HYPOTHYROIDISM – A NURSING ANALYSIS

In this draft case, hypothyroidism is critically analyzed using global best practices and with focus on altered physiology and path physiology. Mrs. Smith (name changed for the reason of confidentiality), a 60-year old, female patient, was presented with chief complaints of cold intolerance, weight-gain despite decreased appetite, bradycardia, constipation, fatigue, lethargy and puffiness of eyes. At the time of admission of the patient the following parameters were recorded:

Vital signs                                                            Lab Test
BP -      130/90                                                      Hb -          13.8 gm/dl [12-16 gm/dl]
Pulse – 50/min                                                      TLC -       11,000 [4,000 – 11,000/ul]
RR -     20/min                                                       Platelets -   2.45 lacs [1.50 – 4.0 lacs]
Spo₂ -   95%

Renal Function Test                                         Thyroid Test  
B. urea        – 2.5[10-40mg/dl]                          TSH -        7 µIU /mL   [0.25-5.0µIU/mL]
B. creatinines – 1.2 [0.5-1.4mg/dl]                    T3     -       0.80nmol/L [0.92-2.33nmol/L], T4 – 40nmol/L [60-120nmol/L]

Critical Analysis:
Mrs. Smith came to the hospital with signs and symptoms of hypothyroidism (Black & Hawks, 2005). Hypothyroidism is a hormonal disorder which affects the neuroendocrine control of the body. Hypothyroidism is a clinical syndrome resulting from the deficiency of the thyroid hormones: T3 (tri-iodothyronine) and T4 (thyroxin). This disorder can range from sub-clinical hypothyroidism with no obvious symptoms, to severe hypothyroidism with overt symptoms (Smeltzer et al, 2004).

In hypothyroidism there is decrease in production ofT3 and T4 by the thyroid gland. From the above diagrammatic representation, it can be clearly made out that when there is decreased production of T3 and T4, there occurs a negative feedback cycle directed at the hypothalamus. Usually, when the hypothalamus does not have a negative feedback, it starts increasing the production of TRH (Thyrotropin-Releasing Hormone) which acts on the pituitary gland to increase the production of TSH (Thyroid-Stimulating Hormone). In hypothyroidism, in spite of raised TSH levels, T3 and T4 levels are low because the thyroid gland is unable to produce them in sufficient quantities (Tripathi, 2003) (Kasper et al, 2001).

Mrs. Smith had puffiness of both eyes when she came to the hospital. She also had non-pitting edema. Non-pitting edema occurs due to increased quantities of hyaluronic acid and chondroit in sulfate binding with the protein occurring in the interstitial space, causing the total quantity of interstitial fluid to increase. Since this interstitial fluid is of a gel nature, it is immobile, and consequently the edema in hypothyroidism is the non-pitting type (Guyton and Hall, 2006).

Normally, thyroid hormones increase active transport of ions through the cell membranes. One of the enzymes that increase its activity in response to thyroid hormones is Na+-K+-ATpase which increases the rate of transport of sodium and potassium ions through the cell membrane of tissues. This process uses energy and increases the amount of heat produced in the body. It has been suggested that this is one of the mechanisms by which thyroid hormones increases the body’s metabolic rate (Guyton and Hall, 2006). Since there was a deficiency of thyroid hormones in Mrs. Smith’s body, the activity of Na+-K+-ATpase enzymes decreases, leading to a decrease in the metabolic rate. The mitochondria inside the muscle fibers requires three chemicals – glucose, Vitamin –B, and the thyroid hormone T3 – to generate ATP (Adenosine Triphosphate) (Kasper et al, 2005). In Mrs. Smith’s body there is a decrease in T3, so ATP is depressed, leadingto energy within the cell for metabolism decreasing, resulting in decreased metabolism. The decrease in metabolism leads to dysfunction in Mrs. Smith’s body, like fatigue, which is due to the decrease in ATP levels and muscles not getting therequisite energy for relaxation. Cold intolerance is also due to the same process,as the decrease in ATP levelsresultsless heat being produced, leading to a fall in Mrs. Smith’s body temperature falls.Thedecreasein appetite, due to a decrease in the motility of the intestinal tract, is once again again attributable to a reducedbasal metabolic rate (Richard, 2005).

Mrs. Smith’s heart rate was 50 bpm (beats per minute). A heart rate of less than 60 bpm is regarded as bradycardia (Steadmen, 2000). Normally, T3 increases beta receptors in the blood. In Mrs. Smith’s body the decrease in T3 enzymes means less production of beta receptors, which leads to a fall in the heart rate, because beta receptors control the heart rate (Goldman and Ausiello, 2008).

Mrs. Smith also experienced weight gain despite the loss of appetite.This is due to the decreased secretion of thyroid hormones. The normal effect of thyroid on metabolic products is explained in flowchart 1 (Guyton and Hall, 2006), and how hypothyroidism leads to weight gain is explained in flowchart 2(Goodman and Gilman’s, 2002).

Constipation is another symptom which occurs due to decreased metabolism.Decrease in metabolism alters the function of the small intestine, whichmeans that the peristaltic waves of the small intestine are reduced, which give rise to constipation (Kumar & Clark, 2006).

Mrs. Smith was started on treatment with Levothyroxine sodium. Levothyroxine sodium acts, similar to endogenous thyroxine, to stimulate metabolism and reverse the metabolic rate.It also increases the rate of energy exchange and increases the maturation rate of the epiphyses. Levothyroxine sodium is absorbed rapidly from the gastrointestinal tract after oral administration. The aim of the treatment is to normalize increased thyrotrophic levels (TSH) (Katzung,2001)

To summaries, the above information will assist nurses to recognize early signs and symptoms of hypothyroidism,and recognize its effect on the regulation of body functions. This will help nurses intervene early and educate patients in self-care.