Monitoring during Thoracic Surgery

One of the most common methods of predicting for fluid responsiveness involves analysis of the arterial waveform as it varies with respiration: designated systolic pressure variation, pulse pressure variation (PPV), or stroke volume variation (SVV). Many anesthesia monitors can perform this analysis and display the resultant value, although it appears thet anesthesiologists are able to make accurate visuaal judgements via estimation as well. PPV (and any other methods mentioned) is based on the concept that as inthratoracic pressure varies while a patient is being ventilated with positive pressure, venous return to the heart varies inversely with intrathoracic pressure. This effectively provides a "mock" fluid bolus with each breath predicting how a patient may respond (or not) to a fluid challenge. The problem is that with an open chest, these measures may be biased.

In my opinion, ERAS protocols , referring to early recovery after surgery, thoracic surgery here particularly, has nothing to do with invasive monitoring. Don't forget that arterial line insertion, could be helpful not just in monitoring arterial pressure and derivate calculations, but also in sampling blood gases, which, despite the fact that hypoxemia during one-lung ventilation decreased drastically during the last three-four decades, is still a problem during these procedures. Nevertheless, in very lightly invasive procedures (see response below) and a "healthy" patient, a non-invasive hemodynamic monitoring might be enough.

As I responded above, an arterial line may help for blood sampling for blood gas analysis too, not only blood pressure. Nevertheless, in a relative healthy patient (a very small wedge resection, pneumothorax talcage, etc.) with a "good" surgeon, an anesthesiologist who knows his own limits, a non-invasive hemodynamic monitoring might be enough, despite the fact that nowadays we don't have any study demonstrating the superiority of such a monitoring during thoracic procedures. Therefore, the majority of centers performing "classical" thoracic procedures are still using nowadays an arterial line.

Thank you for your interest.Neurosonology is an integral part of the arsenal of brain D5 especially in the newborn. Echo-Doppler is probably the most complete and accurate modality for monitoring the cerebral circulatory status of our patients. As recommended, we work in TCCS (Transcranial Color-Coded Sonography triplex) in order to have all the information not only qualitative (morphological) but also quantitative (measurement of flows, velocities and index) in the different arterial branches of the polygon of Willis. This is all the easier as in the newborn and the baby, the fontanelles are open and represent real windows open to the brain. In this context, we have encouraged our neurosurgical colleagues to use these tools in a mediate way directly in contact with the brain matter in order to have a new tool to improve their intraoperative location. However, there are some precautions to be taken when using these tools, particularly the fact that each neurosonographic sequence should be limited to less than 30 seconds, or even a maximum of one minute, in order to limit the risk of heating the brain material when it comes into contact with the ultrasound probe and the ultrasound rays.

-Thank you for your interest.This is a very broad question. I will try to be as clear and synthetic as possible.The study you refer to was published last year in JAMA (Effect of Regional vs General Anesthesia on Incidence of Postoperative Delirium in Older Patients Undergoing Hip Fracture Surgery / JAMA 2021; 327: 50-58). I think the main explanations may be as follows. Firstly, despite the 2229 initial patients and the 950 patients finally randomised, this kind of study certainly lacks D9 To give you an example, 20 years ago, in the ISPOCD2 study, the similar comparison of task 12 applied to more than 10000 patients showed nothing (which is why these data were not published). Secondly, I think that as systematic as this study may be, the methodology is probably unfortunately too globalised and not specific enough. Other more specific and sensitive biomarkers should be added to the clinical psychometric tests. Finally, thirdly, as we learn more and more about the pathophysiology of POD and PND, it seems increasingly clear that the problem is not necessarily the pharmacological anaesthetic interaction with the brain but rather the state of the brain itself when it arrives at the perioperative period. What seems to make the difference is the state and "resilience" in the perioperative period of the patient's cerebral lymphatic drainage (if this drainage is clogged up due to lack of sleep or other factors, if it is deregulated by various factors; there will be a problem) Secondly, the function of axon-dendritic transport proteins (the kinesins) and thirdly the protein function of certain areas of the cerebral cortex, in particular the enthorinal (deep temporal region). If these three systems are even slightly impaired or fatigued, there is a risk of POD/PND. In short, I think we are not looking where we should be looking at the moment.Now, from a more monitoring point of view, but especially from a more practical point of view, I confirm the importance and interest of multimodality in BFM. However, as I tried to explain at the beginning of my presentation, we need to integrate new tools (pEEG and FNIRS) and define the right methodology both to determine intraoperative states at risk postoperatively and to qualify potentially problematic preoperative states or situations.If you want to continue this discussion, I am at your disposal. But you have to spend enough time on it.

Thank you for your interest.In practice, from a practical point of view, we perform the baseline just after induction, when the hemodynamic situation is stabilized but before the patient is settled.

However, in some particularly fragile patients (ASA3, 4 or with multiple risk factors) it is possible to take the time to prepare things before induction. This remains exceptional

Thank you for your interest.Well observed. That is the whole point of bimodality. First of all, any change must be homogeneous. To be taken into account, an event must include a logical modification in both modes. They serve as respective controls for each other. If a change is only seen in one of the two modalities, it must be questioned and put into perspective usually leads to a cause or explanation. A weakening in the power of the EEG or pEEG is proportional to the risk of an EEG suppression occurring with the inherent risks of this problem. Concurrently with the occurrence of an EEG suppression (or even one to two minutes before) the values of the NIRS and especially the fNIRS parameters will also change. Thus we can have a much more complete view of the cerebralvascular coupling where cerebral oximetry indicates the state of capillary and venular perfusion of the grey matter while on the other side the pEEG shows us the consequence(s) of a lesser perfusion, i.e. neuronal dysfunction that can go as far as EEG suppression. If you want to go beyond this first level of response, I am at your disposal but it will take some time to get to the end of the discussion.

Thank you for your interest.Good question. You need to think of this type of BFM (the pEEG will be all the more so) as a matrix on which the different frequency power and time parameters (e.g. suppression) are interdependent in their respective downward or upward changes.Weakening of power in the alpha band and especially that during the perioperative period of alpha oscillations (physiologically different from the spontaneous alpha frequencies when a patient is awake) represents a state or situation at risk for the occurrence of EEG suppression simply because the lower neuronal power brings the neuron that much closer to the threshold for EEG suppression (this is among other things the basis of the notion of frailty that I have discussed) The recommendation for an anaesthetist when detecting this is to look carefully at the trend in PSI which generally, even between 25 and 50 is more often between 25 and 30 than between 30 and 50. Thus in this context, it is imperative to decrease the doses of anaesthetics (a recommendation of the order of 30-40% compared to a normal adult seems to be more and more authoritative) and to titrate more and more progressively any deepening or adaptation of the anaesthetic scheme. I remain available to continue this discussion if you are interested.

Thank you for your interest.Of course I am integrating neurosonology into the BFM management of this kind of situation which is particularly risky for the brain of patients who are already potentially fragile from a cerebral point of view. Monitoring (TCCS -transcranial color-coded sonography) of continuous laminar or pulsatile cerebral flow according to the surgical period is extremely specific and sensitive not only concerning the qualification of the intraoperative cerebral state of 

the patient but also the prediction of cerebral recovery (cognitive but not only...) during the immediate postoperative period. We use transcranial Doppler through the temporal window(s) and in this context we are collaborating in the development of a fully autonomous and automated robotic version (cf Novaguide) (not negligible in the context of this type of complex and time consuming anaesthesia). I remain at your disposal to go further in this discussion.

Patient body movement during the robotic-assisted thoracic surgery may lead to serious consequences; thus, it is very important to have perfect neuromuscular blockade and neuromuscular monitoring. Although the continuous infusion of neuromuscular blocking drugs might not improve surgical conditions with no significant benefits on the other outcomes, it is recommended to consider the use of deep neuromuscular blockade with continuous infusion of rocuronium for patients undergoing robotic-assisted thoracic surgery, providing continuous monitoring of neuromuscular transmission and appropriate reversal with sugammadex before extubation.

 The laryngoscopy and intubation without relaxants require far greater depth of anesthesia (in spite of transtracheal lidocaine or lidocaine spray) than with relaxants. The use lidocaine in various forms to suppress responses associated with airway instrumentation. Laryngotracheal spray is commonly used by anesthesiologists.Use of additional drugs, particularly topical lidocaine, may be valuable adjuncts and should be considered, however, it is not absolutely necessary.

There is strong evidence supporting faster and more complete reversal of both moderate and profound rocuronium-induced NMB with sugammadex when compared with traditional cholinesterase inhibitors. In the thoracic surgical population, this advantage translates into more tangible long-term benefits. These include reduced postoperative pulmonary complications and atelectasis, and reduced length of hospitalization. The balance of evidence is strongly tipped in favor of more routine use of sugammadex for the reversal of rocuronium-induced NMB in thoracic surgery. 

I have no experiences in neonatal cardiac anesthesia. I can not answer the question.

1. Generally, in the majority of the patients, 37F for women and 39F for men can be used without  problem 2.Again, if a patient is significantly "bigger" or "smaller" than average, one size thicker/thinner can be used empirically.3.However, it is always a good idea to check the chest x-ray for an extraordinary thick or (more important) extraordinary thin trachea an main bronchıs. 4. Possible problemsare usually due to theunexpected thin main bronchus (rather than trachea); therefore try to check the thickness of main bronchus, if possible. 5. Using a bronchial blocker is the ultimate solution for the problem

I try to imagine the disorders you expect from imaging in this setting. 

Pneumothorax : make ultrasound only

Pleural effusion : idem

Fluid overload : idem

Pericardial tamponade : idem

Pulmonary embolism : idem (BLUE-protocol) in first intention (never a post-operative X-ray will show me such a disorder)

Pneumonia : ultrasound first, X-ray welcome the same day for having a more “familiar” document for follow up

Complete atelectasis : ultrasound most of the time. 

Small atelectases : ?? I would say neither ultrasound nor X-ray, but CT directly...... (maybe I am very wrong - the lack of perfect & simple gold standard slows down my research)

Checking central line placement : X-ray if the only question is, does my catheter touch the superior caval vein perpendicularly`?

And because this is not my field, I ignore probably other issues specific to this post-surgical phase. Although I work often in the direct surrounding of Emmanuel Martinod...

Therefore, and this is only my opinion, I cannot make a YES or NO answer.

Minor (or not so minor) issue`: the surgeon should know that we will perform ultrasound. The dressings should be done, as far as possible, in function of the foreseen focal ultrasound. That is, as small as possible (in hospital Tenon, Paris, Francis Bonnet told me some surgeons do not make dresssings any longer... if I understood correctly). 

I remind the spirit of the LUCIFLR project`: to decrease, in the 3 next decades, the number of X-rays by one third, and the number of CT of TWO thirds. CT is my main challenger`! We can make few X-rays, not a major challenge.