Inferiorly buy cheap forzest 20mg on line erectile dysfunction oil, it is bounded by the hepatic into anterior and posterior subphrenic spaces actu- flexure of the colon and the peritoneal reflections at ally occurs order forzest 20 mg line causes of erectile dysfunction in 20 year olds, but such compartmentalization of the beginning of the transverse mesocolon and medi- abscesses frequently takes place by the formation ally by the second portion of the duodenum as it of pyogenic membranes buy forzest amex erectile dysfunction vacuum pump demonstration. Laterally, it communicates deep to the liver around the margin of the right coronary ligament with the subphrenic space The Left Subphrenic Space above and the right paracolic gutter in the flank. The suspending coronary ligament of the left lobe of Although these two compartments communicate the liver, unlike the right, is attached superiorly, freely anatomically, they are frequently separated by almost in the center of the abdomen and more ante- the development of pyogenic membranes. It is quite small and usually insignificant The Right Subphrenic Space for the margination of abscess cavities. The anatomic spaces surrounding the left lobe of the liver are The right subphrenic space is a large continuous thus freely communicating. Generally, therefore, the compartment extending over the diaphragmatic whole left side should be considered as one potential surface of the right lobe of the liver to its margina- 5,7 abscess area. The mesenteric attachments of the left tion posteriorly and inferiorly by the right upper quadrant, i. A structure of particular significance in the left upper quadrant of the abdomen is the phrenicocolic 9 ligament (Figs. This is a strong falciform peritoneal fold that extends from the ana- tomic splenic flexure of the colon to the diaphragm at the level of the 11th rib. Older literature refers to it also as the ‘‘sustentaculum lienis,’’ since it is in immediate inferior relationship to and serves the purpose of sup- porting the spleen at its tip. Its importance in limiting the spread of infection is based on the anatomic fact Fig. The intraperitoneal spaces around the left lobe of the liver and the spleen are freely continuous (gray area). The phrenicocolic ligament partially bridges the junction between the perisplenic space and the left paracolic gutter. The lesser sac resides above the transverse mesocolon and medial to the splenorenal ligament. The Lesser Sac The foramen of Winslow is limited above by the caudate lobe of the liver, behind by the vena cava, and During fetal life, the development of the dorsal meso- anteriorly by the hepatoduodenal ligament and its gastrium and the rotation of the stomach cut off a contents (portal vein, hepatic artery, and bile ducts). This structure supports the spleen (Sp) as it extends from the splenic flexure of the colon (C) to the left diaphragm and is in continuity with the gastrosplenic ligament (arrowheads) seen on end. The foramen of Winslow is generally only large enough to admit the introduction of one to two fingers, but in vivo it represents merely a potential communication between the greater and lesser peritoneal cavities. A larger lateral compartment to the left infer- the lesser omentum, the stomach and duodenal bulb, iorly (Fig. It is bounded inferiorly by the transverse colon and the mesocolon, although a The base of the fold can be identified indirectly by well-defined inferior recess persists in a few individuals virtue of its typical location and associated vessels between the anterior and the posterior reflections of the (Fig. On the A prominent oblique fold of peritoneum, the gas- right side, the space extends just to the right of the tropancreatic plica, is raised from the posterior midline, where it communicates, at least potentially, abdominal wall by the left gastric artery. The plica is behind the free edge of the lesser omentum with the a fatty triangular structure measuring 2–3 cm in cross right subhepatic space via like foramen of Winslow section at its base and is inclined toward the posterior (Figs. This fold often Computed tomography clearly demonstrates the divides the lesser sac into two compartments: 14,15 anatomic characteristics of the lesser sac. A smaller medial compartment to the right com- lated fluid collections in perihepatic spaces and hepa- 16 posed of the vestibule to the lesser sac, where the tic fissures. Lesser omentum and stomach cut and section removed from greater omentum and transverse colon. Drawing shows potential inferior extension of lesser sac between the layers of the greater omentum. The dynamic pathways of flow of intraperitoneal The Spread and Localization fluid in vivo have been established in a series of adult 18,19 of Intraperitoneal Abscesses patients by peritoneography. The peritoneal reflections and recesses provide watersheds and drai- Meyers has documented that the spread of infection nage basins for the spread and localization of infection within the peritoneal cavity is governed by (a) the site, (Table 5–1). Secondary signs include scoliosis, elevation or splinting of a diaphragm, localized or generalized ileus, and pulmonary basilar changes. These pathways and localizing features are evident not only by conven- tional radiologic techniques, but they have also been confirmed by ultrasonography, isotopic studies, 21 and computed tomography. Knowledge of the pre- ferential pathways of spread and subsequent compart- mentalization permits the early diagnosis of abscess 18,20,21 formation often remote from its site of origin. Pelvic Abscesses Fluid introduced into the inframesocolic compart- ment almost immediately seeks the pelvic cavity, first filling out the central pouch of Douglas (cul- 22 de-sac) and then the lateral paravesical fossae (Fig. A small amount in the left infracolic space readily pursues this course, but on the right, it Fig. Right Subhepatic and Subphrenic Abscesses From the pelvis, fluid ascends both paracolic gutters. Passage up the shallower left one is slow and weak, and cephalad extension is limited by the phrenicocolic 18 ligament. It then progresses deep to the inferior edge of the liver into the right subhepatic space, particularly draining into its posterior exten- sion (Morison’s pouch) (Fig. Abscess formation may coalesce in the ante- the caudate lobe of the liver anteriorly, the intraabdominal segmentoftheesophagustotheleft, and the inferior vena cava rior subhepatic space, but this is unusual. This is formed by the triangular groove between the lateral aspect of the descending (a) a soft-tissue mass; duodenum and the underlying right kidney, just above (b) a collection or pattern of extraluminal gas; the beginning of the transverse mesocolon (Fig. This drai- (d) loss of normally visualized structures; nage pathway from the pelvis is so constant that if the 78 5. The gastropancreatic plica (white arrowheads), within which courses the left gastric artery (black arrowhead), is a structure of some dimension. Ao ¼ aorta; C ¼ inferior vena cava; cl ¼ papillary process of caudate lobe; St ¼ stomach; Sp ¼ spleen. Based on this anatomic feature, the potential clinical loculation of fluid to one or the other compartment can be anticipated. The subperitoneal fat near the base of origin within the gastropancreatic plica is identifiable (open arrow). On the left, note the posterior extent of the lesser sac bounded by the splenorenal ligament within which distal splenic vessels course (arrowhead). Radiologic–Anatomic Classification of Intraperitoneal Abscesses Supramesocolic Inframesocolic Right subphrenic Pelvic Anterior Paracolic Posterior Right Right subhepatic Left Anterior Infracolic Posterior Right (Morison’s pouch) Left Left subphrenic Lesser sac Modified with permission from Meyers and Whalen. It is important to recognize that only after Mori- son’s pouch is contaminated does the infected material reach the right subphrenic space (Fig. The fluid extends around the inferior edge of the liver or laterally from Morison’s pouch along the inferior reflection of the right coronary ligament and then ascends in the flank to the space above the dome Fig. The triangular-dependent recess of Morison’s pouch is opacified by a small amount of contrast medium. This is bounded posteriorly by the kidney (K), medially by the descending duodenum (D), and inferiorly by the proximal transverse colon (C).
To obtain this it is practice purchase forzest with american express erectile dysfunction diabetes medication, the actual number would be calculated from necessary to calculate a confidence interval (see Figs 4 forzest 20 mg overnight delivery erectile dysfunction with normal testosterone levels. The graphs can provide three contains the true value with 95% (or other chosen percent- pieces of information: (1) the number of subjects that need age) certainty forzest 20 mg without a prescription erectile dysfunction treatment on nhs. The range may be broad, indicating uncer- to be studied, given the power of the trial and the difference expected between the two treatments; (2) the tainty, or narrow, indicating (relative) certainty. A wide power of a trial, given the number of subjects included and the difference expected; and (3) the difference that can be 17Altman D G, Gore S M, Gardner M J, Pocock S J 1983 Statistical detected between two groups of subjects of given number, guidelines for contributors to medical journals. It is also necessary to make an estimate of the not; it is a warning against placing much weight on (or con- likely size of the difference between treatments, i. Adequate power is often defined as giving an dence intervals are extremely helpful in interpretation, 80–90% chance of detecting (at 1–5% statistical signifi- particularly of small studies, as they show the degree of un- cance, P ¼ 0. It is rarely worth starting a trial that has less than non-significant results may be especially enlightening. Small numbers of patients inevitably give low precision and low power to detect differences. Types of error In its most rigorous form it demands equivalent groups of patients concurrently treated in different ways or in The above discussion provides us with information on the randomised sequential order in crossover designs. In principle the there is no difference between treatments may either be ac- method has application with any disease and any cepted incorrectly or rejected incorrectly. It may also be applied on any scale; it does not necessarily demand large numbers of patients. Randomisation attempts to con- and 1 indicates its complete acceptance; clearly the level for trol biases of various kinds when assessing the effects of a must be set near to 0. Fundamental to any trial are: investigators will accept a 5% chance that an observed dif- • A hypothesis. The probability of detecting Other factors to consider when designing or critically this error is often given wider limits, e. It is up to the investigators to decide the target difference20 22 • The use of interim analyses. Hodder and 19Altman D G, Gore S M, Gardner M J, Pocock S J 1983 Statistical Stoughton, London. If there is a ‘father’ of the modern scientific guidelines for contributors to medical journals. Differences in trial outcomes fall into three monitoring committee is given access to the results as these are grades: (1) that the doctor will ignore, (2) that will make the doctor accumulated; the committee is empowered to discontinue a trial if the wonder what to do (more research needed), and (3) that will make the results show significant advantage or disadvantage to one or other doctor act, i. Response in relation to the dose of characteristics change over time or there is a change in a new investigational drug may be explored in all phases recruitment policy. Dose–response trials serve a number the treatment groups will be of nearly equal size. The therapeutic efficacy of a novel drug is most out the influence of preconceived hopes of, and uncon- convincingly established by demonstrating superiority to scious communication by, the investigator or observer by placebo, or to an active control treatment, or by demon- keeping him or her (the second ‘blind’ person) ignorant strating a dose–response relationship (as above). At the same time, the technique provides another not necessarily superiority, but either equivalence or non- control, a means of comparison with the magnitude of pla- inferiority. The device is both philosophically and practi- possible advantages of safety, dosing convenience and 24 cally sound. Examples of a possible outcome in a ‘head to head’ compar- The double-blind technique should be used wherever ison of two active treatments appear in Figure 4. In the former, certain pharmacokinetic variables of a new formulation have to fall within specified (and regu- lated) margins of the standard formulation of the same ac- 23Note also patient preference trials. The advantage of this type of trial is that, if to participate in a clinical trial, give consent and are then randomised to a bioequivalence is ‘proven’, then proof of clinical equiva- particulartreatmentgroup. Inspecialcircumstances,randomisationtakes place first, the patients are informed of the treatment to be offered and lence is not required. In a trial of simple mastectomy Design of trials versus lumpectomy with or without radiotherapy for early breast cancer, recruitment was slow because of the disfiguring nature of the Techniques to avoid bias mastectomy option. A policy of pre-randomisation was then adopted, letting women know the group to which they would be allocated The two most important techniques are: should they consent. Recruitment increased sixfold and the trial was completed, providing sound evidence that survival was as long with • Randomisation. Five-year results of a randomised clinical trial comparing total mastectomy and segmental mastectomy with and without Randomisation. Introduces a deliberate element of radiotherapy in the treatment of breast cancer. New England Journal chance into the assignment of treatments to the subjects of Medicine 312:665–673). However, the benefit of enhanced recruitment may be limited by potential for introducing bias. It provides a sound statistical basis for 24 Modell W, Houde R W 1958 Factors influencing clinical evaluation of the evaluation of the evidence relating to treatment effects, drugs; with special reference to the double-blind technique. Journal of and tends to produce treatment groups that have a the American Medical Association 167:2190–2199. This can often be avoided either Blinding should go beyond the observer and the ob- by separating treatments with a ‘wash-out’ period or by served. None of the investigators should be aware of treat- selecting treatment lengths based on a knowledge of the ment allocation, including those who evaluate endpoints, disease and the new medication. The crossover design is assess compliance with the protocol and monitor adverse best suited for chronic stable diseases, e. Breaking the blind (for a single subject) should chronic stable angina pectoris, where the baseline condi- be considered only when the subject’s physician deems tions are attained at the start of each treatment arm. The knowledge of the treatment assignment essential in the pharmacokinetic characteristics of the new medication subject’s best interests. It is not, of course, used with new chemical In the factorial design, two or more treatments are evalu- entities fresh from the animal laboratory, whose dose ated simultaneously through the use of varying combina- and effects in humans are unknown, although the subject tions of the treatments. The simplest example is the may legitimately be kept in ignorance (single blind) of the 2 Â 2 factorial design in which subjects are randomly allo- time of administration. Single-blind techniques have a cated to one of four possible combinations of two treat- place in therapeutics research, but only when the double- ments A and B. These are: A alone, B alone, A þ B, blind procedure is impracticable or unethical. The main uses of the factorial Ophthalmologists are understandably disinclined to re- design are to: fer to the ‘double-blind’ technique; they call it double- masked. Some common design configurations Establish dose–response characteristics of the • Parallel group design combination of A and B when the efficacy of each has been previously established. This is the most common clinical trial design for confirma- tory therapeutic (Phase 3) trials. Subjects are randomised to Multicentre trials one of two or more treatment ‘arms’.
Ten weeks later buy cheapest forzest erectile dysfunction treatment by injection, the patient formed buy forzest online erectile dysfunction doctors in memphis tn, strong consideration should be given to cre- presents with recurrent pelvic abscess and is taken ating a diverting loop ileostomy purchase forzest 20 mg otc erectile dysfunction medications that cause, particularly as the to the operating room for drainage. If ab- biopsy-proven adenocarcinoma involving the lower dominoperineal resection is necessary to achieve pole of the abdominal incision is identified and ex- negative margins, it should be performed. Preoperative chemoradiation for locally ad- vanced rectal cancer: rationale, technique, and results of treatment. Response to preoperative chemoradiation increases the use of sphincter-preserving sur- gery in patients with locally advanced low rectal carcinoma. Improved overall survival among responders to preoperative chemoradiation for locally advanced rectal cancer. Anal sphincter preservation in locally advanced low rectal adenocarcinoma after preoperative chemoradiation therapy and coloanal anastomosis. His chemotherapy regi- men is changed to irinotecan/capecitabine salvage, but the patient continues to experience disease progression. The patient is a 38-year-old man who initially pre- sented 8 years previously with rectal bleeding. He had a strong family history of colon cancer: both his paternal aunt and his paternal uncle had died of colon cancer, and his father had known colonic Case Continued polyps. Colonoscopic evaluation revealed a sessile polyp at Abdominal examination is unremarkable except for 15 cm; biopsies confirmed moderately to poorly dif- a well-healed midline incision, and examination of ferentiated adenocarcinoma. Bone scan further confirms and then returned to his oncologist with a 6- abnormal uptake in the area overlying the sacrum. He 15 cm; pathologic examination reveals moderately denies any history of trauma to the back or lower to poorly differentiated adenocarcinoma. There is no evidence of hepatic metastases spinal stenosis, herniated disc, cauda equina syn- or retroperitoneal/mesenteric adenopathy. Imaging studies to fully assess the extent of local disease and to rule out metastatic disease should be performed prior to sur- gical intervention. Case Continued The patient is treated with a neoadjuvant chemo- therapy regimen (5-fluorouracil, leucovorin, and irinotecan) to induce potential tumor shrinkage. The patient undergoes mechanical and antibiotic bowel preparation and then is taken to the operat- ing room for exploratory laparotomy. Sagittal cuts confirm abnormal signal in the pre- Involvement of the bladder necessitates cystectomy. The patient is then placed in the prone tumor with contiguous abdominal viscera and position. Initial sacral dissection is completed, with mobilization of the margin tissue was positive for malignancy; this was sacrum from the gluteus muscles, sacral laminecto- re-excised to a clear margin 48 hours later, at which my with preservation of the nerve roots, and time the posterior wound was closed with gluteus osteotomy of the sacrum. Division of the sacrum is patient’s previous exposure to the maximal dose of achieved with an oscillating saw. He geon’s finger is positioned anteriorly, protecting the also receives adjuvant chemotherapy consisting of underlying intra-abdominal contents. Initial sacral two cycles of 5-fluorouracil and irinotecan, which margin tissue was positive for malignancy; this was due to toxicities is changed to 5-fluorouracil and re-excised to a clear margin 48 hours later, at which oxaliplatin for four more cycles. Case 36 153 His functional status is excellent, and he returns to thigh tourniquets are inflated, thereby isolating the work without difficulty. Unfortunately, the patient pelvic circulation, and chemotherapeutic agents are again begins experiencing sciatica-like pain radiat- infused in a serial fashion using the extracorporeal ing down his left leg. Isolated pelvic perfusion for unresectable cancer using a balloon occlusion technique. The patient has transfemoral access and vascular isolation, with the received multiple courses of chemotherapy using extracorporeal circuit and standard hemodialysis the best available agents for recurrent or metastatic technology. Using transfemoral access and intraoperative fluoroscopy, balloon Despite improvements in adjuvant therapy regi- occlusion catheters and infusion catheters are insert- mens and the virtually universal adoption of total ed into the inferior vena cava and the aorta. New success with management of recurrent rectal offer no hope of long-term survival. Ann Surg Oncol tion of pelvic recurrence can provide 5-year survival 1999;6:131–132. Isolated pelvic perfu- rates of up to 30%, similar to those seen after resec- sion for unresectable cancer using a balloon occlusion tech- tion of solitary metastases to the lung, liver, or nique. Abdominosacral who experiences locoregional recurrence after the resection of recurrent rectal cancer in the sacrum. Treatment of locally We have found isolated pelvic perfusion to be useful recurrent rectal carcinoma—results and prognostic factors. Int in such cases, offering excellent palliation of pelvic J Radiat Oncol Biol Phys 1998;40:427–435. The most common malignant cause is a rec- tal adenocarcinoma (possibly within a tubulovillous adenoma). More rare causes include benign lym- phoma, lipoma, leiomyoma, fibroma or heman- gioma, and malignancies such as carcinoid, malig- nant lymphoma, and leiomyosarcoma. The initial manage- ment of a rectal polyp is primarily aimed at complete removal of the lesion, obtaining tissue for a histologic diagnosis, and exclusion of other colonic polyps. Case Continued The lesion is biopsied for histologic examination, and further investigations are arranged, including colonoscopy and subsequent transanal resection of the lesion. Histology of the removed lesion reveals a deeply in- vasive (beyond muscularis propria) neuroendocrine tumor or carcinoid, 1. Squamous epithelium at the origin and, unless particularly poorly differentiated, anorectal margin can be visualized in relation to the they contain the typical dense-core secretory gran- distal edge of the resected tumor. Chromogranin A is localized to the secretory gran- ules and is regarded as a powerful universal marker for neuroendocrine tumors. Clinicopathological staging and classification are as follows: (a) benign nonfunctioning tumor of small size ( 2 cm), within the mucosa or submucosa, without angioinvasion; (b) uncertain behavior non- functioning, greater than 2 cm diameter, within the mucosa or submucosa, or angioinvasive tumors; (c) low-grade malignant tumor, well-differentiated en- docrine carcinoma; deeply invasive tumors extend- ing beyond the submucosa, usually functioning; and (d) high-grade malignant poorly differentiated neu- roendocrine carcinoma (i. The incidence of carcinoid tumors of the rectum is on the increase in clinical practice. Rectal carci- noids are diagnosed in relatively young patients, at an average age of 56 years, and have a three fold Figure 37. All biochemical investigations Preoperative imaging and biochemical tests are ob- are normal. The re- ■ Approach excision reveals residual tumor present in the base, Imaging investigations that are important for deter- but also multiple foci of tumor up to and including mining the local extent of the disease and excluding the new resection margins. Transanal resection using a variety of techniques Biochemical tests that should be obtained in- and equipment offers the ability to resect higher le- clude the following. Aggressive sur- Serum chromogranin A is a neuroendocrine gery such as anterior resection carries a higher risk marker that is present in the majority of carcinoid than the metastatic potential of the lesion, whereas tumors irrespective of origin. Serum chromogranin adequate local resections carry a comparatively low 158 Case 37 risk. Other authors have Recommendation reported successful treatment with local or radical surgery, with disease-free survival in several, but not Given the radioinsensitivity of carcinoids, and the all, cases. Assessment of tumors endoscopically and resection of the mesorectum, radiotherapy is not of- by endoanal ultrasound should also guide treatment fered.
If unsuccessful forzest 20 mg for sale erectile dysfunction even with cialis, the larynx can easily be examined with a fexible fbreoptic laryngoscope under local anaesthetic order forzest 20 mg line erectile dysfunction drugs natural. Recurrent laryngeal nerve injury will result in paralysis of the unilateral vocal cord generic 20 mg forzest mastercard erectile dysfunction 4xorigional. Upon observing this, a detailed examination is undertaken to determine the underlying cause. The chest is carefully examined for signs of collapse and effusion, which may be secondary to bronchial carcinoma. There is a benign gastric ulcer on the lesser curvature of the stomach, seen at gastroscopy. In particular, seek anaesthetic/critical care help at any point if you are unable to cope or think you may reach the limits of your competency. Patients who are semiconscious and unable to tolerate an oral airway will not tolerate endotracheal intubation or laryngeal mask insertion without additional sedation and so you must seek additional help to secure the airway. If the patient is apnoeic or has very shallow respiration then ventilation using a bag/valve /mask system is required (Fig. With appropriate training, attempting to insert a laryngeal mask airway Apply a pulse oximeter to allow you to assess can often be simpler, quicker and easier than that oxygen administration is improving the attempting intubation. Once the patient has intubation, you should keep in mind the risk of stabilised, the oxygen concentration can be regurgitation and aspiration of stomach contents decreased to maintain adequate saturations: and apply cricoid pressure prior to laryngoscopy. Remember that Neither technique should be attempted by the pulse oximetry does not indicate hypercapnia. This is sized from the angle of the mandible to the mouth, and inserted upside down and rotated as it is inserted. There is currently no evidence that one technique is superior to the other, and often the chosen technique will depend as much on local practice as patient factors. It is, therefore, important for surgeons to be aware of, prevent and deal with the common complications of tracheostomy. Documentation of the type of tube and size should be in the patient’s notes and this should always be checked where possible. Safer long term Fixed versus adjustable flange Adjustable flange tubes can be used to overcome short-term anatomical problems such as swollen neck but are not suitable for longer term use Fenestrated versus non-fenestrated Fenestrations allow patients to talk with a tracheostomy tube in situ. Not used in ventilated patients Information on tube size should be located on the flange; unfortunately, there is no uniformity of tracheostomy tube size with regard to length and dimensions so this needs to be checked for each type of tube. As a general rule, most adult females can accommodate a tube with an outer diameter of 10 mm, while for most men a tube with an outer diameter of 11 mm is suitable. Selecting appropriate tube size is important to maximise the internal tube dimensions and reduce the work of breathing through the tube. However, an over-sized tube can cause pressure necrosis and damage the tracheal mucosa. A tracheostomy tube that is too small will need over-inflation of the cuff to prevent accidental displacement. A partially • determine when the procedure was performed displaced tracheostomy tube is just as dangerous and what type of tracheostomy the patient as a blocked or completely removed tube. Tubes should not be changed within key factor to determine is if the airway is patent. It will usually be to ensure that the track has formed properly safer to remove a partly dislodged tube. The • on the wards, single lumen tubes are generally patient can be given oxygen via facemask and unfavourable due to the risk of blockage. These should be replaced with a tracheostomy If there are problems once the tracheostomy has with a removable inner tube to facilitate been removed, you should not try to replace it. If the patient can Tracheostomy site bleeding on the ward may cough, expectorate, phonate and protect the occur because of erosion of blood vessels in airway with the cuff deflated, and is maintaining and around the stoma site. Bleeding may settle good oxygen saturations on minimal oxygen with conservative management. However, if it concentrations, the prospects for decannulation results from erosion of a major artery in the root are good. The best time for decannulation is of the neck, the bleeding will be massive and is usually in the morning as the patient has rested a life-threatening emergency. This should be overnight and their condition can be observed managed as follows: during the remainder of the day. Correct any abnormalities and ensure As a general rule, the following steps are necessary: blood for transfusion is available • ensure that the appropriate equipment is • bleeding may be temporarily stemmed by available (Table 3. Acute postoperative atelectasis, respiratory failure sputum retention, pneumonia or depression • be familiar with common methods of of respiration by analgesic, sedative or respiratory support neuromuscular blocking drugs fall into this • understand the basic concepts of mechanical category. Once the patient has PaO2 (kPa) stabilised, the rule is to give the minimum added oxygen to achieve the best oxygenation. Signal recognised if they are: processing produces a display of heart rate • dypnoeic, tachypnoeic or apnoeic and arterial oxygen saturation (SaO2). The patient may be a known keep the SaO2 above 94% and to set the alarms asthmatic, chronic bronchitic or may recently accordingly. The examination should initially be clinical, based on simple ‘Look, Listen and Feel’ techniques The pulse oximeter is fooled by carboxyhaemoglobin described in the assessment chapter and aimed at into giving an erroneously high reading. Other detecting the physiological changes of developing factors that impede accurate pulse oximetry respiratory failure. Over-transfusion, • cardiac arrhythmias conversely, brings the risk of fluid overload and • profound anaemia increased blood viscosity. An elevated white cell • diathermy count may indicate concurrent infection that may • bright lights be pneumonic in origin. You should Chart examination may reveal changes in be familiar with the practical skill of sampling respiratory rate, temperature, pulse rate, blood and the interpretation of these results. A deteriorating trend in any of these the presence or absence of myocardial ischaemia, physiological variables is an essential diagnostic rhythm and rate, abnormalities of which may tool and accurate charting cannot be over be responsible for the onset or worsening of emphasised. For patients with lower radiology department is dangerous and should not oxygen requirements, nasal cannulae may be delay treatment. Radiographic changes often lag used, but remember that oxygen should be behind the clinical changes and it is important to administered to patients to keep their SaO2 treat the patient, not the X-ray. Communicate with nursing staff chest X-rays must follow a systematic approach and ensure that they are aware of the increased as described in Table 4. Important aspects to be considered ability to climb a flight of stairs in one go or to are patient positioning, mobilisation, exercises to conduct everyday tasks also provides valuable encourage deep breathing, suction of respiratory information. If the patient they have for respiratory disease such as inhalers is already on antibiotics, these should be taken and nebulisers. Consider use of nebulised saline before the next dose when antibiotic blood levels to loosen secretions. These give better respiratory disease), prescribe nebulised salbutamol results since they are uncontaminated by upper and ipratropium. Conversely, over-use Frequent assessment of all surgical patients, of opiates leads to narcotisation, and airway and but especially those at high risk, is important.