Hypertension
Hypertension in pregnancy here
- pathophysiology of HT differs in black adults compared to South Asians and whites. eg, HT is commonly of the low renin type, sensitivity of BP to salt intake is often increased, and the ability to excrete ingested salt is impaired (60–70%)
- Black patients may also have relatively higher concentrations of intracellular calcium
- South Asians appear to respond to antihypertensive drug treatment in a similar manner to whites
- The excellent blood pressure lowering efficacy of diuretics and calcium channel antagonists in hypertensive black patients is related to their characteristic volume expansion, salt sensitivity and low renin profile. Diuretics should be used for initial treatment unless there is an absolute or relative contraindication (for example, gout).
- there is evidence of a greater decrease in blood pressure among hypertensive black patients when compared to white patients when they receive an equivalent dose of a diuretic
- Calcium channel blockers are also extremely effective antihypertensive drugs in black patients.
- Angiotensin converting enzyme (ACE) inhibitors, β blockers, and angiotensin receptor antagonists are generally less effective as monotherapy in black hypertensives, because of the tendency towards a low renin state and a lower cardiac output, with increased peripheral resistance
there is no evidence of relationship between BP measured in the ED and pain or anxiety
High BP in the ED
HT General Management strategy
| Step 1 | Dual low (1/2) dose combination | ACE inhibitor or Angiotensin Rec Blocker Dihydropyridine Ca++ blocker |
|---|---|---|
| Step 2 | Dual full dose combination | |
| Step 3 | Triple combination | |
| Step 4 | Triple combination + Spironolactone + other | |
 |  |
| ACE inhibitors | eg. ramipril, captopril, enalapril, lisinopril |
|---|---|
| Angiotensin Rec blocker aka angiotensin II inhibitors | eg. valsartan, losartan and candesartan |
| Calcium-channel blockers (CCBs) 3 subgroups | 1. benzothiapines eg. diltiazem 2. dihydropyridines eg. amlodipine, nifedipine 3. phenylalkylamines eg. verapamil |
Diuretics
The thiazide class is heterogenous and can be further subdivided into compounds containing the benzothiadiazine ring structure
- the thiazide-type (e.g., hydrochlorothiazide)
- and those lacking the benzothiadiazine ring—the thiazide-like (e.g., chlorthalidone and indapamide) drugs.
- metolazone - a quinazoline diuretic related to the thiazide class.
- Thiazide-like agents are longer acting
Hypertensive Emergency
| Labetalol | Initial 20-50mg over at least 1 minute. Can be repeated every 5 minutes to a maximum of 200mg OR titrate infusion starting at 2mg/min. Then infusion 2mg/min, titrated as required |
|---|---|
| Nicardipine | Infusion of 2.5-5mg/hr. Increase according to response by 0.5 1mg every 15 minutes to a maximum of 15mg/hr |
| Sodium Nitroprusside | Initially 0.5-1.5mcg/kg/min.Titrate up in increments of 0.5 mcg/kg/minMax up to 8 mcg/kg/min |
| Hydralazine | Initial 5-10mg slow bolus. Then repeat boluses or infusion 50-100 mcg/min |