38
and ketosis usually do not exist in this case, so etco2 does not decrease. It should be
noticed that other factors, such as potential sepsis and respiratory dysfunction, can
alter etco2 [77].
HHNC has a complex pathophysiology yet similar to DKA. This situation usually does not arise suddenly, but will last for a few days. The length of time depends
on the overall health of the patient. HHNC usually occurs in the elderly and in
patients who are weak due to comorbidities. The major effect in HNNC is a decrease
in insulin action, which stimulates a large counter-regulation mechanism that
increases serum glucose. Once insulin function declines, glycogen breakdown
(release of glucose stored in glycogen form), gluconeogenesis (internal manufacture of glucose inside the body), and reduction in peripheral glucose absorption will
predominate. After that fluid is drawn into the extracellular space due to hypoglycemia, stimulating osmotic diuresis, ultimately causing hypotension and volume deficiency. The patient is initially able to maintain the vascular volume by a continual
fluid intake, but the diuretic will eventually exceed the system. Remember that other
conditions, such as sepsis, can lead to further exhaustion of capacity [78] (Table 1.3).
Conclusion
In this chapter the basic physiology of endocrine system including glands and their
respective hormones is summarized. All endocrine glands produce one or more hormones which regulate many body functions and maintain homeostasis inside the
body. All of these hormones play crucial role in many body functions and the over
and under secretion of any of these hormones may lead to several metabolic disorders. Some of these metabolic disorders are life threatening so a balance should be
maintained in these hormonal secretions. Most of endocrine hormones are regulated
by a negative feedback mechanism to keep these hormonal secretions in check. But
sometimes due to some problem in the negative feedback mechanism of endocrine
hormonal secretion, any damage to endocrine gland, endocrine gland’s tumor, infection, disease, or a genetic disorder may cause hormonal imbalance leading to several metabolic disorders.
Conflict of Interest The authors declare that they have no conflicts of interest.
Table 1.3 Common causes and signs and symptoms of HHNC
Causes
Signs and symptoms
Trauma, drugs, myocardial infarction,
Cushing’s syndrome, sepsis, cerebrovascular
accident (stroke), dialysis, CNS insult (e.g.,
subdural hematoma), hemorrhage, pregnancy
Fever, dehydration, vomiting and abdominal
pain, hypotension, tachycardia, rapid breathing,
thirst, polyuria or oliguria, polydipsia, focal
seizures, altered LOC, focal neurologic deficits
A. Ahsan et al.
and ketosis usually do not exist in this case, so etco2 does not decrease. It should be
noticed that other factors, such as potential sepsis and respiratory dysfunction, can
alter etco2 [77].
HHNC has a complex pathophysiology yet similar to DKA. This situation usually does not arise suddenly, but will last for a few days. The length of time depends
on the overall health of the patient. HHNC usually occurs in the elderly and in
patients who are weak due to comorbidities. The major effect in HNNC is a decrease
in insulin action, which stimulates a large counter-regulation mechanism that
increases serum glucose. Once insulin function declines, glycogen breakdown
(release of glucose stored in glycogen form), gluconeogenesis (internal manufacture of glucose inside the body), and reduction in peripheral glucose absorption will
predominate. After that fluid is drawn into the extracellular space due to hypoglycemia, stimulating osmotic diuresis, ultimately causing hypotension and volume deficiency. The patient is initially able to maintain the vascular volume by a continual
fluid intake, but the diuretic will eventually exceed the system. Remember that other
conditions, such as sepsis, can lead to further exhaustion of capacity [78] (Table 1.3).
Conclusion
In this chapter the basic physiology of endocrine system including glands and their
respective hormones is summarized. All endocrine glands produce one or more hormones which regulate many body functions and maintain homeostasis inside the
body. All of these hormones play crucial role in many body functions and the over
and under secretion of any of these hormones may lead to several metabolic disorders. Some of these metabolic disorders are life threatening so a balance should be
maintained in these hormonal secretions. Most of endocrine hormones are regulated
by a negative feedback mechanism to keep these hormonal secretions in check. But
sometimes due to some problem in the negative feedback mechanism of endocrine
hormonal secretion, any damage to endocrine gland, endocrine gland’s tumor, infection, disease, or a genetic disorder may cause hormonal imbalance leading to several metabolic disorders.
Conflict of Interest The authors declare that they have no conflicts of interest.
Table 1.3 Common causes and signs and symptoms of HHNC
Causes
Signs and symptoms
Trauma, drugs, myocardial infarction,
Cushing’s syndrome, sepsis, cerebrovascular
accident (stroke), dialysis, CNS insult (e.g.,
subdural hematoma), hemorrhage, pregnancy
Fever, dehydration, vomiting and abdominal
pain, hypotension, tachycardia, rapid breathing,
thirst, polyuria or oliguria, polydipsia, focal
seizures, altered LOC, focal neurologic deficits
A. Ahsan et al.