Search

(Int J Obstet Anes. 2022;49:103245)Spinal anesthesia is often assessed by the subjective method of cold and light touch perception. Inadequate anesthesia can cause pain during surgery and negligence claims. Infrared thermography (ITH) objectively measures skin surface temperature, which increases during spinal anesthesia due to blood vessel dilatation and increased blood flow. There have been conflicting results in studies investigating skin temperature changes during neuraxial anesthesia in nonpregnant patients. This study aimed to determine whether ITH measured consistent and significant skin temperature changes during spinal anesthesia for cesarean delivery (CD).

Plagiocephaly is a common asymmetry of the skull giving the impression that the subject, usually a neonate, has suffered a compressive force acting unilaterally. Normally innocuous, it is a postural deformity that can be suggestive of other significant abnormalities, e.g. joint dysplasia. Although intuitive measurements of plagiocephaly appear in the literature there is little evidence of analytical evaluation. This paper describes a measurement methodology based on black and white photography. A flat-bed scanner and a personal computer facilitated the transformation of the prepared photograph to standard tagged image file formatat 256 grey scale. A utility was used to convert the file scan to a monochrome bitmapimage which was displayed on the screen and subjected to an algorithm to compute the centroid of the cranial profile. Radials that emerge from the centroid to the cranial circumference at five degree intervals map to a signal display that represents the plagiocephaly.

Analysis of small oscillations in heart rate (known as heart rate variability or HRV) associated with the activity of homeostatic reflexes can provide a noninvasive measure of autonomic reflex function. We have investigated the effects of surgical stimulation on autonomic reflex function by assessment of changes in HRV. Healthy female patients undergoing laparoscopic tubal ligation were anaesthetized with either thiopentone-nitrous oxide-isoflurane (group I; n = 13) or continuous propofol infusion (group P; n = 13). Power spectral measurements of HRV (HRVtot = total HRV power; %HRVlo = percent of HRV power in the low frequency range) were obtained at the following times; control; before incision; after incision (3 min, 10 min and before skin closure). Compared with control values, measurements of HRVtot before incision were reduced significantly in both groups (group P: 16 (SEM 3)% of control; group I: 2.5 (0.7)% of control). With surgical stimulation, mean HRVtot in group P was restored to 55 (13)% of control (P < 0.01 compared with measurement before incision), whereas mean HRVtot in group I remained at less than 4% of control (ns). %HRVlo increased also in group P, from 49 (7)% to 75(3)% (P < 0.05), consistent with a shift in sympathetic-parasympathetic balance towards sympathetic dominance. These results suggest that surgical stimulation may have significant effects on the autonomic reflexes mediating HRV, and that such effects vary with anesthetic technique.

Tracheal intubation carries a risk of accidental oesophageal intubation; this is increased with inexperienced trainees, and in patients with a difficult airway. The recent introduction of an angulated laryngoscope, the Belscope, may permit a better view of the vocal cords and increase the accuracy of orotracheal intubation. To determine how easy it is to learn to use the Belscope compared with the traditional Macintosh laryngoscope, a group of medical students attempted to intubate a mannikin which had been modified to simulate a difficult intubation. Time to intubation was fast with both laryngoscopes, although faster with the Macintosh, but the Belscope produced an unexpected greater incidence of failed intubation.