Postoperative Apnea Research Articles

Prolonged apnea, caused by remifentanil, during awakening from anesthesia for emergency ventriculoperitoneal shunt placement

Respiratory depression may occur after use of most opioid drugs, but only one case of prolonged apnea after intraoperative administration of the ultra-short-acting opioid, remifentanil, has been reported [1]. We present a neurosurgical patient with prolonged postoperative apnea that was probably caused by remifentanil. A 70-year-old man (height 168 cm, weight 50 kg) with a complicated history of multiple neurosurgical and radiation treatments for a parasellar chordoma underwent emergency ventriculoperitoneal shunting for acute hydrocephalus. Two weeks previously, he had undergone tracheostomy under general anesthesia with propofol, sevoflurane, and remifentanil, with no postoperative respiratory depression. The anesthetic protocol used in the instance reported here was the same as the one used previously. Anesthesia was induced with propofol 60 mg, remifentanil 0.3 µg/kg per minute, and rocuronium 30 mg and was maintained with end-tidal sevoflurane concentration 1 vol% and remifentanil 0.05–0.1 µg/kg per minute. No opioids other than remifentanil were administered. The surgery lasted 60 min and was completed without complications, with normal blood pressure and bladder temperature throughout. On awakening from anesthesia, the patient had prolonged apnea that did not respond to sugammadex but was successfully reversed by naloxone. Because of the naloxone-reversible nature of the apnea, absence of any opioids other than remifentanil, and absence of other common factors associated with delayed awakening, it is likely that the respiratory depression was caused by remifentanil. The pharmacogenetic variant suggested by Nelson et al. [1] as a cause of abnormal response to remifentanil could be excluded because there

Postoperative apnea after inguinal hernia repair in formerly premature infants: impacts of gestational age, postconceptional age and comorbidities

PurposeIt is common practice for premature infants undergoing elective inguinal hernia (IH) repair to be hospitalized for postoperative apnea monitoring. This study evaluated the risk of apnea after IH repair with regard to gestational age (GA) and postconceptional age (PCA) in formerly premature infants.MethodsFormerly premature infants who had undergone elective IH repair between 01/2000 and 12/2012 were reviewed retrospectively in terms of GA, PCA, body weight, and comorbidities. All postoperative apneas were evaluated.ResultsA total of 428 formerly premature infant charts were reviewed. Eleven babies had postoperative apnea. Infants younger than 45 weeks PCA were found more prone to develop postoperative apnea after IH repair. In older infants (PCA between 46 and 60 weeks), comorbidities create predisposition to apnea postoperatively. These comorbidities are bronchopulmonary dysplasia, necrotizing enterocolitis and former apnea episodes. Anemia and lower birth weight are also risk factors.ConclusionThis study suggests that low GA and PCA, low birth weight, anemia, and complicated past medical history affect respiratory complication rates, particularly apnea in formerly premature infants undergoing elective IH repair. Severe apneas occurred earlier than mild ones. Overnight monitoring is mandatory in small infants with low GA and PCA. Otherwise healthy, older infants may be operated on outpatient basis.

Laparoscopic inguinal hernia repair in premature neonates: is it safe?

With advances in clinical medicine, many premature babies nowadays can have excellent survival outcomes. As the incidence of inguinal hernias in this group is high and there is scarce data in the literature regarding the optimal timing for repair, this study aims to review our experience in laparoscopic repair in premature infants. In our centre, premature neonates with inguinal hernia noted during hospitalization were offered laparoscopic repair when the body weights reached 2.5kg unless there is contraindication for laparoscopy. A retrospective review was carried out for all premature neonates who underwent laparoscopic inguinal hernia repair from 2001 to 2011. The operative results, complications, incarceration risk and postoperative apnea risk were recorded. A total of 79 premature neonates received laparoscopic inguinal hernia repair during this period. The mean gestational age at birth was 31.9weeks (27-36weeks) and the mean gestational age at operation was 46.5weeks (33-92weeks). One patient had incarceration and required emergency operation while waiting for the elective repair. The mean operative time was 44.9min (25-93min). One patient (1.3%) had recurrence. No postoperative apnea was noted in any patient. Laparoscopic hernia repair is safe and feasible in premature neonates when they attain reasonable body size, as long as there is excellent anaesthesia support. Low risk of incarceration was noted in this study and it is worth waiting for the body weight to build up and hence facilitate laparoscopic repair.

Anaesthetic considerations in a prematurely born infant with congenital hypothyroidism presenting for cataract surgery

Anaesthetic management of the premature infant is a challenge. This is owing to the immaturity of his or her organ systems and the possible presence of sequelae of premature birth, such as bronchopulmonary dysplasia, apnoea, patent ductus arteriosus and intraventricular haemorrhage. The premature infant is at risk of developing postoperative apnoea, hypothermia and hypoglycaemia until his or her postgestational age is more than 60 weeks. Conditions such as congenital bilateral cataract and congenital hypothyroidism may be associated with other birth defects and syndromes. Recommendations for early cataract surgery may necessitate anaesthetising premature infants with postconceptional ages less than 60 weeks, or those who have had recently diagnosed medical conditions, such as hypothyroidism. We describe the anaesthetic considerations in a, so far, unreported scenario of a premature infant with bilateral congenital cataract and congenital hypothyroidism who presented for cataract surgery.

Postoperative Obstructive Sleep Apnea and Delirium?

Postoperative Obstructive Sleep Apnea and Delirium?

Postoperative apnea, respiratory strategies, and pathogenesis mechanisms: a review

Recovery from anesthesia is ideally routine and uneventful. After extubation, the recovering postoperative patient ought to breathe without supportive care or additional oxygenation. It has been demonstrated in previous studies that postoperative pulmonary complications are clinically relevant in terms of mortality, morbidity, and length of hospital stay. Compromised postoperative ventilation can be described as the condition in which the postoperative patient does not have satisfactory spontaneous ventilation support and adequate oxygenation. Causes of impaired ventilation, oxygenation, and airway maintenance can be mechanical, hemodynamic, and pharmacologic. This review describes prevalence and differential diagnosis, including co-morbidities of postoperative apnea. The physiological mechanisms of breathing and prolonged postoperative apnea are also reviewed; these mechanisms include influences from the brainstem, the cerebral cortex, and chemoreceptors in the carotid and aortic body. Causes of prolonged postoperative apnea and management are also discussed.

Repair of duodenal atresia under spinal anesthesia in a low-birth-weight preterm neonate: case report

Duodenal atresia is a well-recognized cause of neonatal bowel obstruction. General anesthesia with tracheal intubation is the traditional anesthetic technique for surgical correction of this condition. Metabolic abnormalities and fluid deficits coupled with residual anesthetics are known to increase the risk of postoperative apnea, prolonging the operating room time and delaying extubation. Spinal anesthesia (SA) is an accepted alternative to general anesthesia in formerly preterm infants. In the current literature, there are reports of successful use of SA for simple infraumbilical surgery and, occasionally, for upper abdominal surgery, but there is no information on the use of SA in neonates for duodenal atresia repair. We present a case of duodenal atresia in a preterm infant at a gestational age of 30 weeks with coexisting bronchopulmonary dysplasia successfully repaired under SA. Further studies that compare the adverse effects with the potential advantages of SA are warranted before future recommendations are made for neonates who are undergoing upper abdominal surgery.

Computer‐assisted quantitative upper airway analysis following modified uvulopalatal flap and lateral pharyngoplasty for obstructive sleep apnoea: a prospective case‐controlled study

The study aims to perform static and dynamic quantitative assessment of the anatomical changes of the upper airway before and after modified uvulopalatal flap and lateral pharyngoplasty and comparison of the improvement in airway dimensions, collapsibility and extent of normalisation to that of control patients. Prospective case-controlled study. Computer-assisted quantitative measurement is used to compare upper airway parameters before and after modified uvulopalatal flap and lateral pharyngoplasty in patients with obstructive sleep apnoea (OSA). Patients with obstructive sleep apnoea diagnosed on sleep study and failed positive airway pressure therapy. Sleep study results, upper airway parameters and symptom score following surgery and its comparison to normal patients to assess the degree and extent of normalisation. Thirty-five study and 32 control subjects were recruited and completed the study. All the retropalatal airway dimensions like area, transverse diameter, longitudinal diameter and collapsibility showed statistically significant improvement following surgery. The success rate of this surgery is 43% (15 of 35) overall, 58% (14 of 24) for patients with isolated palatal obstruction and only 9% (1 of 11) for patients with multi-level obstruction. Comparing obstructive sleep apnoea to the control subjects, there are obvious and logical differences in their biostatistics, sleep study parameters and airway dimensions. The postoperative obstructive sleep apnoea retropalatal longitudinal diameter has a higher tendency of normalising to be comparable to those of control patients. Modified uvulopalatal flap and lateral pharyngoplasty is an effective surgical technique for the treatment of obstructive sleep apnoea. The surgery increases the resting retropalatal dimensions and reduces the retropalatal collapsibility.

Hemodynamic changes during spinal anesthesia in premature infants with congenital heart disease undergoing inguinal hernia correction

There are conflicting reports on the effects of spinal anesthesia (SA) on hemodynamics. Data on the hemodynamic effects of SA in infants with congenital heart disease (CHD) are limited. We reviewed our experience with 44 unsupplemented SA with 1 mg·kg(-1) of either hyperbaric tetracaine or bupivacaine in premature and former premature infants with noncyanotic CHD. Hemodynamics and oxyhemoglobin saturation (SpO(2)) were assessed. Neither preoperative fluid boluses nor atropine was administered to any of the infants. There was no significant change in systolic, diastolic, or mean blood pressures from pre-SA induction compared with end of surgery. Heart rate showed a small but systematic decline (mean change of 10 beats per minute, P < 0.01) but was within the normative range values for age. There was a small, but clinically insignificant increase in SpO(2) across the time course. Intraoperatively, two infants developed transient apneic spells. No infant developed postoperative apnea, oxygen desaturation, or bradycardia. The data suggest that SA with 1 mg·kg(-1) of either hyperbaric tetracaine or bupivacaine can be used safely as the sole anesthetic for inguinal hernia repair in infants with noncyanotic CHD even when fluid restricted and apparently causes minimal respiratory complications in these infants.

Management of Anesthesia for Rubinstein-Taybi syndrome

Management of Anesthesia for Rubinstein-Taybi syndrome

Suspension of the tongue to the digastric tendon following resection of the anterior mandibular arch for oral cancer prevents postoperative tongue fall and avoids the need for tracheostomy

Resection of the anterior arch of the mandible leads to tongue fall and postoperative stridor because of the detachment of tongue musculature from the mandible. In this article, a simple method of tongue suspension is described which would prevent such complications and the need for tracheostomy. This study was carried out on patients with oral cancer requiring resection of the anterior arch of the mandible as a part of the surgical resection at a tertiary centre. This study was performed on 32 patients with oral cancer requiring resection of the anterior arch of the mandible as a part of the surgical resection. Following an appropriate resection of the oral cancer (including the anterior mandibular arch) and neck dissection, a silk suture is used to loop the tongue musculature on either side to the intermediate tendon of the digastric muscle. This technique of tongue suspension was used in 32 patients who required resection of the anterior mandibular arch for oral cancer. Prophylactic tracheostomy was not performed. One patient developed stridor at extubation and required temporary tracheostomy. All other patients could be successfully extubated within 12 h of surgery and none experienced postoperative stridor or sleep apnea. One other patient required temporary tracheostomy for pulmonary toilet as he developed aspiration pneumonitis related to nasogastric feed. This simple method of tongue suspension to the digastric tendon prevents postoperative tongue fall and obviates the need for tracheostomy in most instances.

Spinal anesthesia for noncardiac surgery in infants with congenital heart diseases

To compare hemodynamic parameters in infants with congenital heart disease (CHD) undergoing noncardiac surgery (NCS) under awake spinal anesthesia (SA) with controls without CHD also undergoing SA. NCS poses a twofold higher mortality risk in infants with CHD. SA might be a good alternative to general anesthesia (GA) in this setting. The files of 84 infants were reviewed; 42 had CHD and 42 were controls without CHD. Primary outcome measures were percent decrease in mean arterial pressure (%MAP decrease) and heart rate (%HR decrease)from baseline to the lowest intraoperative value. One-way analysis of variance(ANOVA), ANOVA with repeated measures, Pearson chi-square test, Fisher's exact test, and Pearson correlation were used for statistical analysis.Time to discharge was analyzed with the nonparametric Mann–Whitney U-test. There were no significant between-group differences in %MAP decrease and %HR decrease; no significant associations and correlations between %MAP decrease or %HR decrease and other variables; and no correlation between %MAP decrease and %HR decrease. A %MAP decrease of >20% was documented in 11 patients with CHD (26.2%) and 10 controls (23.8%); a lowest intraoperative HR of <100 b.min)1 was recorded in two study patients (4.8%) and four controls (9.5%) (P = NS for both). There were no cases of high SA or conversion to GA and no need for mechanical ventilation or inotropic support intra/postoperatively. These preliminary findings show that hemodynamic parameters in infants with CHD undergoing NCS under awake SA are not different from controls without CHD and that SA appears to be safe in infants with CHD.

Bloc caudal associé à une anesthésie au masque facial (sévoflurane) chez le nourrisson à haut risque d’apnée : étude observationnelle

Objective In order to reduce the risk of postoperative apnoea, awake spinal anaesthesia or awake caudal anaesthesia are recommended for hernia surgery in newborn babies and former premature infants aged less than 60 weeks of amenorrhoea. However, additional sedation is sometimes necessary. Our working hypothesis was that a general anaesthesia with a face mask (sevoflurane) with no opiates nor neuromuscular blocking agents, maintaining the infant's spontaneous breathing and combined with a caudal anaesthesia, could provide a safe and effective alternative. Study design The epidemiological and technical data about the patient and the anaesthesia, as well as any per- and postoperative complications, were collected prospectively and analysed retrospectively. Patients and methods Ninety-eight infants undergoing hernia surgery were included during the period from 2003 to 2008. Results Caudal anaesthesia proved successful at first attempt in 69% of the infants (term or premature). Three attempts were needed in 8% of the infants born at term and 2% of the infants born prematurely. One failure was recorded. Seven patients presented one episode of peroperative apnoea; they were easily taken care of by means of brief face mask ventilation. The follow-up of these seven infants did not reveal any reappearance of postoperative apnoea/bradypnoea. Conclusion The technique proposed is an effective alternative to the awake locoregional anaesthesia techniques: it provides excellent conditions for surgery and presents similar perioperative morbidity and risk of postoperative apnoea.

Predictive factors of PACU stay after herniorraphy in infant: a classification and regression tree analysis

Herniorraphy is a common surgical intervention in infants, particularly in those born prematurely. Prematurity and perioperative sedation have been shown to be risk factors for postoperative apnea. However, their influence upon PACU stay duration has not been evaluated. The goal of this study was to investigate predictive factors for PACU stay in infants undergoing herniorraphy. This study is a retrospective analysis of perioperative data in infants <6 months of age undergoing herniorraphy during the period November 2007-November 2009. Collected data included age, gestational age at birth, post-conceptional age, weight, weight at birth, type of anesthesia (spinal vs general), perioperative administration of opioids and paracetamol, duration of surgery, duration of PACU stay, and apnea in PACU. Data analysis used classification and regression trees (CART) with a 10-fold cross-validation. Two hundred and ninety-six patients were included in the analysis. Five parameters were found to predict the duration of PACU stay: a post-conceptional age below 45 weeks, prematurity, general anesthesia, postoperative opioid administration, and the use of intraoperative regional analgesia. CRT method allows constructing a decision tree with eight terminal nodes. The percentage of explained variability of the model and the cross-validation were 79.7% and 76.6%, respectively. Our study allows construction of an accurate predictive tree for PACU stay during herniorraphy in infants <6 months. Parameters found to influence the duration of PACU stay were related to anesthesia techniques and perinatal outcomes.

Patterns of Caffeine use in a Neonatal Intensive Care Unit (NICU)

Background: Caffeine is indicated for apnea of prematurity (AOP). Reports of decreased incidence of cerebral palsy and cognitive impairment have increased its use. Recently it is widely used for other neonatal morbidities including in infants with respiratory distress syndrome (RDS) and chronic lung disease (CLD), periextubation and in postoperative apnea. No specific dosing guidelines for indications other than AOP being available.Purpose: Determine the patterns of use of caffeine in a NICU.Methods: Retrospective data on infants admitted between 11/2008 - 6/2010 on caffeine including demographics, caffeine dose, duration, date started, apnea, bradycardia and desaturation events and respiratory support ( mechanical ventilation (MV), CPAP duration or need for oxygen at 36 weeks corrected age ). Use was defined at RDS/CLD prevention for caffeine started before day of life (DOL) 7 (indication 1(IND1)) and AOP prevention/treatment if started after DOL 7 (IND 2).Results: 124 infants. 56 received caffeine for IND1 and 69 for IND2. The gestational age (28+/−2.6 vs. 27+/−2.5 weeks, p=0.03), MV days (14+/−24 vs. 30+/−32, p=0.01) and need for oxygen at 36 weeks (N=48/56 (85%) vs. N=67/69 (97%)) were different for both groups. The loading dose at start of treatment was significantly different for the two groups (17.2+/5.9 vs14.1+/4.9 mg/kg, p=0.0004) while the maintenance doses were similar (5.4+/−0.05 vs. 5.1+/−1.1 mg/kg, p=0.06)Conclusion: Starting caffeine in the first 7 days of life reduced the duration of MV and the need for oxygen at 36 weeks corrected age in this cohort. Loading doses were significantly different for each indication.

Retrospective review of ilioinguinal‐iliohypogastric nerve block with general anesthesia for herniotomy in ex‐premature neonates

We examine the efficacy and complications of general anesthesia with ilioinguinal-iliohypogastric nerve block performed on ex-premature neonates undergoing inguinal herniotomy. The ex-premature neonate has many co-morbidities and is at risk of postoperative apnea and bradycardia. Anesthesia techniques aimed to provide good surgical conditions include general anesthesia and central neuroaxial techniques. There are still significant complications after these techniques and none is superior. A retrospective search of our department's computer database was conducted on ex-premature neonates, post-menstrual age of 48 weeks and under, who received general anesthesia and ilioinguinal-iliohypogastric nerve block for bilateral inguinal herniotomy from 1997 to 2009. Eighty-two neonates were selected. All medical notes were traced and information including the demographics, co-morbidities and perioperative data were obtained. The mean gestational age was 30.3 weeks (sd ± 3.2) and the mean post-conception age was 40.0 weeks (sd ± 3.1). Mean birth weight was 1284 g (sd ± 518) and mean weight at the time of surgery was 2795 g (sd ± 958). Thirty-two (39.0%) neonates had apnea of prematurity, which required caffeine treatment. Thirty-five (42.7%) neonates required intubation for ventilatory support preoperatively. There was a good success rate of the ilioinguinal-iliohypogastric nerve block in 73 (89.0%) patients. They were deemed successful clinically by the attending anesthesiologist. No perioperative rescue opioid was required. Four neonates had postoperative apnea requiring intervention. Ilioinguinal-iliohypogastric nerve block has a success rate similar to other techniques and when combined with general anesthesia, provides a viable alternative technique of anesthesia in these high-risk patients.

The Double-Opposing Buccal Flap Procedure for Palatal Lengthening

Velopharyngeal dysfunction has been treated with either a pharyngeal flap or sphincteroplasty with varying degrees of success. Both of these entities have their own series of problems, with sleep apnea and nasal mucous flow disruptions at the forefront. The purpose of this study was to review the senior author's (R.J.M.) experience performing the double-opposing buccal flap for palatal lengthening. All patients who were treated with double-opposing buccal flaps between October of 1994 and July of 2007 were reviewed. These patients presented with varying degrees of velopharyngeal dysfunction showing some degree of velar movement at the time of surgery. Preoperative and postoperative speech results were reviewed for comparison. Twenty-seven patients underwent palatal lengthening, with an average length of follow-up of 58 months. Distal flap necrosis occurred in two patients. The level of intelligibility (65.4 percent versus 95.5 percent) and resonance (moderately hypernasal versus normal resonance) improved significantly postoperatively (p < 0.0001). Only one patient required the addition of a pharyngeal flap for persistent velopharyngeal dysfunction, and there were no postoperative issues with sleep apnea. The double-opposing buccal flap is an effective technique for lengthening the palate, improving speech, and decreasing the risks of postoperative sleep apnea. All patients experienced a dramatic improvement in their resonance and intelligibility. This technique appears most effective in patients with intact velar movement who demonstrate a small to moderate posterior velar gap. The double-opposing buccal flap is a useful means of treating velopharyngeal dysfunction, thus serving as an adjunct when improving pharyngeal closure.

Statistical model for postoperative apnea–hypopnea index after multilevel surgery for sleep-disordered breathing

The objective of the study was to formulate a statistical model for postoperative apnea-hypopnea index (AHI) 3 and 12 months after multilevel surgery using the predictors preoperative AHI, body mass index (BMI) and age. The study design was a prospective cohort study. Data of 144 patients were collected prospectively 3 and 12 months after multilevel surgery for obstructive sleep apnea syndrome (OSAS) or upper airway resistance syndrome with excessive daytime sleepiness. The primary endpoint postoperative AHI and the secondary endpoint success according to the Sher criteria (postoperative AHI <20 h and >50% reduction of preoperative AHI) were modeled with multiple linear and logistic regression using the predictors preoperative AHI, BMI, age and the indicator whether the patient had undergone a tonsillectomy. Preoperative AHI and tonsillectomy had a highly significant positive influence on postoperative AHI after 3 months, whereas the influence of preoperative BMI was only marginally significant but numerically rather large. Age was not a significant decisive factor. The success according to the Sher criteria was highly significantly determined by the circumstance whether the patient had undergone a tonsillectomy, but not by the other predictors preoperative BMI or age. The responder rate with and without tonsillectomy was 58 and 19%, respectively. The odds ratio to be a responder if a tonsillectomy was conducted was 5.7. This study provides statistical models predicting postoperative AHI and success according to the Sher criteria after multilevel surgery for OSAS.

Day case and short stay surgery: 2

Day case and short stay surgery: 2

Automated Off-Line Respiratory Event Detection for the Study of Postoperative Apnea in Infants

Previously, we presented automated methods for thoraco-abdominal asynchrony estimation and movement artifact detection in respiratory inductance plethysmography (RIP) signals. This paper combines and improves these methods to give a method for the automated, off-line detection of pause, movement artifact, and asynchrony. Simulation studies demonstrated that the new combined method is accurate and robust in the presence of noise. The new procedure was successfully applied to cardiorespiratory signals acquired postoperatively from infants in the recovery room. A comparison of the events detected with the automated method to those visually scored by an expert clinician demonstrated a higher agreement (κ = 0.52) than that amongst several human scorers (κ = 0.31) in a clinical study . The method provides the following advantages: first, it is fully automated; second, it is more efficient than visual scoring; third, the analysis is repeatable and standardized; fourth, it provides greater agreement with an expert scorer compared to the agreement between trained scorers; fifth, it is amenable to online detection; and lastly, it is applicable to uncalibrated RIP signals. Examples of applications include respiratory monitoring of postsurgical patients and sleep studies.