Should manometry be routinely used during thoracentesis? Yes, but not without some basic physiologic understanding!

Approach to malignant pleural effusions: Role of pleural manometry exemplified by case scenarios

“…Now, to remove confusion, authors suggest using the term “unexpandable lung” to refer to both the above entities. [5] I agree with this concept, and this cannot be more clearly explained than to look at the example of the patient in Figure 1. This patient had active malignant infiltration of the pleura as portrayed by pleural fluid cytological examination.…”

“…The reason may be that many pulmonologists may not understand the physiological basis for performing pleural manometry. [5] Lack of pleural subspecialty training or fellowship programs and the absence of pleural subspecialty clinics may also contribute to the former. [6] Furthermore, performing pleural manometry has not been shown to have an effect on better patient outcomes.…”

“…The development of chest pain, rather than cough, has been found to be associated with lower closing pleural pressures and should be considered an indicator to stop further thoracentesis. [8] Such chest pain can be very severe[5] and as in the patient described in Figure 1, and may be associated with dyspnea and hypoxemia leading to respiratory failure. Reexpansion pulmonary edema may have also contributed to the sudden worsening of respiratory status in this patient.…”

“…Pleural pressure recording can be done during thoracentesis by connecting the aspiration catheter and attached syringe to an undamped U-manometer, an overdamped U-manometer (with the interposition of a resistor to restrict the respiratory swings in order to obtain more accurate recordings), or a digital handheld pleural manometer. [25] The overdamped water U-manometer is as accurate as the digital handheld pressure transducer devices. [2] There are no studies that have directly compared the accuracy of readings obtained between the undamped and overdamped water manometers.…”

Pleural Pressure Pulse in Patients with Pleural Effusion: A New Phenomenon Registered during Thoracentesis with Pleural Manometry

“…Therefore, it could have not been done with a simple water manometer or an overdamped water manometer used in earlier studies [24]. This shows that modern, sensitive, electronic manometers can still provide new data that shed light on pleural pathophysiology and interactions between pleural cavity, as well as lung and heart functions [25]. As an example, the authors of one recent study in which an electronic tracking of pleural pressure was applied suggested that cough during therapeutic thoracentesis could exert a beneficial effect by producing an increase of pleural pressure and preventing an excessive pleural pressure decrease during pleural fluid withdrawal [26].…”