Welcome back readers. Last time we covered wound packing associated with hemorrhage control. In past articles we also have covered the application of the CAT and SOFTT tourniquets to stop major hemorrhage associated with arterial bleeds of the upper and lower extremities. This month we are going to wrap up hemorrhage control and start our journey into the effects of major blood loss on the human body. We will also explore what we can do to minimize its effects until we can get our injured to more affinitive care and treatment. In order to be effective first responders you must perform effective blood sweeps secondary to addressing major arterial bleeds. This ensures that you increase your chances of identifying additional injuries and indicators of additional underlying problems that need to be addressed during patient care.
Let’s start with effective blood sweeps. Not all major bleeds are visible to the eye at first glance. Even if the major bleeds are evident and easily identifiable you must still follow up with effective blood sweeps to ensure you do not have any secondary bleed sources to treat. If a major bleed has been stopped with the effective application of a tourniquet, you must still follow up with blood sweeps to ensure all hemorrhage issues are covered and treated effectively.
Blood sweeps are performed by sweeping both hands over the casualty’s entire body. Work from head to toe stopping every few inches to look at your hands for signs of blood. Do not sweep an entire area then check your hands for blood. If you do this, you will not be able to pinpoint where the blood came from. By stopping every few inches and checking for signs of blood, you will be able to locate the injuries quickly and address the problems they may present that much quicker. While performing blood sweeps use your finger tips to perform the sweep. You will find that most gunshot entry wounds do not always produce that much blood at the wound site. By using your fingertips you will fill the impression made by the bullet hole when your finger crosses over the wound. This technique is especially helpful in low light conditions.
Performing Blood Sweeps:
- Complete a full body “Blood Sweep”. Using your hands, rapidly palpate “Head-to-Toe”, and look for any hemorrhaging wounds that may have been missed visually.
- Start at the head by palpating the top and back of the head first. Stop to look at your hands for traces of blood. Also visually inspect the ears, nose, eyes, and mouth for signs of bleeding.
- Move down to the neck and sweep the back of the neck while visually looking at the throat.
- From the neck move down to the arms. Sweep one extremity at a time by starting at the shoulder and sweeping to the elbow. At the elbow, stop your sweep to visually check your hands for blood. Resume your sweep at the elbow and move down to the hands.
- After you finish sweeping the upper extremities, start back at the shoulders and sweep the chest and abdomen. Log roll the casualty towards you and sweep the back while visually inspecting as well. Roll the casualty back in a supine position and move down the body.
- Sweep the buttocks and the pelvis.
- Move down to the legs and sweep each lower extremity starting at the upper thigh sweeping down to the knee. The knee is a good stopping point to again visually inspect your hands for blood. Once done, then continue down to the feet with your sweeps to complete your blood sweeps.
Remember to stop every few inches or so to check your hands for blood. Blood sweeps are done very quickly and can accomplished in two minutes or less. Practice these at home with a family member and become comfortable performing them and develop that muscle memory needed to get proficient. Be aggressive but thorough while performing your skills. Start slowly and gradually work at speed, but never place speed before proficiency. Performing blood sweeps is the last step we will explore in hemorrhage control. Now that we have learned how to control major hemorrhage, let’s move on to the effects major blood loss has on our casualty.
Shock is an abnormality of the circulatory system that results in an inadequate amount of blood flow and oxygen to organs and tissues. Shock happens when tissue perfusion does not meet metabolic demands. The initial diagnosis of shock is based upon the clinical appreciation of the presence of inadequate organ perfusion and tissue oxygenation. The most important step in managing shock is to recognize its presence.
Cycle of Shock:
- Trauma of any kind to human body.
- Depressed circulation due to blood loss.
- Tissues and organs receive an inadequate supply of blood and nutrients.
- Rapid heart rate and weak pulse from blood loss.
- Blood vessels in extremities constrict to conserve blood, causing cold, clammy skin. This is the body’s method of rerouting blood to needed tissue and vital organs.
- Low levels of oxygen and nutrient supplies to the body tissues cause a decrease in body temperature.
- Decrease in waste elimination from lungs and kidneys.
- Low levels of oxygen to breathing control centers of the brain make respiration rapid and shallow.
- Nervous system reaction results in perfuse sweating.
- Muscles in the blood vessel walls relax and blood pressure drops.
- Leaking capillaries lead to loss of vital blood plasma causing circulatory depression and thirst.
- Unconsciousness and death will result if not corrected.
The following terminology is important to understanding the function of the cardiovascular system. We have discussed the cardiovascular system in previous articles, so let us take a moment to do a quick review. A good basic understanding of this system is important in the understanding of shock and how the bodies systems are affected by rapid blood loss.
- Systolic Blood Pressure- the force of the blood against blood vessels produced by ventricular contraction. Normal systolic blood pressure is 120-140 mmHg (mm of mercury) in the average adult. This is the top number represented in a clinical blood pressure reading.
- Diastolic Blood Pressure- the pressure remaining in the blood vessels while the heart is at rest. Normal diastolic blood pressure is 60-80 mmHg in the average adult. This is the bottom number represented in a clinical blood pressure reading.
- Pulse Pressure- the difference between the systolic and diastolic blood pressure. This the reading you get when you palpate a radial pulse at the wrist and count the beats you feel for one minute. Normal pulse pressure in adults ranges from 80-100.
- Capillary Refill Test- A quick test performed on the nail beds is an indicator of tissue perfusion (the amount of blood flow to the tissue) and dehydration. You perform this test by placing the tip of a finger between your index finger and thumb. Pinch the fingertip and release. Visually watch the nail bed and it should blanch out white from the pressure of the pinch. The nail bed should return to pink in color in three seconds or less. If it does, then this is a good indicator of good tissue perfusion at a distal location. Normal capillary refill in adults should be three seconds or less. Anything longer is a indication of poor tissue perfusion.
- Normovolemic- normal fluid balance.
- Hypovolemic- too low volume.
- Nervous System- Autonomic nervous system with its two components known as the sympathetic and parasympathetic (has restrictive control of the heart and vessels) nervous system. The parasympathetic slows the heart rate, increases intestinal peristalsis and gland activity, relaxes sphincters (blood vessel muscles) allowing vessels to dilate. The sympathetic nervous system controls the fight-or-flight response, accelerates the heart rate, constricts blood vessels and increases blood pressure.
Anatomy of the Cardiovascular System:
In previous articles we have discussed the cardiovascular system and its components. We will again take a moment to do a quick review of the cardiovascular system and its components, since it is the system that is affected by major hemorrhage and shock in our casualty. The cardiovascular system consists of a pump (the heart), a container (the vascular system), and circulating fluid (the blood). The pump (heart) is a four chamber muscle. The container (arteries, veins and capillaries) holds the blood that transports oxygen and nutrients to the body’s cells. The fluid (blood and blood plasma) carries the oxygen and nutrients to the cells in exchange for waste products.
Types of Shock:
Shock is typically classified by its causes. Shock can occur in three ways that are associated with failure of some component of the cardiovascular system – either volume, container, or pump. The major types of shock are:
The type of shock we are dealing with in this article on severe blood loss is Hypovolemic. Hypovolemic shock is due to the loss of body fluids. The heart and lungs are functioning normally, however, there is not enough circulating volume within the circulatory system to carry the required amount of oxygen and nutrients to the body’s cells and vital organs.
Hemorrhagic shock is a form of hypovolemic shock due to severe loss of blood. This is the most common form of shock found in tactical situations and on the battlefield. Like we have discussed in previous articles, the amount of blood that can be lost before death occurs will vary from individual to individual. The average adult blood volume is 5 to 6 liters. Normally a loss of 25% to 40% of the person’s total blood volume will create a life-threatening condition. Massive hemorrhage may be fatal within 6—120 seconds. Treatment of major hemorrhage must take priority over securing the airway in tactical medicine. A good rationale: Death will occur from massive hemorrhage within as little as 60 seconds. The body can go up to 4 minutes without oxygen before permanent damage or death occurs.
Causes of Hypovolemic Shock:
- Loss of whole blood, external hemorrhage.
- Loss of blood into the body cavity (thoracic, abdominal, or pelvic region) or into the muscle/tissues (into the quadriceps with a femur fracture), internal hemorrhage.
- Loss of plasma associated with burns over large body surface area.
- Loss of extracellular fluids from severe vomiting or diarrhea, profuse sweating without fluid replacement (Metabolic).
Signs and Symptoms:
Signs and symptoms seen with hemorrhagic shock are usually linked with the amount of blood lost and the casualty’s internal reaction to this blood lost. Do not rely on the Blood Pressure (BP) as the main indicator of shock. More attention should be paid to pulse, respiratory rate, and skin perfusion (cold clammy skin resulting from poor perfusion). The following are guidelines relating to the approximate amount of blood loss and the body’s expected reaction and manifestation to this blood loss. Remember these parameters are only guidelines and should not be taken as absolute amounts of associated blood loss. Take notice of the different levels of shock and how they progress without medical intervention.
Levels of shock:
- Compensated Shock – Less than 15% blood loss has occurred. An effective bandage will stop the bleeding and the effects on the body are minimal-to-none. Below you will notice the effects on the body are only some anxiety suffered from being wounded.
- Moderately Decompensated Shock – More blood is lost and the body is starting to react. The container has a leak so pulse pressure is dropping. Respiratory rate is starting to increase and capillary refill is slightly delayed. This is due to the body shunting the blood to the extremities to keep the vital organs supplied with oxygen rich blood. Your casualty will begin to get agitated at this point.
- Decompensated Shock – Pulse pressure drops even more as blood loss continues. Respiratory rate increases and capillary refill is seriously delayed at this point. The body is compensating by re-routing the needed blood to support life. This affects the brain as well and confusion kicks in.
- Irreversible Shock – The body can not compensate any longer. It has done all it can to make up for severe blood loss and it begins to shut down. At his point it is very unlikely you will be able to salvage life. Body organs, cells and tissue are starting to die from lack of oxygen and nutrient rich blood.
I had an Emergency Room Physician give me a quote years ago that stuck with me. He told me that “Shock is a momentary pause in the process of death. Treat the shock and you can prevent death most of the time. If you do not recognize the signs and symptoms of shock, death will surely prevail.”
Use the reference cheat sheet below. Keep it in your blowout kit to help you recognize the signs and symptoms associated with hypovolemic shock.
Note: Cut this chart out and laminate to keep as a reference in your blowout kit. This is a very good guideline for helping with signs and symptoms associated with hemorrhagic shock.
As you look at the chart above you will see some acronyms that I need to help you get familiar with. The following should break these down for you to help you understand the terms associated with these acronyms:
- EBL = Estimated Blood Loss. This is your observation of the amount of blood found on or near your casualty. It takes time and practice to get accurate with estimating blood loss. I have included another chart below to help you with EBL. Use this cheat sheet to your advantage and keep it in your blowout kit as a handy reference.
- ML = Milliliters. Blood is usually measured in liters or milliliters. One ML is equal to One CC of liquid. 1000ml is equal to One Liter. Large IV Bags are 1000ml of fluid or you could say 1000cc of fluid.
I hope this article helps you to recognize shock and its associated signs and symptoms. Practice your blood sweeps from time to time on a family member to build that needed muscle memory. This concludes bleeds for us this month and next month we are moving on to the airway. Until then remember to pass on firearm safety to your children and family. Lead by example by doing the basics right every time. Until next month, this is “Doc” McBryde and I’m Oscar Mike.