**5.3 Potential COVID-19 carriers**

There is enough evidence that many COVID-19 patients are asymptomatic or have only mild symptoms, but they can transmit the virus to other people. There are difficulties in the detection of these asymptomatic carriers, which hinders the prevention and control of this pandemic [66]. A systematic review and meta-analysis [67] found that the proportion of asymptomatic among COVID-19 positive people is high with a substantial transmission potential in communities, therefore, asymptomatic carriers occupy a decisive place in the management of this global crisis.

## **5.4 Vaccinated and unvaccinated patients**

Morbidity and mortality have decreased in vaccinated people due to vaccineinduced immunity against SARS-CoV-2. On the other hand, it has been shown that vaccinated people can be asymptomatic carriers, especially of the Delta variant, and they constitute another transmission factor [68]. During the last two outbreaks of the pandemic, unvaccinated people tend to develop more clinical complications, and their death rate is higher. This last group represents a management and contagion challenge similar to the beginning of this pandemic. Unfortunately, antivaccine people represent an important group and continue to be a factor that favors the persistence of this disease and only a few countries have taken drastic measures against this group.

In vaccinated patients, it is important to consider two facts—1) complications secondary to vaccines, especially the rare possibility of myocarditis and pericarditis that has been described after the application of COVID-19 mRNA vaccines (i.e., Moderna and Pfizer-BioNTech). This potential complication has been seen mainly in men under 30 years of age, which makes surveillance in this group of vaccinated people necessary [69, 70]. COVID-19 viral vector vaccines (i.e., Johnson & Johnson/ Janssen and Oxford/Astra-Zeneca) use a modified version of adenovirus, which expresses a stabilized spike protein on its surface but is incapable of replicating. Similar to the Astra-Zeneca vaccine, the Johnson & Johnson vaccine was temporarily paused because of reports of thrombotic events. 2) The second point regarding vaccine is the time of vaccination in relation to the time of surgery anesthesia. To date, there are no scientifically proven guidelines on when to apply the vaccine in relation to the surgical moment. Some medical groups have recommended vaccination programs in this clinical setting [71, 72]:


#### *Regional Anesthesia in Times of COVID-19 DOI: http://dx.doi.org/10.5772/intechopen.104977*


These recommendations could be modified in the near future when there are data based on new scientific evidence obtained from prospective studies. It is worthy to remember that vaccinated people can get COVID-19 and be carriers or have mild to severe manifestations.

#### **5.5 Patients without COVID-19**

Fortunately, this is the largest group in the midst of this health crisis. Theoretically, all patients without COVID-19 scheduled for an anesthesiological procedure could be managed as before this pandemic. However, in this era of COVID-19, there are many controversies, because scientific advances change every day, health systems have not yet recovered 100%, and many patients and HCWs are still afraid of contagion and death. The most cautious conduct is to manage each patient as if they were a potential transmitter of SARS-CoV-2. As above mentioned, there is evidence that COVID-19 carriers are asymptomatic, but easily transmit the virus to other individuals. It is this group of carriers that have forced us to handle ALL of our patients with widely recommended preventive recommendations.

At Lotus Med Group outpatient and short-stay plastic surgery unit, we suspended all activity for 6 weeks at the beginning of the pandemic. Before we restart the consultation and the surgery, we elaborated a plan for approaching our patients:


This regulation was modified according to the new information available and the availability of resources. The rapid IgM and IgG serological tests were substituted by the RT-PCR, which must be performed between 3 and 5 days prior to the consultation/surgery. Patients with a positive result are postponed for surgery or consultation and must have another PCR test with a negative result. All staff received a PCR test and when vaccinations became available, all staff were vaccinated immediately.

#### *Topics in Regional Anesthesia*

Most of the surgical procedures performed in our unit are done with subarachnoid anesthesia [73]. General anesthesia is used only in breast surgeries, chest liposuctions, some cases of combined or very prolonged surgical procedures, or when there is a contraindication to regional anesthesia. All facial surgery is performed with local anesthesia and intravenous sedation, administering nasal oxygen with flows of 0.5–1 Lt/min.
