Optimal Track: perioperative management of high-risk surgical patients

Unfortunately, procedure related morbidity and mortality are an inevitable part
of surgical practice. Much research has been directed on strategies that reduce
complications due to surgical procedures. Especially the technical aspects of
operations and the individual performance of surgeons have been studied
intensively. Compared to these aspects the system has been poorly studied
although structural changes in perioperative management have been shown to have
significant impact on morbidity and mortality. For example, fast track surgery
and perioperative hemodynamic optimization have shown to reduce both morbidity
and mortality.

Major postoperative complications occur in a relative small group of high risk
patients. Various scoring systems have been designed to identify the individual
patient at increased risk for developing perioperative mortality and
morbidity[8-10]. Identifying these patients has both logistic and clinical
advantages. Patients at increased risk may benefit from additional
perioperative therapy. Several tools and perioperative management strategies
have been proposed and investigated in these high risk surgical patients.

There are many different audit tools designed to estimate the risk of a patient
on morbidity and mortality. Their merit in surgical practice has been well
established. For this study, the identification of risk in surgical patients
score (IRIS) will be used for identifying high-risk patients. This scoring
system is a strong predictor of mortality and morbidity in surgical patients
treated at the Zaandam Medical Centre (ZMC). Furthermore, it is easy to use and
relies on objective parameters. Patients with an IRIS score of four and higher
are considered to be at high risk for developing complications.

At this moment high risk surgical patients receive a non-standardized level of
care. More intense monitoring of these patients and perioperative hemodynamic
optimization has been shown to improve outcome in high risk surgical patients.
Furthermore, using fast track principles speeds up the rehabilitation process
and diminishes complications that occur due to overlong hospital stay, such as
nosocomial infections and pressure ulcers.

In 1988 Shoemaker and colleagues published the results of an observational
study on hemodynamic values in surgery, trauma and critically ill patients.
Compared to non-surviving patients, survivors demonstrated significantly higher
values of oxygen delivery (over 600 ml/min/m2) and consumption. It was
hypothesized that optimizing the circulation in high risk patients before
surgery would reduce cardiovascular stress and as an effect reduce mortality
and morbidity.This hypothesis was evaluated in several randomized clinical
trials.

The first trial on hemodynamic optimization in high risk surgical patients was
performed by Shoemaker et al. In this study, subjects included in the
intervention group had hemodynamic target values based on the median values
achieved by survivors of a previous observational study. Subjects were
monitored using balloon-tipped pulmonary artery and radial artery catheters.
This trial demonstrated a rather large reduction in both mortality and
morbidity (protocol mortality 4%, control 38%). Regarding the methodology
several pitfalls and shortcomings of this trial should be mentioned; treatment
protocols were not clearly mentioned, the control group did not receive
standardized treatment and the study was not blinded.
To address these concerns Boyd et al. executed a subsequent trial. In this
study both control and intervention group were treated with strict protocols. A
reduction of both mortality and morbidity was shown in the intervention group.
Pearse et al. also showed a reduction in morbidity and hospital stay in high
risk patients undergoing major vascular or abdominal surgery. In this study,
patients that were included in the treatment group received hemodynamic
optimization based on the DO2, measured with lithium indicator dilution and
pulse power cardiac output. Hemodynamic optimization was started and continued
after surgery. The objective was to attain an oxygen delivery of at least 600
ml/min/ m2. No difference in mortality was found between the hemodynamic
optimization group and the control group. A similar study on hemodynamic
optimization in high risk surgery patients was interrupted because subjects
included in the control group displayed a significant higher mortality. Several
other randomized controlled trials with similar design and treatment protocols
were executed. Yu et al and Wilson at al. both reported favorable outcomes in
high risk surgical patients receiving hemodynamic optimization.
Not all randomized studies showed a clear effect on mortality and morbidity.
The multicenter study performed by Sandman et al showed no significant
differences in mortality and morbidity. One of the potential explanations for
this finding is the lack of a strict protocol. In stead patients were treated
according to a guideline. Two other studies investigated the role of a fixed
dose dopexamine on the outcome of surgical patients. Neither study showed a
significant effect on mortality and morbidity. The results of hemodynamic
optimization are likely to be better when treatment is tailored to the
requirements of the individual patient. Several reviews and meta-analysis
performed showed interventions aimed at hemodynamic optimalization in high risk
surgical patients to reduce both mortality and morbidity.

Recently a non invasive cardiac output monitoring device; the FloTrac / Vigileo
monitoring system was introduced. The system uses arterial wave form to
calculate stroke volume. Use of this device has shown to reduce perioperative
morbidity in the high risk population requiring surgery.

Fast track surgery
Danish surgeon Henry Kehlet developed a so-called fast track recovery
multimodal programme. The programe incorporates preoperative, intraoperative
and postoperative evidence-based techniques that optimize patient outcomes.
Results of fast track programs have shown; fewer complications, a reduction in
costs, a reduction in hospital length of stay, quicker return to work and
normal activities.
The program includes several aspect of the perioperative treatment; Hypothermia
has a negative effect on a patients stress response. Therefore during surgery
body temperature should be controlled. Previous studies have demonstrated a
positive relation between body temperature control and postoperative wound
infections. Anesthesia that reduces surgical stress will contribute to the
patients recovery. The use of neuraxial blockade and the use of epidural
anesthesia has been shown to reduce the patients stress response.
Postoperative pain is an important factor in the recovery of the patient.
Efficient pain control encompassing thoracic epidural anaesthesia and non-opoid
pain management has been demonstrated to reduce hospital stay. Furthermore
pre-operative counselling of the patient, early postoperative feeding and
mobilisation have demonstrated to reduce hospital length of stay and patient
satisfaction.

This study aims to introduce a specialized clinical pathway (Optimal Track) for
the perioperative management of the high risk surgical patient. In this pathway
fast-track surgery principles and perioperative hemodynamic monitoring and
optimization are combined. By applying this approach we aim to reduce mortality
and morbidity in this group of patients. As a consequence of this reduction we
expect a shortened postoperative recovery and an improved quality of life in
these patients.
To date, no study has addressed the combined impact of a fast-track principles
and perioperative hemodynamic monitoring and optimization on high risk surgical
patients.

To investigate the feasibility of the introduction of a specialized clinical
pathway (Optimal Track) for the high risk surgical patient. In this pathway
high risk surgical patients will receive treatment according to fast-track
principles. Furthermore, patients will be admitted to a perioperative care unit
for perioperative haemodynamic monitoring and if necessary optimization.

An observational Pilot study

Hemodynamic monitoring/ optimisation

Radial artery canulation may be complicated with arterial spasms. In this case
the contra lateral radial artery will be selected. Furthermore, placement of a
radial artery catheter may be complicated in rare instances with local
infection or blockage of the artery. In cases of infection the radial canule
will be removed. Blockage of the radial artery after placement or removal of
the radial canule, will in general not lead to ischemia because of collateral
circulation of the hand.