Fact #1: Constipation - is a condition in which bowel movements are infrequent or incomplete, often associated with difficulty passing dehydrated stool.

Fact #2: Constipation occurs in 10% to 15% of population

Fact #3: Three chief Risk Factors of Constipation are: advanced age, comorbid disease and chronic opioid use

Fact #4: The colon performs several complex functions to form stool. Constipation may result from mechanical, metabolic, or functional disorders

Fact #5: Slow transit constipation is caused by impairment of the phasic colonic motor activity. Prolonged delay in the transit time due to abnormalities of colonic innervation causing delay of stool transit through the colon. There's primary dysfunction of motor innervation/ myenteric plexus (interstitial cells of Cajal)

Sodium oxybutyrate (natrii oxybutyras, gamma-hydroxybutyric acid) have sedative, central muscle relaxant and antihypoxic effects, potentiates activity of narcotic and not narcotic drugs. For an induction of anaesthesia sodium oxybutyrate is used in a dose of 90-110 mg/kg by the dropwise intravenous infusion within 5 minutes. It is desirable to execute infusion of 200-300 ml 1% glutamic acid's solution previously. In order to short time of induction of anaesthesia by sodium oxybutyrate in a dose of 30-40 mg/kg can be combined with 200-250 mg of sodium thiopental.

Ketamine (Ketalar, Calypsol) causes dissociative anaesthesia. Ketamin has expressed analgetic effect without a respiratory depression and depression of laryngeal reflex. In subnarcotic doses the drug is non-competitive antagonist of NMDA receptors, interfering with interaction of these receptors with exciting amino acids (one of mechanisms of sensitization).  At patients with concomitant disturbances of respiratory and cardiovascular systems, especially with bronchospastic syndrome, hypovolemia, cardiac failure (myocardial) delicacy (but not an ischaemic heart disease!), ketamine is more preferable drug for   induction of anaesthesia.

Barbiturates (sodium Thiopental, Hexenal, Brietal) prolong open time of GABA-dependent channels. This occurs at postsynaptic membrane of brain neurones and increases time of chlorine ions entrance in the excitatory cell and cause membrane depolarisation. In major doses barbiturates:

✓ have GABA-mimetic effects (activation of GABA-receptors)

✓ depress effects of exciting amino acids (aspartate and a glutamate)

✓ increase an excitation threshold of neurones

✓ quench convulsive impulses (anticonvulsant activity)

✓ retard carrying out of nerve impulses by spinal cord internuncial neurons, promoting muscle relaxation.

The up-to-date ventilators are able to generate into a respiratory contour (breathing circuit) three basic waveforms of flow:

✓ the squared waveform — a constant flow during an inspiration

✓ the descending waveform — the peak quantity of flow is delivered at the inspiration beginning and then flow level drops

✓ the sinusoidal waveform — flow gradually accrues to the middle of inspiration and then gradually drops.

Benzodiazepines (diazepam, midazolam, phenazepam etc.) are more effective as soporific drugs, administered at the night before operation. Besides, benzodiazepines possess soothing effect, anticonvulsant activity, sedative effect and cause amnesia. Anxiolytic activity of benzodiazepines is displayed by ability to reduce inner disturbing, pavor, alarm and psychoemotional pressure. Flumazenil is a benzodiazepine specific antagonist. It is rather important in the case of quickly remove the phenomena of benzodiazepine overdose.

Central chemoceptors are situated in myelencephalon and react to changes of рН in cerebrospinal fluid (CSF, liquor). рН level of CSF is very sensitive to changes of PaC0₂. At the increasing of PaC0₂ a рН of CSF respectively decreases. Hence a powerful impulsion from chemoreceptors passes into respiratory center, causing the increase of minute ventilation, due to increase of respiratory rate. Peripheral respiratory chemoreceptors are situated, basically, in carotid arteries and an aorta arch. These receptors react mainly on the decrease of PaC0₂ and lesser — on the decrease of blood рН. The most significant influence of peripheric chemoreceptors begin at decrease of PaC0₂ less than 70 mm hg, while at patients with COPD (chronic obstructive pulmonary disease) — less than 60 mm hg.