Removing Ventilatory Life Support

Carr J Smith
and Carol B Smith
Reproduced with Permission

A number of serious illnesses or injuries can lead to respiratory failure. This condition is characterized by the inability of the heart and lung systems to maintain adequate tissue oxygenation and to remove carbon dioxide from the lungs. Respiratory failure is a critical condition requiring immediate emergency treatment to prevent death.

Long-term illness, traumatic injury, severe infection, and brain disorders may contribute to respiratory failure. Respiratory distress usually precedes respiratory failure and is noted by increased heart rate and adverse changes in breathing rates and patterns. In the majority of cases, the event that precedes respiratory distress is an airway obstruction.

When signs of respiratory distress are observed in a hospitalized patient, emergency personnel are alerted. If the distress cannot rapidly be brought under control, the patient is transferred to the intensive care unit (ICU) for additional care. In the 1960s, only major hospitals had ICUs. Today, almost all of the 6,000 acute care hospitals in the US have ICUs, with large hospitals having a number of specialized ICUs (Raffin, Shurkin, and Sinkler 1988). The $80 billion per year cost of maintaining the approximately 78,000 ICU beds in the US amounts to approximately 1% of the Gross Domestic Product (Snider 1994).

When the patient "codes," i.e., stops breathing, a mask connected to a bag containing air and extra oxygen is placed over the face and pressure is used to force air into the lungs. If the patient can not breathe without assistance, a slender endotracheal tube is inserted into the mouth and guided down the airway into the lung. This procedure is termed "intubation." The tube is then attached to a ventilator machine whose main function is to "ventilate" the body, i.e., to remove the waste product carbon dioxide, from the lungs. With the initiation of mechanical ventilation, the doctor, patient, and family members should begin a regular dialogue regarding treatment options and progress.

Modern computerized ventilators enable the patient to "come off the ventilator" as soon as possible. Weaning from mechanical ventilation entails a transition period from total ventilatory support to spontaneous breathing (Mancebo 1996).

Predicting Patient Outcome

The probability of successful withdrawal from mechanical ventilation is based on the patient's clinical condition. While the overall death rate for all ICU patients is 15% to 20% (Raffin 1989), this figure is skewed downward by the large number of patients without life-threatening conditions and those admitted for short periods of time. Excluding postoperative patients and overdose cases, the overall mortality rate in the US for ICU patients is closer to 30% to 40%.

During an average stabilization period of 24-48 hours, the maximum resources of the hospital are directed at the patient. If needed, the patient can be taken from the ICU to surgery or specialized imaging areas. Paradoxically, the chance for severe morbidity or death increases as the period of time in the ICU increases. The paradox is explained by ICU patients being at risk for infection, with the risk positively correlated with time in the unit, as well as deficits in immune function.

At the time of ICU admission, physicians can experience significant difficulty in determining whether a given patient will improve (Lynn et al. 1997). In addition, there is great disparity among physicians in their judgment regarding when to withhold or withdraw life support. A large survey study (Cook, Guyatt, and Jaeschke 1995) demonstrated the range of opinion that can exist among ICU team members. This ICU study queried 149 attending physicians, 142 resident physicians and 1,070 nurses regarding 12 clinical scenarios. Several factors were identified by the respondents as influencing the decision process, including likelihood of long-term survival, mental status prior to the current illness, and age of the patient. Among the twelve clinical scenarios, the same treatment option was chosen by more than half the respondents in only one case. Polar opposite extremes of treatment plans were chosen by more than 10% of the respondents in eight of twelve scenarios.

After three days in the ICU, however, the ability to estimate the probability of hospital mortality becomes more accurate (Knaus 1989). Therefore, the ability to predict long-term outcome increases with time as both the amount of information regarding the patient's condition increases and as clinical events take their natural course.

Principles for Decision Making

Critical care professionals should operate under the Hippocratic tradition that seeks to restore health and relieve suffering. Traditionally, the framework used as a general guide for practitioners regarding what they are ethically required to do, and to refrain from doing, was based on a set of duties. These duties included an obligation to respect life, to do what is best for the patient, to be faithful to patients' reasonable expectations, and to avoid doing harm.

While some ethicists view the withholding and withdrawing of life-supporting treatment as morally equivalent, many physicians make a distinction based on the identity of the decision-making agent regarding the patient's death. For example, Slomka (1992) has argued that the moral responsibility for the patient's death in the case of withdrawal of care is shared with family members, while the moral responsibility for the patient's death in the case of withholding treatment falls to the patient.

Considerations about whether to withhold and withdraw life support from critically ill patients now occur in well over half of all deaths in many intensive care units. Withdrawal of life support occurs more often than withholding of life support. Cardiopulmonary resuscitation is the therapy most frequently withheld and mechanical ventilation is the therapy most frequently withdrawn. The withdrawal of mechanical ventilation is usually gradual, and often facilitated by the administration of sedatives and analgesics (Daly, Thomas and Dryer 1996; Luce 1997).

In general, physicians prefer to withdraw life support methods that are scarce, expensive, invasive, artificial, unnatural, emotionally taxing, high technology, and rapidly fatal when withdrawn. Physicians are reticent to withdraw forms of therapy requiring continuous rather than intermittent administration, and forms of therapy that cause pain when withdrawn {Asch and Christakis 1996).

Role of Advance Directives

Determining the patient's wishes regarding life-sustaining treatment varies somewhat by institution. At Durham Regional Hospital, an affiliate of Duke University, the attending physician discusses DNR ("do not resuscitate") status with the newly admitted patient. If the attending physician is not available, a resident physician can substitute. During this doctor-patient interaction, the specifics of treatment options are discussed. These treatment options include the desire of the patient to either receive or refuse intravenous fluids (these directives remain controversial, especially in Catholic institutions), antibiotics, or antiarrhythmic drugs. Far from being just a one-time discussion, DNR status is repeatedly re-evaluated and confirmed with the patient as conditions change.

The doctor-patient communication regarding DNR status is independent of the presence of a living will (also known as an advance directive), because the patient may have changed his or her mind since the writing of the will. When a DNR order is written into the patient's chart, but does not mention specifics regarding treatment options, and the patient no longer has decisional capacity, the next of kin is usually called to determine the wishes of the family. When the doctor has not had the opportunity to directly communicate with the patient regarding his or her wishes, the desires of family members can frequently override both a living will and a DNR status. Sometimes cardiopulmonary resuscitation is initiated and continued until patients' family members arrive at the bedside at the time of death.

Avoiding Potential Confusion

The word euthanasia comes from combining the Greek prefix eu-, meaning "well, easily, good, true" with the Greek word for death, "thnnatos." The active/passive terminology currently in use within the American medical community regarding euthanasia represents a potential source of ethical confusion. Mosby's MedicaL Dictionary defines euthanasia as either "active" or "passive." Passive euthanasia is defined as "allowing the person to die by withholding treatment." Raffin (2000) expands upon this definition and describes passive euthanasia as withholding or withdrawing life support from patients who will not regain a reasonable quality of life.

What is the problem with the nomenclature of active and passive euthanasia? The basic problem is that this terminology ignores t" issue "of intent. Whether by commission or omission, the intent must not be to kill the patient. The Catechism of the Catholic Church(1994; rev. 1997) states, "Whatever its motives and means, direct euthanasia consists of putting an end to the lives of handicapped, sick, or dying persons." Further, the Catechism explains, "Discontinuing medical procedures that are burdensome, dangerous, extraordinary, or disproportionate to the expected outcome can be legitimate; it is the refusal of 'over-zealous' treatment. Here one does not will to cause death; one's inability to impede it is merely accepted" (nn. 2277-8).

Whether by active or passive means, the moral basis of direct euthanasia and withdrawal of treatment are profoundly different. Because the terms "active" and "passive" euthanasia do not respect this distinction they should be avoided when discussing withdrawal of care. Unfortunately, as these terms have achieved general usage in many biomedical circles, the need to clarify their inherent differences, both to the biomedical community and the general public, remains a major challenge.