Berguer recently recommended11
adjusting the operating table so that the height of the prone patient is at the level of the surgeon's upper thigh. The minimal vertical range of the operating table was not specified. Furthermore, the hands should be positioned at the level of the elbow with the forearm in a horizontal position. No mention was made of which handle to use. In the case of shank and pistol handles, the forearm position causes an ulna deviation, similar to the insertion angle of the instrument.
The manipulation of an axial handle is awkward in this position, causing severe pain, cramps, and fatigue.15
For the rod handle, the horizontal arm position recommended by Berguer11
may be adequate, as it usually results in an almost neutral wrist angle.
To determine adequate operating table heights, other elbow angles should also be considered. Bullinger recommends an elbow angle of 90°-120° for continuous work.20
Contrary to the 90° angle, the 120° angle requires an operating table height that–according to the type of handle used and the height of the surgeon–should be as much as 10 cm lower. A table that can be adjusted within this range by the surgeon him- or herself seems desirable. This could be accomplished either by a foot switch14
or a voice or hand controlled switch.
Differently designed handles should not be used simultaneously at the same insertion angle, because this requires different postures at shoulder level for adequate manipulation. But sometimes, when working with instruments at different insertion angles, it may be necessary to use different types of handles to achieve an ergonomic posture.
The difference between the two extreme positions, small surgeon, axial handle, EA 120°, IA 40° vs. tall surgeon, rod handle, EA 90°, IA 20°, is 33.5 cm. The lowest level for the abdominal wall is 70 cm. Accordingly the table should be positioned at a height of 30 cm for a patient with a sagittal abdominal diameter of 40 cm. Although, below the knee of the surgeon, even this level may be too high for some surgeons because the proband's height was at the 50th percentile. OR-tables that fit to 50% of surgeons could be a big advantage, because it is alarming that the currently available operating tables are too high for 95% of surgeons performing laparoscopic procedures.
For the lower position of the operating table, the following hygienic aspects should be considered: the distance between the operating level (abdominal wall) and the “floor” is equally reduced by the common use of a standing stool for different heights of surgeons and assistants. These stools, however, are neither convenient nor large enough to accommodate the surgeon and the paddle equipment. Furthermore, they also cause problems with regard to hygiene as it does not make a difference whether a standing stool elevates the floor or the table itself is lowered. For an ergonomic working posture, it is necessary to position the patient's abdominal wall at the height of the upper thigh as described by Berguer11
and demonstrated in the present study. This interferes with the classic teaching that the surgeon's gown is only sterile above the belt; however, a literature search did not reveal any data that would support this rule. To avoid contamination via the surgeon, the gown should reach down to the ankles.
In open surgery, the patient is also often positioned very low. For example, in the reversed Trendelenburg position, the foot part of the operating table, depending on the model, may come close or even touch the floor.
Following consultation with the Institute for Hospital Hygiene and Environmental Medicine, University Hospital Freiburg, we assume that such a low positioning of the patient per se does not bear the danger of bacterial contamination provided the floor is regularly cleaned in between surgical procedures. However, as in open surgery, the drapes should not touch the floor.
Therefore, the draping system has to be modified to meet the hygienic requirements for a low table height in laparoscopy as well as to allow for extreme positions in open surgery.
In the future, the problem of inadequate adjustability of OR-tables may be solved in part by the advent of robotically assisted surgery. For now, however, robotics has technical, hygienic, and ergonomic deficiencies that should be solved over the next decades. Furthermore, surgical procedures requiring the manual expertise of a surgeon and, therefore, an ergonomic work environment has to exist.
For laparoscopic surgery, special tabletop imposts are currently offered by different manufacturers of operating tables.14
Now the manufacturers are challenged to design new operating table posts to support the needs of surgeons and to optimize the safety and outcome for patients undergoing laparoscopic surgery.