Vasoconstrictors may improve the quality of the block by delaying washout of drug from the orbit buy genuine dostinex menopause how long does it last. There is concern buy 0.5mg dostinex with amex women's health clinic lawrence ks, however, that epinephrine, the most common vasoconstrictor additive, may compromise retinal perfusion113; it is best avoided in patients with glaucomatous optic nerve damage. Without question, however, hyaluronidase has been the most popular ancillary agent used to modify ocular local anesthetic actions since it was introduced by Atkinson in 1949. It acts by hydrolyzing hyaluronic acid, a natural substance that binds cells together, keeping them cohesive. Perhaps as a consequence of past national shortages, many facilities choose to obtain hyaluronidase from local compounding labs. In recent years, tainted medications from compounding facilities have led to multiple deaths due to fungal meningitis in chronic pain patients and permanent blindness in macular degeneration patients. Hyaluronidase is currently widely available in a human recombinant formulation, obviating the need for compounded formulations. Digital pressure and mechanical devices have been used to soften the globe prior to surgery. The Super Pinky ball and the Honan Intraocular Pressure 3471 Reducer (The Lebanon Corporation, Lebanon, Indiana) are examples. General Principles of Monitored Anesthesia Care Many advocate the intravenous administration of an appropriate agent immediately prior to ocular regional anesthesia to provide comfort and amnesia. After the block has been performed, the patient should be relaxed but sufficiently responsive to avoid head movement associated with snoring or sudden abrupt movement on awakening. Perioperative patient movement is a leading cause of patient eye injury and anesthesiologist liability. Clearly, patients under monitored64 sedation must be capable of remaining relatively still, responding rationally to commands, and maintaining airway patency. Undersedation should likewise be avoided because tachycardia and hypertension may have deleterious effects, especially in patients with coronary artery disease. Curiously, a significant fraction of patients who have had cataract extraction on both eyes perceive the second eye surgery as being longer in duration, more painful, and/or generally more unpleasant. Adequate ventilation about the face is essential to avoid carbon dioxide accumulation, particularly because supplemental oxygen can delay signs of desaturation and hypoventilation. The adequacy of the sedated patient’s ventilation should be assessed by clinical signs as well as exhaled carbon dioxide. These investigators prospectively studied the incidence and nature of interventions required by anesthesia personnel in 1,006 consecutive cataract operations (both phacoemulsification and extracapsular techniques were included) performed under peribulbar block. They also analyzed germane information, including patient demographic data, medical history, and preoperative laboratory tests, for ability to predict those patients at greatest risk for intervention. They found that 37% of patients required some type of intervention and that in general the majority of those interventions could not have been predicted before surgery. The interventions ranged from minor forms, such as verbal reassurance and hand holding, to administering such intravenous medications as supplemental sedation or antihypertensive, pressor, or antiarrhythmic agents, or to providing respiratory assistance. Although hypertension, lung disease, renal disease, and a diagnosis of cancer were related to interventions, these four conditions combined accounted for only a small portion of the needed interventions. Moreover, although many of the interventions were relatively minor, several were more serious, and 30% 3473 of the interventions were considered (by the involved anesthesia personnel) to be critical to the success of the operation. In view of the fact that topical anesthesia produces analgesia that is less profound and provides operating conditions that are less ideal than regional or general anesthesia, it seems likely that anesthesia care is equally appropriate to provide comfort, support, and indicated drugs for these patients as well. For both ethical and surgical reasons, the ophthalmologist’s attention must not be distracted from the microsurgical field. Anesthetic Management in Specific Situations “Open-Eye, Full-Stomach” Encounters The anesthesiologist involved in caring for a patient with a penetrating eye injury and a full stomach confronts special challenges. As in all cases of trauma, attention should be given to the exclusion of other injuries, such as skull and orbital fractures, intracranial trauma associated with subdural hematoma formation, and the possibility of thoracic or abdominal bleeding. Although regional anesthesia is often a valuable alternative for the management of nonfasted trauma patients, this option had traditionally been considered contraindicated with penetrating eye injuries because of the potential to extrude intraocular contents via pressure generated by injection of local anesthetics. Needle instrumentation of the orbit, squeezing of the eyelids, and pressure due to bleeding are additional reasons that regional anesthesia was typically avoided in open-globe scenarios. Nonetheless, some anecdotal case reports of successful use of ophthalmic blocks in this setting have been published. A significant number of injuries were caused by intraocular foreign bodies and dehiscence of cataract or corneal transplant incisions. Blocked eyes tended to have more anterior, smaller wounds than those repaired via general anesthesia. There was no 3474 outcome difference—that is, change of visual acuity from initial evaluation until final examination—between the eyes repaired via regional versus general anesthesia. Moreover, combined topical anesthesia and sedation for selected patients with open-globe injuries has also been reported. Many no longer maintain hospital privileges, creating impetus to operate on eye injury patients on an ambulatory surgical basis in their own facilities. For some patients, general anesthesia in an ambulatory surgery center may confer an unacceptable level of systemic risk. In those scenarios, selection of regional or topical anesthesia for repair of traumatic eye injuries may be a prudent alternative. Nonetheless, general anesthesia remains the accepted modality for many traumatic eye injury patients. Preoperative prophylaxis against aspiration may involve administering H receptor antagonists to elevate gastric fluid pH2 and to reduce gastric acid production. Traditionally, an induction agent with nondepolarizing neuromuscular blocking drug technique was described as the method of choice for the emergency repair of an open eye injury; however, this method has its disadvantages, including risk of aspiration and difficult airway. Several studies have explored the use of large doses of nondepolarizing muscle relaxants to accelerate the onset of adequate relaxation for endotracheal intubation. Moreover, the cardiovascular side effects of tachycardia and hypertension may prove worrisome in patients with coronary artery disease. Succinylcholine offers the distinct advantages of swift onset, superb intubating conditions, and brief duration of action. Although the advisability of this technique has been debated vociferously, McGoldrick129 pointed out that the 1957 watershed article of Lincoff et al. This includes several reports of cases in which succinylcholine was given to forestall impending vitreous prolapse only to have a prompt expulsion of vitreous occur. It is an oligosaccharide chelating agent that rapidly reverses the effects of aminosteroid neuromuscular blocking agents, particularly rocuronium. Recovery of over 90% train-of-four responses may be accomplished in less than 120 seconds. It was hoped that rapacuronium, with its swift onset, would emerge as a viable alternative to succinylcholine. However, rapacuronium is no longer available in the United States because of its role in triggering intractable bronchospasm in some patients. New ultrashort-acting nondepolarizing alternatives to succinylcholine are currently undergoing clinical investigation in human volunteers. When confronted with a patient whose airway anatomy or anesthetic history suggests potential difficulties, the anesthesiologist should consult with the ophthalmologist concerning the probability of saving the injured eye. In selected instances, general anesthesia may be avoided by using topical or regional anesthesia.
Virtually all liver diseases can recur in grafted livers generic dostinex 0.5mg without prescription menopause uterine cramps, including autoimmune diseases discount 0.5mg dostinex otc women's health big book of exercises download, fatty liver, and hepatitis C. The degree of liver dysfunction from recurrent disease should be evaluated by hepatologists and by using standard laboratory tests. For lung transplant recipients with a tracheal anastomosis, denervation has occurred below the level of the suture line, and the cough reflex is diminished or absent. These patients are at increased risk of retained secretions and pneumonia and have an increased airway hyperreactivity and bronchospasm. Because most lung transplants are now being done with bronchial instead of tracheal anastomoses, the risk of tracheal suture line stenosis or disruption with manipulation is markedly diminished. Advantages of regional anesthetic techniques in lung transplant patients include minimization of airway manipulation and decreased infectious risk. Significant decreases in forced expiratory volume in 1 second, vital capacity, and total lung capacity and an obstructive pattern may indicate acute rejection. Arterial blood gas in the presence of rejection will show an increased alveolar—arterial gradient from stable baseline gases, along with perihilar infiltration on chest x-ray. If the patient is suspected of having an active pulmonary process, consultation with Pulmonary Medicine for a possible diagnostic bronchoscopy should be considered prior to surgery. Transplanted hearts are denervated, affecting perioperative management significantly. The transplanted heart cannot respond to indirect acting agents, such as ephedrine and even dopamine, or to peripheral attempts to induce hemodynamic changes, such as carotid massage, Valsalva maneuver, or laryngoscopy. The native P wave will not conduct to the implanted heart, and these nonconducted P waves should not be confused with complete heart block. Dobutamine can also be helpful; norepinephrine and epinephrine should be reserved for refractory cardiogenic shock. Because the denervated heart does not reflexively compensate for hemodynamic changes induced by regional anesthetics, general anesthesia is usually preferred. Preoperative evaluation of heart transplant recipients should focus on cardiac functional status. New findings should be discussed with the cardiology consultant to determine need for stress testing or myocardial biopsy. Invasive monitors should be placed only when warranted by the clinical status and surgical procedure. Report of the Ad Hoc Committee of the Harvard Medical School to Examine the Definition of Brain Death. Effect of brain death and donor treatment on organ inflammatory response and donor organ viability. Hemodynamic and oxygen transport 3709 patterns after head trauma and brain death: implications for management of the organ donor. Hormonal therapy of the brain-dead organ donor: experimental and clinical studies. Arginine vasopressin significantly increases the rate of successful organ procurement in potential donors. Effect of a lung protective strategy for organ donors on eligibility and availability of lungs for transplantation: a randomized controlled trial. Preconditioning, postconditioning, and remote conditioning in solid organ transplantation: basic mechanisms and translational applications. Effects of donor pretreatment with dopamine on graft function after kidney transplantation: a randomized controlled trial. Risk quantification of early outcome after lung transplantation: donor, recipient, operative, and post-transplant parameters. Validation of a pediatric bedside tool to predict time of death after withdrawal of life support. Simultaneous liver and kidney transplantation from donation after cardiac death donors: a brief report. Donation after circulatory death for liver transplantation: a meta-analysis on the location of life support withdrawal affecting outcomes. Comparison of three perioperative fluid regimes for laparoscopic donor nephrectomy: a prospective randomized dose-finding study. Optimization of cardiac preload during laparoscopic donor nephrectomy: a preliminary study of central venous pressure versus esophageal Doppler monitoring. Chronic pain following donor nephrectomy: a study of the incidence, nature and impact of chronic post-nephrectomy pain. Live donor liver transplantation: a valid alternative for critically ill patients suffering from acute liver failure. Estimates of early death, acute liver failure, and long-term mortality among live liver donors. Anesthetic complications including two cases of postoperative respiratory depression in living liver donor surgery. The impact of a surgical protocol for enhanced recovery on living donor right hepatectomy: a single-center cohort study. Hemodynamic and hormonal responses to the sudden interruption of caval flow: insights from a prospective study of hepatic vascular exclusion during major liver resections. Intra-operative isovolemic hemodilution is safe and effective in eliminating allogeneic blood transfusion during right hepatic lobectomy: comparison of living donor versus non-donors. Epidural analgesia provides better pain management after live liver donation: a retrospective study. Surgically placed abdominal wall catheters on postoperative analgesia and outcomes after living liver donation. Hepatic resection-related hypophosphatemia is of renal origin as manifested by isolated hyperphosphaturia. Adult-to-Adult Living Donor Transplantation Cohort Study Group: laboratory test results after living liver donation in the adult-to-adult living donor liver transplantation cohort study. National variation in use of immunosuppression for kidney transplantation: a call for evidence-based regimen selection. Inhibition of nuclear translocation of 3712 calcineurin suppresses T-cell activation and prevents acute rejection of donor hearts. Anesthetic and perioperative management of adult transplant recipients in nontransplant surgery. Tacrolimus-associated posterior reversible encephalopathy syndrome after solid organ transplantation. Prolonged neuromuscular blockade and ventilatory failure after renal transplantation and cyclosporine. Rhabdomyolysis and acute kidney injury secondary to interaction between simvastatin and cyclosporine. Randomization trial of steroid-free induction versus corticosteroid maintenance among orthotopic liver transplant recipients with hepatitis C virus: impact on hepatic fibrosis progression at one year. Immunomodulation with rabbit anti- thymocyte globulin in solid organ transplantation. Serum sickness after treatment with rabbit anti-thymocyte globulin in kidney transplant recipients with previous rabbit exposure.
Intraoperative use of shorter- acting relaxants might decrease the incidence of residual paralysis but does 3877 not eliminate the problem purchase dostinex 0.5mg fast delivery women's health center yarmouth maine. Marginal reversal can be more dangerous than near-total paralysis because a weak purchase dostinex paypal menstruation vaginal itching, agitated patient exhibiting uncoordinated movements and airway obstruction is more easily identified. A somnolent patient exhibiting mild stridor and shallow ventilation from marginal neuromuscular function might be overlooked, allowing insidious hypoventilation and respiratory acidemia or regurgitation with aspiration to occur. Safety of techniques designed to44 avoid reversal of short- and intermediate-duration relaxants has not been substantiated, and reversal of nondepolarizing relaxants is recommended. Patients with neuromuscular abnormalities such as45 myasthenia gravis, Eaton–Lambert syndrome, periodic paralysis, or muscular dystrophies exhibit exaggerated or prolonged responses to muscle relaxants. Even without relaxant administration, these patients can exhibit postoperative ventilatory insufficiency. Diaphragmatic contraction is compromised in some postoperative patients, forcing more reliance on intercostal muscles and reducing the ability to overcome decreased compliance or increased ventilatory demands. Impairment of phrenic nerve function from interscalene block, trauma, or thoracic and neck operations can “paralyze” one or rarely both diaphragms. However, with high work of breathing, muscle weakness, or increased ventilatory demands, a nonfunctional diaphragm impairs minute ventilation. The ability to sustain head elevation in a supine position, a forced vital capacity of 10 to 12 mL/kg, an inspiratory pressure more negative than −25 cm H O, and tactile2 train-of-four assessment imply that strength of ventilatory muscles is adequate to sustain ventilation and to take a large enough breath to cough. However, none of these clinical end points reliably predicts recovery of airway protective reflexes, and failure on these tests does not necessarily indicate44 3878 the need for assisted ventilation. By using these noninvasive techniques, patients can often overcome some of the above discussed issues interfering with normal respiration, thus reducing the risk of remaining intubated or reintubation. Occasionally, a clinical picture suggests ventilatory insufficiency when ventilation is adequate. Voluntary limitation of chest expansion to avoid pain (splinting) causes labored, rapid, shallow breathing characteristic of inadequate ventilation. Splinting seldom causes actual hypoventilation and usually improves with analgesia and repositioning. Ventilation with small tidal volumes due to thoracic restriction or reduced compliance seems to generate afferent input from pulmonary stretch receptors, leading to dyspnea, labored breathing, and accessory muscle recruitment in spite of appropriate minute ventilation. Finally, spontaneous hyperventilation to compensate for a metabolic acidemia might generate tachypnea or labored breathing, which is mistaken for ventilatory insufficiency. Patients with high V· /V· are at greater risk for postoperativeD T ventilatory failure. Occasionally, an acute increase in deadspace contributes to respiratory acidemia in postoperative patients. Decreased cardiac output can transiently increase V· /V· by decreasing perfusion to well-ventilated,D T nondependent lung and is the most common cause of acute increase in 3879 deadspace in the acute care setting. Deadspace may appear high if an inhalation interrupts the previous exhalation and spent alveolar gas is retained. This “gas trapping” occurs when high airway resistance lengthens the time required to exhale completely, or if improper inspiration/expiration ratios or high ventilatory rates are used during mechanical ventilation. Increased Carbon Dioxide Production Carbon dioxide production varies directly with metabolic rate, body temperature, and substrate availability. Inadequate Postoperative Oxygenation Systemic arterial partial pressure of oxygen (PaO ) is the best indicator of2 pulmonary oxygen transfer from alveolar gas to pulmonary capillary blood. Arterial hemoglobin saturation monitored by pulse oximetry yields less information on alveolar-arterial gradients and is not helpful in assessing impact of hemoglobin dissociation curve shifts or carboxyhemoglobin. Adequate arterial oxygenation does not mean that cardiac output, arterial perfusion pressure, or distribution of blood flow will maintain tissue oxygenation. Sepsis, hypotension, anemia, or hemoglobin dissociation abnormalities can generate tissue ischemia despite adequate oxygenation. In postoperative patients, the acceptable lower limit for PaO varies with2 3880 individual patient characteristics. A PaO below 65 to 70 mmHg causes2 significant hemoglobin desaturation, although tissue oxygen delivery might be maintained at lower levels. Maintaining PaO between 80 and 100 mmHg2 (saturation 93% to 97%) ensures adequate oxygen availability. Little benefit is derived from elevating PaO above 110 mmHg because hemoglobin is2 saturated and the amount of additional oxygen dissolved in plasma is negligible. Distribution of Ventilation Loss of dependent lung volume commonly causes V·/Q· mismatching and hypoxemia. Reduced ventilation in dependent lung is particularly damaging47 because gravity directs pulmonary blood flow to dependent areas. Right upper lobe collapse secondary to partial right main stem intubation is a frequently overlooked cause. During one-lung anesthesia, the weight of unsupported mediastinal contents, pressure from abdominal contents on the dependent diaphragm, and lung compression all reduce dependent lung volume. Gravity and lymphatic obstruction promote interstitial fluid accumulation and further V·/Q· mismatching. This “down lung syndrome” may appear as unilateral pulmonary edema on the chest film. Postoperatively, acute pulmonary edema from overhydration, ventricular dysfunction, airway obstruction, or increased capillary permeability (e. Small airway occlusion from compression, retained secretions, or aspiration leads to distal hypoventilation and hypoxemia, as does main stem intubation. If possible, patients should recover in a semisitting or reverse Trendelenburg position to reduce abdominal pressure on the diaphragms. Intubation for delivery of noninvasive ventilation does not mandate positive-pressure ventilation. In postoperative2 patients, position affects oxygenation if gravity forces blood flow to areas with reduced ventilation. For example, placing a poorly ventilated lung in a dependent position can reduce PaO. When possible, avoid placing an atelectatic or diseased lung in a dependent position. Placing poorly ventilated parenchyma in a nondependent position could improve V·/Q· matching, but positioning a diseased lung in an “up” position may promote drainage of purulent material into the unaffected lung. Hypoventilation must be severe to cause hypoxemia based on the alveolar gas equation, and can be completely masked by even small amounts of supplemental oxygen administration. Complete apnea or airway obstruction by a foreign body, soft-tissue edema, or laryngospasm as well as very high small airway resistance all lead to rapid depletion of alveolar oxygen, and preclude effective ventilation. Volume displacement of oxygen could also occur during severe hypercarbia in a patient breathing ambient air, although acidemia is often a greater problem. If arterial oxygen content decreases 3883 or tissue extraction increases, P O falls. The lower the P O in blood that is2 2 shunted or flows through low V·/Q· units, the greater the reduction of PaO. In postoperative patients, shivering, infection, and hypermetabolism lower P O by increasing peripheral oxygen extraction. Low cardiac output2 and hypotension also lower P O by decreasing tissue oxygen delivery.
The dose of oral midazolam increases with decreasing age order 0.5 mg dostinex fast delivery menstruation postpartum, although few bother to consider this very important factor purchase 0.25mg dostinex overnight delivery 40 menstrual cycle. To minimize the aftertaste, the dose should be swallowed in a single bolus and then followed with a small volume of water. For children too young to swallow midazolam from a cup, it should be instilled into the lateral gutters of the mouth using a needleless syringe to prevent the child from spitting it out. Judgment should be exercised when considering oral midazolam premedication for a child who is crying continuously as few strategies, including parental presence at induction, may provide anxiolysis. Alternative oral premedications include ketamine (5 to 6 mg/kg),108 clonidine (2 μg/kg),253 and dexmedetomidine (2 μg/kg). Some have combined oral midazolam and ketamine in a 50:50 mixture with good success. Both clonidine and dexmedetomidine take 60 to 3094 90 minutes to effect sedation and anxiolysis. They may produce bradycardia and sedation that persist beyond the duration of the anesthetic. By this route, ketamine has an onset of action of 3 to 5 minutes and a duration of 30 to 40 minutes. Induction Techniques Inhalational Induction In North America, the most common technique for inducing anesthesia in children undergoing elective surgery is an inhalational induction. Infants and children of all ages, including those who are crying and upset, can be successfully anesthetized using this approach. Distracting upset and crying children using a warm, reassuring, and calm manner often permits a successful induction of anesthesia by face mask. The notion that distraught children should be treated with “brutane” by holding children down and forcing a mask on their face with 8% sevoflurane flowing has no place in pediatric anesthesia and may psychologically scar the child for life. If the child had a poor previous experience with anesthesia, it is important to understand the nature of the past experience and design an anesthetic to minimize their anxiety. In preschool-age children, distraction techniques and premedication are key strategies to minimize the anxiety associated with separating from their 3095 parents and undergoing induction of anesthesia. The author offers children (>3 years of age) a choice of several flavored lip balms to mark inside the mask. For younger children (<3 years of age), the author flavors the face mask for them. The smell obscures the plastic smell of the mask but more importantly it distracts the child and offers a topic for discussion. Troposmia, which means a distorted perception of an odor, is an interesting strategy in which the child is told that the flavor that was applied to the mask will transform into his/her favorite flavor as anesthesia is induced. Using this approach, 80% of children interviewed postoperatively confirmed that they smelled their favorite flavor as they were anesthetized. With the child seated on the operating table with his/her back to the anesthesiologist’s chest (or on your lap if a diaper is worn) and at least a pulse oximeter (with more monitors as tolerated), a flavored face mask is applied over the mouth and nose with 5 to 7 L/min of a mixture of 70% nitrous oxide and 30% oxygen. The adjustable pressure-limiting valve should be completely open to avoid resistance to exhalation. During this time, the child should be distracted by singing a song or telling a joke or story until the end-tidal N O concentration exceeds ∼50% or the child ceases to respond to2 verbal stimulation. At this point, the inspired concentration of sevoflurane is increased in one step from 0% to 8%. If the sevoflurane concentration is increased in smaller increments, then a protracted period of excitement may ensue. If sevoflurane is introduced at the same time as the nitrous oxide, unpremedicated children will reject the mask because of the strong odor of sevoflurane, potentially resulting in an aversion to or fear of face masks, which almost certainly will present difficulties for future anesthetics. If apneic or hypopnea occurs (as is common after premedication), ventilation may be assisted manually and gently. Bilateral air entry in the chest, the presence of a87 capnogram, and no air entry audible over the upper epigastrium confirm proper placement of the tube. The2 inspired concentration of sevoflurane may be reduced to 2% to 3% inspired and nitrous oxide reintroduced. The child with mask phobia poses a real challenge for those attempting to induce anesthesia by mask. Irrespective of the reason for the mask phobia, if the mask is the focal point of the fear, it should be eliminated. In these cases, anesthesia may be induced without a face mask by inserting the elbow of the breathing circuit between two fingers and interlacing the fingers of his/her two hands (with flavor applied to the gloves) (Fig. With the hands cupped under the child’s chin and 70% nitrous oxide in oxygen flowing, the hands slowly close in over the child’s mouth. Because nitrous oxide is heavier than air, the cupped hands act as a reservoir for the nitrous oxide. Suction tubing may be held in close proximity to minimize spread of anesthetic to those nearby. As soon as the child stops responding, the elbow of the circuit is inserted into the mask and the mask is applied to the face to seal the airway. Figure 43-5 For the child who fears the face mask, the mask is removed and the elbow of the breathing circuit is inserted between interlaced fingers in the hand. The hands are gradually brought closer to the child’s mouth from below the chin (nitrous oxide is heavier than air), until they completely cover the mouth. B: At that point, either sevoflurane may be added to the fresh gas or a face mask applied to the face, or both. If the child is not mask-phobic, the anesthesiologist may deliver sevoflurane from the outset of the anesthetic without the child smelling the sevoflurane by rotating the face mask 90 degrees so the cuff on the mask occludes the nares. This eliminates/decreases the smell of sevoflurane and allows anesthesia to be induced smoothly. However, to be successful, the child should practice inhaling maximally through the mouth and exhaling to residual volume (e. The anesthesia breathing circuit should be primed with 8% sevoflurane (with or without 70% nitrous oxide) as evidenced by the agent analyzer. This is achieved by flushing the circle circuit and a 2- to 3-L reservoir bag three to four times with 8% sevoflurane in 70% nitrous oxide, exhausting the contents of the circuit each time through the scavenging system. Once the child has mastered the breathing maneuver, the child exhales to residual volume, at which point the face mask and the primed breathing circuit is applied and held tightly to the face. The child is instructed to take a single deep breath through the mouth and hold it for as long as he/she can. While the child is holding his/her breath, the anesthesiologist counts aloud slowly to distract the child. The child may be supine or sitting for this induction, but if the child is sitting, an assistant stand behind the child to support him/her when he/she loses consciousness. As discussed earlier, a gradual introduction of the inhaled anesthetics may proceed smoothly in cooperative patients and one variation on that approach is demonstrated in the video. First, a topical local anesthetic cream can be applied to the skin to prevent the pain of the needle puncture. Because propofol is a phenol derivative, it causes pain when injected into the small peripheral veins of children. A bolus injection of propofol causes transient hypopnea or apnea with a minor decrease in heart rate and blood pressure.