Journal Club 2018-2019

    ...Dr Tenure gave a concise review of the Combes et al article. This was a randomized trial that compared ARDS patients given ECMO with those given standard mechanical ventilation and ECMO for rescue. Continuous ECMO did not lower the 60 day mortality significantly. Pulmonologist Dr. Paul Richman noted that that physicians who are very pro ECMO thought that the study was stopped too early. Extending the study timeframe and recruitment of more patients, might have revealed a significant benefit to ECMO.
   Dr. Yau gave an excellent review on the Guérin C et al. article. This prospective, multicenter, randomized controlled trial of 466 patients in France and Spain, explored whether prone positions improved survival among patients who received mechanical ventilation with PEEP (5 cm H₂O) and in who the partial pressure arterial oxygen to fraction of inspired oxygen was less than 150 mmHg. The researchers found that early prone position sessions decreased both 28 day and 90 day mortality. Dr Paul Richman noted that, although rotoprone beds can be ordered if needed, it is not necessary to use them. The same results can be obtained by manual turn/flip of the patient ( similar to what we do in the OR for prone cases.) It was also noted that the low body habitus of Europeans makes for easier access to the abdomen. All that might be necessary is placement of a blanket under the shoulders and hips. This option is less useful in the US patient population where the BMI is much higher overall.

    Dr. Wetcher gave a terrific review of the Wijeysundera et al article. He clearly explained the assessment tools of CPET (cardiopulmonary exercise testing), DASI (Duke Activity Status Index), the blood test NT pro-BNP, and METS. This multi-center prospective cohort found that subjective assessment of functional capacity should not be used in clinical practice. It was suggested from the study that clinicians should use the DASi questionnaire and NT pr BNP testing to assess perioperative cardiac risk and CPET possibly to predict complications after major elective noncardiac surgery. It was discussed that what is done in our preoperative testing at SB is more precise on elaboration of specifics with activity. Subjective questions are advantageous here.
   Dr. Mouch gave a concise review of the Glance et al. article. He explained the risk calculators based on (NSQIP) National Surgical Quality Improvement and (RCRI) Revised Cardiac Risk Index. These can be used to assess the risk of cardiac adverse events after noncardiac surgery. Agreement across these calculators is poorly understood. The article showed that there is a wide variability in the predicted risk of cardiac complications using different risk -prediction tools. In addition, inclusion of more that one prediction tool in clinical guidelines could lead to different decision-making for some patients. The mapping of NSQIP data to RCRI risk factors is not perfect. This could lead to less accurate RCRI predictions. Interestingly, the age of a patient and ASA status have withstood the test of time as a good predictors. It is better to use the info for prevention instead of talking about the failure to rescue. Of course, all of these issues should ideally be addressed 6 months before the patient comes for surgery.

    Dr. Mcmanus gave a concise review of the Pereira et al article. This elaborates on the information we have on PEEP. The authors hypothesized that low fixed PEEP might not fit all patients and that individual titrated PEEP during anesthesia might improve lung function during an after surgery. This study found that optimal PEEP values for patients with normal lungs under general anesthesia vary significantly. Individual optimal PEEP intraoperatively reduces driving pressure and improves respiratory compliance and oxygenation as well as reduce the incidence of postop atelectasis.
   Dr. Al-bizri gave an excellent review on the Persson et al article. The authors found that the large variation in mechanical properties among healthy patients stresses the need for individualized vent settings based on measurements of lung and chest wall mechanics. Transpulmonary driving pressure measured by the two methods under general anesthesia suggests us of a non invasive PEEP step method in this patient population. Interestingly, it was noted in discussion that maybe the next generation of ventilators will allow for further optimization of PEEP.

    Dr. Grymes gave an excellent review of the Hakim et al article. Two cases were presented. Submucosal dissection of the retropharyngeal tissues occurred during attempted nasal endotracheal intubation. Possible complications that can occur with nasal intubation are physiologic, occlusive, and trauma. Techniques involved in the nasal tracheal intubation were also reviewed such as vasoconstriction, comparing nasal patency, thermosoftening, and appraising size of the tube, and placement of a red rubber catheter over the ETT prior to advancing it. These suggestions can help with atraumatic passage of the ETT intranasally. Also positive pressure ventilation should never be attempted unless the ETT is in the trachea. If there is unnoticed retropharyngeal dissection, it can worsen with attempts to ventilate. The force can create pneumomediastinum or pneumothorax. CT can help diagnose and late bleeding can compromise airway so there should be inpatient observation for this.
   Dr. Chen gave an concise review of the paper Influence of the Kim et al paper. They found that nasal tip lifting can help the tracheal tube pass through the lower pathway, which is the safer route during nasotracheal intubation.
   We reviewed the NYS guidelines on the Topical use of Phenylephrine in the Operating Room (Groudine et al). This review was done to bring awareness to the clinical problems of using topical vasoconstrictors in the OR. The index case was reviewed. It was seen that topical phenylephrine in the surgical field can result in significant hypertension. We reviewed that the guidelines for NYS hospitals:

1. initial doses of phenylephrine for adults should not exceed 0.5 mg (4 drops of a 0.25 solution).
   For children (up to 25 kg), the initial dose should not exceed 20 microg/kg.
2. the minimal doses of phenylephrine for vasoconstriction should be given.
3. a calibrated syringe should be used
4. the anesthesiologist should be aware of all peri-op meds given
5. Htn may not require immediate treatment
6. use of beta blockers and calcium channel blockers should be avoided
7. if a beta blocker is given, then glucagon may be considered to counteract the loss of cardiac contractility

    Dr. Lee gave a concise review of the Cheng et al. article. This retrospective study compared the effect of HTS and mannitol on lowering the ICP burden of these patients. 3% HTS was found to be superior in reduction of the ICP of TBI patients compared to 20% mannitol after Decompressive craniectomy. There was no additional benefit in terms of short term mortality. Here at SB we tend to give mannitol as requested by the surgeon. Another reason is that it is recommended that HTS be given via a central line. It was also mentioned though that some do give mannitol via 16 # piv.
   Dr. Ericksen gave an excellent review on the Wang et al article. This article described a open blinded end point randomized controlled trial of 2839 patients with spontaneous intracerebral hemorrhage. They found that mannitol seemed safe but may not improve outcome in patients with acute intracerebral hemorrhage. We discussed that studies can take years and as this study using the propensity score could take months and then further research could be done afterward. Because results were not so impressive, there were no warranted further studies.

    Dr. Sanchez gave a good review of the Vedel et al. article. This RCT reported that targeting a MAP of 70- 80 mm Hg as opposed to 40-50 mm Hg during CPB with fixed and equal blood flow did not affect the volume or number of new perioperative cerebral infarcts. Clinically, neurological injury is an important complication of CPB dependent cardiac surgery. Evidence on optimal BP and blood flow management is still needed. The trial surmised that vasopressor mediated elevated MAP to physiologic values during CBP with blood flow 2.4 L/min/m2 doesn't oppose DWI (diffusion weighted imaging ) evaluation of neurological injury or POCD. Some limitations of the study were the single center design and the lack of blinding of the interventional team. Also a statistically significant difference in age between groups was found and since age is an independent risk factor for stroke and POCD, that is unfortunate. The heterogeneous risk profiles in the study could be viewed as either a strength or a limitation.
    Dr. Zabirowicz gave a concise review of the article by Sun et al. Hypotension is a potentially modifiable risk factor for perioperative stroke. This study suggested that MAP may be an important intraoperative target to reduce the incidence of stroke in patients undergoing CPB. It was noted that what is done clinically and surgically is very important. The technique the surgeon uses to treat the aorta affects the incidence of CVA. In addition, placement of the cannula is important. Off-pump vs on-pump was also considered. The importance of having the anesthesiologist follow-up these patients through the post-op period. We discussed what is done for a neurological event at SB. We consider it important to waken the patient 30 min after surgery rather than keep the patient intubated. This way, if a neurological event is detected, the patient can be sent for a CT and get follow-up care with IR. This should provide the patient with a better postoperative course and less morbidity related to the neurological event. We had a great discussion about the how, in the past, CPB surgery was combined with CEA. It is actually not advantageous to repair both at the same time. The choice of which to do first other depends on how the patient presents.