Evaluation of external pressure to the sacral region in the lithotomy position using the noninvasive pressure distribution measurement system

Impact of shear stress on sacral pressure injury from table rotation during laparoscopic colorectal surgery performed in the lithotomy position

This study aimed to evaluate the impact of shear stress on surgery-related sacral pressure injury (PI) after laparoscopic colorectal surgery performed in the lithotomy position. We included 37 patients who underwent this procedure between November 2021 and October 2022. The primary outcome was average horizontal shear stress caused by the rotation of the operating table during the operation, and the secondary outcome was interface pressure over time. Sensors were used to measure shear stress and interface pressure in the sacral region. Patients were divided into two groups according to the presence or absence of PI. PI had an incidence of 32.4%, and the primary outcome, average horizontal shear stress, was significantly higher in the PI group than in the no-PI group. The interface pressure increased over time in both groups. At 120 min, the interface pressure was two times higher in the PI group than in the no-PI group (PI group, 221.5 mmHg; no-PI group, 86.0 mmHg; p < 0.01). This study suggested that shear stress resulting from rotation of the operating table in the sacral region by laparoscopic colorectal surgery performed in the lithotomy position is the cause of PI. These results should contribute to the prevention of PI.

Prediction of tissue deformation based on mechanical and physiological factors in the prone position during surgery

AIM

This study aimed to predict tissue deformation based on the pressure applied while lying in the prone position and physiological factors.

METHODS

Healthy volunteers were instructed to lie on mattresses of four different hardness levels (50, 87.5, 175, and 262.5 N). The order in which the mattresses were used was randomized per participant. Pressure at the iliac crests was measured using a pressure mapping sensor sheet. Participants were placed in the prone position for 10 min, with pressure data used from the latter 5 min. For the tissue deformation at the iliac crests, our previous study data were used. Multiple regression analysis was used to identify predictive mechanical and physiological factors.

RESULTS

The distance between the left and right greater trochanters, maximum interface pressure and age were significant predictors for compression of the skin and soft tissue. Significant predictors of internal soft tissue displacement were the distances between the left and right anterior superior iliac spines and greater trochanters. No factors predicted skin surface displacement.

CONCLUSIONS

Our study provided predictive factors that may be measured easily in a clinical setting to reduce the risk of pressure ulcers during surgery in the prone position.

Surface Pressures in Lower Extremity Splints: A Biomechanical Study

Background

Though ubiquitously used in orthopaedic trauma, lower extremity splints may have associated iatrogenic risk of morbidity. Although clinicians pad bony prominences to minimize skin pressure, the effect of joint position on skin pressure and, more specifically, changing joint position, is understudied. The purpose of this biomechanical study is to determine the effect of various short-leg splint application techniques on anterior ankle surface pressure in the development of iatrogenic skin pressure ulcers.

Methods

Various constructs of lower extremity, short-leg splints were applied to 3 healthy subjects (6 limbs total) with an underlying pressure transducer (Tekscan I-Scan system) on the skin surface centered on the tibialis anterior tendon at the level of the ankle. All subjects underwent anterior ankle surface pressure assessment when padding was applied in maximum plantar flexion and neutral position for conventional short-leg splints application in clinically relevant patient scenarios. Percentage change from initial contact pressure centered on the tibialis anterior with cast padding were calculated.

Results

The percentage change in anterior ankle contact pressure when padding was applied in maximum plantar flexion (PF) and then definitively placed in neutral was increased at least 2-fold without the addition of plaster in lower extremity short-leg splints. Removing anterior ankle padding following final splint application in neutral reduced contact forces at the anterior ankle 46% and 59% in splints applied in maximum PF and neutral ankle position, respectively.

Conclusion

The present study is the first of its kind to underscore and quantify clinically relevant technical pearls that can be useful in reducing risk of iatrogenic risk of skin breakdown at the anterior ankle when placing short-leg splints, mainly, that it is imperative to apply padding in the intended final splint position and to remove anterior ankle padding following splint application when able.

Level of Evidence

Level IV, biomechanical study with clear hypothesis.

The effectiveness of curvilinear supine position on the incidence of pressure injuries and interface pressure among surgical patients

BACKGROUND

Intraoperative pressure injury is still a major problem of perioperative nursing. Reducing the peak interface pressure is a valid clinical intervention for reducing the incidence of intraoperative pressure injuries. However, studies of repositioning and pressure-redistributing for surgical patients are still lacking. In this context we aimed to evaluate the effect of a curvilinear supine position on incidence of pressure injury with surgical patients in a hospital setting.

METHODS

This was a prospective, randomized, controlled study, carried out from May to December 2016, included 104 surgical patients from a university hospital in China (experimental group, n = 52; control group, n = 52). Incidence of pressure injury, interface pressure, comfort and satisfaction scores from surgeons, anesthesiologists, OR nurses were recorded. Mann-Whitney U Chi-square test was used for difference of pressure injury's incidence and mixed linear model was used for interface pressure.

RESULTS

Overall the intervention group had significant fewer intraoperative pressure injuries than the control group (0 patients [0%] vs. 9 patients [17.65%], p = 0.002). Compared with control group, the experimental group had significantly lower interface pressures in the sacrum and heel regions (F = 23.81, p < 0.001; F = 60.71, p < 0.001). The subjects felt comfortable in two groups were 40(80%) vs. 3(5.88%) (experimental group vs. control group), respectively (p < 0.001).

CONCLUSIONS

Curvilinear supine position could significantly decrease the incidence of perioperative pressure injuries in surgical patients with surgery duration more than three hours. Considering these results, we recommend that curvilinear supine position use as effective interventions to inform perioperative care delivery, reducing perioperative pressure injuries. These findings may serve to guide the application of pressure redistribution in the surgical positioning of patients during prolonged surgery.