*Anaesthetic Considerations in Gastrointestinal Endoscopies DOI: http://dx.doi.org/10.5772/intechopen.96687*


#### *Anaesthetic Considerations in Gastrointestinal Endoscopies DOI: http://dx.doi.org/10.5772/intechopen.96687*

these group of patients are not candidate for day case surgery or out of hospital setting. Sedative, anesthetics and opioid promote pharyngeal collapse, airway obstruction and alter normal respiratory response to obstruction and apnea in patients who suffer from obstructive sleep apnea which might increase the jeopardy of mortality and morbidity. Moreover, obese patients have significant reduction in functional residual capacity and rapidly desaturated [8]. Establishment of intravenous access, airway management, positioning and monitoring of obese patients are extremely difficult and require well trained sedative practitioners as well as immediate help.

### *5.2.2 Elderly patients*

The patient's upper age limit for outside-hospital procedures should be individually defined. The decision is based on considerations such as the invasiveness and length of the procedure, comorbidity, chronic medications and whether there is aftercare at home. Patients older than 65 years of age should be carefully selected for potential reduced organ function and increased occurrence of co-existing diseases. These patients often have limited reserves and can become degraded more rapidly and have more cardiac events. There is a strong correlation between advanced age and median successful dose reduction for all central nervous system medications regardless rout of administration.

#### *5.2.3 Pregnancy*

Gastrointestinal endoscopy in pregnant women should only be carried out if it's strongly indicated and deferred to the second trimester wherever possible.

The pregnant woman should be properly aware of the essence of the procedure, the possible advantages and complications, including the risks resulting from sedative medications, on herself and the fetus, and should take a fully informed decision. Whenever possible, procedures should be carried out without any sedation, thus preventing ventilatory dysfunction as well as subsequent hypoxemia and potential teratogenicity. In situations where sedation is inevitable, a minimum clinically appropriate dosage must be maintained for sedative agents. Further advices involve maternal and fetal monitoring during endoscopy, and putting the patient in a lateral decubitus position, to avoid the vena caval and aortic compression through the gravid uterus, and applying the bipolar current to electrocoagulation.

Teratogenic effects of propofol and fentanyl in humans have never been proved conclusively and these agents have strong safety records in appropriate pregnant doses. While a correlation between benzodiazepine use and oral cleft abnormalities has been identified, this finding has not been verified by later case–control studies. Since the duration of organogenesis is during the first trimester of pregnancy, it is widely advised that all but truly emergency endoscopic procedures requiring sedation be delayed until later in pregnancy in order to prevent possible teratogenicity. A meta-analysis of anesthetic exposure studies during pregnancy concluded that the only potential issue concerning general-anesthetic exposure is a small increase in the incidence of miscarriage. Although most current anesthetic and analgesic agents cross the placental barrier to varying degrees, their possible adverse fetal effects tend to be limited a and if administered judiciously, are well tolerated by the fetus. It should be stressed, however, that all the published recommendations are backed by minimal evidence, especially in the case of colonoscopy, and that adherence to those recommendations could not guarantee an uneventful course of pregnancy and the development of the fetus [9, 10].

#### *5.2.4 Children*

Pediatric patients are less supportive than adult patients, and their parents also feel more anxiety about the procedure. The effect of sedation varies according to the age of pediatric patients [11]. Children below the age of 6 months may have little anxiety and may be easily affected by sedation. Patients who are six months of age or older, however, have already developed unusual anxiety and will require that their parents stay with them during induction. For children of school age, sedating them is surprisingly challenging as they have developed concrete thinking. As a result, to minimize their level of discomfort, it is advised to carefully address what to expect during the operation.

#### **5.3 Fasting guidelines**

Preoperative fasting prior to a procedure carried under sedation is contentious. Some authorities regard it as unnecessary, especially in dentistry and emergency medicine; the idea being Airway protective reflexes are intact during mild and moderate sedation but may be lost during deep sedation. However, if deep sedation is planned, via dissociative or non-dissociative techniques, the following fasting duration recommendations should be followed: [12].


In situations where mild to moderate sedation fails to facilitate the procedure, and the patient is not adequately fasting as above, the procedure should be halted. In an emergency, a general anesthetic can be considered with a rapid sequence induction technique.

#### **6. Procedure monitoring**

The Academy of Medical Royal Colleges in Safe Sedation Practice for Healthcare Procedures describes the principles of monitoring during and after the procedure. All sedation team members shall have a comprehensive knowledge of monitoring equipment and an interpretation of the information provided by monitoring devices.

The sedation technique employed is to decide what degree of monitoring is appropriate. This means either basic/standard sedation or advanced sedation.

During basic/standard techniques in which only one individual pharmacological agent is used, respiratory and cardiovascular systems typically are not affected. The intermittent examination of vital signs, e.g. sedation level, anxiety, skin color and breathing habits, is sufficient. A pulse oximetric and non-invasive blood pressure monitor are mandatory for extended procedures [13, 14].

When advanced sedation methods are deployed, the following must be controlled and documented:


Patients undergoing PSA tolerate capnography applied via a nasal cannula, side-stream examination and transcutaneous approaches. Capnography is not compulsory for mild sedation, but is strongly advised in patients with fragile ASA II, elderly, obese, obstructive sleep apnea patients, and patients with respiratory problems such as chronic obstructive pulmonary disease (COPD) Nevertheless, Capnography can never replace ventilation/respiration clinical monitoring. If capnography is unavailable, use of a precordial stethoscope may be helpful.

6.**Heart Rhythm and Rate:** For most levels of sedation, the pulse rate, as recorded by pulse oximetry, should be enough. Electrocardiography (ECG) is not necessary in moderate sedation, where regular verbal communication with the patient is established. However, when using advanced sedation procedures, an ECG is recommended for extended sedation or in delicate ASA II patients, patients with underlying cardiovascular disease and the elderly.

7.**Non-invasive (NIBP) blood pressure.** NIBP must be monitored at all sedation stages.
