renal system consists of the kidneys, ureters, and bladder (p. 961).
A 7-year-old boy is a patient in your intensive care unit. He was on a camping trip with his family when he accidentally fell on the campfire, causing severe second- and third-degree burns over 60% of his body. The clinical care team tells his parents that it will be critical to maintain their son’s airway and keep his fluid levels high.
In order to conserve fluid to maintain tissue perfusion, we take a closer look at the renal system. Norris (2019) demonstrates that the renal system consists of the kidneys, ureters, and bladder (p. 961). The kidney is made up of multiple lobes and about a million nephrons. Nephrons help to filter the blood in our body and get rid of the waste build up in our bodies (Norris, 2019, p. 961). The kidney is provided by the renal artery for blood supply which branches out to provide to the lobes (Norris, 2019, p. 962). Nephrons are not regeneratable and tend to decrease in functional status with age (Norris, 2019). Nephrons are grouped into two groups: cortical nephrons, making up 85% of nephrons and juxtamedullary nephrons, which concentrate urine (Norris, 2019). The two capillary systems that provide for the nephrons include the glomerulus and the peritubular capillary network (Norris, 2019). Through these, fluid and solutes are purified, and urine can be prepared for removal. Within the glomerular capillary membrane, there are three levels which include the capillary endothelial layer, the basement membrane, and the single-celled capsular epithelial layer (Norris, 2019, p. 964). Within the tubular components of the nephron, there are four sections which include the proximal convoluted tubule draining into the Bowman capsule, the loop of Henle, the distal convoluted tubule, and the collecting tubule collecting filtrate (Norris, 2019, p. 965).
Kidneys help to produce urine, but in order to complete this task, they must do so by glomerular filtration and tubular reabsorption and secretion (Norris, 2019, p. 965). The glomerular filtration rate is on average 125 ml/minute or 180 L/day and is measured through blood work collected through venipuncture and seen as the glomerular filtration rate (GFR) (Norris, 2019, p. 965). Multiple ions, such as sodium, potassium, chloride, calcium and phosphate ions, can be filtered and reabsorbed during the process of filtration through active transport (Norris, 2019, p. 966). The renal system is widely supported by the sympathetic system caused by angiotensin II, antidiuretic hormone (ADH), and endothelin which can cause constriction (Norris, 2019, p. 970).
In your initial post answer the following questions:
- The father is confused and asks you why his son’s fluid level is important after a burn. How would you explain this to him?
A burn victim’s first several days are crucial due to the loss of skin, especially if second- and third-degree burns have occurred. The skin helps to maintain heat, homeostasis, and fluid balance within the body (Namdar et al, 2010). When this 7-year-old boy fell into the campfire and caused severe burns to his body, his dermis and epidermis was damaged and caused his totally burned surface area (TBSA) to be drastic. The intensive care unit (ICU) then will calculate his daily infusion-diuresis-ratio (IDR), in order to determine how much fluid loss and replacement will be needed for replenishment (Namdar et al, 2010). When the burn occurs, several inflammatory mediators are released, such as histamine, prostaglandins, thromboxane, and nitric oxide, which then create a more permeable membrane for the capillaries making them “leaky” so to speak (Haberal, Abali, & Karakayali, 2010). The boy will become edematous due to the loss of tissue and begin to seep fluid and heat in the next several hours and days, causing radical changes to temperature and electrolyte balances (Namdar et al, 2010). With these new changes in place for the body, dehydration begins to take place. This produces free radicals and reactive oxygen species (ROS), which are deadly and causes cellular membrane dysfunction (Haberal, Abali, & Karakayali, 2010). This can then cause interference in sodium-ATPase activity, which demonstrates edema and hypovolemia. Approximately 12 hours after the injury of a burn, intravascular hypovolemia and hemoconcentration develops and the highest levels of vasoactive mediators have been achieved. As a result, cardiac output declines to conserve for other organs suffering from the decreased plasma volume and the vasoactive mediators that are attributing to the burn (Haberal, Abali, & Karakayali, 2010). The initial steps overall are to conserve fluid to maintain tissue perfusion.
- After your explanation, the father nods that he understands. He then asks how you will measure his son’s fluid levels. How would you respond?
The TBSA is calculated and the intensive care unit (ICU) then will calculate his daily infusion-diuresis-ratio (IDR), in order to determine how much fluid loss and replacement will be needed for replenishment (Namdar et al, 2010). Serum sodium concentration can then be used to determine the needs of how much fluid resuscitation will be needed for fluid maintenance to keep the boy hydrated for the next several crucial days (Namdar et al, 2010). At the time of admission, intravenous lines will be placed, preferably large bore and at least two, in order to rapidly infuse colloidal fluids into the boy, and then a urinary catheter will be placed in order to accurately measure urine output (Namdar et al, 2010). We as clinicians would want to assess blood work frequently for electrolyte imbalances to assure that if there were changes, such as hyponatremia or hyperkalemia, we would correct them appropriately and timely (Healthfully, n.d.).
- As a clinician with knowledge of physiology, which aspects of this boy’s condition would you be most concerned about?
As a clinician, the main aspects to be concerned about with this patient is airway, fluid maintenance, electrolyte imbalances (such as hyponatremia and hyperkalemia), arrythmias, wound management, hygiene, antibiotics, and pain (Holland, DiGiulio, & Gonzalez del Rey, 2012). In the case of this patient, it is known what happened, and it is possible that the patient fell face first or at least inhaled the campfire, damaging or compromising the airway. There is a possibility of needing to be intubated or having an advanced airway. Fluid maintenance is needed because as 60% of the body has been burned, that is 60% of the skin that is missing and edematous, which will lose heat and fluid loss. Replacement will be needed and at a rapid infusion to avoid hypovolemia. Electrolyte imbalances will ensue due to the shock to the body of loss of tissue and heat. Some symptoms of electrolyte imbalances may include confusion, vomiting, nausea, weak pulses, muscle weakness, seizures, fatigue, and arrythmias (Healthfully, n.d.). Hyponatremia occurs to the burn victim due to the blood from the destroyed tissue and the burns on the body. Hyperkalemia happens to the burn victim due to the destruction of the burned flesh (Healthfully, n.d.). Arrythmias may occur due to the electrolyte imbalances. Hygiene, antibiotics and wound management all are in a group together as if not completed together they tend to be detrimental. Without one another, the burn wound can suffer causing further issues for the patient to not heal fast. And lastly, overall pain management will be a main factor so that the patient remains as comfortable as they can during the process of healing, debridement, and other treatments
