OBESITY IN ANAESTHESIA, PRE- AND POSTOPERATIVE CARE
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Source: OECD Obesity is a widespread problem these days, as the Western lifestyle paired with a lack of exercise have led to a steep increase in obesity rates around the world. To anaesthesia care providers, obese patients impose a challenge as they require different approaches compared to lean patients. APPROACHES TO PRE-OXYGENATION AND INDUCTION IN OBESE PATIENTS Number of overweight and obese people worldwide China France United States Australia United Kingdom Germany 2013 1980 2,100 million 857 million Apart from their mass, which makes obese patients more difficult to handle in the preparation for surgery, they also require special care during the entire anaesthesia process. Standard anaesthesia induction typically includes a brief period of pre-oxygenation to ensure sufficient oxygen levels during the intubation process. Bearing in mind the challenges obesity imposes on surgical patients, the following may be consi- dered during pre-oxygenation and induction of general anaesthesia for obese patients. OBESE PATIENTS DURING RECOVERY AND IN THE POSTOPERATIVE PHASE The effects of obesity that can cause problems in the preoperative phase persist during recovery and postoperative care, where obese patients face a higher risk of respiratory complications. During that phase, obese patients… Possible countermeasures are similar to those in the pre-oxygenation and induction phase. They include: Obese patients not only require adapted approaches during pre-oxygenation, induction and maintenance of general anaesthesia. Modified respiratory care techniques in the immediate postoperative period have also been shown to be important in preventing postoperative pulmonary complications. Source: Dräger WHY OBESE PATIENTS POSE A CHALLENGE OBESITY IN ANAESTHESIA, PRE- AND POSTOPERATIVE CARE 2000 2013 21% 20% 31% 20% 9% 25% 24% 35% 28% 15% 7% Keeping the patient in an elevated position Continuous positive airway pressure (CPAP) Non-invasive ventilation Reduces abdominal pressure and the weight imposed by the chest wall -> improves lung volumes and extends the period of apnoea without desaturation. Prevents atelectasis formation, reinflates collapsed areas of the lung. Reduces the load of breathing, provides a longer tolerance of apnoea before desaturation. May complicate tracheal intubation and increase the risk of hypotension. High oxygen concentrations may produce resorption atelectasis. Experts recommend using high oxygen concentrations during pre-oxygenation of obese patients to increase margin of safety before intubation. Perform a lung-recruitment manoeuvre following endotracheal intubation and utilize optimal PEEP during subsequent mechanical ventilation. Elevate the patient's head and trunk. Apply positive airway pressure during pre-oxygenation. Consider the fraction of inspired oxygen during pre-oxygenation and induction. Difficult mask ventilation/intubation Let the patient breathe normally for 3-5 minutes or let him take 5-8 deep breaths Use a high inspiratory oxygen concentration of 100% to fill the lung with oxygen Administer anaesthetic drugs and manually ventilate the patient Intubate the patient, check etCO 2 and auscultate to ensure bilateral ventilation and absence of gastric insufflation Switch to controlled ventilation Anaesthesia care providers need to anticipate difficulties in mask ventilation and intubation of obese patients. While difficult mask ventilation occurs in nearly 5 percent of all patients undergoing surgery with anaesthesia, difficult intubations are particularly prevalent among obese patients. Obese patients Lean patients 15.5 % 2.2 % The risk of serious complications in airway management is reported to be four times higher for obese patients than it is for lean patients. Prevalence of obesity among adults in selected countries pre-oxygenation and induction Gently lay the mask on the patient's face Frequently-used approach to As a result, oxygen levels drop much faster during the apnoea phase of intubation than they do in non-obese patients. The time of apnoea before the patient suffers clinically relevant arterial oxygen desaturation is significantly shorter. ... an increase of anaesthesia induced atelectasis ... a ventilation/ perfusion mismatch ... increased oxygen consumption ... reduced lung volumes ... increased work of breathing Fast desaturation/more atelectasis Obesity results in … Rate of difficult intubations Measure Upsides Possible downsides 1 2 3 4 ... are more likely to develop acute respiratory failure ... have higher rates of pneumonia ... develop more atelectasis after extubation This approach may not work for obese patients though, as their anatomy and physiology puts them at a higher risk of developing hypoxemia during anaesthesia induction. 1 2 3 4 5 6 !!!! ! O2
Transcript of OBESITY IN ANAESTHESIA, PRE- AND POSTOPERATIVE CARE
Source: OECD
Obesity is a widespread problem these days, as the Western lifestyle paired with a lack of exercise have led to a steep increase in obesity rates around the world. To anaesthesia care providers, obese patients impose a challenge as they require different approaches compared to lean patients.
APPROACHES TO PRE-OXYGENATION AND INDUCTION IN OBESE PATIENTS
Number of overweight and obese people worldwide
ChinaFranceUnitedStates
Australia UnitedKingdom
Germany
20131980 2,100 million857 million
Apart from their mass, which makes obese patients more difficult to handle in the preparation for surgery, they also require special care during the entire anaesthesia process. Standard anaesthesia induction typically includes a brief period of pre-oxygenation to ensure sufficient oxygen levels during the intubation process.
Bearing in mind the challenges obesity imposes on surgical patients, the following may be consi-dered during pre-oxygenation and induction of general anaesthesia for obese patients.
OBESE PATIENTS DURING RECOVERY AND IN THE POSTOPERATIVE PHASEThe effects of obesity that can cause problems in the preoperative phase persist during recovery and postoperative care, where obese patients face a higher risk of respiratory complications.
During that phase, obese patients… Possible countermeasures are similar to those in the pre-oxygenation and induction phase. They include:
Obese patients not only require adapted approaches during pre-oxygenation, induction and maintenance of general anaesthesia. Modified respiratory care techniques in the immediate postoperative period have also been shown to be important in preventing postoperative pulmonary complications.
Source: Dräger
WHY OBESE PATIENTS POSE A CHALLENGE
OBESITY IN ANAESTHESIA, PRE- AND POSTOPERATIVE CARE
2000 2013
21% 20%
31%
20%
9%
25% 24%
35%
28%
15%
7%
Keeping the patient in an elevated position
Continuous positive airway pressure (CPAP)
Non-invasive ventilation
Reduces abdominal pressure and the weight imposed by the chest wall -> improves lung volumes and extends the period of apnoea without desaturation.
Prevents atelectasis formation, reinflates collapsed areas of the lung.
Reduces the load of breathing, provides a longer tolerance of apnoea before desaturation.
May complicate tracheal intubation and increase the risk of hypotension.
High oxygen concentrations may produce resorption atelectasis.
Experts recommend using high oxygen concentrations during pre-oxygenation of obese patients to increase margin of safety before intubation.
Perform a lung-recruitment manoeuvre following endotracheal intubation and utilize optimal PEEP during subsequent mechanical ventilation.
Elevate the patient's head and trunk.
Apply positive airway pressure during pre-oxygenation.
Consider the fraction of inspired oxygen during pre-oxygenation and induction.
Difficult mask ventilation/ intubation
Let the patient breathe normally for 3-5 minutes or let him take 5-8 deep breaths
Use a high inspiratory oxygen concentration of 100% to fill the lung with oxygen
Administer anaesthetic drugs and manually ventilate the patient
Intubate the patient, check etCO2 and auscultate to ensure bilateral ventilation and absence of gastric insufflation
Switch to controlled ventilation
Anaesthesia care providers need to anticipate difficulties in mask ventilation and intubation of obese patients. While difficult mask ventilation occurs in nearly 5 percent of all patients undergoing surgery with anaesthesia, difficult intubations are particularly prevalent among obese patients.
Obese patients Lean patients
15.5 % 2.2 %
The risk of serious complications in airway management is reported to be four times higher for obese patients than it is for lean patients.
Prevalence of obesity among adults in selected countries
pre-oxygenation and induction
Gently lay the mask on the patient's face
Frequently-used approach to
As a result, oxygen levels drop much faster during the apnoea phase of intubation than they do in non-obese patients. The time of apnoea before the patient suffers clinically relevant arterial oxygen desaturation is significantly shorter.
... an increase of anaesthesia
induced atelectasis
... a ventilation/perfusion mismatch
... increased oxygen
consumption
... reduced lung volumes
... increased work of breathing
Fast desaturation/more atelectasisObesity results in …
Rate of difficult intubations
Measure Upsides Possible downsides
1
2
3
4
... are more likely to develop acute respiratory failure
... have higher rates of pneumonia
... develop more atelectasis after extubation
This approach may not work for obese patients though, as their anatomy and physiology puts them at a higher risk of developing hypoxemia during anaesthesia induction.
1
2
3
4
5
6
!!!!
!
O2
