Many lower abdominal robotic surgeries need a steep Trendelenburg position , but the whole surgical team must be concerned with the physiological consequences. The classic Trendelenburg position was initially described with the torso supine and the legs upon the shoulders of an assistant with 45° head-down tilt. However, the term is now often used to describe any head-down position, including the steep Trendelenburg used for laparoscopic and robotic surgery [12]. In the steep position the patient must be stabilized at the surgical table not to slide down. A gel mattress or a vacuum mattress can be used to help sliding avoidance at the surgical table in the steep position [10]. The Trendelenburg position is associated with reduced total lung capacity, compliance, and increased airway pressures. Lung volume approaches closing capacity with resultant atelectasis and shunt. The endotracheal tube can be displaced with the table movement so the ventilation must be periodically checked for selective intubation. Many complications may be associated with this position because nondangerous complications such as light facial edema or more dangerous complications such as facial and airway edema may lead to respiratory distress in some cases [13]. Regarding hemodynamics the Trendelenburg position associated with the pneumoperitoneum is associated with elevation of pulmonary arterial pressure and central venous pressure and cardiac index decrease by as much as 50% [14, 15]. There are also some reports of visual loss after the steep Trendelenburg position associated with posterior ischemic optic neuropathy [16]. Intraocular pressure (IOP) is increased in the steep Trendelenburg position and the increase is time related. In general, robotic surgery in the steep Trendelenburg position appears to pose little or no risk from IOP increases in patients without pre-existing ocular disease [17], but there may be additional risks for patients with glaucoma. Unfortunately there are no current guidelines for monitoring and preparing patients with glaucoma undergoing surgical procedures, but there are some successful cases described [18].

It remains to be elucidated whether the Trendelenburg position increases intracranial pressure (ICP). It’s well known that the head-down tilt increases central venous pressure and impairs venous drainage of the head. Other factors that can be involved with possible increase in ICP is the elevated impedance of drainage of the lumbar venous system secondary to the elevated intra-abdominal pressure, that may decrease reabsorption of cerebrospinal fluid. Chin et al. evaluated sonographic optic nerve sheath diameter (ONSD) to identify ICP. Their study did not definitively prove that there is a rise in ICP with the steep Trendelenburg position, but proposes that the ONSD provides a better understanding of the effect of the transient steep Trendelenburg position [19].

The reverse Trendelenburg position is used in the upper abdominal laparoscopic and robotic surgeries. Regarding respiratory function this position can increase residual functional capacity and avoid collapse of the inferior area of the lungs. The patient will have an increased venous return and must be prepared to tolerate this fluid challenge [1]. Sliding on the surgical table can also occur in the reverse position and the same caution must be taken.

Depending on the procedure, the arms can be alongside the body with limited access for the anesthesiologist, thus the venous access and also monitors such as arterial line and pulse oxymeter must be well positioned and correctly functioning before the beginning of the surgery. Some precautions are also important to avoid brachial plexus injury. The head must be in neutral position to stretch the brachial plexus and the occiput must be protected; if possible the head must be slightly moved in order not to have prolonged pressure at the same point because such pressure can cause postoperative alopecia [20]. Arm boards can be used and it is preferred to tuck the arms to the patient’s sides with the palms facing the thighs, avoiding abduction, external rotation, or extension of the arms. The patient must be stabilzed at the surgical table and to avoid stretching the brachial plexus and acromium a cross-chest strap technique can be used as described by Shveiky et al. [20]. The cross-chest strap technique uses two straps of foam material placed over the acromio-clavicular joint level and the contralateral breast. Each strap is secured to the table with wide tape, without any pressure on the shoulders.

In some surgeries the legs must be spread and positioned at holders that must be padded and at the same height. The adequate positioning is not easy, especially in obese patients, so sufficient personnel are necessary to prevent lumbosacral injury and hyperflexion of the hips. Another important precaution when the arms are along the body and the legs at holders is to watch out for the position of the fingers to prevent crush injury when moving the leg holders [10].