Respir Care Clin N Am
· 2004 Mar · PMID 15062225
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Hospital-based pulmonologists, intensivists, respiratory therapists, and others are trained in the triage of limited ICU assets and function well in the chaos this environment often entails. Additionally, many intensivis...Hospital-based pulmonologists, intensivists, respiratory therapists, and others are trained in the triage of limited ICU assets and function well in the chaos this environment often entails. Additionally, many intensivists and other providers often participate in hospital disaster planning and drills. Their education, training, and utility outside this setting are often limited,however. Managing the turbulence surrounding a disaster outside an ICU requires special training and skills to optimize safety, security, and effectiveness of the response effort. Failure to orchestrate the many parties that arrive at the scene risks having various types of providers independently seeking to do good but failing to cooperate or share limited resources of people and equipment. The result may be endangerment of personnel and the in-completion of critical tasks. Health care providers who normally work in a health care facility must participate in disaster planning activities to prepare themselves and the irinstitutions better for disasters that may occur. Critical to that preparation is an understanding of the organizational framework of disaster management, both inside and outside the hospital. This preparation ensures safety if the individual leaves the hospital to support the disaster scene (an action that is not recommended, as discussed previously) and quality care. Understanding whom to ask for resources and the constraints surrounding multidisciplinary disaster response can only improve the care ultimately provided at the bedside.
Respir Care Clin N Am
· 2004 Mar · PMID 15062224
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Unfortunately, a mass casualty caused by chemical or biologic terrorism has become a real threat to the United States. A well-considered preparedness plan is needed to minimize tOe impact of a chemical or biologic attack...Unfortunately, a mass casualty caused by chemical or biologic terrorism has become a real threat to the United States. A well-considered preparedness plan is needed to minimize tOe impact of a chemical or biologic attack on civilians and responders. This article describes some of the key elements in a preparedness plan, specifically issues regarding early detection, decontamination. and personal protection. Although chemical and biologic terrorism is often considered as a single entity, there are important distinctions in detection, decontamination, and personal protection procedures that effect preparedness planning. Therefore, any preparedness plan needs to be flexible enough to deal with both biologic and chemical terrorism. Preparedness plans also need to be thorough enough to deal with the differences in response to a variety of specific chemical or biologic agents.
Respir Care Clin N Am
· 2004 Mar · PMID 15062223
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Threat assessment for weapons of mass destruction is a complex task,requiring many assumptions. As a general rule, weapons of mass destruction are expensive, complex, and difficult-to-use weapons. It is not likely that a...Threat assessment for weapons of mass destruction is a complex task,requiring many assumptions. As a general rule, weapons of mass destruction are expensive, complex, and difficult-to-use weapons. It is not likely that any current terrorist group has the capability to strike the United States with a weapon capable of producing millions of casualties. Smaller-scale attacks with weapons of mass destruction, however. may result in significant disruption from social and psychologic changes. even though actual casualty rates would probably be quite low. It is., however, highly unlikely that any terrorist attack on the United States could completely undermine national security or threaten the survival of the United States as a nation.
Respir Care Clin N Am
· 2003 Dec · PMID 14984068
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The ultimate efficacy of prone positioning in ARDS is difficult to evaluate because of heterogeneous study populations, the variances in the duration of the prone position, and the small sample sizes used in most studies...The ultimate efficacy of prone positioning in ARDS is difficult to evaluate because of heterogeneous study populations, the variances in the duration of the prone position, and the small sample sizes used in most studies. Prone positioning offers an easy, readily available treatment option for refractory hypoxemia. Although there is a rationale supporting the hypothesis that prone ventilation could reduce the mortality of ARDS patients, currently there are insufficient clinical data to support this hypothesis.
Respir Care Clin N Am
· 2003 Dec · PMID 14984067
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In a recent review of the data for fluid strategies and ARDS, fluid restriction or diuretic use was graded as "reasonably justifiable by available scientific evidence" and as "strongly supported by expert critical care o...In a recent review of the data for fluid strategies and ARDS, fluid restriction or diuretic use was graded as "reasonably justifiable by available scientific evidence" and as "strongly supported by expert critical care opinion". Until the ARDS Network trial is published, only general guidelines regarding fluid management with or without specific vascular filling pressures from a pulmonary artery catheter can be made. Ultimately, the rationale for restricting fluid is to reduce hydrostatic pressures as much as possible. It seems most reasonable to maintain the lowest PAOP in ARDS patients that still maintains adequate circulating blood volume, mean arterial perfusion pressures, and cardiac output to provide sufficient oxygen delivery. Other clinical variables such as central venous pressure, urinary output, acid-base status, and lactate, serum urea nitrogen, and serum creatinine levels may help in judging the adequacy of a patient's intravascular volume, especially if central vascular pressure measurements are not available. Measures to reduce total body water, including flood restriction and diuretic use, seem to be of some benefit. Vasopressor use is especially important when systemic perfusion pressures are inadequate to maintain organ blood flow but should not be used to create supranormal levels of oxygen delivery.
deBoisblanc BP, Girod-Espinoza A, Welsh DA
… +1 more, Taylor DE
Respir Care Clin N Am
· 2003 Dec · PMID 14984066
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Hemodynamic monitoring of critically ill patients, especially those who have ALI or ARDS, is a widely practiced compilation of techniques that largely have not been demonstrated to improve patient outcomes. Indeed, some...Hemodynamic monitoring of critically ill patients, especially those who have ALI or ARDS, is a widely practiced compilation of techniques that largely have not been demonstrated to improve patient outcomes. Indeed, some techniques, such as use of the PAC, may actually be harmful. It seems unlikely that monitoring devices themselves are unreasonably risky to use. Rather it seems more likely that operator errors in gathering and interpreting hemodynamic data and in selecting the appropriate treatment strategies are the culprits. There is promise that ongoing clinical trials and better provider education will soon result in evidence-based recommendations for monitoring the circulation in this patient population.
Respir Care Clin N Am
· 2003 Dec · PMID 14984065
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In ARDS, when acidosis complicates LPV, the goal of alkali therapy is to maintain arterial pH at a safe level (> or = 7.20). A pure respiratory acidosis generally does not require alkali therapy. If the Pplat is greater...In ARDS, when acidosis complicates LPV, the goal of alkali therapy is to maintain arterial pH at a safe level (> or = 7.20). A pure respiratory acidosis generally does not require alkali therapy. If the Pplat is greater than 30 cm H2O, and the respiratory rate equals the upper limit (35-40 breaths/minute), then V(E) is slowly titrated down by approximately 1 L/hour, so that PaCO2 increases by 10 mm Hg/hour or less. Alkali therapy is indicated for either a metabolic acidosis or a mixed acidosis. The choice of buffer is based on the type of acidosis, cardiorespiratory status, and lung mechanics. Slow infusions of NaHCO3 can be used to treat non-anion gap metabolic acidosis and some forms of increased anion gap acidosis. Using NaHCO3 to treat type A (hypoxia-related) lactic acidosis can be hazardous, particularly under conditions of hypoxemia, inadequate circulation, and limited alveolar ventilation. Under these circumstances, THAM is the preferable buffer because it does not increase PaCO2 and is excreted by the kidneys. When renal failure is present, CRRT is indicated to manage acidosis. When ARDS is complicated by traumatic or hemorrhagic shock, overresuscitation with Cl(-)-rich solutions should be avoided to prevent metabolic acidosis.
Respir Care Clin N Am
· 2003 Dec · PMID 14984064
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The increased understanding of the pathophysiology of ALI that has been achieved over the last decade has led to several new pharmacologic approaches for the prevention and management of ALI and ARDS. Based on in vitro i...The increased understanding of the pathophysiology of ALI that has been achieved over the last decade has led to several new pharmacologic approaches for the prevention and management of ALI and ARDS. Based on in vitro information and animal model data, many of these strategies seem quite compelling. Nevertheless, to date, no specific pharmacologic approach for the prevention or treatment of ARDS has been conclusively validated in clinical trials. Active basic and clinical research continues, and it is hoped that these investigations will lead to new therapies that can be applied by the clinician to improve clinical outcomes for patients who have ALI and ARDS.
Barbas CS, de Matos GF, Okamoto V
… +3 more, Borges JB, Amato MB, de Carvalho CR
Respir Care Clin N Am
· 2003 Dec · PMID 14984063
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In the experimental setting, repeated derecruitments of the lungs of ARDS models accentuate lung injury during mechanical ventilation, whereas open lung concept strategies can attenuate the injury. In the clinical settin...In the experimental setting, repeated derecruitments of the lungs of ARDS models accentuate lung injury during mechanical ventilation, whereas open lung concept strategies can attenuate the injury. In the clinical setting, recruitment manuevers that use a continuous positive airway pressure of 40 cmH2O for 40 secs improve oxygenation in patients with early ARDS who do not have an impairment in the chest wall. High intermittent positive end-expiratory pressure (PEEP), intermitent sighs, or high-pressure controlled ventilation improves short-term oxygenation in ARDS patients. Both conventional and electrical impedance thoracictomography studies at the clinical setting indicate that high PEEP associated with low levels of pressure control ventilation recruit the collapsed portions of the ARDS lungs and that adequate PEEP levels are necessary to keep the ARDS lungs opened allowing a more homogenous ventilation. High PEEP/low tidal volume ventilation was seen to reduce inflammatory mediators in both bronchoalveolar lavage and plasma, compared to low PEEP/high tidal volume ventilation, after 36 hours of mechanical ventilation in ARDS patients. Recruitment maneuvers that used continuous positive airway pressure levels of 35-40 cmH2O for 40 secs, with PEEP set at 2 cmH2O above the lower inflection point of the pressure-volume curve, and tidal volume < 6 mL/kg were associated with a 28-day intensive care unit survival rate of 62%. This contrasted with a survival rate of only 29% with conventional ventilation (defined as the lowest PEEP for acceptable oxygenation without hemodynamic impairment with a tidal volume of 12 mL/kg), without recruitment manuevers (number needed to treat = 3; p < 0.001). In the near future, thoracic computed tomography associated with high-performance monitoring of regional ventilation may be used at the bedside to determine the optimal mechanical ventilation of the ARDS keeping an opened lung with a homogenous ventilation.
Respir Care Clin N Am
· 2003 Sep · PMID 14690071
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The evidence supports the idea that mechanical ventilation can potentially cause further lung injury. The only ventilator manipulation that so far has been shown definitively to reduce injury and improve mortality is the...The evidence supports the idea that mechanical ventilation can potentially cause further lung injury. The only ventilator manipulation that so far has been shown definitively to reduce injury and improve mortality is the reduction of VT to 6 mL/kg PBW or lower and targeting Pplat to 30 cm H2O or lower. Much research is needed to provide further guidance in applying ventilatory support techniques.
Respir Care Clin N Am
· 2003 Sep · PMID 14690070
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Ventilator-induced lung injury has been established as a significant risk to patients receiving PPV. Animal studies have provided definitive experimental data that support the existence of VILI. Clinical studies have imp...Ventilator-induced lung injury has been established as a significant risk to patients receiving PPV. Animal studies have provided definitive experimental data that support the existence of VILI. Clinical studies have implied the role of VILI in ARDS and ALI patients. In patients who have ARDS or ALI, however, VILI cannot be distinguished from exacerbation of the primary condition. Animal and clinical studies that clearly show elevated levels of cytokines when PPV is applied beyond certain limits support the concept that an inflammatory process is activated by PPV. Whether the induction of inflammatory mediators contributes to the mortality or morbidity of the ventilated patient has not been established. A potential role for anti-inflammatory therapeutic agents is promising. Therefore, the following considerations can guide the clinical care of ventilator patients: Alveolar pressure exposure (plateau pressure) should be limited to less than 32 cm H2O. Positive end-expiratory pressure should be applied to avoid end-expiratory collapse and reopening. Tidal volume should be set at approximately 6 mL/kg or further guided by plateau pressure limitation. Although studies suggest that reducing Ti, flow, and f may be important in avoiding VILI, there are no current guidelines. The results of preliminary studies investigating the preventative potential of respiratory acidosis, prone positioning, or careful vascular pressure management seem promising. Inflammatory response in VILI has been established, but a role for intervention, such as general or specific suppression of the response, has not been established.
Respir Care Clin N Am
· 2003 Sep · PMID 14690069
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The interpretation of P-V curves is uncertain for several reasons: the influence of chest wall compliance, differences in regional lung compliance and intrapulmonary gas distribution, lung volume history, lung recruitmen...The interpretation of P-V curves is uncertain for several reasons: the influence of chest wall compliance, differences in regional lung compliance and intrapulmonary gas distribution, lung volume history, lung recruitment beyond the LIP, peripheral airway fluid movement, expiratory-flow limitation, differences between inflation and deflation limb characteristics, and interobserver variability in curve analysis. In addition, many studies of acute lung injury have constructed P-V curves following disconnection from the ventilator. The inevitable lung volume changes that occur may alter the elastic and viscoelastic behavior so that the resulting P-V curve characteristics may not accurately reflect conditions during mechanical ventilation. More extensive research seems to be required before P-V curves are used as a routine guide for mechanical ventilation therapy in ARDS. Furthermore, this article suggests that titrating PEEP or VT according to the inflation-limb P-V curve should be done with caution, because the mechanical significance of this information is open to question. Current research suggests the possibility that PEEP could be targeted according to the slope of deflation-limb compliance, because this measure may more accurately reflect global alveolar closing pressures. This type of analysis can be done only by transferring data into software programs that can perform sophisticated curve fitting, and such programs are not readily available to most clinicians. From a practical standpoint, there is no compelling clinical evidence that adjusting mechanical ventilation according to the P-V curve improves mortality or morbidity in ARDS as much or more than can be achieved simply by decreasing the VT and Pplat.
Respir Care Clin N Am
· 2003 Sep · PMID 14690068
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Respiratory mechanics research is important to the advancement of ARDS management. Twenty-eight years ago, research on the effects of PEEP and VT indicated that the lungs of ARDS patients did not behave in a manner consi...Respiratory mechanics research is important to the advancement of ARDS management. Twenty-eight years ago, research on the effects of PEEP and VT indicated that the lungs of ARDS patients did not behave in a manner consistent with homogenously distributed lung injury. Both Suter and colleagues] and Katz and colleagues reported that oxygenation continued to improve as PEEP increased (suggesting lung recruitment), even though static Crs decreased and dead-space ventilation increased (suggesting concurrent lung overdistension). This research strongly suggested that without VT reduction, the favorable effects of PEEP on lung recruitment are offset by lung overdistension at end-inspiration. The implications of these studies were not fully appreciated at that time, in part because the concept of ventilator-associated lung injury was in its nascent state. Ten years later. Gattinoni and colleagues compared measurements of static pressure-volume curves with FRC and CT scans of the chest in ARDS. They found that although PEEP recruits collapsed (primarily dorsal) lung segments, it simultaneously causes overdistension of non-dependent, inflated lung regions. Furthermore, the specific compliance of the aerated, residually healthy lung tissue is essentially normal. The main implication of these findings is that traditional mechanical ventilation practice was injecting excessive volumes of gas into functionally small lungs. Therefore, the emblematic low static Crs measured in ARDS reflects not only surface tension phenomena and recruitment of collapsed airspaces but also overdistension of the remaining healthy lung. The studies reviewed in this article support the concept that lung injury in ARDS is heterogeneously distributed, with resulting disparate mechanical stresses, and indicate the additional complexity from alterations in chest wall mechanics. Most of these studies, however, were published before lung-protective ventilation. Therefore, further studies are needed to refine the understanding of the mechanical effects of lung-protective ventilation. Although low-VT ventilation is becoming a standard of care for ARDS patients, many issues remain unresolved; among them are the role of PEEP and recruitment maneuvers in either preventing or promoting lung injury and the effects of respiratory rate and graded VT reduction on mechanical stress in the lungs. The authors believe that advances in mechanical ventilation that may further improve patient outcomes are likely to come from more sophisticated monitoring capabilities (ie, the ability to measure P1 or perhaps Cslice) than from the creation of new modes of ventilatory support.
Respir Care Clin N Am
· 2003 Sep · PMID 14690067
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Acute respiratory distress syndrome (ARDS) is a heterogeneous process that results in diffuse alveolar damage. It is associated with a variety of causative factors that can be grouped into two general categories, those a...Acute respiratory distress syndrome (ARDS) is a heterogeneous process that results in diffuse alveolar damage. It is associated with a variety of causative factors that can be grouped into two general categories, those associated with direct lung injury through the airways and those associated with indirect lung injury through the blood stream. Regardless of whether injury originates within or outside the lung, a systematic inflammatory response is triggered. This article reviews some of the physiologic alterations associated with ARDS before focusing on the derangement in the cellular environment.
Respir Care Clin N Am
· 2003 Sep · PMID 14690066
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Acute lung injury and ARDS have been clinically recognized syndromes for nearly 30 years. During that time, the understanding of the risks, pathophysiology, and outcomes has changed and improved. The definition for this...Acute lung injury and ARDS have been clinically recognized syndromes for nearly 30 years. During that time, the understanding of the risks, pathophysiology, and outcomes has changed and improved. The definition for this disease has evolved in an attempt to identify more accurately and reliably a more homogeneous patient population that could be expected to have similar responses to the disease and therapies. The most widely accepted definition is that developed by the AECC in 1994 and now commonly used in epidemiologic studies and clinical trials. Estimates of the incidence of the disease and of mortality are significantly affected by variability in definitions used. Current estimates of the incidence of ALI, however, range from 3 to 75 cases/100,000 population/year. Mortality estimates range from 30% to 40%. Although mortality has improved from more than 60% 20 years ago, ALI survivors are still faced with an increased risk of death as well as significant decrements in physical function and quality of life through the first 12 months after hospital discharge. A great deal of progress has been made in the understanding and management of ALI patients. Now, as the search for new therapeutic options continues, equal attention must be focused on studying and improving qualitative outcomes for this group of patients.
Respir Care Clin N Am
· 2003 Jun · PMID 12911292
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Because of the inherent difficulty of quitting smoking and the enormous health and societal burden of smoking, a multitude of interventions have been developed and tested for their efficacy in sustaining abstinence in sm...Because of the inherent difficulty of quitting smoking and the enormous health and societal burden of smoking, a multitude of interventions have been developed and tested for their efficacy in sustaining abstinence in smokers. Although most smokers' attempts to quit on their own end in failure, with 12-month abstinence rates as low as 5.7%, several psychosocial and pharmacological interventions have been noted for substantially increasing, even doubling or tripling abstinence rates. Given the substantial costs of treating illnesses caused by smoking, even a 1% increase in abstinence rates is notable for its public health benefit. Moreover, research has indicated that it may take the majority of smokers several attempts at quitting before total continuous abstinence is achieved. Thus any quit attempt should be construed as a step forward in the direction of sustained abstinence. The relative ease with which clinician-initiated effective treatments can be implemented. and evidence that many smokers would like to stop smoking and look to health-care practitioners for guidance and motivation, suggest that pulmonary medicine specialists can have a substantial impact on morbidity and mortality associated with smoking.
Respir Care Clin N Am
· 2003 Jun · PMID 12911291
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Many patients with lung cancer develop airway obstruction and hemoptysis. Endoscopic palliation can relieve symptoms and improve the quality of life for many patients. Patient factors, lesion characteristics and location...Many patients with lung cancer develop airway obstruction and hemoptysis. Endoscopic palliation can relieve symptoms and improve the quality of life for many patients. Patient factors, lesion characteristics and location, and regional expertise are important to consider when planning therapy. Cost, convenience, time to relief of symptoms, duration of palliation, and the need for serial procedures should also be considered. Further advances in technology will likely allow better palliation in the future. A wide armamentarium of modalities and careful communication with the patient's other providers are essential for optimal patient outcome.
Respir Care Clin N Am
· 2003 Jun · PMID 12911290
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Modern platinum-based combination chemotherapy has played a major role in the therapeutic approach to unresectable stage III and IV NSCLC. Randomized phase III trials clearly documented a survival as well as palliative b...Modern platinum-based combination chemotherapy has played a major role in the therapeutic approach to unresectable stage III and IV NSCLC. Randomized phase III trials clearly documented a survival as well as palliative benefit to treatment in patients with stage IV NSCLC who have a good PS (PS 0-1). The optimal therapeutic approach in patients with poor PS (PS 2) has not yet been defined. Recent trials that focused on the elderly suggested that they receive benefits from chemotherapy that are similar to their younger counterparts. The benefit from chemotherapy seems to occur early (initial 3 to 4 cycles) and prolonged therapy is not indicated. Second-line therapy that is administered upon progression was shown to provide survival and palliative benefits. In unresectable stage III NSCLC, the addition of chemotherapy to TRT improves long-term survival and has the potential to cure a minority of patients. Although sequential and concurrent chemoradiotherapy approaches have improved survival in phase III trials, concurrent strategies seem superior in comparative trials. New techniques in radiation therapy, such as three-dimensional treatment planning, may allow safer administration of both modalities concurrently and allow higher doses of TRT to be delivered. In unresectable stage III and stage IV NSCLC, the role of the new "targeted" therapies is currently being defined in several randomized, phase III trials. It is imperative that physicians who care for patients with advanced NSCLC be aware of these trials and attempt to enroll their patients, if possible. It is only through the successful and timely completion of well-designed clinical trials that we will advance our knowledge of improved treatment options for our patients with this disease.
Respir Care Clin N Am
· 2003 Jun · PMID 12911289
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Therapy for locally advanced NSCLC has evolved into a multidisciplinary effort. Patients who are considered for this approach should undergo rigorous testing to accurately stage their disease. Patients with pleural effus...Therapy for locally advanced NSCLC has evolved into a multidisciplinary effort. Patients who are considered for this approach should undergo rigorous testing to accurately stage their disease. Patients with pleural effusions (with rare exception) are not candidates for intensive combined modality therapy. Appropriate patients for combined modality therapy should have a good performance status (generally Zubrod 0 or 1), adequate pulmonary function, absence of significant heart, lung, or other medical diseases, and be appropriate candidates for combination chemotherapy and thoracic surgery or thoracic radiotherapy. Several lessons can be learned from looking broadly at the phase II and phase III combined modality experience. The available data do not support the routine use of postoperative therapy in patients with completely resected disease. Treatment with chemotherapy before surgery or radiation has demonstrated survival benefit in patients with stage III disease. The French phase III trial of induction chemotherapy in patients with early stage disease found an 11-month improvement in overall survival (P = 0.15) and a significant increase in the risk of death for patients with stage I and II disease. The ongoing U.S. intergroup trial (SWOG 9900) and European trials will help to further define the role of chemotherapy in patients with clinical stage IB, II and IIIA NSCLC. Clinical trials should be conducted to compare preoperative chemoradiotherapy with preoperative chemotherapy. The recently completed intergroup 0139 trial (chemoradiation followed by surgery or not) should help to define whether surgery and radiation are required in the management of stage IIIA NSCLC. Finally, further improvement in survival with the use of "newer" cytotoxic agents seems unlikely as phase III trials in metastatic NSCLC have not demonstrated marked superiority over cispiatin-based regimens. Ongoing trials are assessing the incorporation of newer, biologic-based "targeted" therapies. Despite the dismal findings of trials of postoperative therapy, many patients continue to have surgery as their initial treatment followed by postoperative therapy. In contrast, trials with induction treatment seem to offer improved survival. It is time for a true multidisciplinary approach to the treatment of locally advanced NSCLC. Pulmonary physicians, thoracic surgeons, medical oncologists, and radiation oncologists should meet before the initiation of treatment to plan the most appropriate therapy for the individual patient.
Turrisi AT, Bogart J, Sherman C
… +1 more, Silvestri G
Respir Care Clin N Am
· 2003 Jun · PMID 12911288
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Radiotherapy has an expanding role in all phases of treatment of nonsmall cell lung cancer. Evolutions in technique, such as three-dimensional conformal radiotherapy, hold the promise for more effective treatment of pati...Radiotherapy has an expanding role in all phases of treatment of nonsmall cell lung cancer. Evolutions in technique, such as three-dimensional conformal radiotherapy, hold the promise for more effective treatment of patients with early stage disease who are not candidates for surgical intervention. Multimodality therapy for patients with locally advanced disease is evolving rapidly, with evidence accruing as to the optimal schedules and doses of radiotherapy and combination chemotherapy. Palliative dose schedules are being refined that maximize patient comfort while providing substantial symptom relief.