Fast track at airports in Spain. Fast-Track Recovery Program - Fast-Track Surgery Refusal of premedication

It's no secret that MikroTik produces Software-Baser routers and the CPU takes over most of the traffic processing. This approach has the advantage of being you can program almost any functionality and maintain a relatively uniform system for all devices. But in terms of speed, they will always lag behind routers with specialized chips.

Programmatic packet processing has several disadvantages:

1. Lack of wire speed - a processor (especially a single core) cannot run faster than specialized chips.
2. Locks. With really large volumes of traffic (for example, DoS / DDoS), you may not be able to connect to the router even through the console interface, because all processor time will be occupied by traffic processing.
3. The complexity of scaling. You cannot add a module that increases the speed of processing packets in hardware.

Developers go to various hardware and software solutions to improve the situation:

1. Switch-chip on inexpensive models allows processing Layer2 traffic bypassing the CPU.
2. SoC with a good network chip (CCR line).
3. Using hardware encryption
4. Various technologies that reduce the number of software processing for packages (FastPath and FastTrack), they will be discussed.

SlowPath vs FastPath

SlowPath is the basic traffic path through the internal subsystems of MikroTik, it can be quite varied and, the longer the path, the higher the load on the CPU and the more the speed drops.

FastPath - algorithms that allow traffic to be transmitted without going through large enough processing blocks.

Terms of use and support on devices

Most modern routers and boards from MikroTik support FastPath, but the wiki has a detailed list:

And a separate list for non-ethernet interfaces:

For FastPath to work properly, support from both the inbound and outbound interfaces is required. Only hardware queues should be enabled on interfaces.

Last but not least, FastPath really dislikes fragmented traffic. If the package is fragmented, it will definitely get stuck on the CPU.

FastPath and Bridge

Bridge is a software interface used to create Layer2 communication between multiple hardware (or software) interfaces. If you combine 4 ethernet interfaces in the bridge on the router (and enable hw = yes) and one wireless, then traffic between ethernet interfaces will go bypassing the software interface, and traffic between ethernet and wireless will use the software bridge. On routers with several chips (for example, RB2011), traffic between interfaces from different chips will use the capabilities of the software bridge (sometimes, to reduce the load, the interfaces are simply connected with a patch cord and in general it works).

FatsPath - refers only to traffic coming through the CPU (software bridge), usually it is traffic between interfaces from different chips, or the hw = yes option is disabled.

On Packet Flow, the traffic passing through the Bridge looks like this:

And in more detail:

It is included in the bridge settings (the setting is the same for all bridge interfaces) -> ->, there you can also see the counters.

For FastPath to work in Bridge, the following conditions must be met:

1. There is no vlan configuration on bridge interfaces (I think this is not relevant for the CRS series, where vlan is configured at the hardware level, but I could be wrong)
2. There are no rules in / interface bridge filter and / interface bridge nat, these are the same blocks from the second scheme that the frame passes through.
3. The ip firewall is not enabled (use-ip-firwall = no). A good feature for capturing traffic and debugging the network, but rarely turns on on an ongoing basis.
4. Don't use mesh and metarouter
5. The following are not running on the interface: sniffer, torch and traffic generator.

FastPath and Tunnel

In two words: a tunnel interface is the encapsulation of some packets into the payload of other packets. If you go along PacketFlow, then the red lines mark the original packet, blue - the original packet encapsulated in a tunnel protocol packet (for example, ipip or gre; eoip gets (and comes from) in the bridging decision; with tunnel ipsec it is still more interesting, but not related to fastpath).

Tunnel traffic in FastPath will not be visible in: firewall, queues, hotspot, vrf, ip accounting. But some of the packets will continue to be transmitted via SlowPath, this must be taken into account when configuring the Firewall.

For FastPath to work on tunnel interfaces, the following conditions must be met:

1. Do not use ipsec encryption
2. Avoid packet fragmentation (configure mtu correctly)
3. Enable allow-fast-path = yes on the tunnel interface

FastPath and Layer3

Layer3 is the transfer of packets between subnets, the router builds routing tables and, based on them, forwards the packet to the next hop.

On Packet Flow, network layer transit traffic looks like this:

go deeper

and even deeper

For FastPath to work on Layer3, the following conditions must be met:

1. Do not add rules to the firewall (not at all, even nat).
2. Do not add entries to Address Lists.
3. Do not configure Simple Queues and Queues Tree for parent = global, or interfaces on which you plan to receive a working FastPath.
4. Disable Connection tracker. The auto option was introduced precisely for FastPath to work in the absence of rules in the firewall.
5. Do not use / ip accounting.
6. Do not use / ip route vrf.
7. Do not configure / ip hotspot.
8. Do not add ipsec policies.
9. Route Cache must be enabled.
10. Running sniffer, torch and traffic generator interfere with FastPath.

It is included in the ip settings: ->, there you can also see the counters of successfully processed packets.

Screenshot from home router. I have a fairly loaded firewall, several always-on L2TP / IPSec connections and queues. You may not even dream of FastPath.

FastTrack

IP packet marking technology for fast passage through Packet Flow.

For FastTrack to operate, the following conditions must be met:

1. Route Cache and FastPath must be enabled and active.
2. Correct traffic marking configuration.
3. Works only for UDP and TCP traffic.
4. Don't use mesh and metarouter.
5. Do not use actively: / tool mac-scan and / tool ip-scan.
6. Running sniffer, torch and traffic generator interfere with FastTrack.

Traffic marked as fasttrack will not be processed in:

1. Firewall filter (although this is controversial, I'll show you why in the example);
2. Firewall mangle;
3. IPSec;
4. Queues with parrent = global;
5. Hotspot;

If something interferes with the fasttrack packet, it will be transmitted like all remaining packets along the slow path.

Enabled by adding a rule (see below) to the Firewall. FastTrack marks only packets from the established connection (you can mark new as well, but then there will be problems with NAT). The filter table is used, since when marking fasttrack in prerouting, there will again be problems with NAT.

Synthetic test

And (for the last test) what was configured and how it worked:
The filtering rules continued to process traffic (if you disable allowing for established, related traffic went to drop), in postrouting + mangle packets were caught that did not get into FastTrack.

In Connection Tracker, you can track FastTrack connections by the flag of the same name.

In Counters -> you can see that FastTrack is active and running, but FastPath is not.

Instead of a conclusion

Should I use it or not?

• FastPath for Bridge - Definitely yes. At least reduces the load on the CPU.
• FastPath for Tunnels - No. It works dimly, turns off if encryption is present.
• FastPath for Layer3 - Arguably, most of the router's capabilities are lost. In a large, closed from the wild Internet, the network can have its (small) payoff.
• FastPath for MPLS / VLAN / Bonding / VRRP - Enabled automatically if possible. There is no separate control option.
• FastTrack - For home and SOHO configurations, no queues and paranoid firewalls will do. Synthetic tests with one client look good; in practice, you need to very closely monitor the traffic that leaked past FastTrack and look for the cause.

An exclusive service that allows, in the presence of an airport employee, without wasting time and comfortably going through all the formalities at the airport, such as: registration, special control, passport control, boarding a plane.

Upon arrival You will be met at the boarding bridge, taken through passport control to the VIP room, where your luggage will be delivered. A customs officer will come to you to complete the paperwork. Transport will be reported.

If the VIP service is booked in less than 24 hours, the cost of the service increases by 25%.

Providing quick access to all airport fast track formalities at Barcelona airport from 23.00 to 7.00, as well as on holidays, implies an increase in the cost of the service by 25%. Sunday + 10%. Payment by cash or card.

On departure You can also use this service. We need to agree on the meeting place in advance.

The service includes:

meeting at the airport,

fast passage of registration, special control and passport control,

Fast track is an ideal solution for passengers who value their time. This service implies passing all formalities (registration for a flight, customs and passport control) in an accelerated mode and without queues, accompanied by an airport representative. This service is very popular with frequent travelers and families with small children. Fast track service is currently not available at all airports. Where this service is not provided, you can take advantage of the possibilities of the VIP rooms, which often means going through all the necessary procedures in the room and without queuing.

Fast track service fees at airports

• Pulkovo from 7500 rub.
• Zhukovsky from 6500 rub.
• Turkey
  • Antalya from 130 euros,
  • Istanbul from 165 euros,
• Paris from 120 euros,
• Milan from 170 euros,
• Rome from 170 euros,
• Bangkok from 135 euros,
• Shanghai from 210 euros,

- these are just a few cities where we provide fast track service. You can order a VIP room, which includes going through the formalities in the room without a queue.

What does the Fast track service include upon departure

Having prepared to leave for the airport, the passenger contacts the assistant and agrees with him about the time of the meeting, which takes place at the check-in counters. Arriving at the airport, the employee meets the passenger and accompanies him through all the necessary formalities (depending on whether the passenger arrives on an international flight or on a domestic flight). Thus, the passenger passes all procedures in the common room, but without queues and in an accelerated mode. After passing all the checks, the assistant leaves the passenger in the duty-free zone, or, at the request of the guest, takes him to the boarding gate.

What does the Fast track service on arrival include?

The meeting of the arriving passenger and the airport employee takes place either at the exit from the plane, or before passport control. Further, already together, they go through passport control, avoiding the queue and, as a result, in an accelerated mode. The assistant also assists in obtaining the passenger's baggage and accompanies the guest to the exit from the airport.

Fast track service for children

As a rule, children from 2 to 12 years old are served with a 50% discount, and children under 2 years old are served free of charge.
Group and family fares are popular at many international airports. 2 children up to 12 years old can be calculated as 1 adult.

Benefits of ordering Fast track service from Travelmart

Despite all the achievements of modern medicine, the percentage of postoperative complications remains at a fairly high level. Based on numerous studies, it can be concluded that many methods of managing patients in the perioperative period are ineffective, for example, fasting before surgery, prolonged preoperative bowel preparation, routine use of nasogastric tubes and drainage of postoperative wounds, prolonged bed rest.

In search of a solution to the problem of reducing the number of postoperative complications and accelerating the rehabilitation of patients in the postoperative period at the end of the 90s in the XX century, the Danish anesthesiologist-resuscitator Professor N. Kehlet proposed a multimodal program, the main goal of which was to reduce the stress response of the body to surgery. patients after planned surgery.

This program is called "Fast-Track Surgery" (fast track in surgery). The concept of "Fast - track" covers all phases of perioperative therapy: preoperative, intraoperative and postoperative. The growing interest in this program is reflected in abdominal surgery, oncology, gynecology, urology, and other surgical disciplines.

• Preoperative patient information.
• Refusal from mechanical bowel preparation before surgery.
• Refusal of preoperative fasting of the patient and the use of special carbohydrate mixtures 2 hours before the operation.
• Refusal of premedication.
• Prevention of thromboembolic complications.
• Antibiotic prophylaxis.
• Minimal surgical access and minimally invasive surgery.
• Adequate infusion volume during surgery.
• Regional anesthesia and short-acting analgesics.
• Avoiding routine abdominal drainage.
• Intraoperative normothermia.
• Effective pain relief in the postoperative period.
• Prevention of nausea and vomiting. Early enteral nutrition.
• Early mobilization. (Wind J., 2006).

The "Fast - track" program has no clear boundaries and strictly defined points, it is a dynamically developing concept. In its development, an important role is played by the use of new techniques, approaches to treatment, the use of new pharmacological agents, and the renewal of the arsenal of medical and diagnostic equipment.

Nowadays, there is an active development of new components such as blood-saving technologies, targeted infusion therapy, prevention of cognitive disorders in the perioperative period, which require additional study.

Preoperative period

Patient information

At the preoperative stage, a surgeon and an anesthesiologist-resuscitator talk to the patient. The task of doctors is to explain to the patient the plan of his treatment. It is important to focus on the role of the patient himself: to explain the importance of early activation after surgery, the importance of early enteral nutrition, breathing exercises.

It has been proven that detailed information about surgical intervention and anesthetic management, a description of what will happen to them in the perioperative period, help to reduce fear and anxiety, and reduce the length of hospital stay.

Within the framework of the "Fast - track" program, the anesthesiologist - resuscitator plays an important role in the patient's treatment. The main task of which is the preoperative assessment of the patient's condition, the preparation of the patient for surgery, which consists in correcting the existing disorders associated with the underlying and concomitant pathology.

Avoiding mechanical bowel preparation

For many years, mechanical preparation before surgery was considered a routine procedure. This was substantiated by the hypothesis that cleansing the intestine will reduce the bacterial contamination of the intestine, and this, in turn, will reduce the number of postoperative complications (abscess, peritonitis, intestinal anastomosis leakage, wound infection) during operations accompanied by opening its lumen.

Contrary to traditional beliefs, this type of preparation leads to dehydration, prolonged postoperative paresis of the gastrointestinal tract. Preparation with enemas has no advantages and, in particular, in terms of the inconsistency of the anastomoses of wound infections and other complications, the need for a subsequent operation.

In a 2012 meta-analysis that included 13 randomized trials (5373 patients), mechanical bowel preparation did not reduce the incidence of postoperative complications, including anastomotic leakage, overall wound infection, extra-abdominal septic complications, reoperations, and death. ...

The absence of the effect of mechanical preparation on reducing the incidence of complications after cystectomy with the use of segments of the small intestine for urine diversion was also shown. To date, a number of European surgical associations have excluded mechanical bowel preparation from the guidelines for elective abdominal surgery.

Refusal of preoperative fasting of the patient

For a long time, fasting was a routine method of preparing a patient for surgery. This was based on the theoretical assumption that refraining from food intake reduces the risk of aspiration of gastric contents.

This hypothesis was first questioned back in 1986. In 2003, MS Brady et al. published a meta-analysis of 22 randomized trials of preoperative fasting. The results showed that stopping the intake of any fluids 2 hours before surgery did not increase the incidence of aspiration complications in elective surgery compared with that in patients who fasted from midnight to surgery. There were also no differences in the amount of gastric contents and its pH level.

To date, it is known that preoperative fasting decreases glycogen reserves and induces postoperative insulin resistance. In the early postoperative period, in response to surgical aggression, there is a significant release of a large amount of stress hormones, such as adrenaline, norepinephrine, cortisol, glucagon, catecholamines, as well as a large number of inflammatory mediators (cytokines). As a result, the effect of insulin decreases and insulin resistance develops.

Using the principles of evidence-based medicine, it has been demonstrated that preoperative fasting decreases glycogen reserves and induces postoperative insulin resistance. As a result, the use of 150 ml of dextrose (glucose) 2 hours before the operation is justified, which also helps to reduce the feeling of hunger, thirst, discomfort, fatigue, and, consequently, the stress response. In addition, carbohydrate therapy reduced postoperative nitrogen losses and prevented the development of insulin resistance.

Refusal of premedication

One of the conditions for the implementation of the "Fast - track" surgery program is the refusal of premedication with a change in the intraoperative anesthesia scheme. Premedication is effective for correcting psychoemotional status, but does not correspond to the concept of "Fast-track" surgery, as it increases the patient's awakening time after the completion of the surgical intervention.

The traditional scheme of pain relief, including premedication based on a narcotic analgesic, can be the cause of excessive sedation in the postoperative period, which is considered a significant factor in the development of postoperative cognitive dysfunction, which unpredictably lengthens the rehabilitation period for surgical patients. To reduce the total dose of narcotic analgesics, these drugs are excluded from premedication.

Prevention of thromboembolic complications

In the clinical practice of a doctor of any specialty, especially surgery, timely diagnosis, treatment and, of course, prevention of deep vein thrombosis (DVT) and PE are extremely important.

Venous thromboembolic complications (VTEC) is a collective term that combines saphenous and deep vein thrombosis, as well as pulmonary embolism (PE). The frequency of deep vein thrombosis and thromboembolism of the pulmonary artery in modern conditions, taking into account the preventive measures taken, varies, according to various sources, from 0 to 6.4%, while in large series this frequency does not exceed 1%.

In patients with a surgical profile, the source of PE in more than 90% of cases is thrombosis in the inferior vena cava system. On average, their frequency is 1 in 1000. More than 30% of cases of pulmonary embolism and deep vein thrombosis are directly related to general surgical interventions, in orthopedic operations their frequency is already about 50%.

It is known that extensive surgical interventions, like any other type of injury, include the mechanism of a systemic inflammatory response, which consists in the production and release of a large amount of biologically active substances into the blood. The cytokine cascade activates leukocytes and promotes their adhesion to the vascular endothelium. The powerful oxidants released by activated leukocytes cause the death of endothelial cells, followed by the exposure of the subendothelial layer.

In addition, thrombus formation is facilitated by the release of tissue thromboplastin into the bloodstream directly during tissue excision, which significantly activates the coagulation system, and prolonged immobilization of patients in the postoperative period, which promotes blood stasis in the venous bed.

Prevention of thromboembolic complications in patients with an increased risk of thrombosis is widely used in surgical practice and includes elastic compression of the lower extremities and the use of low molecular weight heparins. Numerous studies have proven the effectiveness of pharmacological prevention of VTEC using unfractionated (UFH) and low molecular weight heparin (LMWH). In a study involving 4195 patients operated on the colon and rectum, it was demonstrated that pharmacological prophylaxis reduces the incidence of VTEC from 1.8% to 1.1%, as well as the overall mortality from colorectal cancer.

Antibiotic prophylaxis

Of course, one of the most important criteria for early rehabilitation of patients is the absence of septic complications in the postoperative period. According to the Russian multicenter study ERGINI, surgical site infection (SSI) accounts for about 15% of all nosocomial infections developing in emergency hospitals in the Russian Federation.

Infections of the surgical site have a great impact on the duration of hospitalization of patients, when they occur, the patient's stay in the hospital is significantly increased up to 16.7 days and the cost of hospitalization increases.

Microbial contamination of the surgical wound is inevitable even with ideal adherence to the rules of asepsis and antisepsis. By the end of the operation, in 80-90% of cases, the wounds are seeded with various microflora, most often Staphylococcus aureus, KNS, Enterococcus spp. and Escherichia coli ..

In studies in which the quantitative content of microorganisms in tissues in the operation area was studied, it was shown that with contamination exceeding 105 microorganisms per 1 g of tissue, the risk of RI increases significantly. In addition, the properties of microorganisms are important: their ability to cause invasion, produce toxins (typical for gram-negative microorganisms), attach and survive in host tissues (typical for gram-positive microorganisms).

In order to prevent purulent complications in the postoperative period, antibacterial drugs are used. Many studies have shown that a short course of prophylaxis, which begins shortly before skin incision, is as effective as a long course (24 hours or more). The spectrum of activity of the prescribed antibiotics should include aerobic and anaerobic bacteria.

Studies on the efficacy of various types of skin treatments showed that the overall incidence of postoperative wound infections was 40% lower in the group where the concentrated alcohol solution of chlorhexidine was used than in the group where povidone iodine was used. However, there is a risk of injury and thermal burns if diathermy is used in the presence of alcoholic solutions to treat the skin.

Intraoperative period

Regional anesthesia and short-acting analgesics

“Balanced Anesthesia / Analgesia” is the centerpiece of an accelerated patient recovery program after surgery. To date, it has already become known that the need for the use of long-acting anesthetics is somewhat overestimated and is accompanied by a delay in recovery due to inadequate fluid intake and late activation of the patient in the postoperative period.

The introduction into clinical practice of fast and short-acting volatile (sevoflurane) and intravenous (propofol) anesthetics, opioids (remifentanil) and muscle relaxants made it possible to expand the indications for outpatient operations, shorten the recovery period, and reduce the need for long-term monitoring. Preference is given to short-acting drugs - propofol, midazolam and remifentanil - which make anesthesia more manageable and shorten the recovery time after anesthesia.

The use of regional epidural and spinal (spinal) anesthesia is accompanied by improved lung function, reduced stress on the cardiovascular system, less intestinal paresis and better analgesia.

The deliberate use of regional anesthesia allows not only to effectively block pain impulses, but also to a certain extent to level the pathophysiological changes caused by surgery. It has also been proven to reduce the risk and incidence of thromboembolic, respiratory complications, myocardial infarction, renal failure, as well as the need for blood transfusion and the incidence of infectious complications.

It has been proven that postoperative ileus is closely associated with pain, activation of the sympathetic nervous system caused by surgical exposure, blockade of afferent pain signals and efferent sympathetic reflex arcs, intra- and postoperative epidural anesthesia minimizes the effect of the surgical stress response on intestinal function, accelerates the resumption of peristalsis, thereby providing early passage of flatulence and stool.

In abdominal surgery, blockade of nociceptive stimuli and efferent sympathetic responses minimizes the effect of operational aggression on the intestines, which helps to accelerate the resumption of peristalsis. A catheter placed before surgery can be used for prolonged epidural analgesia with continuous administration of drugs through a special pump.

Epidural anesthesia has been shown to reduce the need for postoperative opiate use, which in turn may affect the incidence of postoperative nausea and vomiting. Epidural anesthesia allows segmental anesthesia (for example, only the mid-thoracic segments) and is the optimal method of postoperative analgesia (with an epidural catheter). Such anesthesia can be carried out in the postoperative period for several days (on average, three days).

In a study by VM Muehling et al. in the group of patients in whom epidural analgesia was used as one of the components of the "Fast - track" protocol for lung resection, there was a decrease in the incidence of pulmonary complications from 35 to 6.6%. In addition, with a high degree of evidence, the advantage of epidural analgesia compared to opioid analgesia in the postoperative period with open surgical interventions in relation to pain correction was established, prolonged epidural analgesia was better at reducing pain after 6, 24 and 72 hours than patient-controlled opioid analgesia, (mean difference (HR) 1.74, 95% CI (1.30-2.19), 0.99, 95% CI (0.65-1.33), and 0.63, 95% CI (0.24- 1.01), respectively, reducing the incidence of postoperative nausea and vomiting, as well as pneumonia (OR) 0.54; 95% CI (0.43-0.68) regardless of the level of epidural catheter insertion).

Nowadays, there is a revival of interest in inhalation anesthesia (IA), which has long been the most widespread in the world. Sevoflurane was the first drug for AI registered in the Russian Federation. Considerable experience has been accumulated on the use of this anesthetic in our country and a large number of works have been published. The recognized advantages of modern AI include good controllability and safety, quick onset of the effect and cessation of anesthetic action, and accuracy of dosage based on the minimum alveolar concentration (MAC). The depth of anesthesia is changed by turning the vaporizer knob on the anesthesia machine, and the MAC serves as a reproducible depth reference.

A promising method is also catheterization of the surgical wound with the introduction of a solution of local anesthetics for postoperative anesthesia, which makes it possible to transfer patients to specialized departments. However, the presence of a catheter in the epidural space or in the postoperative wound limits mobility and slows down the rehabilitation of patients, having a negative impact on the timing of Fast-Track-accompaniment of surgical patients.

Minimal surgical access and minimally invasive surgery

Of course, the volume of the operation plays an important role in the process of rehabilitation of patients in the postoperative period. But the choice of online access is also very important. Pain and pulmonary dysfunction have been shown to be less common when transverse or oblique incisions are used instead of a long vertical laparotomic incision, presumably due to fewer dermatomes involved.

Today we are witnessing the heyday of the era of endoscopic surgery. Minimally invasive surgery is distinguished by a lesser severity of pain syndrome, a relatively low risk of complications and a shorter hospital stay. To date, there are reliable data on the possibility of performing laparoscopic operations for diseases that are most often the cause of peritonitis: acute appendicitis, acute destructive cholecystitis, pancreatic necrosis, perforated stomach ulcers and DNA.

Also, a smaller amount of damage to the peritoneum during laparoscopy reduces the number of adhesive postoperative complications, and minimal surgical trauma contributes to the early restoration of all body functions, especially the motility of the small intestine. Whereas laparotomy, in turn, is a rather traumatic intervention, and in turn is capable of aggravating stress disorders, loss of protein and electrolytes, suppressing immune defense mechanisms in the postoperative period, and causing a number of severe complications.

However, the use of a laparoscopic approach, despite minimal trauma to the anterior abdominal wall, does not relieve patients of postoperative pain. The cause of pain in the postoperative period during laparoscopic operations is irritation of the peritoneum with carbonic acid formed during the hydration of carbon dioxide used in carboxyperitoneum.

In patients operated on in the absence of gas insufflation using isopneumatic mode with laparolifting, there is practically no postoperative pain, or it is mild. According to L. Lindgren et al., Only 8% of patients operated on in the gasless laparoscopy regimen complained of postoperative shoulder pain - compared with 46% of those operated on using pneumoperitoneum.

However, the pain caused by laparoscopic surgery is less severe than after laparotomy. Randomized studies have demonstrated the effectiveness of laparoscopic surgery versus open access when using accelerated rehabilitation protocols.

Adequate infusion volume during surgery

The main goal of intraoperative fluid therapy is to maintain normal stroke volume and hemodynamics to ensure normal tissue and organ perfusion. The basis of this approach is active fluid therapy, as well as the early use of sympathomimetics and pressor amines.

Uncontrolled infusion therapy at the intraoperative stage can lead to hyper- and hypovolemia. It is also known that the uncontrolled use of pressor amines due to vasoconstriction can lead to anastomoses failure in abdominal surgery. The amount of required infusion cannot be determined in advance as a fixed volume of solutions, it must be individual for each patient.

Hypervolemia caused by absolute or relative redundancy of the volemic load contributes to an increase in capillary permeability and the development of tissue edema, which can serve as the basis for a vicious circle of capillary leakage. It has been proven that hypervolemia can lead to iatrogenic edema.

In conditions of hypovolemia, the risk of various complications in the postoperative period also increases. The intestinal mucosa is constantly regenerating, has a high degree of metabolic activity and, thus, is extremely vulnerable to ischemia. In addition, the surgical trauma itself triggers a cascade of pathophysiological reactions, which in turn lead to an increase in capillary permeability and causes the release of liquid blood particles outside the vascular bed. The imbalance in favor of crystalloid solutions and their use in a volume of 5 ml / kg doubles the edema.

In this regard, the concept of targeted therapy (CNT) is gaining popularity, which allows individualizing the administration of solutions and vasoactive drugs based on algorithms for assessing various hemodynamic variables. It was found that the CNT makes it possible to optimize the state of the intravascular sector, thereby maintaining tissue perfusion and oxygenation at the proper level, contributing to improved outcomes after major surgical interventions.

Intraoperative normothermia

Compliance with intraoperative normothermia as one of the elements of the "Fast - track" program is designed to help prevent a number of complications in the early postoperative period. A decrease in temperature by 1-2 ° C during surgery can lead to peripheral vasoconstriction and a decrease in oxygen delivery to the tissues.

The development of intraoperative hypothermia entails a number of pathological reactions, resulting in deterioration of hemostasis with an increase in intra- and postoperative blood loss, increased postoperative tremors with increased oxygen consumption and an increased risk of myocardial ischemia.

In particular, a decrease in temperature has a negative effect on the blood coagulation system (increased blood viscosity, lengthening of clotting time, thrombocytopenia), the immune system (immunosuppression associated with impaired phagocytosis, activation of the complement system, production of cytokines and antibodies), the cardiovascular system (decrease cardiac output, vasodilation, increased release of catecholamines). It has been proven that the provision of normothermia and prevention of tremors lead to a decrease in the number of cardiovascular and infectious complications, an increase in hemodilutional tolerance and a faster recovery after general anesthesia. Warming patients before surgery also has a positive effect on maintaining temperature.

Postoperative period

Effective pain relief

A key element of the accelerated recovery concept is adequate postoperative pain relief. It is pain that is the main irritating element of surgical treatment. The optimal analgesic regimen after major surgery should provide a sufficient level of pain relief, facilitate early mobilization, more active restoration of bowel function and nutrition, and also not cause complications.

It is pain that acts as the main subjective factor that slows down the process of accelerated rehabilitation of patients. By themselves, postoperative pain sensations represent only the visible part of the iceberg, being the root cause of the development of a pathological postoperative symptom complex.

Postoperative pain not only causes the patient's psychoemotional discomfort, but also stimulates the activity of the sympathoadrenal system, which, under certain conditions, negatively affects vital organ functions, triggers the mechanisms of the formation of chronic postoperative pain syndrome. It was found that the course of the postoperative period and long-term results of surgical treatment are determined by the quality of anesthesia.

Quite often, in order to relieve pain in the early postoperative period, narcotic analgesics are used. However, their effective analgesic dose is often close to the dose at which respiratory depression, sedation, paresis of the gastrointestinal tract, and dysfunction of the urinary and biliary tract develop. Opioids also have a pronounced emetogenic effect, increasing the frequency of episodes of nausea and vomiting in the postoperative period, while the severity of the emetogenic effect is directly proportional to the administered dose. This negatively affects the condition of patients in the postoperative period, complicates their activation, contributes to the development of respiratory and thromboembolic complications.

Non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most promising and effective pathogenetic agents for blocking peripheral pain receptors (nociceptors). Today, the classic scheme of analgesia in the postoperative period, within the framework of the "Fast-track" program, includes a combination of opioids, NSAIDs and paracetamol. The appointment of NSAIDs in multimodal pain relief regimens is reasonable and effective, especially in terms of prevention of opioid aftereffect.

The mechanism of action of NSAIDs is associated with inhibition of cyclooxygenase (COX) 1 and 2, suppression of prostaglandin synthesis, as a result of which pronounced analgesic, antipyretic and anti-inflammatory effects are noted. Along with the central analgesic effect of NSAIDs, their peripheral action is also noted, associated with an antiexudative effect, which leads to a decrease in the accumulation of pain mediators and a decrease in mechanical pressure on pain receptors in tissues.

The use of funds of this group allows to reduce the frequency of postoperative nausea and vomiting, to reduce the degree of sedation, to ensure early mobilization and enteral nutrition.

Prevention of nausea and vomiting

The problem of postoperative nausea and vomiting occurs in 25-35% of all surgical patients and is the main cause of patient dissatisfaction with treatment, in addition, due to this complication, discharge from the hospital is often delayed.

To date, the prevention of nausea and vomiting consists in the appointment of GCS, antiemetics, serotonin agonists and in the rejection of narcotic analgesics in the postoperative period. The introduction of dexamethasone at a dose of 4-8 mg into the premedication regimen and the use of ondansetron at a dose of 4-8 mg at the final stage of anesthesia can reduce the incidence of this unpleasant and unsafe complication.

Epidural anesthesia and transverse abdominal block have been shown to reduce the need for postoperative opiate use, which in turn may affect the incidence of PONV. In addition to improving well-being, effective prevention of nausea and vomiting contributes to the early onset of enteral nutrition and the restoration of intestinal peristalsis.

Early enteral nutrition

Traditionally, the introduction of patients in the postoperative period provides for the absence of enteral nutrition, intravenous infusion for 4-5 days. Numerous studies have shown that just replacement parenteral nutrition is accompanied by an increase in septic complications.

In seriously ill patients in the postoperative period, conditions often arise, as a result of which the centralization of blood circulation occurs. As a result, adequate perfusion and oxygenation of the gastrointestinal tract is impaired. This leads to damage to the cells of the intestinal epithelium with impaired barrier function. Degenerative changes in the intestinal wall occur after a few days of rest, and they progress, despite the provision of adequate parenteral nutrition in full.

Disorders are aggravated if nutrients are absent for a long time in the lumen of the gastrointestinal tract, since mucosal cells receive nutrition largely directly from the chyme. It has been proven that complete functional rest of the intestine leads to atrophy of its mucous membrane.

The intestinal mucosa also serves as a protective barrier that isolates pathogenic microorganisms in its cavity from circulating blood. If this barrier is destroyed, pathogens can invade the mucous membrane, gaining access to the vessels. This process is called translocation. The latter, perhaps the most important cause of latent sepsis in severely ill patients, is regarded as the first step towards multiple organ failure syndrome.

In turn, a balanced and correctly selected EP helps to reduce the severity of the stress response of the body and hypercatabolism, to more quickly restore the basic functions of the intestine. The early introduction of nutrients into the intestine helps to maintain the functional and structural integrity of the intestinal epithelium, the synthesis of IgA by lymphoid tissue, and a decrease in bacterial translocation; the number of infectious complications is reduced.

There is also evidence that the direct entry of nutrients into the intestinal lumen leads to an increase in metabolic processes and an improvement in blood circulation, which results in a faster restoration of the functional state of the intestinal wall, normalization of protein metabolism and increased immunity.

Early enteral nutrition can shorten the recovery time of intestinal functions, limit the volume of intravenous infusion, which also leads to a decrease in the risk of postoperative complications.

Early mobilization

Last but not least, early mobilization is a component of an accelerated recovery program. Prolonged stay in bed, in addition to subjective problems of perception of the treatment process and a decline in well-being, increases the frequency of thromboembolic complications, respiratory disorders, reduces muscle strength and increases the risk of hemodynamic disorders.

Early muscle mobilization and training has been shown to improve respiratory function and tissue oxygenation, reduce muscle weakness, and reduce the risk of deep vein thrombosis and pulmonary embolism.

Activation of the patient according to the "Fast - track" protocol begins immediately after the resumption of orientation in his own personality, space and time, restoration of the ability to perform active movements of the body and limbs, provided the pain syndrome is at the level of 0-3 points on the visual analog scale and there are no signs of respiratory distress and circulation.

Conclusion

The promising initial results obtained with the Fast-tcrack program of accelerated recovery raise the question of the need to change the well-established traditional system of management of patients with surgical pathology in order to improve postoperative results. The "Fast - track" surgery program requires further study of each of the available elements, as well as the development and introduction of new elements into practice.

Basnaev U. I., Mikhailichenko V. Yu., Karakursakov I. E.