• Users Online: 755
  • Home
  • Print this page
  • Email this page
Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contacts Login 

 Table of Contents  
Year : 2019  |  Volume : 6  |  Issue : 3  |  Page : 377-378

Respiratory arrest after spinal anaesthesia: a conundrum for anesthesiologists

Pandit Bhagwat Dayal Sharma Post Graduate Institute of Medical Sciences Rohtak, Rohtak, Haryana, India

Date of Submission26-Jun-2018
Date of Acceptance05-May-2019
Date of Web Publication29-Aug-2019

Correspondence Address:
MBBS, MD Anaesthesiology Jyoti Sharma
H. No. 313, Sector 14, Rohtak, Haryana, 124001
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/roaic.roaic_51_18

Rights and Permissions

Spinal anesthesia is one of the most important and commonly performed technique in anaesthesia practice. Complications such as nausea, vomiting, restlessness, hypotension, and bradycardia may occur. We present two cases of apnea that occurred after approximately 30 min of spinal anesthesia during an otherwise uneventful ongoing surgery. Although the exact cause of apnea was unclear, it seems to be due to an interplay of multiple factors.

Keywords: apnea, conundrum, multiple factors, spinal anesthesia

How to cite this article:
Bala R, Sharma J, Kumar R, Malhan S. Respiratory arrest after spinal anaesthesia: a conundrum for anesthesiologists. Res Opin Anesth Intensive Care 2019;6:377-8

How to cite this URL:
Bala R, Sharma J, Kumar R, Malhan S. Respiratory arrest after spinal anaesthesia: a conundrum for anesthesiologists. Res Opin Anesth Intensive Care [serial online] 2019 [cited 2020 Feb 20];6:377-8. Available from: http://www.roaic.eg.net/text.asp?2019/6/3/377/265721

  Case I Top

A 70-year-old women, ASA II was planned for reduction and fixation of trochanter fracture. On examination, blood pressure (BP) was 136/72 mmHg, pulse 92/min, without any other significant findings. Patients routine investigation such as hemoglobin, blood counts, urea, creatinine, and sugar were within normal limits. In the operating room, ECG, pulse oximeter, and BP cuff were attached. Intravenous line was secured with 18 G intravenous cannula and Ringer’s lactate was started. Under aseptic precaution, spinal anesthesia was administered at 11 a.m., in sitting position and midline approach with 25 G Quincke’s spinal needle at L3–L4 intervertebral space, with 2.8 ml of 0.5% heavy bupivacaine administered slowly. Then the patient was made supine and oxygen was given through a venturi mask at 4 l/min. EtCO2 was monitored throughout the procedure. Modified bromage score 4 and sensory block at T10 achieved at 5 min BP was 104/66 mmHg, HR 85/min, SPO2 99%. During the ongoing surgical procedure, at 11:35 a.m., the EtCO2 graph disappeared and the patient became apneic and unresponsive even to painful stimuli. There was no hypotension, bradycardia, or desaturation. Bag and mask ventilation was started immediately and the patient regained consciousness and spontaneous respiration after 8–10 min. The level of sensory block was checked again and was at T10. Rest of the intraoperative and postoperative period was uneventful.

  Case II Top

A 56-year-old women of ASA I was planned for excision of vaginal mass under spinal anaesthesia. After attaching the monitors and securing 18 G intravenous line, spinal anesthesia was administered under aseptic precaution, in sitting position and via midline approach with a 23 G Quincke spinal needle at L3–L4 intervertebral space, with 2.6 ml of 0.5% heavy bupivacaine administered slowly. A similar event occurred approximately after 30 min of spinal administration. The patient regained consciousness at about 15 min of bag mask ventilation. Vitals were maintained throughout and the rest of the period was uneventful. The level of sensory block was checked again and was at T8.

  Discussion Top

As seen in both cases, the event is more or less similar but what could be the possible cause or explanation for such events is still a conundrum for the anesthesiologists. We have analyzed individual possible causes for transient apnea that occurred in two of our cases of spinal anesthesia. Adjuvant neuraxial opioids or concurrent systemic sedatives have been reported to cause apnea many times. However, both of these were not administered to our patients. Epilepsy, diabetes, or any other comorbidities associated with unconsciousness were also not present. Hypoperfusion of the brainstem is another possible cause. However, there was no hypotension or it may have gone undetected [1],[2]. A total spinal block can cause respiratory arrest due to paralysis of intercostal muscles. This is more common in patients with compromised pulmonary functions [1]. But in our patients, the highest sensory block was T8 in one and T10 in other. The episode of apnea that occurred was for a transient period and improved after manual ventilation; a total spinal block is associated with a prolonged period of apnea and a higher level of blockade [1]. Bhati et al. [3] and Chan et al. [4] individually reported cases of loss of consciousness that occurred after 12–20 min of spinal injection. The authors attributed the event to a possibility of subdural block. However, subdural injection causes a longer period of apnea and associated motor block in the higher segments after regaining consciousness. Acharya et al. [5] reported four cases of apnea and loss of consciousness after spinal anesthesia for lower segment caesarean section. Oxytocin was labeled as the culprit by the authors. Another possibility that could be thought of is the presence of impurities in drug formulation. However, in both of our cases, the drug administered was of a different manufacturing company. So, we cannot attribute the event to manufacturing error. Capnometry can be performed in spontaneously breathing patients by placing the EtCO2 sensor near the nose. Although simultaneously administering oxygen with capnometry can lead to a discrepancy of EtCO2 and PaCO2 due to dilution, a flow rate of at least 6 l/min gives an accurate measurement of EtCO2 [6]. At lower flow rates, the exact value of EtCO2 may not be reliable but the presence of graph and its trend can provide adequate information [7].

  Conclusion Top

We have described loss of consciousness in two cases who had a successful spinal block that occurred without any hemodynamic instability. Despite investigations, we were unable to determine the cause. We can only speculate that an interplay of all these factors rather than a sole cause may have accounted for this most unusual event. Literatures support either of these causes as a possibility for apnea during a subarachnoid block, but the exact cause still remains a conundrum.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Birnbach DJ, Browne IM. Anesthesia for obstetrics. Inc Miller’s Anaesthesia. 6th edition. UK: Elsevier; 2005. pp. 2307–2344.  Back to cited text no. 1
Morgan G, Mikhail M, Murray M. editors. Obstetrics anesthesia. In clinical anaesthesiology. 3rd edition. USA: McGraw Hill; 2002.  Back to cited text no. 2
Bhati FS, Vijayvergia VK, Jain VL, Sharma M. Loss of consciousness following spinal anaesthesia for cesarean section − a case report. Indian J Anaesth 2004; 48:57–58.  Back to cited text no. 3
  [Full text]  
Chan YK, Gopinathan R, Rajendram R. Loss of consciousness following spinal anaesthesia for caeserean section. Br J Anaesth 2000; 85:474–476.  Back to cited text no. 4
Acharya SP, Marhatta MN, Amatya R. Unexplained apnoea and loss of consciousness during sub arachnoid block for caesarean section. Kathmandu Univ Med J (KUMJ) 2009; 7:419–422.  Back to cited text no. 5
Oberg B, Waldau T, Larsen VH. The effect of nasal oxygen flow and catheter position on the accuracy of end-tidal carbon dioxide measurements by a pharyngeal catheter in unintubated, spontaneously breathing subjects. Anaesthesia 1995; 50:695–698.  Back to cited text no. 6
Fukuda K, Ichinohe T, Kaneko Y. Is measurement of end-tidal CO2 through a nasal cannula reliable? Anesth Prog 1997; 44:23–26.  Back to cited text no. 7


Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

  In this article
Case I
Case II

 Article Access Statistics
    PDF Downloaded50    
    Comments [Add]    

Recommend this journal