[Safety of propofol administration by the staff of a gastrointestinal endoscopy unit]

Nonanesthesiologist-administered propofol sedation for colonoscopy is safe and effective: a prospective Spanish study over 1000 consecutive exams

BACKGROUND AND STUDY AIMS

Propofol is increasingly being used in sedated colonoscopy. This paper assesses the safety and efficacy of nonanesthesiologist-administered propofol in a large series of colonoscopies.

PATIENTS AND METHODS

A prospective registry of consecutive American Society of Anesthetics (ASA) class I and II outpatients undergoing colonoscopy was carried out. Propofol, administered by a nurse under an endoscopist's supervision, was the sole sedative agent used.

RESULTS

Of the 1000 patients (563 women/437 men, mean age 57, range 8-89 years) included in the study, 57.4% showed ASA I and 42.6% ASA II characteristics. The cecal intubation rate was 96.9%. 48.2% of the procedures were for therapeutic purposes. The mean propofol dose was 177 mg (range 50-590 mg). Doses correlated inversely with patient age (r=-0.38; P<0.001) and were lower in ASA II patients (P<0.001) and in diagnostic (rather than therapeutic) exams (P<0.001). The average recovery time (from extracting the colonoscope to patient discharge) was 18.6 min (range 4-75) and longer in ASA II patients (P=0.05). A pulse oximetry saturation of less than 90% and a decrease in systolic blood pressure of more than 20 mmHg were observed in 24 (2.4%) and 385 (35.8%) patients, respectively. Both events were more frequent in patients older than 65 years (P<0.05); the latter was more common in ASA II patients.

CONCLUSION

Colonoscopy under endoscopist-controlled propofol sedation in low-risk patients is safe and effective, allowing for a complete exploration, although patients at least 65 years old and/or classified as ASA II are more likely to present a decrease in blood pressure and have a prolonged recovery time.

Effect of propofol on proliferation and apoptosis of gastric mucosal cells in gastric ischemia-reperfusion injury in mice

AIM: To observe the changes in proliferation and apoptosis of gastric mucosal cells in gastric ischemia-reperfusion (I/R) injury, and to clarify whether propofol has a gastric protection effect and the possible mechanisms involved.

METHODS: Seventy-two Kunming mice were randomly divided into four groups: sham operation group, I/R injury group, fat emulsion group, and propofol group. Except the sham operation group, I/R injury was induced in other groups by clamping the celiac artery for 30 min and allowing reperfusion for 1h. The mice were finally sacrificed to observe morphological changes and investigate gastric mucosal damage index (GMDI). The histological changes of the stomach were observed using light microscopy. The content of malondialdehyde (MDA) and activity of superoxide dismutas (SOD) in gastric mucosal cells were measured by colorimetry analysis. Immunohistochemistry and TdT-mediated d-UTP-biotin nick end-labeling (TUNEL) assay were used to observe PCNA expression and apoptosis in gastric mucosa, and the expression of Bax and Bcl-2 proteins was determined by Western blot.

RESULTS: Severe mucosal lesions induced by gastric I/R were considerably reduced following administration of propofol (25 mg/kg); mucosal and submueosal hyperemia, edema, and deep erosion were improved significantly. Compared to the I/R group, treatment with propofol significantly reduced gastric mucosal MDA content and cell apoptosis (33.9% ± 1.3% vs 60.8% ± 6.9%, P < 0.01), enhanced SOD activity, promoted cell proliferation (16.0% ± 1.8% vs 6.4% ± 1.2%, P < 0.01), and regulated Bax (0.453 ± 0.025 vs 0.268 ± 0.023, P < 0.01) and Bcl-2 (0.513 ± 0.014 vs 0.752 ± 0.015, P < 0.01) protein expression.

CONCLUSION: Propofol protects against gastric gastric I/R injury possibly by promoting gastric mucosal cell proliferation and inhibiting apoptosis.

Endoscopist experience as a risk factor for colonoscopic complications

AIM

We aimed to determine the incidence of colonic perforation (CP) following colonoscopy and postpolypectomy bleeding (PPB) in a teaching hospital, assessing the influence of endoscopist experience as a risk factor.

METHOD

All colonoscopies performed between 1995 and 2008 were reviewed. Demographic data, endoscopic procedure information, incidence of CP and PPB, and endoscopist experience were recorded.

RESULTS

In the 14-year period, 25,214 endoscopic colonic procedures were performed, and 3991 patients underwent polypectomy. The overall CP risk was 0.51/1000 procedures; and PPB 14.7/1000. The relative risk (RR) ratio of complications was 2.8/1000 procedures. The RR rate was highest for endoscopists performing less than 591 procedures per year (4.0/1000 [95% CI, 3.7-4.3] vs 2.9/1000 [95% CI, 2.6-3.2]), P < 0.001).

CONCLUSION

The complication rate after colonoscopy was comparable to that previously reported. Colonoscopy carried out by a low-volume endoscopist was independently associated with bleeding and perforation.