question: Why do people not bleed constantly during surgery?
comment: Smaller bloodvessels that are cut close themselves through blood coagulating but for bigger arteries surgeons have clamps that close the vessels to prevent a bleed out. Thats is why its extremely important to tell a surgeon or dentist or who ever is going to cut you in anyway if you are taking any blood thining medication. Because if you are the bloodvessels won't be able to close themselves and even the smallest cut will bleed continously which quickly can become dangerous for the patient. My dad is a dentist and has had several instances where this has happened.
passages: Bleeding complications may be treated immediately during the procedure by cauterization via the instrument. Delayed bleeding may also occur at the site of polyp removal up to a week after the procedure, and a repeat procedure can then be performed to treat the bleeding site. Even more rarely, splenic rupture can occur after colonoscopy because of adhesions between the colon and the spleen.
  
  Section::::Risks.:Anaesthesia.
   At some point, most commonly 7 to 11 days after the surgery (but occasionally as long as two weeks after), bleeding can occur when scabs begin sloughing off from the surgical sites. The overall risk of bleeding is approximately 1–2%. It is higher in adults, especially males over age 70 and three quarters of bleeding incidents occur on the same day as the surgery. Approximately 3% of adults develop bleeding at this time which may sometimes require surgical intervention.
   Bleeding can occur along the EVD insertion tract or in the several layers of the meninges that prohibit passage into the brain. If drilling or dural puncture is not successful, the surgeon may dissect away dura and create a secondary bleed known as an epidural or subdural hemorrhage. Bleeding from EVD placement can be life-threatening and can require neurosurgical intervention in some cases. The risk of hemorrhage with EVD placement is increased if the patient suffers from coagulopathy.
  
  Section::::Complications.:Mechanical.
  
  Mechanical complications from EVD placement can be categorized into:
  
  BULLET::::- Malplacement
   Post-operative care is very similar to the palliative care received, with the exception that the patient no longer requires PGE or the surgical palliation procedures. Additionally, the patient is kept on a cooling blanket for a period of time to prevent fever, which could cause brain damage. The sternum is not closed immediately which allows extra space in the thoracic cavity, preventing excess pressure on the heart, which swells considerably following the surgery; the sternum and incision are closed after a few days, when swelling is sufficiently reduced.
  
  Section::::Treatment.:Follow-up.
   Many causes of decreased blood flow during surgery are systemic, i.e. they decrease blood flow throughout the body. Studies have shown that nearly all perioperative PION patients suffered from prolonged periods of low blood pressure during the operation and postoperative anemia. The average perioperative PION patient loses 4 liters of blood during surgery, and the majority receive blood transfusions. Massive blood loss is just one cause of low blood pressure. Medications used for general anesthesia can also lower blood pressure. The average surgery duration in PION cases is 7 to 9 hours, which increases the risk of prolonged low blood pressure.
   Since catheters are placed within blood vessels there is always a risk of bleeding during placement and while the catheter is in place. Bleeding can range from localized hematoma (bruise) to hemorrhage (profuse bleeding).
  
  Thrombosis
   The rates of a surgical wound opening after surgery has remained constant. When a wound opens after surgery, the hospital stay becomes longer and the medical care becomes more intensive if a surgical wound opens after surgery.
  
  Section::::Complications.:Infection.
   ions should be confirmed. Some surgeons utilize 100 micrometres between each section, and some utilize 200 micrometres between the first two sections, and 100 micrometres between subsequent sections (10 crank of tissue set at 6 to 10 micrometre is roughly equal to 100 micrometres if one allows for physical compression due to the blade).
  
  Section::::Technique.:Blood thinners.
   If blood patches alone do not succeed in closing the dural tears, placement of percutaneous fibrin glue can be used in place of blood patching, raising the effectiveness of forming a clot and arresting CSF leakage.
  
  Section::::Treatment.:Surgical drain technique.
   Bleeding is the most common postoperative early complication after implantation or explantation of LVADs, necessitating reoperation in up to 60% of recipients. The implications of massive blood transfusions are great and include infection, pulmonary insufficiency, increased costs, right heart failure, allosensitization, and viral transmission, some of which can prove fatal or preclude transplantation. When bleeding occurs, it impacts the one year Kaplan-Meier mortality. In addition to complexity of the patient population and the complexity of these procedures contributing to bleeding, the devices themselves may contribute to the severe coagulopathy that can ensue when these devices are implanted.
   In cases that do not involve shock, the patient is generally administered a proton pump inhibitor (e.g. omeprazole), given blood transfusions (if the level of hemoglobin is extremely low, that is less than 8.0 g/dL or 4.5–5.0 mmol/L), and kept NPO, which stands for "nil per os" (Latin for "nothing by mouth", or no eating or drinking) until endoscopy can be arranged. Adequate venous access (large-bore cannulas or a central venous catheter) is generally obtained in case the patient suffers a further bleed and becomes unstable.
  
  Section::::Management.:Significant blood loss.
   Occasionally, there may be leakage of fluid or blood from the incision wound, a study shows that 7.4 percent people are affected within 30 days post operation. However this normally settles in time and does not indicate a problem with the bypass itself. 
  
  Section::::Complications.:Heart problems.
   Section::::Risks and Side Effects.
  
  Post operative bleeding can occur in the first few days after surgery. There may be moderate swelling anywhere from 1 to 5 days. Temporary numbness can occur and in some rare cases can last for years. There may be temporary tightness in the suture line and/or scalp sensitivity.
  
  Section::::Cost.
   Blood or blood expanders may be administered to compensate for blood lost during surgery. Once the procedure is complete, sutures or staples are used to close the incision. Once the incision is closed, the anesthetic agents are stopped or reversed, and the patient is taken off ventilation and extubated (if general anesthesia was administered).
  
  Section::::Description of surgical procedure.:Post-operative care.
   Section::::Post war surgical career.:Vascular surgery.
   Significant post-operative primary bleeding occurs in 0.2-2.2% of people, and secondary bleeding in 0.1-3.3%. It is estimated 1.3% of people will have a delayed discharge (of 4 to 24 hours) due to a complication, and up to 3.9% will require repeat admission to hospital. The main reasons for either keeping a person in hospital, or readmitting them after tonsillectomy are uncontrolled pain, vomiting, fever, or bleeding. Death occurs as a result in between 1 in 2,360 and 56,000 procedures. Bleeding accounts for one-third of deaths. As the procedure is done under general anesthesia, there are anesthesia risks.
  
  Section::::Complications.:Immune system.
   Dogma in vascular bypass technique says to obtain proximal and distal control. This means that in a vessel with flow through it, a surgeon must be have exposure of the furthest and nearest extents of the blood vessel in which the bypass is being created, so that when the vessel is opened, blood loss is minimized. After the necessary exposure, clamps are usually used on both the proximal and distal end of the segment. Exceptions exist where there is no blood flow through the target vessel at the area of proposed entry, as is the case with an intervening occlusion.
   10–20% of traumatic hemothoraces require surgical management. Larger hemothoraces, or those that continue to bleed following drainage may require surgery. This surgery may take the form of a traditional open-chest procedure (a thoracotomy), but may be performed using video-associated thoracoscopic surgery (VATS). While there is no universally accepted cutoff for the volume of blood loss required before surgery is indicated, generally accepted indications include more than 1500 mL of blood drained from a thoracostomy, more than 200 mL of blood drained per hour, hemodynamic instability, or the need for repeat blood transfusions. VATS is less invasive and cheaper than an open thoracotomy, and can reduce the length of hospital stay, but a thoracotomy may be preferred when hypovolaemic shock is present. The procedure should ideally be performed within 72 hours of the injury as delay may increase the risk of complications. In clotted hemothorax, VATS is the gold standard procedure to remove the clot, and is indicated if the hemothorax fills 1/3 or more of a hemithorax. The ideal time to remove a clot using VATS is at 48–96 hours, but can be attempted up to nine days after the injury.
   Doctors disagree on the issues of scarring with not suturing versus resolution of the swelling allowed by leaving the wounds open to drain fluid. Since the incisions are small, and the amount of fluid that must drain out is large, some surgeons opt to leave the incisions open, while others suture them only partially, leaving space for the fluid to drain out.
  
  Section::::History.
   A common consequence in ECMO-treated adults is neurological injury, which may include intracerebral hemorrhage, subarachnoid hemorrhage, ischemic infarctions in susceptible areas of the brain, hypoxic-ischemic encephalopathy, unexplained coma, and brain death. Bleeding occurs in 30 to 40 percent of those receiving ECMO and can be life-threatening. It is due to both the necessary continuous heparin infusion and platelet dysfunction. Meticulous surgical technique, maintaining platelet counts greater than 100,000/mm, and maintaining the target activated clotting time reduce the likelihood of bleeding.
  
  Section::::Complications.:Blood.
   Section::::Vascular access.
   The durability of endovascular arterial procedures is generally good especially when viewed in the context of their common clinical usage i.e. arterial disease occurring in elderly patients and usually associated with concurrent significant patient comorbidities especially ischemic heart disease. The cost savings from shorter hospital stays and less morbidity are considerable but are somewhat balanced by the high cost of imaging equipment, construction and staffing of dedicated procedural suites, and of the implant devices themselves.
   These issues were addressed in a systematic review of total versus supracervical hysterectomy for benign gynecological conditions, which reported the following findings:
  
  BULLET::::- There was no difference in the rates of incontinence, constipation, measures of sexual function or alleviation of pre-surgery symptoms.
  
  BULLET::::- Length of surgery and amount of blood lost during surgery were significantly reduced during supracervical hysterectomy compared to total hysterectomy, but there was no difference in post-operative transfusion rates.
  
  BULLET::::- Febrile morbidity was less likely and ongoing cyclic vaginal bleeding one year after surgery was more likely after supracervical hysterectomy.
   When the necessary procedures are complete, the catheter is removed. Firm pressure is applied to the site to prevent bleeding. This may be done by hand or with a mechanical device. Other closure techniques include an internal suture and plug. If the femoral artery was used, the patient will probably be asked to lie flat for several hours (3 to 6) to prevent bleeding or the development of a hematoma. Trying to sit up or even lift the head is strongly discouraged until an adequate clot has formed. The patient will be moved to a recovery area where he/she will be monitored.
   BULLET::::- By degree of invasiveness of surgical procedures: Minimally-invasive surgery involves smaller outer incision(s) to insert miniaturized instruments within a body cavity or structure, as in laparoscopic surgery or angioplasty. By contrast, an open surgical procedure such as a laparotomy requires a large incision to access the area of interest.
  