

PowerPoint presentations on ARDS (I) (II)
Excellent PowerPoint on Critical care in pregnancy

(1)Acute respiratory distress syndrome in pregnancy;Daniel E. Cole, MD; Tara L. Taylor, MD; Deirdre M. McCullough, MD; Catherine T. Shoff, DO;Stephen Derdak, DO (Crit Care Med 2005; 33[Suppl.]:S269 –S278)

(2)Acute Respiratory Distress Syndrome inPregnancy and the Puerperium: Causes,Courses, and Outcomes
Obstetrics & Gynecology:May 2001 - Volume 97 - Issue 5 - p 760-764

Monday, 11 January 2010

Conn's Syndrome in pregnancy

In pregnancy there is physiological up regulation of renin-angiotension-aldosterone system.

A powerpoint explaining Conn's syndrome

Image explaining Renin-Angiotensin-Aldosterone cascade

(I)Adrenal adenoma(60-80%)
(II)Adrenal hyperplasia(20-40%)
(III)Adrenal carcinoma rare

Clinical features
(I) Hypertension
(II)Muscle weakness

(II)radioactive selenium cholesterol test should be delayed until after delivery.
(III)suppressed renin activity
(IV) increased plasma aldosterone
(V)MRI of abdomen

Multidisciplinary care involving Obstetrician,Endocrinologist and Physicians.
Hypertension should be controlled by anti hypertensives (labetolol,methyldopa,nifidipine)

Hypokalaemia managed by
(A) Potassium supplementation
(B)Potassium sparing diuretics Amelioride is preferred over spironolactone because of anti androgenic property of the latter that could lead to feminizing a male fetus.

Surgery is effective in adrenal adenoma or carcinoma but the value is limited in adrenal hyperplasia.Surgery could be postponed until after delivery.If surgery is indicated for

(i) Fluid & electrolyte balance should be maintained.

(I) Pituitary and adrenal disorders complicating pregnancy:Chandraharan, Edwin; Arulkumaran, Sabaratnam

Current Opinion in Obstetrics and Gynecology:April 2003 - Volume 15 - Issue 2 - pp 101-107

(2)Nelson-Piercy C. Handbook of obstetric medicine. Taylor & Francis; 2002.

(3)Swiet MD. Medical disorders in obstetric practice. Wiley-Blackwell; 2002.
(4)Laparoscopic treatment of primary hyperaldosteronism in a pregnant patient
(5)Primary aldosteronism in pregnancy.Matsumoto J, Miyake H, Isozaki T, Koshino T, Araki T.J Nippon Med Sch. 2000 Aug;67(4):275-9

Sunday, 3 January 2010

Cushing's Syndrome in Pregnancy

Excellent Powerpoint on Cushing's syndrome


(i)adrenal adenoma-disproportionately more common in pregnancy(40-50% Vs 17-19%)

(iii)ectopic ACTH

Clinical features

(I) Weight gain
(II) Hypertension
(III)Glucose intolerance
(IV)Purple striae

The above features aren't uncommon in pregnancy.

(V)Proximal myopathy

Changes in normal pregnancy

raised (i)total cortisol (ii)free cortisol levels (iii) urinary cortisol (iv) cortisol binding globulin

Corticotropin releasing hormone is secreted by placenta.

How does Cushing's Syndrome affects pregnancy?

(I) In untreated Cushing's syndrome hypothalamic pituitary axis is suppressed,so the patients tend to infertile.

(II) most common complications are hypertension & diabetes

(III) less frequent complications are osteoporosis,delayed wound healing and psychiatric complications

(IV) fetal complications -miscarriage,prematurity,intrauterine growth restriction & still births.

Maternal cortisol can cross the placenta.

(i)Increased rate of miscarriage
(ii)Premature delivery
(iii)Still birth


Tests used for diagnosis

Pregnancy specific ranges should be examined

(i) 24 hour urinary free cortisol-Higher cutoff need to be used in pregnancy.

(ii)midnight serum cortisol -Physiological nocturnal drop is the serum cortisol level is also observed Cushing's syndrome.Higher cut off values should be used.

(iii)dexamethasone suppression test-

2 types of test

(A)overnight dexamethasone suppression test-1mg dexamethasone given at 23.00 hrs and serum cortisol is measured at 9am

(B)48 hour dexamethasone suppression test 0.5 mg given

6 hourly(9.00,15.00,21.00,3.00 hrs).Serum cortisol measured 9.00 at

the start & end of test.

The suppression effect on cortisol by dexamethasone is diminished in normal pregnancy.

So the usefulness of dexamethasone suppression is limited in pregnancy.

Once the Cushing's syndrome is confirmed, further tests done find the aeitiology.

If ACTH level is low adrenal imaging with MRI is useful.However adrenal' incidentaloma'(non secreting adrenal tumors can be found in 2-1% of abdominal CT's.It is important to correlate the CT findings to clinical & biochemical findings.

If ACTH level is elevated,high dose dexamethasone suppression test helps in differentiating between pituitary source vs ectopic ACTH.MRI of head or MRI of chest & abdomen can be arranged accordingly.

High dose of dexamethasone suppress cortisol in Cushing's disease but the suppression fails in adrenal adenoma & ectopic ACTH secretion.

ACTH measurement-ACTH level reduced in adrenal adenoma.

CRH (corticotropin releasing hormone) stimulation test-Pituitary tumors would show rise in cortisol but adrenal adenoma & Ectopic ACTH wouldn't.


Multidisciplinary approach involving Obstetrician,Endocrinologist,Anaesthetist and Surgeon is important.

It's important to control the blood pressure and diabetes mellitus.

Definitive treatment options depend on aeitiology.
(I) Adrenal adenoma-Adrenalectomy
(II)Cushing's disease-Transsphenoidal treatment,Medical treatment or adrenalectomy.

adrenalectomy in Pitutary adenoma could lead to Nelson syndrome

(III)Ectopic ACTH-resection of the source.

medical treatment can be used but generally surgery is the preferred.

Medical treatment options


(II)ketoconozole-This crosses the placenta,so there is a theoretical risk of inhibition of fetal adrenal cortex. Ketaconozole is also teratogenic in animal studies.

(III)metyrapone-can cause severe hypertension.

Medical treatment isn't currently recommended due to potential adverse side effects on fetus.

Post natal

(I) lactation is discouraged because

(a)there is possibility permanent galactorrhoea.

(b)drugs may be secreted into breast milk(ex.cyproheptadine)

(II) Neonate should be reviewed for potential intrauterine suppression of hypothalmic pituitary adrenal axis suppression.

(i) Cushing's syndrome in pregnancy: an overview.Vilar L, Freitas Mda C, Lima LH, Lyra R, Kater CE.
Arq Bras Endocrinol Metabol. 2007 Nov;51(8):1293-302.

(ii)Cushing syndrome in pregnancy .Deborah J. Cook, MD, FRCPC,Robert H. Riddell, MD, FRCPath,John D. Booth, MD, FRCPC. CMAJ, VOL. 141, NOVEMBER 15, 1989,pp1059-1061

(3)Nelson-Piercy C. Handbook of obstetric medicine. Taylor & Francis; 2002.

(4)Swiet MD. Medical disorders in obstetric practice. Wiley-Blackwell; 2002.

(5)Pituitary and adrenal disorders complicating pregnancy:Chandraharan, Edwin; Arulkumaran, Sabaratnam
Current Opinion in Obstetrics and Gynecology:April 2003 - Volume 15 - Issue 2 - pp 101-107