Valsalva manoeuvre in pressure-controlled mode better technique for unmasking of bleeders, finds Study
The Valsalva manoeuvre (VM) is used intraoperatively to unmask hidden venous bleeders during hemostasis in head and neck surgery, thyroid surgery, and craniotomy, as well as to aid in tasks like evaluating autonomic neuropathy, localizing venous air embolism, and facilitating internal jugular vein cannulation and pain management during skin puncture before certain medical procedures. Recent study compared the effectiveness of an anesthesia machine-generated Valsalva maneuver (VM) under pressure-control (PC) mode versus the traditional manual delivery of the VM in patients under general anesthesia. The primary outcome was to measure changes in the internal jugular vein (IJV) diameter, while secondary outcomes included heart rate (HR), mean arterial pressure (MAP), time to achieve desired plateau airway pressure, number of patients with bleeders unmasked, and surgeon satisfaction.
The study included 60 adult patients randomized to either the manual VM group (Group M, n=30) or the controlled ventilation VM group (Group C, n=30). In Group M, VM was delivered manually by partially closing the adjustable pressure limiting valve to 40 cmH2O and manually compressing the reservoir bag. In Group C, VM was delivered in PC mode at 40 cmH2O pressure.
The results showed that VM in the PC mode produced significantly greater dilatation of the IJV diameter in both the mediolateral (0.36 cm in Group C vs 0.23 cm in Group M, p=0.004) and anteroposterior (0.26 cm in Group C vs 0.19 cm in Group M, p=0.044) directions compared to the manual VM technique. The fall in MAP was also more significant in the PC mode group at 20 seconds after VM initiation and immediately after VM release.
The incidence of unmasking of covert bleeders and surgeon satisfaction were higher in the PC mode group. The time to achieve the required plateau airway pressure was shorter in the PC mode group compared to the manual VM group. In conclusion, performing the Valsalva maneuver in the pressure-controlled mode was found to be a better technique based on improved IJV diameter changes, hemodynamics, identification of bleeders, and higher surgeon satisfaction compared to the traditional manual delivery of the Valsalva maneuver in patients under general anesthesia.
Key Points
Here are the 6 key points from the research paper:
1. The study compared the effectiveness of an anesthesia machine-generated Valsalva maneuver (VM) under pressure-control (PC) mode versus the traditional manual delivery of the VM in patients under general anesthesia.
2. The primary outcome was to measure changes in the internal jugular vein (IJV) diameter, while secondary outcomes included heart rate (HR), mean arterial pressure (MAP), time to achieve desired plateau airway pressure, number of patients with bleeders unmasked, and surgeon satisfaction.
3. The study included 60 adult patients randomly assigned to either the manual VM group (Group M, n=30) or the controlled ventilation VM group (Group C, n=30). The manual VM was delivered by partially closing the adjustable pressure limiting valve to 40 cmH2O and manually compressing the reservoir bag, while the controlled ventilation VM was delivered in PC mode at 40 cmH2O pressure.
4. The results showed that the VM in the PC mode produced significantly greater dilatation of the IJV diameter in both the mediolateral and anteroposterior directions compared to the manual VM technique. The fall in MAP was also more significant in the PC mode group.
5. The incidence of unmasking of covert bleeders and surgeon satisfaction were higher in the PC mode group. The time to achieve the required plateau airway pressure was shorter in the PC mode group compared to the manual VM group.
6. In conclusion, performing the Valsalva maneuver in the pressure-controlled mode was found to be a better technique based on improved IJV diameter changes, hemodynamics, identification of bleeders, and higher surgeon satisfaction compared to the traditional manual delivery of the Valsalva maneuver in patients under general anesthesia.
Reference -
Shah SB, Chaudhary V, Chawla R, Hariharan U, Ghiloria N, Dubey JK. Comparison of two techniques of administering the Valsalva manoeuvre in patients under general anaesthesia: A randomised controlled study. Indian J Anaesth 2024;68:821‑7.
