Vascular surgery

We examine the challenges with open aortic aneurism repair as well as highlighting the role of hemodynamic monitoring in this key clinical area

“Results showed significantly less fluid or adjusted all complications in the IGFT group.”
Bisgaard et al. 2013

 

Patients undergoing open abdominal aortic aneurism repairs would be categorized as high-risk and require close fluid and drug management.

When the aortic clamp is on, it is imperative to not over fill the patient.

It is a challenge ensuring an adequate cardiac output and oxygen delivery whilst being fluid restrictive during this phase.

When the vascular clamp is removed, blood pressure drops and an immediate assessment of patients hemodynamic status is required in order to provide the necessary fluid or drug response.

Advanced hemodynamic monitoring is required to achieve careful administration of fluids and drugs in patients undergoing an AAA repair.

During the clamp on phase, use of the hemodynamic monitoring is key in ensuring an adequate cardiac output is achieved and so fluid can be restricted confidently.

When the clamp is removed, hemodynamic monitoring is key in ensuring an adequate amount of fluid and drugs are administered to respond to the sometimes dramatic hemodynamic shift.

Haemodynamic optimisation in lower limb arterial surgery: Room for improvement?

Haemodynamic optimisation in lower limb arterial surgery: Room for improvement?

Patient Population
High-risk peripheral vascular surgery.

LiDCO Monitor
LiDCOplus oxygen delivery (DO2) GDT target.

Trial Design
Randomised GDT vs standard care.

Outcome Impact
Significantly less fluid or adjusted all complications in the IGFT group.

BACKGROUND
Goal-directed therapy has been proposed to improve outcome in high-risk surgery patients. The aim of this study was to investigate whether individualised goal-directed therapy targeting stroke volume and oxygen delivery could reduce the number of patients with post-operative complications and shorten hospital length of stay after open elective lower limb arterial surgery.

METHODS
Forty patients scheduled for open elective lower limb arterial surgery were prospectively randomised. The LiDCOplus system was used for hemodynamic monitoring. In the intervention group, stroke volume index was optimised by administering 250 ml aliquots of colloid intra-operatively and during the first 6 h post-operatively. Following surgery, fluid optimisation was supplemented with dobutamine, if necessary, targeting an oxygen delivery index level ≥ 600 ml/min(/) m(2) in the intervention group. Central hemodynamic data were blinded in control patients. Patients were followed up after 30 days.

RESULTS
In the intervention group, stroke volume index, and cardiac index were higher throughout the treatment period (45 ± 10 vs. 41 ± 10 ml/m(2), P < 0.001, and 3.19 ± 0.73 vs. 2.77 ± 0.76 l/min(/) m(2), P < 0.001, respectively) as well as post-operative oxygen delivery index (527 ± 120 vs. 431 ± 130 ml/min(/) m(2), P < 0.001). In the same group, 5/20 patients had one or more complications vs. 11/20 in the control group (P = 0.05). After adjusting for pre-operative and intraoperative differences, the odds ratio for ≥ 1 complications was 0.18 (0.04-0.85) in the intervention group (P = 0.03). The median length of hospital stay did not differ between groups.

CONCLUSION
Peri-operative individualised goal-directed therapy may reduce post-operative complications in open elective lower limb arterial surgery.

Multimodal intraoperative monitoring: Observational case series in major peripheral vascular surgery

Multimodal intraoperative monitoring: Observational case series in major peripheral vascular surgery

Patient Population
High-risk peripheral vascular surgery.

LiDCO Monitor
LiDCOrapid as the hemodynamic part of a multimodal monitoring approach.

Trial Design
Actual mortality after multimodal approach vs predicted V-POSSUM.

Outcome Impact
30-day mortality at 0.8% significantly lower than the 9% mortality predicted by the V-POSSUM amputation rate less than 2% after one year. Post-operatively only 8% (10 patients) went to a high dependency unit (HDU).

BACKGROUND
Recent guidelines from the National Institute for Health and Care Excellence (NICE) and the UK National Health Service (NHS) have stipulated that intra-operative flow monitoring should be used in high-risk patients undergoing major surgery to improve outcomes and reduce costs. Depth of anesthesia monitoring is also recommended for patients where excessive anesthetic depth is poorly tolerated, along with cerebral oximetry in patients with proximal femoral fractures.

OBJECTIVE
The aims of this descriptive case series were to evaluate the impact of a multimodal intra-operative strategy and its effect on mortality and amputation rate for patients with critical leg ischaemia.

METHODS
In an observational case series, 120 elderly patients undergoing major infra-inguinal bypass between 2007 and 2012 were included in this retrospective analysis of prospectively collected data. Nominal cardiac output (nCO, LiDCOrapid), bispectral index to monitor depth of anaesthesia (BIS, Medtronic) and cerebral oxygenation, rSO2 (Invos, Medtronic) readings were obtained before induction of general anesthesia and throughout surgery. 30-day, 1-year mortality and amputation rates were analysed. Demographics and physiological parameters including correlation with V-POSSUM, age, gender and other co-morbidities were statistically analysed.

RESULTS
Thirty-day mortality rate was 0.8% (n = 1). V-POSSUM scoring indicated a predicted mortality of 9%. Amputation rate was less than 2% at one year. Only 8% of patients (10 of 120) were admitted to a high dependency unit (HDU) postoperatively. 30-day mortality in our case series was lower than predicted by V-POSSUM scoring.

CONCLUSIONS
Use of multimodal intra-operative monitoring with the specific aim of limiting build-up of oxygen debt should be subjected to a randomised controlled study to assess the reproducibility of these results.

Green D, Bidd H, Rashid H. Multimodal intraoperative monitoring: An observational case series in high risk patients undergoing major peripheral vascular surgery. Int J Surg (2014);12(3):231-6. doi: 10.1016/j.ijsu.2013.12.016. Epub 2014 Jan 8.

30-day mortality at 0.8% significantly lower than the 9% mortality predicted by the V-POSSUM amputation rate less than 2% after one year. Post-operatively only 8% (10 patients) went to a high dependency unit (HDU).

LiDCOrapid – Hemodynamic Monitoring in Action

View Video >

“Results showed significantly less fluid or adjusted all complications in the IGFT group.”
Bisgaard et al. 2013

 

The LiDCOunity monitor is a single platform which combines both the LiDCOplus and LiDCOrapid functions. This provides a single solution to monitoring needs throughout the hospital. The clinician can choose which mode is most appropriate to the clinical situation. The LiDCOunity can be used non-invasively, minimally invasively with a radial arterial line and can be calibrated with the lithium dilution technique.  Find out more

The LiDCOplus hemodynamic monitor provides a continuous, reliable and accurate assessment of the hemodynamic status of critical care and surgery patients.  The LiDCOplus is comprised of two technologies: a continuous arterial waveform analysis system (PulseCO™) coupled to a single point lithium indicator dilution calibration system.  Find out more

The LiDCOrapid monitor analyses the blood pressure waveform to provide more information in high-risk surgical and critically ill patients to help with fluid and drug management.  The LiDCOrapid uses the PulseCO™ algorithm which converts blood pressure to its constituent parts of flow (CO, SV) and resistance (SVR). The PulseCO™ algorithm is scaled to each patient with a nomogram using age, height, and weight.  Find out more