By G. Ingvar. College of Saint Joseph.
It is important to keep in mind that the patient with hemoptysis may already have a very limited functional status and that respiratory failure may happen very rapidly buy nitrofurantoin without prescription. For the unstable patient 50mg nitrofurantoin amex, endotracheal intubation should not be delayed and—in addition to general measures that include placing the patient with the bleeding side down buy nitrofurantoin cheap, establishing appropriate intravenous access, and sending appropriate laboratory testing—no time should be wasted in identifying and controlling the source of bleeding. Oftentimes, the source of bleeding may be identified by radiologic studies and controlled by angiographic embolization, but in cases when chest imaging is unrevealing or the bleeding source is thought to be within the airways, one should proceed with diagnostic and therapeutic bronchoscopy . Massive hemoptysis has a high mortality rate, and it is paramount to secure airway patency, identify the bleeding source and apply therapeutic interventions to stop the bleeding. The rigid bronchoscope is superior to the flexible bronchoscope for all these functions because it allows for ventilation and more vigorous suctioning that may help secure the airway and visualize more thoroughly the source of bleeding. The use of other hemostatic therapies such as iced saline, epinephrine, fibrin glue, oxidized regenerated cellulose, or the placement of occlusive balloons, may all be applied successfully through the rigid barrel while maintaining airway patency [8–13]. For these reasons, the rigid bronchoscope remains the instrument of choice for the endoscopic assessment and treatment of massive hemoptysis. Patients often experience progressive dyspnea on exertion when the narrowing involves 50% of the airway lumen, then developing dyspnea at rest when the stenosis reaches 70% of the airway lumen . When the stenosis is severe, a seemingly stable patient may rapidly develop an acute, critical occlusion of the central airway because, for one example, an otherwise mild respiratory tract infection has caused an increase of secretions that are poorly cleared by ineffective cough, occluding the already severely narrowed airway at or near the site of the stenosis. Benign disease processes also may occlude the central airway by extrinsic compression and this may be seen in large goiters, post-pneumonectomy and post- lung transplantation stenosis and vascular malformations. This is the most common cause of benign tracheal stenosis and results from granulation and fibrotic responses to artificial airways at anatomic loci from the supraglottic space to the lower trachea. The endotracheal tube may cause pressure ulceration and necrosis at any point where the tube contacts the airway wall; this may be the posterior commissure of the glottic space, the balloon site or at the tip of the tube. The same applies for a tracheostomy tube where pressure ulcerations and granulation tissues may form immediately above the stoma within the trachea, at the balloon site or at the tip of a tube that rubs against the airway mucosa. Inflammation, ulceration, and necrosis may in turn result in constriction of the airway wall caused by a loss of support from damaged cartilage, obstruction from granulation tissue, fibrosis, and formation of synechiae. Damage from the balloon has been reduced by the development of high- volume, low-pressure cuffs; however, it remains important not to exceed the normal mucosal capillary perfusion pressure of 20 to 30 mm Hg or tracheal injury may occur because of tissue ischemia. If after achieving a cuff pressure of 25 mm Hg there is still an air leak present, it is advisable to use a larger tracheostomy tube rather than to overinflate the balloon . Tracheal stenosis may become apparent soon after what should have been a successful wean from mechanical ventilation when the patient fails extubation because of stridor and respiratory distress requiring immediate reintubation. However, severe airway narrowing also may present as an airway emergency weeks or months after extubation or tracheostomy decannulation. Not uncommonly, these late deteriorations are preceded by ongoing complaints of worsening stridor or dyspnea on exertion that progress to dyspnea at rest. It is important to understand that airway patency is the priority for patients with tracheal stenosis. When the presentation is one of acute respiratory failure, the patient must be intubated with an endotracheal tube immediately. If an endotracheal tube cannot be advanced, then the patient must be taken to rigid bronchoscopy immediately. More importantly, when confronted with tracheal stenosis the specialist must keep in mind that there needs to be a multidisciplinary approach. Ideally, the intensivist; emergency department physician; thoracic surgeon or otorhinolaryngologist; anesthesiologist; and the interventional pulmonologist collaborate to develop a coherent plan of action that considers different alternatives for a safe and successful approach. When the patient is symptomatic but stable, there may be sufficient time to plan for a procedure that will both assess the stenotic segment and potentially relieve the obstruction. However, if the patient is unstable with acute respiratory failure, restoration of airway patency must occur immediately. If it is not possible to pass an endotracheal tube and the stenosis is felt to be proximal, emergent bedside tracheotomy may become the best option because there may not be enough time to transport the patient to the operating room. However, the latter presentation is unusual when patients first arrive at the emergency department and, often, subsequent deterioration may be averted by carefully planning and by quickly treating the stenosis before overt decompensation occurs. The rigid bronchoscope is an invaluable tool because it provides the means to successfully maintain the patency of the airway while the patient is being treated endoscopically, either definitively when the stenosis is simple, or temporarily as a bridge to a planned tracheal resection and reconstruction when the stenosis is complex [16–19]. The interventionalist has multiple, different therapeutic modalities that may be applied through the rigid bronchoscope to restore airway patency. One method is to use sequentially larger diameter rigid barrels to dilate the airway in a secure and gentle manner. For this method, the patient is intubated with a larger diameter tracheal barrel immediately proximal to the stenosed area and then a smaller diameter bronchial barrel is advanced through the stenosis, allowing for the subsequent advancement of larger caliber bronchial barrels until enough of the lumen is restored for spontaneous breathing. Alternatively, after intubation with a tracheal barrel immediately proximal to the stenotic area, Jackson–Pratt dilators can be advanced sequentially under direct visualization with the rigid telescope. Balloon dilatation may also be done, keeping in mind that the airway is completely occluded while the balloon is inflated. With a very tight stenosis one must use gentle maneuvers because dilating against a fixed stenosis can result in tracheal tears, especially where the anterior wall meets the posterior membrane of the trachea. Such tracheal tears can result in more scarring and further restenosis, possibly involving an even longer segment of the trachea. The interventional pulmonologist has different therapeutic modalities at his or her disposal and these include coagulation modalities (i. Complex airway stenoses show more extensive scarring (>1 cm long), sometimes featuring a circumferential hourglass-like constriction or malacia. Complex stenoses may also be “A” shaped because of bilateral collapse of the walls of a fractured cartilage (s. For complex airway stenoses, tracheal resection and reconstruction is the standard of care and, in experienced hands, this is a highly effective surgical procedure with low morbidity and mortality . For the patient with poor reserve, a temporizing endoscopic procedure, as already described, may be attempted and this is often followed with airway stenting. When airway stenting is done, one approach is to leave the stent in place until the patient is able to undergo definitive surgery or, alternatively, to remove the stent after approximately 6 months to 1 year to assess for resolution of the stenosis, an outcome that is possible but uncommon . The flexible videobronchoscope can be advanced through the lumen of the rigid barrel to reach into segmental airways not approachable by rigid bronchoscopy. In some instances, airway stents can be a valuable tool for maintaining airway patency once it has been restored.
Some pneumothoraces are total purchase nitrofurantoin 50 mg mastercard, but most are partial with some remaining apposition of the visceral and parietal pleura at some point in the thorax nitrofurantoin 50mg generic, usually lateral or posterior depending on the size of the pneumothorax buy nitrofurantoin 50 mg line. A lung point is described as the intermittent respirophasic appearance of lung sliding from the edge of the screen (Chapter 11 Video 11. Although 100% specific for pneumothorax, lung point has only a 66% sensitivity for detection of pneumothorax . The A line is a reverberation of the pleural line, caused by echoes which reflect off of the visceral pleura owing to the inability of ultrasound to penetrate aerated lung tissue. The reflected pulse returns to the probe face and is reflected off of its surface to be in turn reflected back from the pleural line. When this pulse returns to transducer, it is interpreted by the ultrasound machine as arising from an identical, but more distant tissue plane. This is known as a reverberation artifact and occurs when there is an air–tissue interface deep to the probe. When present without sliding lung, A lines represent either air between the visceral and parietal pleura (i. They move in synchrony with lung sliding (although mobility is not required, as in the case of B lines in the absence of lung sliding). B lines reflect the presence of a process that infiltrates or widens the interlobular septae of the lung, such as inflammation, neoplasm, or scarring; or that fills the alveolar space [6,7]. Depending on the disease process that is causing the B lines, they may be focal, scattered, or diffuse in distribution. More than two B lines in a single field are considered significant, with the exception that in normal individuals, several B lines may be present in the basilar-dependent rib interspaces. Z-lines are artifacts arising from the pleural line, but attenuate before the periphery and are not as discrete B lines. E Lines are vertical appearing artifacts that arise proximal to the pleural line from subcutaneous emphysema. Consolidation Consolidated lung yields a characteristic tissue density pattern on ultrasound examination (Chapter 11 Video 11. Consolidated lung has an echogenicity that is similar to liver (sonographic hepatization of the lung). If the bronchial structures that supply the affected consolidated lung are patent, the consolidated lung may have sonographic air bronchograms within it, appearing as small hyperechoic foci within the parenchyma. They may be mobile, reflecting movement of air within the bronchus owing to respiratory activity (Chapter 11 Video 11. All causes of airless lung, such as atelectasis (compressive, resorptive, or cicatricial), infiltrative processes (tumor, purulent material as in pneumonia), or severe pulmonary edema with complete filling of the alveolar compartment will yield the ultrasonographic finding of lung consolidation. When evaluating the patient with dyspnea and/or respiratory failure, the critical care clinician associates various profiles described below with the corresponding cause of respiratory failure compromise. This pattern rules out diseases that compromise the alveolar and/or interstitial compartment (pulmonary edema, pneumonia, fibrosis, etc. Identification of a normal aeration pattern of the dyspneic patient where pulmonary embolism is a concern requires the intensivist to perform a study for venous thromboembolism (see Chapter 92 on Venous Thromboembolism). A Lines, Absence of Lung Sliding, Presence of Lung Point When lung sliding is absent with A lines, pneumothorax is a possibility. If no lung point is identified, other methods are required to confirm if there is a pneumothorax, given the low sensitivity of lung point. The presence of lung pulse, B lines, or consolidation also rules out pneumothorax at the interspace being examined. Alveolar/Interstitial Disease: B Line Patterns Detection of profuse B lines at multiple symmetric points over the anterior chest indicates a high probability of an alveolar and/or interstitial process. For instance, when B lines are detected from subsegmental, segmental, lobar, or unilateral distribution, or involving one hemithorax with A line pattern for the rest of the lung, pneumonia is a prime consideration. It may appear as small multifocal areas of consolidation immediately below the pleural interface or in subsegmental, segmental, lobar, whole lung pattern with unifocal or multifocal distribution. The interface between the pleural surface and the consolidation is linear, whereas the interface between the consolidation and the adjacent aerated lung is irregular and often is associated with comet tail artifacts. Pneumonias often contain dynamic air bronchograms, which appear as mobile, branching, and hyperechoic within the parenchyma (Chapter 11 Video 11. Although suggestive of pneumonia, mobile air bronchograms may be found in association with non-pneumonia consolidation; a hypoechoic area with well-defined borders within an area of alveolar consolidation is consistent with necrosis or abscess (Chapter 11 Video 11. The mechanism of the atelectasis may differ (compressive, resorptive, or cicatricial), but there is a characteristic loss of lung volume in association with the alveolar consolidation. Mobile air bronchograms are uncommon, although static air bronchograms are often present, unless the cause for the atelectasis is complete endobronchial occlusion . Compressive atelectasis from a pleural effusion causes the atelectatic lung to float within the effusion often in association with respirophasic or cardiophasic movement of the lung (Chapter 11 Video 11. The dual mechanism of compressive and resorptive atelectasis results in the airless lung that reinflates when the patient is successfully extubated. If the blockage is at the mainstem bronchial level, the affected lung undergoes major volume loss with associated marked ipsilateral shift of mediastinal and cardiac structures. This can occur rapidly if the patient is on a high FiO2 as is the case immediately following endotracheal intubation. The anteroposterior projection combines with rotation, penetration, and density summation artifact to make interpretation difficult. Chest radiography results in a 2D representation of a complex structure, whereas thoracic ultrasonography yields a three-dimensional representation of the thoracic compartment by virtue of the multiple tomographic planes used in the examination. Although chest radiography does remain useful for determining the location of a variety of intrathoracic devices (see Chapter 179 Chest Radiographic Examination), the location of central venous catheters may, in many cases, be determined with ultrasonography (See Chapter 6 Central Venous Catheters). The finding of new onset B lines bilaterally during cardiac stress testing is indicative of inducible cardiac ischemia with increase in left-sided filling pressures . In their scoring system, a value of 0 is assigned to any interspace examined which revealed A lines with sliding lung, a value of 1 to interspaces with regularly spaced B lines consistent with interlobular septal thickening, a value of 2 to interspaces with confluent B lines filling the visualized interspace, and a value of 3 was assigned to interspaces with consolidation. The authors of this report caution that they could not distinguish whether the augmentation of lung volume resulted from lung recruitment or from overdistention of lung. Conversely, if the patient has A line pattern with lung sliding, there is a high probability that the pulmonary occlusion pressure is below 18 mm Hg and probably less that 12 mm Hg .
Once the operator is cer- resources should be considered when choosing a method tain of completion nitrofurantoin 50 mg sale, the woman should be reassured order nitrofurantoin in india. Vacuum aspiration is a straightforward procedure but careful practice is important so that pregnancies are Surgical abortion in the second trimester evacuated completely and safely generic nitrofurantoin 50 mg with mastercard. Asepsis cannot be maintained during an abortion because contamination Electric vacuum aspiration can be performed up to 16 of gloved hands occurs once the woman is touched. Careful and preparation and removal of the fetus and placenta with gentle instrumentation avoids injury to the cervix or specialized forceps, D&E is associated with a low risk of uterus and good communication is needed between the complications and is highly acceptable to women. When operator, the woman and other members of the surgical second‐trimester surgical abortion was compared in a team. Precise techniques vary among providers and with randomized trial with medical abortion, significantly anaesthetic regimens. This section describes electric fewer women found the surgical option worse than vacuum aspiration with local anaesthesia. After confirming the position, size and extraction (D&X), is performed after very wide (median shape of the uterus by bimanual examination, a bivalve 5cm) cervical dilation is achieved using osmotic dilators speculum is placed in the vagina. This is followed by an assisted are cleansed with an antiseptic solution such as chlo- partial breech delivery, decompression of the calvarium, rhexidine. Local anaesthetic is administered by first and delivery of the fetus otherwise intact. Hysterotomy injecting 1–2mL 1% buffered lidocaine at the 12 o’clock and hysterectomy are outdated methods and only used position on the cervical face. Obstruction is applied and, with gentle outward traction, an addi- by a large, distorting cervical or uterine tumour is an tional 18 mL of buffered lidocaine is injected in equal ali- example of when these methods might be employed. Adequate cervical preparation is essential for safe Cervical dilation to the diameter of the suction cannula D&E provision. The amount of cervical expansion is performed with tapered metal or plastic dilators (e. As a general rule, dilation inserted into the mid to upper fundus, taking care not to should be sufficient to insert and open the extraction touch the fundus which causes pain. After this point, longer forceps with wider 604 Early Pregnancy Problems (a) facilitates an easier, faster and safer evacuation. It is also used in response to patient preference or to avoid the risk of transient signs of life should extramural delivery occur. The most frequently used methods are intra-amniotic or intra-fetal injection of digoxin, and fetal intra-cardiac potassium chloride injection. Research is limited, but the few existing comparative studies suggest that feticide before D&E does not confer a clinical benefit and may increase risks. The only randomized controlled trial avail- able found that intra‐amniotic digoxin administered 24 hours before D&E did not reduce the duration of the pro- cedure, blood loss or subjective difficulty of the procedure compared with placebo . In addition, a before and after study found low but increased risks of extramural delivery and infection with the digoxin compared to non- (b) use . Cohort studies of fetal intracardiac potassium chloride injection before D&E differ as to whether it decreases operative times but found increased risks of cervical laceration and uterine atony compared with non- use or D&E in the setting of spontaneous demise [40,41]. D&E can be performed with local anaesthesia, conscious sedation or general anaesthesia. In a study of over 11 000 second‐trimester surgical abortions with intravenous anaesthesia without intubation, there were no cases of pulmonary aspiration supporting the safety of this technique beyond the first trimester . Performing dilatation and evacuation As with any surgical procedure, D&E requires compe-. Skills are usually acquired in a graduated fashion, with competence demonstrated at earlier gestational ages serrated jaws are used, requiring 1. The following describes the typical from 12 to 19mm in diameter, are typical. Misoprostol or mifepristone can be used for cervical Following pre‐procedure checks, anaesthesia is priming before D&E but additional mechanical dilata- induced and the woman is placed into the lithotomy tion is often required. A bivalve or Sims speculum is inserted and rior cervical dilation throughout the second trimester any osmotic dilators in situ are removed and counted. There are two types: laminaria tenaculum is placed and, applying gentle traction, made of compressed seaweed and Dilapan‐S made of additional mechanical dilatation is undertaken if polyacrylate‐based hydrogel. The amniotic fluid is drained passively or cervical canal, these devices swell over several hours actively with vacuum aspiration. They also induce the of amniotic fluid embolism and facilitates extraction release of natural prostaglandins leading to cervical sof- from the lower uterine segment, which lessens the risk tening. Continuous ultrasound is recom- vider‐dependent and although more laminaria are mended to guide instrumentation. Maintaining steady required to achieve the same amount of dilation as traction on the cervix, the forceps are inserted with the Dilapan, a comparative trial found no differences in tips facing upward. Once the internal os is traversed, procedure time, blood loss or need for additional dila- and remaining in the lower uterus, the jaws of the for- tation between devices . A final vac- ● Vacuum aspiration is the preferred method for first‐tri- uum aspiration is performed to remove any remaining mester surgical abortion and D&E in the second blood or tissue. A bimanual exami- ● Surgical abortion may be offered in the earliest weeks nation can ensure the uterine tone is firm and, if of pregnancy following a protocol that includes needed, uterotonics administered before the woman is inspection of the aspirate for the gestational sac and moved into the recovery area. D&E has a similar low Medical abortion rate of complications, although the risk of a major complication increases with gestational age. With D&E, perfora- 50% of abortions in England and Wales and 81% in tion occurs in 2–3 per 1000 procedures. Along with better with a small‐diameter dilator or cannula in a haemody- funding of and access to abortion services in Britain, namically stable woman may be managed conservatively widespread availability of medical abortion in the earliest with careful observation. Larger injuries, including those weeks of pregnancy has likely contributed to the growing associated with D&E, or where there is active bleeding or proportion of abortions performed at less than 10 weeks’ haemodynamic instability, require laparoscopy or lapa- gestation. External tears that are bleeding or larger than although some regimens are effective beyond 63 days. Mifepristone causes cervical softening, decidual necro- Larger or full‐thickness tears at the level of the internal sis and increased myometrial sensitivity to prostaglan- os will usually require operative intervention or emboli- dins. Serious haemorrhage requiring hospitalization or it was found to be effective in only 60–80% of cases. However, when administered 24–48 hours before a pros- Significant bleeding is most commonly due to uterine taglandin analogue, efficacy increased to nearly 100%.
Heart Heart transplantation is the treatment of choice for patients with end- stage congenital and acquired parenchymal and vascular diseases and is recommended generally after all conventional medical or surgical options have been exhausted buy nitrofurantoin 50mg with amex. Mechanical pumps nitrofurantoin 50mg fast delivery, such as implantable ventricular assist devices or the bioartificial heart cheap nitrofurantoin master card, have contributed to this success because they can also serve as a bridge during the time between end-stage cardiac failure and a transplantation. Heart–Lung and Lung Heart–lung and lung transplants are an effective treatment for patients with advanced pulmonary parenchymal or vascular disease, with or without primary or secondary cardiac involvement. This field has evolved rapidly since the first single-lung transplant with long-term success was performed in 1983 (Table 56. The significant increase in lung transplantations is mainly due to technical improvements resulting in fewer surgical complications, as well as to the extremely limited availability of heart–lung donors. Previously, many patients with end- stage pulmonary failure would have waited for an appropriate heart–lung donor. Bilateral single-lung transplants are specifically indicated in patients with septic lung diseases (e. Double en bloc lung transplants have been abandoned because of technical difficulties related to the bronchial anastomotic blood supply. The 55- mile-per-hour speed limit, stricter seat belt and helmet laws, advances in critical care, as well as the trend toward a deceleration of care in patients that have suffered a catastrophic brain injury have all had significant impacts on the number of brain-dead organ donors . In 2016, the three leading causes of death among deceased donors in the United States were cerebral anoxia (e. According to estimates, there are at least 10,500 to 13,800 potential brain-dead donors in the United States per year . According to a study, the overall consent rate (the number of families agreeing to donate divided by the number of families asked to donate) was 54% in the United States, and the overall conversion rate (the number of actual donors divided by the number of potential donors) was 42% . The single most important reason for lack of organ recovery from 45% to 60% of the potential donor pool is the inability to obtain consent [12,24]. Several studies have shown that family refusal to provide consent and the inability to identify, locate, or contact family members to obtain consent within an appropriate time frame are the leading causes for the nonuse of many organs from potential donors [10–13,24]. A public opinion survey showed that 69% of respondents would be very or somewhat willing to donate their organs, and 93% would honor the expressed wishes of a family member . Moreover, 37% of respondents did not comprehend that a brain-dead person should be considered dead and unable to recover, and 59% either believed or were unsure whether or not organs can be bought and sold on the “black market. Finally, racial differences which are likely based on historical distrust in the health care system may adversely impact donation rates as well. For instance, African American families have been consistently found to be less willing to consent to organ donation than White families . Correcting these misperceptions and attempting to increase awareness of the importance of organ transplantation must remain the focus of public educational campaigns [24,29]. Such efforts can be successful, especially among minorities, in whom mistrust and the perception of inequitable access to medical care and organ transplant therapy have led to disappointingly low organ donation and recovery rates [24,45]. It is very important that adequate communication, empathy, and an informative, humane approach to the family of the deceased occur to ensure reasonable consideration of donation. Educational efforts to enhance organ donation must therefore also be directed at health care professionals and medical students, whose views and knowledge of these issues are often inconsistent and limited [29,46]. Optimal use of the Current Donor Pool As a result of the ongoing organ shortage, transplant surgeons have attempted to refine procurement techniques so that maximal use of the available donor pool occurs. Organ recovery techniques also have been adapted to facilitate use of older donors with significant aortic atherosclerosis . The increased use of hypothermic machine perfusion of kidney grafts allows to assess the quality of grafts from marginal donors and facilitates—by improving preservation quality— organ allocation to geographically more distant transplant centers . Improvements in operative technique permit the en bloc transplantation of two kidneys from very young (e. Similarly, transplantation of both kidneys from an adult donor into one recipient is, on occasion, done to avoid discarding suboptimal kidneys with an insufficient individual nephron mass. To maximize the use of livers, adult donor livers can be split and the two size-reduced grafts transplanted into two recipients (e. A similar principle has also been proposed for the pancreas and has been reported on at least one occasion . Explanted livers from patients undergoing liver transplantation for hepatic metabolic disorders that cause systemic disease without affecting other liver functions (e. The combination of split-liver and domino transplantation can even result in transplantation of three adult patients with one deceased donor graft . The advent of single-lung transplants has made it possible to distribute the heart and lungs of one donor to three recipients. Formerly, transplanting a heart–lung bloc into one recipient was the treatment of choice for end-stage pulmonary disease. If the native heart of a heart– lung recipient is healthy, a domino transplant can be performed: the heart–lung recipient donates his or her heart to another patient in need of a heart transplant. In an attempt to optimize use of scarce donor resources, the reuse of previously transplanted hearts, kidneys, and livers has also been reported. The cornerstone for an effective increase in the number of organ donors remains heightened awareness and education of the public, physicians, and other health care professionals to improve consent and conversion rates [11–13,24,29]. Living Donors the use of organs from living donors, traditionally limited to kidney transplants, has been expanded to the liver, small bowel, pancreas, and lung [1,2]. In the more distant past, most living donors were genetically related to the recipient—siblings, parents, and adult children. As a result of the organ shortage, the use of living unrelated kidney donors, who are emotionally, but not genetically, related to the recipient (e. In order to increase the number of live donor transplants even further, paired-kidney- exchange programs and living donor chain transplants have been implemented [56,57]. Currently, there is considerable public debate on providing incentives for living kidney donation [58–61]. The debate centers on concerns that reimbursement might lead to the commercialization of organ donation, with the inherent risk of turning potential donors and transplantable organs into a commodity [59,60]. In the United States, those in support of compensating live donors stress that an Organ Procurement and Transplantation Network–run transparent system of paid living donation would ensure that donors are compensated fairly, eliminate transplant tourism to other countries, greatly diminish the currently existing black market for organs in those countries, and emphasize any potentially interested donor’s autonomy—while at the same time increasing the organ supply [58,61].