Comparison of Intravenous Ketamine with Intrathecal Meperidine in Prevention of Post-anesthetic Shivering after Spinal Anesthesia for Lower Limb Orthopedic Surgeries: A Double-blind Randomized Clinical Trial.

Background: Post-anesthetic shivering is one of the most common complications after anesthesia. Ketamine has been considered to be an effective treatment for post-anesthetic shivering, but the evidence for its therapeutic benefit after spinal anesthesia is limited. The aim of this study was to compare the effects of intravenous ketamine with intrathecal meperidine in the prevention of post-anesthetic shivering after spinal anesthesia for lower limb orthopedic surgeries. Methods: In a double-blind randomized parallel-group clinical trial, a total of 150 patients scheduled for lower limb orthopedic surgeries under spinal anesthesia were selected and randomly divided into three equally sized groups of intravenous ketamine (0.5 mg/kg), intrathecal meperidine (0.2mg/kg) or intravenous normal saline (as placebo). The intensity of shivering in patients were evaluated during surgery and after transfer into the post anesthesia care unit. Also, changes in patients' drowsiness, nausea, vomiting, pruritus, mean arterial pressure, heart rate, and arterial oxygen saturation (SPO2) during surgery and until the end of anesthesia were evaluated. Results: In all times of evaluation (20, 60, 80, 100 and 120 minutes after onset of spinal anesthesia) patients in control group showed a greater intensity of shivering compared to other groups. However, patients who received intrathecal meperidine experienced significantly lower intensity of post anesthetic shivering (p<0.05). The results showed a significant mean arterial pressure and heart rates differences between the three groups, only on 20 and 60 minutes after initiation of spinal anesthesia. The incidence of nausea, vomiting, and pruritus was not significantly different in all three groups, although all patients who received ketamine experienced drowsiness after surgery (p<0.001). Conclusion: The results of the present study showed that, although both intrathecal meperidine and intravenous ketamine could effectively prevent postoperative shivering after spinal anesthesia in lower limb orthopedic surgeries, intrathecal meperidine was associated with more efficacy benefits and a lower frequency of side effects such as post-anesthesia drowsiness.

Extra-intestinal pathogenic Escherichia coli from human and avian origin: Detection of the most common virulence-encoding genes.

Pathogenic Escherichia coli strains cause a wide range of extra intestinal infections including urinary tract infection in humans and colibacillosis in poultry. They are classified into uropathogenic E. coli (UPEC) and avian pathogenic E. coli (APEC) with genetic similarities and variations. Their pathogenicity is related to the virulence-encoding genes like sfa, papG II, ompT, iutA, and iss with zoonotic potentials. One hundred isolated E. coli from patients with urinary tract infection and 100 E. coli from chickens with colibacillosis were evaluated for the presence of the most common virulence-encoding genes including sfa, papG II, ompT, iutA, and iss by multiplex polymerase chain reaction. While the frequency of sfa, papG II, ompT, iutA and iss encoding genes in APEC isolates were respectively 0.00%, 67.00%, 63.00%, 89.00% and 89.00%, the frequency of these encoding genes in UPEC isolates were 18.00%, 40.00%, 40.00%, 74.00% and 48.00%, respectively. Except for sfa, the frequencies of other encoding genes in APEC were more than those in UPEC isolates. The iutA as the most common UPEC encoding gene and iss as the most common APEC encoding gene were the most prevalent virulence factors in the examined E. coli isolates. Finding out the distribution of virulence-associated genes could be helpful to identify similarities and differences between APEC and UPEC isolates in order to provide more substantial evidence of their common virulence traits and potential zoonotic threats.