CHEST TUBE INFORMATION What Size Chest Tube? What Drainage System is Ideal? And Other Chest Tube
Management Questions - Part 2 What Drainage System is Ideal?
Once a chest tube is placed, depending on the clinical indication, a PDU may be attached to provide suction or a water seal to prevent the backflow of air into the pleural space. Similar to chest tube management issues, the appropriate use of PDUs, including suction, is well delineated in the American College of Chest Physicians spontaneous pneumothorax guideline and is less well defined for traumatic and iatrogenic pneumothoraces. Most important, one does not want to select the correct size chest tube for a pneumothorax only to compromise efficient air evacuation by selecting a PDU incapable of accommodating the airflow. Less defined is the role of PDU-generated suction in the setting of pleural liquid collections as found in malignant pleural effusions, parapneumonic effusions, empyema, and hemothorax. Pleural air and free-flowing fluid will generally drain from the chest without need for suction. If the pleural air or liquid is not responding adequately to gravity (nonsuction) water seal drainage, suction may be applied. The American College of Chest Physicians spontaneous pneumothorax guideline suggests attaching the chest tube to a water seal device with or without suction as acceptable in most spontaneous pneumothorax patients. Concerns regarding the use of suction for pneumothorax or pleural liquid removal and the possibility of reexpansion pulmonary edema are beyond the scope of this discussion, and the reader is referred to several other sources. Although single-bottle and two-bottle PDU systems are available, today's readily available and widely used commercial PDUs in the United States use the three-bottle (compartment) system.[9*] The same resistance considerations in choosing a chest tube need to be considered for the connecting tubing and the multicompartment drainage device comprising the PDU. No formula analogous to the Fanning equation exists to determine flow rates for commercially available PDUs. This is likely the result of the relatively complex structure of the three-bottle (compartment) system. Commercial products condense the three-bottle system into a convenient, mobile single module of variable design. The three compartments sequentially, include the collection bottle to trap liquid material and other debris from the patient's pleural space and to allow pleural air to pass through the next two compartments, the water seal bottle to prevent airflow back to the patient's pleural space and to detect an air leak (bronchopleural fistula), and the manometer bottle to regulate the amount of negative pressure transmitted back to the patient from the wall suction device (or equivalent suction source). The manometer bottle may use a water column or a dry system (spring-loaded valve system) to downregulate the wall suction applied. Commercial packaging of PDUs and of chest tubes provides no flow rate information for either air or liquids. This absence of information leaves the clinician unable to compare flow characteristics of these devices and choose objectively the optimal device fitting the clinical situation. The only available assessments of commercial PDUs were published in the 1980s. The evaluated devices are no longer available. A current assessment of commercially available devices notes that PDUs differ considerably in their accommodated flow rates and in the accuracy of delivered negative pressures. The airflow rate capabilities of the PDU assessed at -20 cm water pressure vary widely, with mean values ranging from 10.8 to 42.1 L/minute. The Argyle Sentinel Seal (Sherwood Medical, Tullamore, Ireland) PDU has the lowest flow rate at 10.8 L/minute. This average flow is substantially less than may be encountered in various clinical situations and could lead to the development of a tension pneumothorax. Several PDUs deliver less than 16 L/minute (discussed earlier) at -10 cm water pressure, but all PDUs except the Sentinel Seal deliver greater than 16 L/minute at -20 cm water pressure. Inaccuracy of delivered pressure to the pleural space by a PDU if too Negative could damage the underlying lung and mediastinal structures including the heart and pericardium and, if unexpectedly less negative, can lead to inadequate fluid or air removal. Although many significant differences in assessed commercial devices are found, they are of little clinical importance given the limited absolute magnitude of the inaccuracies. Instead of a complex PDU , simple one-way valve systems incorporating easily collapsible rubber tubing housed in a rigid plastic tube with entrance and exit ports are available and are often included in commercial pneumothorax kits. The Heimlich valve is such a device. Using such a device may allow home management (discussed later), but with clear patient instructions regarding device orientation and maintenance to avoid complications including tension pneumothorax.
Other Recently Addressed Chest Tube Management Questions Ongoing controversy surrounds the question of whether "prophylactic" antibiotics should be used in patients with a chest tube. Given that the majority of such patients have a chest tube in place before antibiotics are administered, this may be more appropriately termed presumptive antibiotic treatment. The majority of publications deal with chest tubes placed in trauma-related circumstances, with the controversy addressed in part by two key recent publications. The evidence-based guideline publication by Luchette et al.and the accompanying editorial by Wilson and Nichols point out the many confounding variables that have yet to be assessed completely, including geographic location (operating room, emergency department, etc.) of tube placement, patient acuity at time of tube placement, personnel placing the tube (surgeon versus nonsurgeon), choice of antimicrobial agent, and duration of therapy. Regardless, the guideline makes a level III recommendation (lowest level of overall evidence support), stating there is sufficient class I (prospective, randomized, double-blinded study) and class II (prospective, randomized, nonblinded) data to recommend prophylactic antibiotic use in patients receiving a chest tube after chest trauma. A first-generation cephalosporin should be used for no longer than 24 hours. The available data suggest there may be a reduction in the incidence of pneumonia but not empyema. The role, if any, of antibiotics in patients receiving a chest tube for nontrauma-related issues is not addressed by the guideline. However, given the often more controlled circumstances of chest tube placement in most nontrauma settings, antibiotics seem unwarranted except for empyema and parapneumonic effusions. The minimum daily volume of chest tube fluid output before tube removal seems established by convention, not evidence, with significant variation. Younes et al. found in 139 prospective, randomized postthoracotomy patients (and validated in 91 subsequent patients) no difference in drainage time, hospital stay, fluid reaccumulation rates, and thoracentesis rates among those patients with their tube removed at a daily tube threshold fluid output rate of </=100 of patients in Such an with and tube cost.
Whether to remove a chest tube at the end of inspiration or the end of expiration is a common question. The randomized assessment of Bell et al. of 102 chest tube removals in 69 trauma patients found no difference in post chest tube removal pneumothoraces rates using either method (end inspiration, 8% occurrence; end expiration, 6%). The presence of hemothorax, history of thoracotomy or thoracoscopy, previous lung disease, or chest tube duration did not affect pneumothorax recurrence.
Conclusions
Chest tubes and PDUs are invaluable and frequently used clinical tools. However, many questions remain unanswered regarding their optimal use. Additional well-done, prospective randomized studies are required to assess many aspects of their use, particularly regarding their timely and appropriate removal. In the meantime, clinicians must be ever vigilant to choose initially the correct-size tube and appropriate PDU to suit the clinical condition prompting chest tube placement, especially in situations with high-volume airflow or viscous pleural fluid production.
Reprint Address
Correspondence to Michael H. Baumann, MD, University of Mississippi
Medical Center, 2500 North State Street, Jackson, MS 39216-4505, USA;
e-mail: mbaumann@medicine.umsmed.edu
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