Peripheral and Mesenteric Perfusion in Elective Surgical Patients
Condition: Peripheral Perfusion; Bowel Ischemia; Colorectal Surgery; Haemodynamic Instability
MeSH terms: Ischemia
Study type: Observational

Summary: 
      An important goal of haemodynamic monitoring and resuscitation is early detection of
      insufficient tissue perfusion and oxygenation. The mesenteric haemodynamic response to
      circulatory shock is complex, and diagnosis of bowel ischaemia poses significant difficulty.
      Assuming blood flow is diverted from the peripheral tissue and the gastrointestinal tract to
      vital organs, during circulatory shock, an objective, simple and non-invasive method of
      detecting peripheral tissue perfusion impairment might detect this at an early stage.

      The peripheral perfusion index (PPI) reflects changes in peripheral perfusion and laser
      doppler flowmetry allows measurement of bowel tissue perfusion.

      The aim of this study is to explore the association between changes in peripheral and
      intestinal perfusion in patients undergoing elective colorectal surgery exposed to
      intraoperative haemodynamic challenges.
    

Detailed description: 
      An important goal of haemodynamic monitoring and resuscitation is early detection of
      insufficient tissue perfusion and oxygenation, but in clinical practice, monitoring and
      resuscitation is routinely based on measuring of blood pressure and heart rate, which might
      be inadequate endpoints for optimal resuscitation. Haemodynamic management targeting cardiac
      output and stroke volume (SV), and to some extent, flow and tissue perfusion is feasible when
      applying minimally-invasive or non-invasive methods, but has been limited to a narrow number
      of critically ill patients and to the intraoperative setting. Another approach to
      resuscitation is aimed at flow and perfusion of vital organs. Ideally, measurements would be
      done directly on these organs, but no feasible methods exist. Assuming blood flow is diverted
      from the peripheral tissue and the gastrointestinal tract to vital organs, during circulatory
      shock, an objective, simple and non-invasive method of detecting peripheral tissue perfusion
      impairment might detect this at an early stage. The peripheral perfusion index (PPI) is
      derived from the photoelectric plethysmographic pulse oximetry signal, which all patients are
      monitored by perioperatively to assess arterial oxygen saturation. The PPI is a numerical
      non-invasive measure representing the ratio between the pulsatile (arterial) and
      non-pulsatile component of the light reaching the pulse oximeter, and PPI decreases in states
      of hypoperfusion. PPI reflects changes in peripheral perfusion and blood volume and decreased
      peripheral perfusion determined by PPI predicts surgical complications and morbidity in acute
      surgical and septic shock patients.

      The mesenteric haemodynamic response to circulatory shock is complex, and diagnosis of bowel
      ischaemia poses significant difficulty for the clinicians due to its non specific
      presentations and lack of a simple diagnostic test. In patients undergoing colorectal surgery
      for malignancy, laser doppler flowmetry allows measurement of bowel tissue perfusion.

      The aim of this study is to explore the association between changes in peripheral and
      intestinal perfusion in patients undergoing elective colorectal surgery exposed to
      intraoperative haemodynamic challenges.
    

Intervention name(s): Haemodynamic monitoring
Intervention type(s): Other
Intervention description(s): see Group description
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        x
      
Keywords: peripheral perfusion; Haemodynamic Instability; mesenteric bloodflow