Patrick Mailloux

The pulmonary artery catheter in critical care.

Pulmonary artery catheterization has been a routine part of care for critically ill patients over the past 25 years. Primary hemodynamic data regarding cardiac output and pulmonary pressures can be utilized to make diagnoses and guide therapy. Tissue oxygen delivery and utilization allow inferences about the efficiency of the cardiopulmonary system and the impact of disease and medical therapies on tissue metabolism. Goals of high level invasive monitoring of cardiopulmonary function with pulmonary artery catheterization are organ salvage and minimizing complications associated with critical illness. Optimizing renal perfusion and minimizing pulmonary congestion with precise volume titration are common reasons for performing pulmonary artery catheterization in the intensive care unit. Despite being reassuring to clinicians that hemodynamic therapy is optimal, multiple data from well conducted clinical studies have not demonstrated outcome benefits to patients related to pulmonary artery catheterization. Less invasive techniques to obtain data regarding hemodynamic function are now entering the clinical arena and are being actively investigated.

Ventilator Autocycling and Delayed Recognition of Brain Death

BackgroundImprovements in technology play an important role in caring for critically ill patients. One example is the advance in ventilator design to facilitate triggering of mechanical breaths. Minimal changes in circuit flow unrelated to respiratory effort can trigger a ventilator breath and may mislead caregivers in recognizing brain death.MethodsWe observed patients with devastating brain injuries in a mixed medical/surgical intensive care unit (ICU) with a high clinical suspicion for brain death including the absence of cranial nerve function with apparent spontaneous breathing during patient-triggered modes of mechanical ventilation. Further clinical observation for spontaneous respirations was assessed upon removal of ventilatory support.ResultsNine patients with brain injury due to multiple etiologies were identified and demonstrated no spontaneous respirations when formally assessed for apnea. Length of time between brain death and its recognition could not be determined.ConclusionWhen brain-dead patients who are suitable organ donors are mistakenly identified as having cerebral activity, the diagnosis of brain death is delayed. This delay impacts resource utilization, impedes recovery and function of organs for donation, and adversely affects donor families, potential recipients of organs, and patient donors who may have testing and treatment that cannot be beneficial. Patients with catastrophic brain injury and absent cranial nerve function should undergo immediate formal apnea testing.

Safe placement of central venous catheters: a measured approach

Introduction. To develop a simple method for safely placing central venous catheters (CVCs) outside the heart from the subclavian or internal jugular vein in compliance with Food and Drug Administration (FDA) and manufacturer guidelines. Methods. Patients requiring CVCs were enrolled into this prospective trial. Central venous catheters were inserted into the subclavian or internal jugular vein from either the right or left side to a depth of 15 cm. Chest radiographs were obtained immediately after insertion of the catheter to check tip placement and to evaluate for mechanical complications. Results. Operators successfully placed 201 of 210 (96%) CVCs outside the heart. Six of these required repositioning. Nine catheter tips were located in an intracardiac position. No cases of pneumothorax, hemothorax, or pericardial tamponade occurred. One case of delayed hydrothorax due to superior vena cava injury occurred. Conclusions. Using a 15-cm insertion depth via the internal jugular or subclavian vein results in safe catheter tip location in the majority of procedures consistent with FDA and manufacturer guidelines.

Applied Physiology and the Hemodynamic Management of Septic Shock Utilizing the Physiologic Optimization Program

Volume management is an important aspect of caring for patients with sepsis. Multiple factors contribute to the challenge of resuscitating septic patients, including volume depletion, a decrease in vascular tone and myocardial depression. Goal directed therapy incorporates the use of physiologic targets to guide fluid resuscitation in this population, taking into account the changes in physiology of a patient with sepsis. Further, evolving technology and knowledge is allowing for a better understanding of endpoints when managing fluids in this critically ill patient group. Patient’s presenting with hypo-perfusion secondary to septic shock benefit from early, aggressive resuscitation in a protocolized manner (Rivers, 2001). The goals of initial resuscitation, to be achieved within 6 hours of presentation, include a central venous pressure of 8 – 12 mmHg, mean arterial pressure (MAP) of ≥ 65 mmHg, urine output ≥ 0.5 mL/kg/hr and a central venous (ScvO2) or mixed venous oxygen saturation ≥ 70% or 65%, respectively (Rivers 2001, Dellinger, 2008). This concept is known as early goal directed therapy (EGDT) (Rivers, 2001).

CRITICAL CARE ISSUES FOR THE NEPHROLOGIST: The Pulmonary Artery Catheter in Critical Care

Pulmonary artery catheterization has been a routine part of care for critically ill patients over the past 25 years. Primary hemodynamic data regarding cardiac output and pulmonary pressures can be utilized to make diagnoses and guide therapy. Tissue oxygen delivery and utilization allow inferences about the efficiency of the cardiopulmonary system and the impact of disease and medical therapies on tissue metabolism. Goals of high level invasive monitoring of cardiopulmonary function with pulmonary artery catheterization are organ salvage and minimizing complications associated with critical illness. Optimizing renal perfusion and minimizing pulmonary congestion with precise volume titration are common reasons for performing pulmonary artery catheterization in the intensive care unit. Despite being reassuring to clinicians that hemodynamic therapy is optimal, multiple data from well conducted clinical studies have not demonstrated outcome benefits to patients related to pulmonary artery catheterization. Less invasive techniques to obtain data regarding hemodynamic function are now entering the clinical arena and are being actively investigated.

Right atrial thrombus leading to altered mental status.

CEREBRAL INFARCTION as a result of emboli originating from the left side of the heart is a well-known pathologic process. In addition, the risk of developing a right atrial thrombus from an indwelling central venous catheter for hemodialysis exists.1 A patient is presented with multiple embolic infarctions in her left hemisphere as the result of a right atrial thrombus coexisting with multiple atrial septal defects, a situation diagnosed only with a Valsalva maneuver during transesophageal echocardiography.

CRITICAL CARE ISSUES FOR THE NEPHROLOGIST: The Pulmonary Artery Catheter in Critical Care: PULMONARY ARTERY CATHETERIZATION

Pulmonary artery catheterization has been a routine part of care for critically ill patients over the past 25 years. Primary hemodynamic data regarding cardiac output and pulmonary pressures can be utilized to make diagnoses and guide therapy. Tissue oxygen delivery and utilization allow inferences about the efficiency of the cardiopulmonary system and the impact of disease and medical therapies on tissue metabolism. Goals of high level invasive monitoring of cardiopulmonary function with pulmonary artery catheterization are organ salvage and minimizing complications associated with critical illness. Optimizing renal perfusion and minimizing pulmonary congestion with precise volume titration are common reasons for performing pulmonary artery catheterization in the intensive care unit. Despite being reassuring to clinicians that hemodynamic therapy is optimal, multiple data from well conducted clinical studies have not demonstrated outcome benefits to patients related to pulmonary artery catheterization. Less invasive techniques to obtain data regarding hemodynamic function are now entering the clinical arena and are being actively investigated.