When the decrease in Calcium level is mild, it has no symptoms. But when the calcium level is severely decreased, it will result in neuromuscular symptoms which are caused by positive bathmotropic effect (is the modification of the degree of excitability of the musculature in general) due to the decreased interaction of calcium with sodium channels. Since calcium blocks sodium channels & inhibits depolarization of nerve & muscle fibers.

SPASMODIC:

• Spasm (carpopedal spasms: Trousseau’s sign).

• Perioral paresthesia.

• Anxious, irritable & irrational.

• Seizures.

• Muscle tone increased in smooth muscle, hence colic, wheeze, & dysphagia.

• Orientation impairment & confusion.

• Dermatitis (e.g., atopic/exfoliative).

• Impetigo herpetiformis.

• Chvostek’s sign; Choreoathetosis; Cataract & Cardiomyopathy (long QT interval on ECG) [5] .

With increased P O 4 3 − :

1. Hypoparathyroidism (includes thyroid or parathyroid surgery), because calcium is tightly regulated by the parathyroid hormone “PTH”. When there is low calcium level, the PTH induces the kidneys to reabsorb the calcium & increase calcitriol secretion (active form of vitamin D), thereby increases the intestinal absorption of calcium & the bones to release the calcium & this action leads to rebalance of the blood calcium levels & thus, when there is absent, decreased, or ineffective PTH, the body loses this regulatory functions & hypocalcaemia occurs. So, hypocalcaemia was firstly attributed to injury, devascularization or inadvertent parathyroid removal.

2. Pseudohypoparathyroidism.

3. Acute rhabdomyolysis.

4. Hypomagnesaemia.

5. Chronic kidney disease.

When hypocalcaemia does not normalize after 6 months, it’s considered as permanent [6] .

Hypocalcaemia has a life-threatening complication such as laryngospasm & cardiac arrhythmias.

According to a study that was done in India, Permanent hypocalcaemia following thyroidectomy causes considerable morbidity. & According to the same study, they find that the overall incidence of hypocalcaemia was 23.6% & that of permanent hypocalcaemia was 1.61% [7] .

The high frequency and occurrence of these post thyroidectomy hypocalcaemia even after simple thyroid lobectomies, and some authors doubted the traditional explanation after analyzing the successive postoperative calcium variations since it seemed doubtful that the parathyroids could experience damage or injury in nearly all thyroidectomies [3] and due to lack of researches about this topic in Sudan, this retrospective study is an attempt to determine the prevalence of hypocalcaemia after thyroid surgery.

What is the prevalence of hypocalcaemia after thyroid surgery?

To measure the frequency of hypocalcaemia after thyroid surgery in Omdurman military hospital in (2018).

1) To estimate the frequency of postoperative hypocalcaemia in patients after thyroid surgery.

2) To determine the association between age & postoperative hypocalcaemia.

3) To measure the association between sex & postoperative hypocalcaemia.

4) To estimate the association between diagnosis & postoperative hypocalcaemia.

5) To measure the association between type of surgery & postoperative hypocalcaemia.

A retrospective cross-sectional hospital-based study, made in patients who underwent thyroid surgery in Omdurman military hospital in (2018).

The study is carried out in Omdurman Military hospital, which were first founded in November 1958 and its first commander was Dr. Hussein Abdu Alrahaman Alshalaly.

The hospital is located in Omdurman near the White Nile bridge {GPS location: 15.615194, 32.458361}, and it contains the following departments: pediatrics, obstetrics and gynecology, medicine, surgery, dentistry, psychiatric, emergency & community medicine.

All patients who present to Omdurman military hospital, department of surgery, seen by surgeons, diagnosed with thyroid diseases & underwent thyroid surgery.

Sudanese patients who underwent thyroid surgery in the area of the study.

Patients who present to the department of surgery in the hospital but not diagnosed with thyroid disease. Thus, underwent other surgery.

Prevalence related independent variables are: age, sex & residence.

Prevalence related dependent variables are: diagnosis, type of surgery & postoperative serum calcium level.

All patients who present to the department of surgery in Omdurman military hospital.

Using the equation:

n = z 2 ∗ p ∗ q / d 2

n: Sample size.

z: Standard deviation (1.96).

p: Proportion of population.

q: Error sample (1 − p).

d: degree of precision (0.05) [8] .

n = (1.96)² * 0.5 * 0.5/(0.05)² = 384.

Due to certain limitations, we include only 124 patients.

Simple random sampling.

A designed pretested checklist.

We entered the data by ourselves in SPSS version 20, we used frequencies & cross tabulations.

Out of 124 checklists were filled from 124 files 100%.

37.9% of the cases were found between the age of 20 and 40 years, 49.2% of the cases were found between the age of 41 and 61 years and 12.9% were found above the age of 61 years (Figure 1).

16.1% of them were males and 83.9% were females (Figure 2).

57.3% of the cases were living in Khartoum state and 42.7% were living in other states (Figure 3).

76.6% of the cases were diagnosed with simple multinodular goiter “SMNG”, 5.6% were diagnosed with toxic multinodular goiter “TMNG”, 4.8% were diagnosed with controlled toxic multinodular goiter “CTMNG”, 5.6% were diagnosed with Recurrent MNG, 0.8% were diagnosed with follicular carcinoma “FCA”, 0.8% were diagnosed with grave’s disease, 2.4% were diagnosed with solitary toxic nodule “STN” and 3.2% were diagnosed with simple diffused goiter “SDG” (Figure 4).

97.6% of patients underwent total thyroidectomy, while 2.4% underwent thyroid lobectomy (Figure 5).

75% of patients had normal postoperative serum calcium and 25% had decreased levels (Figure 6).

There was no relation between sex & postoperative hypocalcaemia (P < 0.001) (Table 1 and Table 2).

Also there was no relation between type of surgery & postoperative hypocalcaemia (Table 3 and Table 4).