Thursday, October 15, 2009

Alcohol withdrawal

Today we discussed alcohol withdrawal syndromes. Some important points:

This is a common problem, accounting for ~25% of ER visits by homeless patients. It is likely under-recognized in patients not presenting specifically for this problem. In Ontario, ~20% of the population has intake of over 14 drinks / week.

Clinical manifestations depend on timing since last drink.

Early (6-36h):
"Minor": anxiety, headache, tremor, diaphoresis, tachycardia, nausea/vomiting.
Seizures: May occur very early (i.e. with EtOH level still high)
Characteristics of withdrawal sz:
1) Generalized, tonic clonic (not focal; focal sz or Todd's paresis suggests alternative cause, which EtOH abusers are also at risk for)
2) May be multiple
3) Short (minutes)
4) Self-resolving, with minimal post-ictal phase

-most commonly visual or tactile. Not associated with decreased LOC.

Delirium tremens
All of above possible, with superimposed autonimic instability (fever, severe HTN, tachycardia). Mortality of DT is ~5%. Major causes for mortality are arrhythmias, ACS, pneumonia.

Treatment principles:
1) Benzodiazepines
2) Vitamin / nutrient supplementation (thiamine, B6)
3) Supportive care

Some points about treatment:
-Medications studied include benzos (long-acting, e.g. diazepam), barbiturates, and propofol. Outside the rare ICU setting, mainstay is long acting benzos.
-Common error is to underdose; it is difficult to cause benzodiazepine toxicity in the typical patient who has EtOH withdrawal
-No role for antipsychotics; they may be harmful by lowering the seizure threshold
-Options for benzo dosing are 1) clinically-driven (e.g. CIWA) or 2) standing/tapering regardless of symptoms
There is RCT evidence (see below) supporting a symptom/sign-driven approach over infusion and taper regardless of clinical status; there was less total benzodiazepine needed, less overall withdrawal severity, and shorter ICU stays in this group.

Click here for the Spies et al RCT of symptom-driven treatment protocol
Click here for a NEJM RCT supporing IV ativan vs. placebo for recurrent EtOH withdrawal seizure prevention

Wednesday, October 7, 2009

COPD management

Classic representation of
"blue bloater" on left- hypoxia, CO2 retention, possible R heart failure.
"pink puffer" on right- preserved blood gases, cachexia, dyspnea
Most COPD patients have features of both, and this classification is not frequently used

COPD stages and therapy
(from GOLD initiative)

0: At risk- pts with chronic symptoms, normal spirometry, exposure to risk factors
Tx: Avoid triggers, smoking cessation, flu vaccine, education

1: Mild COPD- FEV1/FVC below 70% , FEV1 over 80% of predicted, with or without symptoms
Tx: Above, and short-acting bronchodilator

2: Moderate COPD- FEV1/FVC below 70%, FEV1 50-80% predicted
Tx: Above, and regular LA bronchodilator (e.g. tiotroprium), pulmonary rehab

3: Severe COPD- FEV1/FVC below 70%, FEV1 30-50%
Tx: Above, and home O2 if PaO2 below 55
Other treatments rarely used: Theophylline, lung reduction surgery

Etiologies of exacerbations:

Majority are infection-related (80%)- H. Flu (20-30%); S. Pneumo (10-15%); M. Catarrhalis (10-15%); P. Aeruginosa (5-10%); Rhinoviruses (20-25%).

15-20% are from other causes (air pollution, irritants increasing bronchomotor tone)

Treatment components are

1) Bronchodilators (B-ag and anticholinergic)

2) Systemic steroids

3) ABx

4) Ventilatory support if needed (including BiPAP)

Abx choices:

Mild exacerbation: 1 of increased dyspnea, increased sputum purulence, increased sputum volume

Tx: No antibiotics; increase bronchodilator. Symptomatic therapy and monitoring symptoms

Moderate or severe 2 of above 'cardinal symptoms'

In complicated COPD (i.e. at least 1 of age over FEV1 below 50%, over 3 exacerbations per year)
Tx: Respiratory fluoroquinolone, amox-clav; consider cipro if risk for pseudomonas, and obtain sputum culture

In uncomplicated (i.e. none of above) Tx: macrolide, cephalosporin, doxycycline, TMP-SMX .

If abx in previous 3/12, switch classes

Steroids: Trials have demonstrated benefit of systemic steroids for vs. placebo. No mortality benefit, but shorter length of stay, PFT improvement, and symptomatic improvement.
Original trial used Solumedrol 125mg IV q8h; no advantage to this high dose over Prednisone 40-60mg PO x 5-7d. No need for taper of this duration.

Click here for a NEJM review on COPD exacerbations
Click here for the TORCH trial of inhaled corticosteroids in COPD
Click here for the GOLD initiative for COPD staging and management