Sedation induced hypoxemia in lower gastrointestinal endoscopy

Predictive risk factors of cardiorespiratory abnormality for upper gastrointestinal endoscopy in Tibet

BACKGROUND

To explore the predictive factors of cardiorespiratory abnormality in nonsedated patients at high altitude (HA) during upper gastrointestinal endoscopy (UGIE).

METHODS

The pulse and saturated oxygen (SaO2) levels of 993 patients undergoing nonsedated UGIE in Tibet were monitored. Bivariate correlation and logistic regression were used to identify predictive risk factors for hypoxemia.

RESULTS

The basal and minimum SaO2 levels during UGIE of the Tibetan group were significantly higher than those of the non-Tibetan group. The minimum SaO2 and maximum pulse in the HA transient residents groups were significantly higher than those in the HA usual residents groups. The incidences of hypoxemia and severe hypoxemia in the Tibetan groups were significantly lower than those of the non-Tibetan groups. Bivariate correlation and logistic regression showed that race, age (≥ 40 years), residence time in HA (<10 years), and basal SaO2 (<89 %) were sufficiently effective to predict hypoxemia. High-risk hypoxemic patients whose residence time in HA was <2 years were more prone to severe hypoxemia. The combination of the four variables showed superior performance in hypoxemia prognosis (AUC-ROC, 0.941; sensitivity, 83.7 %; specificity, 92.5 %) and severe hypoxemia prognosis (AUC-ROC, 0.968; sensitivity, 90.3 %; specificity, 98.0 %).

CONCLUSIONS

Race, age, residence time in HA, and basal SaO2 of patients in HA were predictive variables for hypoxemia during UGIE. Non-Tibetan patients with age ≥ 40 years, residence time in HA <10 years, and basal SaO2 <89 % were prone to hypoxemia. Among those groups, patients whose residence time was <2 years were at higher risk for severe hypoxemia.

[Sedation in upper gastrointestinal endoscopy. Analysis of tolerance, complications and cost-effectiveness]

INTRODUCTION AND AIM

Sedation of patients is an important complement to endoscopic procedures. The aim of this study was to analyze tolerance, complications and cost-effectiveness in patients undergoing diagnostic upper gastrointestinal endoscopy.

PATIENTS AND METHOD

A total of 357 patients were prospectively studied: 138 non-sedated, 116 sedated with midazolam and 103 sedated with midazolam and meperidine. Subjective tolerance, tolerance perceived by the endoscopist, complications, and cost-effectiveness were evaluated. The Chi-square test was used for the statistical analysis. P-values of less than 0.05 were considered statistically significant.

RESULTS

Subjective tolerance was greater in patients sedated with midazolam and meperidine than in the other groups (p < 0.05). Tolerance perceived by the endoscopist was greater in the group sedated with both drugs than in the group sedated with midazolam (p < 0.05). Subjective tolerance was better in sedated men and women but there was no association between sedation and perceived tolerance according to sex. Subjective tolerance was better in sedated patients older than 70 years than in those younger than 40 years (p < 0.05). Complications were more frequent in sedated patients and the most frequent complication in all the groups studied was mild desaturation; there was a significant difference between the group sedated with midazolam and meperidine and the non-sedated group (p < 0.05). Non-sedation had the best cost-effectiveness ratio but sedation with midazolam and meperidine was the most effective alternative.

CONCLUSION

From the point of view of the endoscopist, endoscopy can be performed without sedation, although subjective tolerance is greater in patients sedated with midazolam and meperidine. Non-sedation is more cost-effectiveness than sedation but if sedation is required midazolam and meperidine achieve better results in terms of effectiveness than midazolam alone.

Conscious sedation and cardiorespiratory safety during colonoscopy

BACKGROUND

Cardiorespiratory events during colonoscopy are common. The effect of sedative premedication on cardiorespiratory parameters during colonoscopy has not been studied in controlled, prospective trials.

METHODS

One hundred eighty patients undergoing colonoscopy were divided into 3 groups: (1) sedation with intravenous midazolam (midazolam group); (2) sedation with intravenous saline (placebo group); and (3) no intravenous cannula (control group). Arterial oxygen saturation (SaO(2)), systolic and diastolic blood pressure and continuous electrocardiogram were recorded prior to, during and after the endoscopic procedure.

RESULTS

Midazolam produced lower SaO(2) values during colonoscopy compared with placebo or control groups (p < 0.001, repeated measures analysis of variance). Systolic and diastolic blood pressure during colonoscopy were lower in the midazolam group than in the placebo group (p < 0.01 and p < 0.05, respectively), but no difference was found between the midazolam and the control groups. Hypotension (systolic blood pressure less than 100 mm Hg) occurred more frequently in the midazolam group (19%) than in the placebo (3%; p < 0.01) or control groups (7%; p < 0.05). ST-segment depression developed in 7% of patients during the recording with no difference between the groups. In 75% of cases ST-depression appeared prior to the endoscopic procedure.

CONCLUSIONS

Premedication with midazolam induced a statistically significant decrease in arterial oxygen saturation and increased the risk for hypotension. However, colonoscopy proved to be a safe procedure both with and without sedation.

Predictive factors of oxygen desaturation during upper gastrointestinal endoscopy in nonsedated patients

BACKGROUND

Hypoxemia can occur during upper gastrointestinal endoscopy with or without pharmacologic sedation. We investigated possible predictive factors of severe oxygen desaturation (SaO2 < 90%) in nonsedated patients undergoing endoscopy.

METHODS

A total of 481 patients who underwent upper gastrointestinal endoscopy without sedation were monitored with continuous pulse oximetry. Multivariate logistic regression analysis was used to identify factors related to the patient, the examination, and the monitoring data that would predict severe desaturation.

RESULTS

Mild desaturation (SaO2 between 90% and 94%) was found in 23.7% of the patients, and severe desaturation (SaO2 < 90%) was found in 6.4%. The variables found to predict severe desaturation were basal SaO2 < 95% (odds ratio 67.7), respiratory disease (odds ratio 30.5), more than one attempt needed for intubation (odds ratio 39.4), emergency procedure (odds ratio 14.9), and American Society of Anesthesiologists score of III or IV (odds ratio 3.9).

CONCLUSIONS

The predictive variables analyzed in this study can be used to identify patients who are at increased risk for desaturation. Such patients require very close monitoring (pulse oximetry at a minimum). Endoscopists and assistants should be especially alert to the possibility of respiratory depression in these patients.

Colonoscopy without sedation

Colonoscopy is routinely performed with conscious sedation. We wanted to determine if colonoscopy can be successfully completed without sedation and to assess patient tolerance and acceptance. One hundred nine consecutive patients undergoing colonoscopy were examined. The risks and benefits of colonoscopy with or without sedation were explained in a standard format. Patients were then given the option of having colonoscopy without premedication. After the procedure, as well as 2 to 5 days later, patients rated on an analog scale (0, no pain; 5, severe) the severity of pain and willingness to undergo colonoscopy in the future without sedation. Eighty patients underwent colonoscopy without prior sedation. Only 6% (n=5) required sedation to complete the examination. When questioned, 5% experienced no pain, 41% slight or mild pain, 34% moderate pain, and 20% severe pain. Seventy-three percent (n=58) were willing to undergo repeat colonoscopy without sedation, 10% (n=8) were undecided, and 18% (n=14) would request sedation. Pain severity was a strong predictor (p=0.001) of future sedation preference. Colonoscopy without sedation may be completed successfully in most patients and does not undermine many patients' willingness to undergo a similar procedure in the future. Sedation by choice is more cost-effective, may be safer, and should be offered as an alternative to routine intravenous sedation.

Sedation and analgesia for colonoscopy: patient tolerance, pain, and cardiorespiratory parameters

BACKGROUND

Colonoscopy is generally performed with the patient sedated and receiving analgesics. However, the benefit of the most often used combination of intravenous midazolam and pethidine on patient tolerance and pain and its cardiorespiratory risk have not been fully defined.

METHODS

In this double-blind prospective study, 150 outpatients undergoing routine colonoscopy were randomly assigned to receive either (1) low-dose midazolam (35 micrograms/kg) and pethidine (700 micrograms/kg in 48 patients, 500 micrograms/kg in 102 patients), (2) midazolam and placebo pethidine, or (3) pethidine and placebo midazolam.

RESULTS

Tolerance (visual analog scale, 0 to 100 points: 0 = excellent; 100 = unbearable) did not improve significantly more in group 1 compared with group 2 (7 points; 95% confidence interval [-2-17]) and group 3 (2 points; 95% confidence interval [-7-12]). Similarly, pain was not significantly improved in group 1 as compared with the other groups. Male gender (p < 0.001) and shorter duration of the procedure (p = 0.004), but not amnesia, were associated with better patient tolerance and less pain. Patient satisfaction was similar in all groups. Oxygen desaturation and hypotension occurred in 33% and 11%, respectively, with a similar frequency in all three groups.

CONCLUSIONS

In this study, the combination of low-dose midazolam and pethidine does not improve patient tolerance and lessen pain during colonoscopy as compared with either drug given alone. When applying low-dose midazolam, oxygen desaturation and hypotension do not occur more often after combined use of both drugs. For the individual patient, sedation and analgesia should be based on the endoscopist's clinical judgement.