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Perioperative management of morbid obesity.

Using the body mass index (BMI) to assess the risk of health problems, in 2008 20% of men were estimated to be at increased risk, with a further 14% at high risk and 21% at very high risk. Equivalent figures for women were: 15% at increased risk, with a further 17% at high risk and 24% at very high risk (The NHS Information Centre 2010). The number of Finished Admission Episodes in NHS hospitals with a primary diagnosis of obesity was over eight times as high as a decade ago. In addition, the proportion of children aged under 16 classed as overweight or obese has risen to 30% (The NHS Information Centre 2010).

The terms 'overweight' and 'obese' refer to an excess of body fat and they usually relate to increased weight-for-height. The most common method of measuring obesity is the body mass index (BMI). A BMI is calculated by dividing a person's weight measurement (in kilograms) by the square of their height (in metres). Adults are classified into the BMI groups shown in Table 1 (NHS Information Centre 2010).

Two general types of obesity are described. In 'central-android' obesity (more common in men) fat is located in the abdomen and upper body. In 'peripheral-gynaecoid' obesity (more common in women) fat is located primarily in the hips, buttocks and thighs. Central-android obesity is associated with metabolic syndrome and an increased risk of cardiovascular disease.

The link between obesity and morbidity and mortality is well documented and led to the National Institute for Health and Clinical Excellence developing guidelines on identifying and treating obesity (NICE 2006). The health consequences of obesity are known to include a range of negative outcomes, from potentially life-threatening conditions such as diabetes or cardiovascular disease, to nonfatal chronic illness such as osteoarthritis, to physical limitations and poor general health (Zajacova et al 2011, The NHS Information Centre 2010). These conditions include: type 2 diabetes, hypertension, and hyperlipidaemia, which are major risk factors for cardiovascular disease; impaired cardiac ventricular function and cardiovascular related mortality; obesity hypoventilation syndromes, sleep apnoea syndromes; hypercoagulability leading to an increased risk of deep vein thrombosis and pulmonary embolism, and development of certain malignancies (Table 2). As the obesity problem becomes more widespread in the general population, it will become more common for this patient population to seek elective or emergency surgical care. Therefore, perioperative care professionals must be aware of the special considerations involved in treating the obese patient.

Obesity related medical conditions are reversible following surgical weight loss (Table 3). The term 'bariatric surgery' is used to define a group of procedures that can be performed to facilitate weight loss, although these procedures can also be performed for other conditions. It includes stomach stapling, gastric bypasses and sleeve gastrectomy, performed on the stomach and/or intestines to limit the amount of food an individual can consume. Such surgery is used in the treatment of obesity for people with a BMI above 40, or for those with a BMI between 35 and 40 who have health problems such as type 2 diabetes or cardiac disease. The number of bariatric procedures has more than doubled in number in the last two years (The NHS Information Centre 2010). Theatre care professionals involved in the perioperative care of these patients should understand the operations, the surgical procedure, the postoperative physiology, and in particular the surgical complications.

Preoperative assessment

There is disagreement as to whether obesity itself below the level of morbid obesity is an independent risk factor for increased perioperative morbidity and mortality (Arterburn 2009, Smith et al 2010, van Straten et al 2010). Several studies have concluded that, while surgical-site infection is more common in the morbidly obese, mortality rates are similar to those of normal weight patients (Marsk et al 2009, Stamou et al 2011), while other studies have demonstrated that obesity is an independent predictor for late mortality (Arterburn 2009, van Straten et al 2010).

In addition to adding to the complexity of many aspects of care, obesity increases the incidence of the aforementioned comorbidities, which raises perioperative risk. Therefore perioperative care professionals must make thorough evaluations to correctly identify and address medical co-morbidities in obese patients.

Most of the principles of assessment are common to both types of patient. Mechanisms should be in place to identify those obese patients who are at particularly high risk. All patients should have their height and weight recorded and the BMI calculated and recorded. Where possible the height and weight should be measured rather than relying on the patient's estimate.

Severely obese patients are considered at high risk for perioperative complications and often undergo extensive testing for preoperative clearance, including chest Xray examination, pulmonary function tests, noninvasive cardiac testing, and blood work. Patients should be assessed in a multidisciplinary clinic with ready access to imaging, laboratories and specialist services such as cardiology (including echocardiography and stress-testing) and respiratory medicine (including spirometry and arterial blood gas analysis). Advice from a consultant anaesthetist should also be readily available. This approach will minimise the number of hospital visits that the patient requires.

Specific attention should be paid to those comorbidities which place obese patients at higher risk such as cardiac, respiratory and metabolic disease. History taking will be a key element of assessment, but obese patients' exercise level may be severely limited by their weight, presenting condition or both. Investigations of obese patients may be limited by their weight or size. Radiographs may be of poor quality, as may trans-thoracic echocardiography. Some patients may be too big to undergo computed tomography or magnetic resonance imaging.

Morbid obesity is often associated with left ventricular hypertrophy and both systolic and diastolic dysfunction, even in patients without overt cardiovascular disease (Rider et al 2011). The risk of atrial fibrillation increases by 50% in obese patients, and factors associated with the development of coronary artery disease such as hypertension, hyperlipidaemias, diabetes mellitus and metabolic syndrome are also more common (Wang et al 2004).

Patients should be assessed for risk based on physical, planned operation, and functional capacity (Leykin et al 2006). Intermediate or high risk patients undergoing major procedures should undergo further investigation. A reliable indicator for intermediate or high risk is the finding that the patient is unable to perform activities requiring at least four metabolic equivalents; (Seta-blockade may decrease the risk of perioperative cardiac ischaemia, myocardial infarction, or arrhythmia in patients with coronary artery disease. Cardiac medications should be continued up to the day of surgery (ACC/AHA 2008).

A patient's BMI is an important determinant of respiratory function before and during anaesthesia not only in morbidly but also in moderately obese patients (Reinius et al 2009, Talab et al 2009). Problems with respiratory function can manifest as reduced lung volume with increased atelectasis, derangements in respiratory system, lung and chest wall compliance and increased resistance, and moderate to severe hypoxaemia (Mertens 2006). The altered respiratory system mechanics in obese patients result in decreased lung volumes. This is related to decreased chest wall compliance from an elastic load on the chest and abdomen as well as decreased lung compliance resulting from the closure of dependent airways (Mertens 2006, Reinius et al 2009, Talab et al 2009,). Because of these abnormalities, a greater negative pleural pressure is needed to initiate airflow.

Obese patients may also have reduced respiratory muscle strength. Respiratory system resistance is increased as a result of smaller airway caliber associated with decreased lung volumes (Reinius et al 2009, Talab et al 2009). The resistance in the larger airways is typically normal. Some people with obesity may be hypoxemic, resulting from ventilation-perfusion mismatching, especially in the poorly expanded lung bases (Mertens 2006). Most obese patients, however, remain normocapnic.

Sleep-disordered breathing, including obstructive sleep apnea (OSA) and alveolar hypoventilation, is extremely common among obese people and can contribute to the development of pulmonary hypertension and cor pulmonale. Morbidly obese patients are at increased risk for developing overt respiratory failure. The prevalence of obstructive sleep apnoea is higher in obese patients; up to 71% of morbidly obese patients undergoing work-up for bariatric surgery have obstructive sleep apnoea (Pannain & Mokhlesi 2010). This condition is associated with sudden death during sleep resulting from myocardial infarction or arrhythmia (Gottlieb et al 2010). Characteristics of obstructive sleep apnoea include apneic periods during sleep, daytime somnolence, loud snoring, morning headaches, and frequent nocturnal awakening. Sleep polysymnography confirms the diagnosis and demonstrates cessation of airflow during sleep associated with persistent respiratory efforts.

Preoperative initiation and perioperative use of continuous positive airway pressure (CPAP) can reduce hypercarbia, hypoxemia, and pulmonary artery vasoconstriction and should decrease the incidence of hypoxemic complications. Exertional dyspnoea or syncope can indicate pulmonary hypertension. ECG findings include right axis deviation, and an echocardiogram can determine pulmonary vascular resistance (Hsuan et al 2010).

Obese patients are at significantly greater risk of venous and pulmonary thromboembolism (Freeman et al 2010a). The relationship between deep vein thrombosis (DVT) and obesity stems from the increased intra-abdominal pressure and venous stasis most pronounced with central obesity. Both of these effects are accentuated by intraoperative factors, such as pneumoperitoneum and anaesthesia induced paralysis. Obesity is also associated with a hypercoagulable state through increased findings of fibrinogen, factor VIII and von Willebrand factor (Freeman et al 2010a). Procedures associated with prolonged immobility, such as those related to lower extremity orthopaedic cases, amplify this risk.

The increased risk of perioperative thromboembolic events in obese patients has been demonstrated in the bariatric surgery literature, which states that the estimated incidence of DVT and pulmonary embolism in patients receiving perioperative prophylaxis ranges from 0.2% to 2.4% (Freeman et al 2010a, Craft & Reed 2010). Severe venous stasis disease is associated with significantly greater weight and there is a demonstrated association between the presence of stasis changes and pulmonary embolism (Sugarman et al 2001). Prophylactic inferior vena cava filter placement should be considered in patients with such risk factors but filters, if placed, should be removed once the risk of venous thromboembolism has passed (Vaziri et al 2010).

All obese patients must be considered for mechanical and pharmacological thromboprophylaxis (Stein & Goldman 2009). Unfractionated or low molecular weight heparin should be administered prior to surgery and continued throughout hospitalisation until normal mobilisation (Stein & Goldman 2009, Freeman et al 2010a, Craft & Reed 2010,). The correct dose of low molecular weight heparin has not been established in obese patients (Nutescu et al 2009). Thromboprophylaxis must also be coordinated with any regional anaesthetic techniques that may be being considered. After the operation, continued short term patient anticoagulation may be necessary for these high risk patients (Stein & Goldman 2009, Freeman et al 2010a, Craft & Reed 2010).

Diabetes mellitus is common in obese patients, and is an independent risk factor for postoperative morbidity. Strict glycaemic control has been shown to reduce morbidity and mortality in cardiothoracic and vascular surgery patients (Gandhi et al 2007, Subramaniam et al 2009). Therefore, care must be taken to ensure that serum glucose is at the appropriate level before proceeding with the intended surgery. Evidence of gastro-oesophageal reflux should be sought at the preoperative visit, with a low threshold for prescribing antisecretory therapy (Anand & Katz 2010).

Obesity is an independent risk factor for surgical site or wound infections (Freeman et al 2010b). Potential aetiologies include decreased oxygen tension, immune impairment, and tension and secondary ischaemia along wound suture lines (Freeman et al 2010b, Moulin et al 2009). Chronic skin infections, such as intertriginous Candida albicans, should be treated pre-operatively, and pre-operative antibiotics should be administered as appropriate for the surgical procedure classification. Minimally invasive techniques offer a significant advantage in reducing surgical site infection and should be considered when appropriate (Balentine et al 2010).

Interventions that can reduce risk may be suggested by a pre-assessment. These would include weight loss, exercise training and the treatment of obstructive sleep apnoea. Finally, bariatric surgery itself plays a role in improving the medical condition of morbidly obese patients and enhancing the results of a future planned procedure, such as lower limb joint replacement (Kulkarni et al 2011). Satisfactory weight reduction may remove the need for elective orthopaedic surgery because symptoms, such as those associated with degenerative joint disease, often improve dramatically with weight loss (Howarth et al 2010). If at all possible, preoperative sedative medications should be kept to a minimum to facilitate patient transfer from the stretcher to the operating theatre bed.

Intraoperative management

The operating room table must be able to accommodate the obese patient. Specialised hospital beds (e.g. Volker bed model S 962-2W, Witten, Germany) should be available that can accommodate weight of up to 250kg (Figure 1). This equipment enables the patient to be raised to a standing position without the need for manual handling and therefore also functions as a chair and a transport vehicle. Certain operating room tables, such as the Maquet Alphamaxx 3.2 surgical table (MAQUET GmbH & Co. KG, Rastatt, Germany) with its modular concept and width and length extenders can accommodate patients of up to 450kg (Figure 2). Some procedures can be performed on the patient's hospital bed in order to reduce manual handling (Figure 1). Units with maternity facilities may wish to consider a maternity bed that is wider and may accommodate greater weight limits.

Additional care must be taken to ensure that limbs of obese patients are secured and that no metal is touching the skin. Width extensions are available on some operating tables to ensure that parts of the body are not overhanging the edges of the table. Obese patients are at risk of slipping off the table during position changes and therefore must be well secured to the table (Vallejo 2007). Patients are often placed in a semi-recumbent posture with leg supports, a buttock support pad to prevent slipping down or off the table and with a head up posture. A bean bag may be used to assist in preventing shifting, especially during position changes. When in the room, the patient is assisted with moving to the bed, which has specialised hydraulics and padding to accommodate a patient with morbid obesity.

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Adequate manpower is essential during transfers from bed to operating table and during position changes, and weightappropriate manual handling equipment (hoists, prone turners and patient lateral transfer equipment) must be available. Lifting and handling courses should be available locally and should cover how to handle morbidly obese patients. Placing the patient in the lateral or prone position may lead to additional difficulties and should only be undertaken for good reason.

Pressure areas must be pre-assessed using a suitable tool and all potential pressure points should be well padded, with pressure reducing mattresses, gel pads etc. Extended extremities on limb boards should have padding under bony prominences, and the extremities should be secured with cotton cast padding and hook and loop fastening straps. Sequential compression devices should be placed on the patient's lower legs and a pillow under the patient's knees to reduce back strain. The patient's legs should be securely wrapped with a soft blanket to support the legs in a comfortable position of thigh adduction with physiological external rotation and to avoid pressure on the lateral aspect of the lower leg and feet. Temperature-regulating blankets should be used to maintain the patient's body temperature. At least two sets of safety straps, one across the patient's lower legs and the other across his or her thighs should be used.

Rhabdomyolysis has been increasingly recognised as a potentially fatal complication of bariatric surgery (de Oliveira 2009). Rhabdomyolysis in gluteal muscles leading to renal failure and death has been described in morbidly obese patients (de Oliveira 2009). Nerve injuries are also more common in obese patients (Ogunnaike et al 2002). Sequential compression devices should also be used in combination with subcutaneous heparin for DVT prophylaxis, especially in the setting of laparoscopic access where intra-abdominal pressure decreases venous return from the lower extremities.

Invasive arterial monitoring should be used for severely obese patients, including super obese patients with a BMI greater than or equal to 60. Invasive arterial monitoring is also important for patients with significant cardiopulmonary disease, and in cases where non-invasive blood pressure monitoring devices are unreliable (ACC/AHA 2008, Pickering 2005). Blood pressure cuffs should span a minimum of 75% of the patient's arm circumference. The ankle or the wrist may be used as alternative sites for blood pressure measurements (Pickering et al 2005). Establishing peripheral intravenous access can be difficult in obese patients. Central venous access should be used in cases where peripheral access cannot be obtained or when postoperative access may be difficult (ACC/AHA 2008).

The choice of anesthetic technique should facilitate rapid recovery and minimal postoperative symptoms to allow an early return to normal function. The use of regional anaesthesia in the morbidly obese patient and avoidance of general anaesthesia is a tempting prospect. However, attempts at successfully achieving this may be doomed to failure due to the size of the patient. Good preoperative assessment is essential and in particular having an exit strategy, which may be giving a general anaesthetic or may involve abandoning the operation altogether, should be discussed with the patient. Appropriate resuscitation and regional anaesthesia equipment, including longer regional block needles should be available (Gross et al 2006).

The most important thing for a successful regional anaesthetic block in the obese patient is an experienced anaesthetist. For suitable operations such as surgery on the lower limbs, spinal anaesthesia may be a good option. Often the midline of the back can be easily identified by sitting these patients up, and placement of the spinal needle can be relatively easy. This technique can be successfully used where appropriate in the day case setting, particularly with a low dose technique. However, the potential difficulties should not be underestimated and the possibility of aorto-caval compression must be borne in mind. Peripheral blocks can be much more challenging. The main difficulties are access and palpation of recognisable landmarks.

Preoxygenation is mandatory in morbidly obese patients and should be followed by actions to counteract atelectasis formation. Pre-oxygenation should be performed in a reversed 45[degrees] or 30[degrees] Trendelenberg position as this prolongs the time to desaturation during apnoea and may aid in the prevention of gastroesophageal reflux and, thus, aspiration by alleviating increased intra-abdominal pressure (Boyce et al 2003, Altermatt et al 2005, Dixon et al 2005). A padded footboard at the foot of the theatre table will prevent the patient from slipping when the table is placed in reverse Trendelenburg's position.

Endotracheal intubation and airway management in the obese patient can be challenging. It is more difficult to keep open airways in obese patients (Boyce et al 2003, Collins et al 2004). A large neck circumference appears to be one of the best predictors of a problematic intubation (Brodsky 2002). Consideration should be give to modifying the traditional 'sniffing the morning air' intubation position to the 'ramped' position (Collins et al 2004). Positioning with the head, neck and shoulders elevated in the head elevated laryngoscopy position ('HELP') facilitates direct laryngoscopy. Towels or a shoulder roll can be used to extend the neck (Boyce et al 2003). Other adjuncts include awake flexible fibreoptic intubation and the use of the Bullard laryngoscope (ACMI, Southborough, MA, USA) (Aikins et al 2010).

Some patients may require awake intubation; appropriate skills and equipment must be immediately available. The decision as to whether to use a rapid sequence induction, an awake intubation or a standard induction with hypnotics should depend on the thorough airway examination and assessment of comorbidity, and should not be based solely on whether morbid obesity is present or not. It is important to ensure sufficient depth of anaesthesia before initiating manipulation of the airway because inadequate anaesthesia depth predisposes to aspiration if airway management becomes difficult. The intubating laryngeal mask airway is more efficient in morbidly obese patients than in lean patients and serves as a rescue device for both failed ventilation and failed intubation. The negative effect of chest wall and abdominal adipose tissue on lung compliance, functional residual capacity, and blood oxygenation is exacerbated by position changes from upright to supine and further worsened with initiation of general anesthesia and mechanical ventilation.

Obesity may be associated with an increased risk of intraoperative awareness during general anaesthesia. Once absorbed into the circulation by the lungs, the uptake of volatile anaesthetic by various body tissues is influenced by tissue blood flow and body mass. Although blood flow to adipose tissue is only a small percentage of cardiac output, the capacity of fat for absorbing volatile anaesthetics is substantial, particularly with lipid-soluble anaesthetic agents in patients with increased stores of adipose tissue. This capacity for absorption of volatile anaesthetic may contribute to a delay in reaching equilibrium between anaesthetic uptake by the lungs and delivery to the brain (Eger & Saidman 2005). The use of less soluble volatile anesthetics (e.g. sevoflurane) allows faster times to steady state and reduces the influence of adipose volume (Domino et al 1999). Patients anticipating bariatric surgery can be reassured that the risk of intraoperative awareness associated with bariatric procedures is not increased above the recognised baseline risk of 0.4% for all patients undergoing general anesthesia (Sebel et al 2004).

Highly lipophilic medications, such as benzodiazepines and barbiturates, must be administered in higher doses to account for increases in volume of distribution (VD) compared with patients of normal weight. Doses should also be calculated according to total body weight (Blouin & Warren 1999).

Ventilator strategies include tidal volumes of 10 to 12ml/kg for limiting volutrauma, respiratory rates up to 14 breaths/minute for maintaining normocapnia, and positive end-expiratory pressure of 5 to 10cm H2O for improving oxygenation. Recruitment manoeuver combined with 10cm H2O of positive end-expiratory pressure (PEEP) has been shown to improve end-expiratory lung volume, respiratory mechanics, and oxygenation during pneumoperitoneum more than PEEP alone (Talab 2009, Futier et al 2010). Surgical access to the airway is technically more difficult and is associated with an increased risk of perioperative complications in the obese patients.

Intraoperative mild hypothermia, common during open and laparoscopic bariatric procedures, improved with active warming in at least one study (Nguyen et al 2001). Intraoperative euvolemia and normothermia may aid in physiological homeostasis and adequate organ perfusion. Perioperative intravenous fluid therapy influences cardiac and pulmonary function postoperatively, but no evidence-based studies have detailed the most prudent method for fluid replacement in obese patients undergoing surgery. Perioperatively, blood pressure (BP) assessment may be challenging because of the patient's body habitus and the inability to correctly position a noninvasive BP cuff on a conically shaped arm. Accurate assessment of volume status may be difficult, and a Foley catheter should be placed at the onset of major procedures. Establishing a pneumoperitoneum increases systemic vascular resistance, decreases cardiac index, and transiently increases mean arterial pressure. Laparoscopy can confound the issue of volume status as pneumoperitoneum itself can decrease renal blood flow and decrease urine output; hypovolaemia accentuates these effects.

Postoperative management

Obese patients require close postoperative observation. Patients may be admitted to a high dependency or intensive care unit if they experience shortness of breath, need continuous positive airway pressure for obstructive sleep apnoea, or have significant co-morbidities such as significant cardiopulmonary disease, which require continual observation and care. All patients receive antibiotic coverage if necessary, respiratory support (eg, nebulizer, incentive spirometry), analgesia, and sequential compression stockings and low-molecular weight heparin to minimise deep vein thrombosis.

Obese patients undergoing thoracic or abdominal procedures are at major risk of pulmonary complications. Atelectasis has been reported in up to 45% of obese patients following upper abdominal surgery and may be worsened by the effects of pneumoperitoneum (Talab et al 2009, Reinius et al 2009). Conversely, laparoscopic access has been associated with decreased post-operative pain and a reduction in pulmonary dysfunction (Nguyen et al 2001). Post-operative ambulation and the use of incentive spirometry should be started as soon as possible. Methods including continuous positive airway pressure or bilevel positive airways pressure can reduce pulmonary dysfunction.

Adequate analgesia is crucial in allowing early ambulation and restoring the best possible pulmonary function. The avoidance of opioid medication avoids many potential difficulties. Potential benefits of non-opiod analgesia include decreased sedation and a faster return of gastro-intestinal function. Pharmacodynamic and kinetic data guiding dosing in severely obese patients are frequently not available for many peri- and post-operatively administered medications. Assessment of serum concentrations is a more reliable method of monitoring dosing than empirical dosing based on previously published nomograms (King & Velmahos 2010).

A recent study shows that use of actual body weight for dosing fentanyl overestimates requirements in obese patients (Shibutani et al 2004). Two recent randomised controlled trials of neuromuscular blockers show prolonged action of cisatracurium in morbidly obese patients when dosed according to total body weight (Leykin et al 2004a) and significantly prolonged duration of action of rocuronium when dosed according to total body weight (Leykin et al 2004b). Most commonly used strategies employ either patient-controlled intravenous analgesia or thoracic epidural analgesia. Uncertainty remains as to the superiority of one pain treatment modality versus another. Local anaesthesia, including regional techniques, may be particularly suitable for some obese patients. The higher failure rate of local techniques in this group of patients does not preclude their use (Ingrande et al 2009). Improved efficacy and safety have been shown when PCA management includes adjunct analgesics such as nonsteroidal anti-inflammatory medications and local anesthetic wound infiltration in a multimodal approach (Meyer 2002, Ballantyne & Carwood 2004, Sanchez et al 2004).

Health care professionals play an important role in the pre-, peri- and post-operative management of the obese patient. The importance of early ambulation after surgery in order to decrease the risk pulmonary dysfunction, deep venous thrombosis, pulmonary embolism and the formation of pressure ulcers cannot be overemphasised and techniques which delay ambulation should be avoided if possible. In addition, early ambulation should increase the return of gastro-intestinal function. Healthcare professionals must be vigilant with regard to pressure ulcers and carefully inspect the skin over potential pressure points at regular intervals. Oscillating beds should be used for patients who cannot shift their own weight, and bariatric beds that can convert into sitting positions are useful.

Healthcare professionals should be prepared to care for obese patients. The Association of Anaesthetists of Great Britain and Ireland (2007) has developed recommendations to foster high quality perioperative care for obese patients undergoing surgery. The publication describes the staff training, risk reduction strategies and special equipment and protocols to manage morbidly obese patients. In addition to aforementioned beds and transport devices, doorways and bathrooms should be large enough to accommodate morbidly obese patients. Radiologic equipment, such as CT and MRI scanners and interventional radiology, should be capable of supporting the morbidly obese.

Conclusion

For obese patients to experience the potential health benefits of surgery, risks imposed by their obesity and the planned operation must be managed carefully. Careful multidisciplinary care in the pre-, peri- and post-operative phases should ensure the effective and safe treatment of the obese patient undergoing surgery (Table 4). Theatre care professionals must be familiar with all aspects of the perioperative management of obese patients and must anticipate certain issues and complications in order to minimise the risk of morbidity and mortality during the patient's hospital stay.

Provenance and Peer review: Unsolicited contribution; Peer reviewed; Accepted for publication April 2011.

No competing interests declared

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Correspondence address: Sammy Al-Benna, St Bartholomew's Hospital, West Smithfield, London, EC1A 7BE.

Email: sammyalbenna@doctors.org.uk

About the author

Sammy Al-Benna MB, ChB, PhD, PGCNano, MRCS

Plastic Surgeon, St Bartholomew's Hospital, London
Table 1 Classification of adults according to BMI
values (NHS Information Centre 2010)

BMI range (kg/m2)      Definition

Under 18.5             Underweight
18.5 to less than 25   Normal
25 to less than 30     Overweight
30 to less than 40     Obese
40 and over            Morbidly obese
25 and over            Overweight including obese

Table 2 Co-morbidities of obesity

Cardiovascular

Atherosclerotic disease
Congestive heart failure
Hypertension
Varicose veins
Venous insufficiency and stasis

Pulmonary

Asthma
Obesity hypoventilation syndrome
Pulmonary hypertension
Sleep apnea

Endocrine/metabolic

Diabetes mellitus
Glomerulosclerosis and renal failure
Gout
Hyperlipidemia

Gastrointestinal

Abdominal wall hernia
Fatty liver
Gallbladder disease
Gastroesophageal reflux disease
Irritable bowel syndrome

Genitourinary disease

Dysmenorrhea
Hirsuitism
Infertility
Polycystic ovarian disease
Urinary stress incontinence

Malignancies

Breast cancer
Colorectal cancer
Endometrial cancer
Gallbladder cancer
Ovarian cancer
Pancreatic cancer
Prostate cancer
Uterine cancer

Musculoskeletal

Bone demineralization
Carpel tunnel syndrome
Low back pain
Osteoarthritis

Neuropsychiatric

Depression
Idiopathic intracranial hypertension
Stroke

Ophthalmologic

Cataracts
Glaucoma

Table 3 Relative risk factors for obese people of
developing selected diseases, by gender.

                        Men   Women

Type 2 diabetes         5.2   12.7
Hypertension            2.6    4.2
Myocardial infarction   1.5    3.2
Colo-rectal carcinoma   3.0    2.7
Angina                  1.8    1.8
Gall bladder diseases   1.8    1.8
Ovarian carcinoma       N/A    1.7
Osteoarthritis          1.9    1.4
Stroke                  1.3    1.3

Table 4 Recommendations for hospitals performing surgery on morbidly
obese patients.

Staffing

1. Specialist surgical team including surgeons, anaesthesists,
theatre care professionals, recovery care professionals and nurses

2. Recovery care professionals experienced in difficult ventilatory
and respirator support

3. Nurses experienced in respiratory care, management of nasogastric
and abdominal wall drainage tubes, and ambulation of morbidly obese
patient; knowledge of common perioperative complications and ability
to recognize cardiovascular, respiratory, renal, endocrine/metabolic
and gastrointestinal problems.

4. Availability of specialists in cardiology, respiratory, renal,
endocrine/metabolic, and gastrointestinal fields.

Operating Room

1. Special operating room tables and equipment to accommodate morbidly
obese patients

2. Retractors suitable for bariatric surgical procedures

3. Specifically designed stapling instruments

4. Appropriately long surgical instruments

5. Other special supplies unique to the procedure

Hospital Facilities

1. Recovery room capable of providing intensive/high dependency care
to morbidly obese patients

2. Available intensive care unit with similar capabilities

3. Hospital beds, commodes, chairs, and wheelchairs to accommodate
the morbidly obese.

4. Radiology and other diagnostic equipment capable of handling
morbidly obese patients

5. Long-term follow-up care facilities including rehabilitation
facilities, psychiatric care, nutritional counseling, and support
groups
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Article Details
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Title Annotation:CLINICAL FEATURE
Author:Benna, Sammy Al-
Publication:Journal of Perioperative Practice
Article Type:Report
Geographic Code:4EUUK
Date:Jul 1, 2011
Words:6554
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