DEFINITION Hypotension is diminished blood pressure Blood pressure is generated by the heart pumping blood into the arteries and is regulated by the response of arteries to the flow of blood.

Pathophysiology Blood pressure is continuously regulated by the autonomic nervous system, using an elaborate network of receptors, nerves, and hormones to balance the effects of the sympathetic nervous system, which tends to raise blood pressure, and the parasympathetic nervous system, which lowers it. The vast and rapid compensation abilities of the autonomic nervous system allow normal individuals to maintain an acceptable blood pressure over a wide range of activities and in many disease states.autonomic nervous systemreceptorsnerveshormonessympathetic nervous systemparasympathetic nervous system

Hypotension is often categorised based on numerous factors. Some common types are: Postural hypotension (orthostatic hypotension) Post-prandial hypotension

PREDISPOSING FACTORS: Administration and ingestion of drugs Prolonged period of recumbency or convalescence Inadequate postural reflex Pregnancy Advanced age Venous defects in legs (e.g. Varicose veins) Recovery from sympathectomy for “essential” hypertension Addison’s disease Physical exhaustion and starvation Chronic postural hypotension (Shy-Drager syndrome)

Signs and symptoms The cardinal symptoms of hypotension include lightheadedness or dizziness. [citation needed] If the blood pressure is sufficiently low, fainting and often seizures will occur.cardinal symptomslightheadednessdizzinesscitation neededfaintingseizures Low blood pressure is sometimes associated with certain symptoms, many of which are related to causes rather than effects of hypotension:

Chest pain Shortness of breath Irregular heartbeat Fever higher than 38.3°C (101°F) Fever Headache Stiff neck

Adverse effect of medicationsmedications Acute, life-threatening allergic reactionallergic reaction Seizures Loss of consciousness Profound fatiguefatigue Temporary blurring or loss of vision

Severe upper back painupper back pain Cough with phlegm Coughphlegm Prolonged diarrhea or vomitingdiarrheavomiting Dyspepsia Dysuria Connective tissue disorder Ehlers-Danlos SyndromeEhlers-Danlos Syndrome Black tarry stools

Clinical criteria Symptoms develop when individual stands Standing pulse increases atleast 30 beats/min Standing systolic blood pressure decreases atleast 25mm Hg Standing diastolic blood pressure decreases atleast 10mm Hg

PREVENTION: PREVENTION IS BASED ON: o Medical history o Physical examination o Dental treatment modifications

MEDICAL HISTORY Are you taking, Medications, drugs, over-the-counter medicines (including aspirin), natural remedies Have you experienced Dizziness, fainting spells, seizures The names of any medications patient may be taking to assist in the maintenance of adequate blood pressure Ephedrine, fludrocortisone acetate

PHYSICAL EXAMINATION The integral part of pretreatment evaluation for all potential patients is the recording of vital signs, including blood pressure, heart rate and rhythm (pulse), respiratory rate, temperature, height and weight.

Dental considerations Basic precautions should be taken in the following patients : Patients with history of postural hypotension Patients receiving sedation (inhalation I.V/I.M/Intranasal) during dental treatment. Patients who have been reclined in the dental chair for a long period

Dental therapy considerations: Slowly reposition the patient upright Stand nearby as the patient stands after treatment

Management Management of hypotension parallels that of vasodepressor syncope Step 1: assessment of consciousness Step 2: activation of office emergency system Step 3: P (position) Step 4: A-B-C (airway-breathing-circulation) Step 5: D (definitive care) Step 5a: administration of O2

Step 5b: monitoring of vital signs Step 6: subsequent management Step 6a: delayed recovery Step 7: discharge

HYPOTENSIVE EMERGENCY PROBLEM: Hypotension results from variety of causes ranging from simple syncope RECOGNITION: It is detected by taking blood pressure The pulse maybe weak and bradycardia may exist with associated shock patient may show restlessness, agitation, confusion, nausea, stupor and coma. The amount of systolic pressure drop is more important than actual systolic blood pressure

TREATMENT SUPPORTIVE TREATMENT: Patient should be placed in the horizontal position with legs elevated Trendelenburg’s should be administered. Vital signs should be determined and monitored frequently. An intravenous line should be inserted for fluid and possible drug administration. If systolic blood pressure is above 80 mm Hg – continue monitoring and supportive while trying to determine the cause. If systolic blood pressure is below 80 mm Hg, vasodepressors are indicated

IF PULSE IS LESS THAN 60: Atropine 0.4 to 0.6 mg I.V. IN PATIENTS RECEIVING PHENOTHIAZINES OR ANTIHYPERTENSIVE MEDICINES: Norepinephrine (levarterenol) 2 to 4 mcg/1 min by infusion or phenylephrine (Neo Synephrine) 2 to 5 mg subcutaneously or intramuscularly or 0.2 mg given intravenously slowly

IF CAUSE IS UNKNOWN OR A MYOCARDIAL INFARCTION OR CEREBROVASCULAR ACCIDENT IS SUSPECTED: One of the least potent vasodepressor Mephentermine (Wyamine) given I.V. or I.M. PREVENTION: Adequate history and correct diagnosis so that proper treatment can be assured