One hundred and twenty healthy, elective surgical inpatients were randomly assigned to one of four groups. Between two and three hours before the scheduled time of surgery all patients ingested a marker dye, phenol red, 50 mg in 10 ml water, with placebo tablet alone (Groups 1 and 2), placebo tablet with 150 ml oral fluid (Group 3), or oral ranitidine 150 mg with oral fluid 150 ml (Group 4). Patients in Group 1 received oral diazepam or no premedication, while those in Groups 2, 3, and 4 received IM narcotic and atropine one hour preoperatively. Following induction of anaesthesia the residual gastric fluid was aspirated through a Salem sump tube and its volume, pH, and phenol red content measured. Mean volumes were Group 1: 24 ml; Group 2: 13 ml; Group 3: 17 ml; Group 4: 14 ml. Mean pH values were Group 1: 2.99; Group 2: 3.03; Group 3: 3.44; Group 4: 5.28. The amount of phenol red in the samples indicated at least 90 per cent gastric emptying had occurred in 90 per cent of patients. We conclude that, in healthy patients, 150 ml oral fluid is almost completely emptied from the stomach within two hours of ingestion, even when followed one hour later by narcotic-atropine premedication.

No abstract

The use of large volumes of irrigation fluid during laparoscopic bile duct exploration does not cause a fall in core temperature.

Discussion The quantitative carbon dioxide analyser is one of the most valuable monitors we have in clincial anaesthesia. Unfortunately, because of their size and cost, these monitors are not available in all areas where tracheal intuhation is carried out. Few hospitals can supply every operating room, emergency room or "crash cart" with one of these devices, and they are not practical for use by medical personnel in "field" settings or by paramedics in their work environment. The pH-sensitive chemical indicator, on the other hand, is small, inexpensive and easy to use, and would be ideal for all the above situations. It is not a replacement for the quantitative carbon dioxide analyser, but if used in conjunction with the usual methods of detecting correct tube placement, it should reduce the number of undiagnosed oesophagcal intubations. References t PotlardBJ, Juntas F. Accidental intubatian of the oesophagus.

p < 0.05). It is well-known that inclusion of the continuity correction greatly improves the validity of the Chi-squared test in this 2 x 2 situation, here comparing the proportions of cases with pain levels 1 + 2 + 3 and level 0 in the two groups.Rather than combine pain levels I , 2 and 3 together a Chi-squared test of homogeneity can be performed on the 2 x 4 data set of their Table 2 . This gives p = 0.095. To overcome fears that the Chi-squared test may not be appropriate in this small sample case a randomisation test',' was carried out. Ten thousand simulations gave p = 0.090 (SD 0.003). No significant difference is observed with these data.A similar randomisation test for the 2 x 2 data case described above yielded p = 0.051 (SD 0.002) which confirmed the nonsignificance of the Chi-square test result.The only significant result is that comparing the proportions of severe pain, level 3, and nonsevere pain, levels O + 1 +2, in the two groups. A Chi-squared test with continuity correction gave p = 0.045. Fisher's exact 2 x 2 test3 gave p = 0.019, and a randomisation test with 10000 simulations gave p = 0.020 (SD 0.001). The result quoted in the paper was p < 0.025.Injection of propofol at 445°C significantly reduced the incidence of severe pain experienced by patients, but more data would be needed to assess the effect of low temperature on the incidence of mild or moderate pain.