How dangerous can low blood pressure be?
Hypovolemic shock, also understood as low perfusion and low blood pressure is caused by insufficient amount of blood in the vascular space that can return to the heart and therefore the heart does not pump enough blood and oxygen to the organs. Low return of blood to the heart is known as decreased preload. A decrease in preload also brings about a decrease in stroke volume as well as a decrease in cardiac output. This explains why Rose presented with a high heart rate – because of the decrease in cardiac output causing low tissue oxygenation and, therefore, the heart rate increases in response to decreased stroke volume. As a result, the blood pressure also decreases. Diagnosis may include using serum lactate which shows low oxygenation in the tissues, arterial blood gas (ABG) to assess the oxygenation of a patient, complete blood count (CBC) to show low hemoglobin (Hb) is and the total number of red blood cells in the body. Treatment of hypovolemic shock may include giving the patient IV fluids to replete their blood volume, blood transfusion, the patient may need coagulation factors if they are bleeding a lot, albumin may also be given if the patient’s blood volume is low and, if necessary for example with Rose, the patient should have surgery to repair damaged blood vessels.
Because Rose showed signs of hypovolaemia – presenting with low blood pressure, high heart rate and low urine output, she was given 100mls fluid resuscitation, NaCl 0.9% to boost her blood volume. This was prescribed on the fluid chart showing the date and time, fluid type, volume/rate, and prescriber’s signature. Before fluid administration, it is essential to confirm the patient’s full name, date of birth and hospital number ensuring they match the prescription. It is also important that the patient has a right size cannula inserted and that both the giving set and bag of fluid are intact, sterile and up to date. Before attaching the prepared IV fluid to the patient, the nurse should inspect the tube/giving set to ensure there are no air bubbles.